Artist depiction of Huygens landing on Titan. Credit: ESA
Twelve years ago today, the Huygens probe landed on Titan, marking the farthest point from Earth any spacecraft has ever landed. While a twelfth anniversary may be an odd number to mark with a special article, as we said in our previous article (with footage from the landing), this is the last opportunity to celebrate the success of Huygens before its partner spacecraft Cassini ends its mission on September 15, 2017 with a fateful plunge into Saturn’s atmosphere.
But Huygens is also worth celebrating because, amazingly, the mission almost failed, but yet was a marvelous success. If not for the insistence of one ESA engineer to complete an in-flight test of Huygens’ radio system, none of the spacecraft’s incredible data from Saturn’s largest and mysterious moon would have ever been received, and likely, no one would have ever known why.
The first-ever images of the surface Titan, taken by the Huygens probe. Image Credit: ESA/NASA/JPL/University of Arizona
As I detail in my new book “Incredible Stories From Space: A Behind-the-Scenes-Look at the Missions Changing Our View of the Cosmos,” in 1999, the Cassini orbiter and the piggybacking Huygens lander were on their way to the Saturn system. The duo launched in 1997, but instead of making a beeline for the 6th planet from the Sun, they took a looping path called the VVEJGA trajectory (Venus-Venus-Earth-Jupiter Gravity Assist), swinging around Venus twice and flying past Earth 2 years later.
While all the flybys gave the spacecraft added boosts to help get it to Saturn, the Earth flyby also provided a chance for the teams to test out various systems and instruments and get immediate feedback.
“The European group wanted to test the Huygens receiver by transmitting the data from Earth,” said Earl Maize, Project Manager for the Cassini mission at JPL, who I interviewed for the book. “That’s a great in-flight test, because there’s the old adage of flight engineers, ‘test as you fly, fly as you test.’”
The way the Huygens mission would work at the Saturn system was that Cassini would release Huygens when the duo approached Titan. Huygens would drop through Titan’s thick and obscuring atmosphere like a skydiver on a parachute, transmitting data all the while. The Huygens probe didn’t have enough power or a large enough dish to transmit all its data directly to Earth, so Cassini would gather and store Huygens’ data on board and later transmit it to Earth.
Boris Smeds was head of ESOC’s Systems and Requirements Section, Darmstadt, Germany. Credit: ESA.
ESA engineer Boris Smeds wanted to ensure this data handoff was going to work, otherwise a crucial part of the mission would be lost. So he proposed a test during the 1999 Earth flyby.
Maize said that for some reason, there was quite a bit of opposition to the test from some of the ESA officials, but Smeds and Claudio Sollazzo, Huygens’s ground operations manager at ESA’s European Space Operation Centre (ESOC) in Darmstadt, Germany were insistent the test was necessary.
NASA’s Deep Space Network is responsible for communicating with spacecraft. Pictured is the Goldstone facility in California, one of three facilities that make up the Network. Image: NASA/JPL
“They were not to be denied,” Maize said, “so they eventually got permission for the test. The Cassini team organized it, going to the Goldstone tracking station [in California] of the Deep Space Network (DSN) and did what’s called a ‘suitcase test,’ broke into the signal, and during the Earth flyby, Huygens, Cassini and Goldstone were all programmed to simulate the probe descending to Titan. It all worked great.”
Except for one thing: Cassini received almost no simulated data, and what it did receive was garbled. No one could figure out why.
Six months of painstaking investigation finally identified the problem. The variation in speed between the two spacecraft hadn’t been properly compensated for, causing a communication problem. It was as if the spacecraft were each communicating on a different frequency.
Artist concept of the Huygens probe descending to Titan. Credit: ESA.
“The European team came to us and said we didn’t have a mission,” Maize said. “But we put together ‘Tiger Teams’ to try and figure it out.”
The short answer was that the idiosyncrasies in the communications system were hardwired in. With the spacecraft now millions of miles away, nothing could be fixed. But engineers came up with an ingenious solution using a basic principal known as the Doppler Effect.
The metaphor Maize likes to use is this: if you are sitting on the shore and a speed boat goes by close to the coast, it zooms past you quickly. But that same boat going the same speed out on the horizon looks like it is barely moving.
“Since we couldn’t change Huygens’ signal, the only thing we could change was the way Cassini flew,” Maize said. “If we could move Cassini farther away and make it appear as if Huygens was moving slower, it would receive lander’s radio waves at a lower frequency, solving the problem.”
Maize said it took two years of “fancy coding modifications and some pretty amazing trajectory computations.” Huygens’ landing was also delayed two months for the new trajectory that was needed overcome the radio system design flaw.
Additionally, with Cassini needing to be farther away from Huygens than originally planned, it would eventually fly out of range to capture all of Huygens’ data. Astronomers instigated a plan where radio telescopes around the world would listen for Huygens’ faint signals and capture anything Cassini missed.
Huygens was released from the Cassini spacecraft on Christmas Day 2004, and arrived at Titan on January 14, 2005. The probe began transmitting data to Cassini four minutes into its descent through Titan’s murky atmosphere, snapping photos and taking data all the while. Then it touched down, the first time a probe had landed on an extraterrestrial world in the outer Solar System.
Because of the communication problem, Huygens was not able to gather as much information as originally planned, as it could only transmit on one channel instead of two. But amazingly, Cassini captured absolutely all the data sent by Huygens until it flew out of range.
“It was beautiful,” Maize said, “I’ll never forget it. We got it all, and it was a wonderful example of international cooperation. The fact that 19 countries could get everything coordinated and launched in the first place was pretty amazing, but there’s nothing that compares to the worldwide effort we put into recovering the Huygens mission. From an engineering standpoint, that might trump everything else we’ve done on this mission.”
The view of Titan from the descending Huygens spacecraft on January 14, 2005. Credit: ESA/NASA/JPL/University of Arizona.
With its ground-breaking mission, Huygens provided the first real view of the surface of Titan. The data has been invaluable for understanding this unique and mysterious moon, showing geological and meteorological processes that are more similar to those on the surface of the Earth than anywhere else in the Solar System. ESA has details on the top discoveries by Huygens here.
Noted space journalist Jim Oberg has written several detailed and very interesting articles about the Huygens’ recovery, including one at IEEE Spectrum and another at The Space Review. These articles provide much more insight into the test, Smeds’ remarkable insistence for the test, the recovery work that was done and the subsequent success of the mission.
As Oberg says in IEEE Spectrum, “Smeds continued a glorious engineering tradition of rescuing deep-space missions from doom with sheer persistence, insight, and lots of improvisation.”
A modest Smeds was quoted by ESA: “This has happened before. Almost any mission has some design problem,” says Smeds, who says he’s worked on recovering from pre- and post-launch telecom issues that have arisen with several past missions. “To me, it’s just part of my normal work.”
For more stories about Huygens, Cassini and several other current robotic space missions, “Incredible Stories From Space” tells many behind-the-scenes stories from the amazing people who work on these missions.
The International Space Station orbiting Earth. Credit: NASA
After the historic Apollo Missions, which saw humans set foot on another celestial body for the first time in history, NASA and the Russian Space Agency (Roscosmos) began to shift their priorities away from pioneering space exploration and began to focus on developing long-term capabilities in space. In the ensuing decades (from the 1970s to 1990s), both agencies began to build and deploy space stations, each one bigger and more complex than the last.
The latest and greatest of these is the International Space Station (ISS), a scientific facility that resides in Low-Earth Orbit around our planet. This space station is the largest and most sophisticated orbiting research facility ever built and is so large that it can actually be seen with the naked eye. Central to its mission is the idea of fostering international cooperation for the sake of advancing science and space exploration.
Origin:
Planning for the ISS began in the 1980s and was based in part on the successes of Russia’s Mir space station, NASA’s Skylab, and the Space Shuttle Program. This station, it was hoped, would allow for the future utilization of low-Earth Orbit and its resources, and serve as an intermediate base for renewed exploration efforts to the Moon, mission to Mars, and beyond.
The Mir space station hangs above the Earth in 1995 (photo taken by the mission crew of the Space Shuttle Atlantis, STS-71). Credit: NASA
In May of 1982, NASA established the Space Station task force, which was charged with creating a conceptual framework for such a space station. In the end, the ISS plan that emerged was a culmination of several different plans for a space station – which included NASA’s Freedom and the Soviet’s Mir-2 concepts, as well as Japan’s Kibo laboratory, and the European Space Agency’s Columbus laboratory.
The Freedom concept called for a modular space station to be deployed to orbit, where it would serve as the counterpart to the Soviet Salyut and Mir space stations. That same year, NASA approached the Japanese Aerospace and Exploration Agency (JAXA) to participate in the program with the creation of the Kibo, also known as the Japanese Experiment Module.
The Canadian Space Agency was similarly approached in 1982 and was asked to provide robotic support for the station. Thanks to the success of the Canadarm, which was an integral part of the Space Shuttle Program, the CSA agreed to develop robotic components that would assist with docking, perform maintenance, and assist astronauts with spacewalks.
In 1984, the ESA was invited to participate in the construction of the station with the creation of the Columbus laboratory – a research and experimental lab specializing in materials science. The construction of both the Kibo and Columbus modules was approved in 1985. As the most ambitious space program in either agency’s history, the development of these laboratories was seen as central to Europe and Japan’s emerging space capability.
Skylab, America’s First manned Space Station. Photo taken by departing Skylab 4 crew in Feb. 1974. Credit: NASA
In 1993, American Vice-President Al Gore and Russian Prime Minister Viktor Chernomyrdin announced that they would be pooling the resources intended to create Freedom and Mir-2. Instead of two separate space stations, the programs would be working collaboratively to create a single space station – which was later named the International Space Station.
Construction:
Construction of the ISS was made possible with the support of multiple federal space agencies, which included NASA, Roscosmos, JAXA, the CSA, and members of the ESA – specifically Belgium, Denmark, France, Spain, Italy, Germany, the Netherlands, Norway, Switzerland, and Sweden. The Brazilian Space Agency (AEB) also contributed to the construction effort.
The orbital construction of the space station began in 1998 after the participating nations signed the Space Station Intergovernmental Agreement (IGA), which established a legal framework that stressed cooperation based on international law. The participating space agencies also signed the Four Memoranda of Understandings (MoUs), which laid out their responsibilities in the design, development, and use of the station.
The assembly process began in 1998 with the deployment of the ‘Zarya’ (“Sunrise” in Russian) Control Module, or Functional Cargo Block. Built by the Russians with funding from the US, this module was designed to provide the station’s initial propulsion and power. The pressurized module – which weighed over 19,300 kg (42,600 pounds) – was launched aboard a Russian Proton rocket in November 1998.
On Dec. 4th, the second component – the ‘Unity’ Node – was placed into orbit by the Space Shuttle Endeavour (STS-88), along with two pressurized mating adapters. This node was one of three – Harmony and Tranquility being the other two – that would form the ISS’ main hull. On Sunday, Dec. 6th, it was mated to Zarya by the STS-88 crew inside the shuttle’s payload bay.
The next installments came in the year 2000, with the deployment of the Zvezda Service Module (the first habitation module) and multiple supply missions conducted by the Space Shuttle Atlantis. The Space Shuttle Discovery (STS-92) also delivered the station’s third pressurized mating adapted and a Ku-band antenna in October. By the end of the month, the first Expedition crew was launched aboard a Soyuz rocket, which arrived on Nov. 2nd.
The structure of the ISS (exploded in this diagram) showing the various components and how they are assembled together. Credit: NASA
No additional modules or components were added until 2016 when Bigelow Aerospace installed their experimental Bigelow Expandable Activity Module (BEAM). All told, it took 13 years to construct the space station, an estimated $100 billion and required more than 100 rocket and Space Shuttle launches, and 160 spacewalks.
As of the penning of this article, the station has been continuously occupied for a period of 16 years and 74 days since the arrival of Expedition 1 on November 2nd, 2000. This is the longest continuous human presence in low Earth orbit, having surpassed Mir’s record of 9 years and 357 days.
Purpose and Aims:
The main purpose of the ISS is fourfold: conducting scientific research, furthering space exploration, facilitating education and outreach, and fostering international cooperation. These goals are backed by NASA, the Russian Federal Space Agency (Roscomos), the Japanese Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA), and the European Space Agency (ESA), with additional support from other nations and institutions.
As far as scientific research goes, the ISS provides a unique environment to conduct experiments under microgravity conditions. Whereas crewed spacecraft provide a limited platform that is only deployed to space for a limited amount of time, the ISS allows for long-term studies that can last for years (or even decades).
Many different and continuous projects are being conducted aboard the ISS, which are made possible with the support of a full-time crew of six astronauts, and a continuity of visiting vehicles (which also allows for resupply and crew rotations). Scientists on Earth have access to their data and are able to communicate with the science teams through a number of channels.
The many fields of research conducted aboard the ISS include astrobiology, astronomy, human research, life sciences, physical sciences, space weather, and meteorology. In the case of space weather and meteorology, the ISS is in a unique position to study these phenomena because of its position in LEO. Here, it has a short orbital period, allowing it to witness weather across the entire globe many times in a single day.
It is also exposed to things like cosmic rays, solar wind, charged subatomic particles, and other phenomena that characterize a space environment. Medical research aboard the ISS is largely focused on the long-term effects of microgravity on living organisms – particularly its effects on bone density, muscle degeneration, and organ function – which is intrinsic to long-range space exploration missions.
The ISS also conducts research that is beneficial to space exploration systems. Its location in LEO also allows for the testing of spacecraft systems that are required for long-range missions. It also provides an environment where astronauts can gain vital experience in terms of operations, maintenance, and repair services – which are similarly crucial for long-term missions (such as missions to the Moon and Mars).
The ISS also provides opportunities for education thanks to participation in experiments, where students are able to design experiments and watch as ISS crews carry them out. ISS astronauts are also able to engage classrooms through video links, radio communications, email, and educational videos/web episodes. Various space agencies also maintain educational materials for download based on ISS experiments and operations.
Educational and cultural outreach also fall within the ISS’ mandate. These activities are conducted with the help and support of the participating federal space agencies and are designed to encourage education and career training in the STEM (Science, Technical, Engineering, Math) fields.
One of the best-known examples of this is the educational videos created by Chris Hadfield – the Canadian astronaut who served as the commander of Expedition 35 aboard the ISS – which chronicled the everyday activities of ISS astronauts. He also directed a great deal of attention to ISS activities thanks to his musical collaboration with the Barenaked Ladies and Wexford Gleeks – titled “I.S.S. (Is Somebody Singing)” (shown above).
His video, a cover of David Bowie’s “Space Oddity”, also earned him widespread acclaim. Along with drawing additional attention to the ISS and its crew operations, it was also a major feat since it was the only music video ever to be filmed in space!
Operations Aboard the ISS:
As noted, the ISS is facilitated by rotating crews and regular launches that transport supplies, experiments, and equipment to the station. These take the form of both crewed and uncrewed vehicles, depending on the nature of the mission. Crews are generally transported aboard Russian Progress spacecraft, which are launched via Soyuz rockets from the Baikonur Cosmodrome in Kazakhstan.
Roscosmos has conducted a total of 60 trips to the ISS using Progress spacecraft, while 40 separate launches were conducted using Soyuz rockets. Some 35 flights were also made to the station using the now-retired NASA Space Shuttles, which transported crew, experiments, and supplies. The ESA and JAXA have both conducted 5 cargo transfer missions, using the Automated Transfer Vehicle (ATV) and the H-II Transfer Vehicle (HTV), respectively.
In more recent years, private aerospace companies like SpaceX and Orbital ATK have been contracted to provide resupply missions to the ISS, which they have done using their Dragon and Cygnus spacecraft. Additional spacecraft, such as SpaceX’s Crew Dragon spacecraft, are expected to provide crew transportation in the future.
Alongside the development of reusable first-stage rockets, these efforts are being carried out in part to restore domestic launch capability to the US. Since 2014, tensions between the Russian Federation and the US have led to growing concerns over the future of Russian-American cooperation with programs like the ISS.
Crew activities consist of conducting experiments and research considered vital to space exploration. These activities are scheduled from 06:00 to 21:30 hours UTC (Universal Coordinated Time), with breaks being taken for breakfast, lunch, dinner, and regular crew conferences. Every crew member has their own quarters (which includes a tethered sleeping bag), two of which are located in the Zvezda Module and four more installed in Harmony.
During “night hours”, the windows are covered to give the impression of darkness. This is essential since the station experiences 16 sunrises and sunsets a day. Two exercise periods of 1 hour each are scheduled every day to ensure that the risks of muscle atrophy and bone loss are minimized. The exercise equipment includes two treadmills, the Advanced Resistive Exercise Device (ARED) for simulated weight training, and a stationary bicycle.
Hygiene is maintained thanks to water jets and soap dispensed from tubes, as well as wet wipes, rinseless shampoo, and edible toothpaste. Sanitation is provided by two space toilets – both of Russian design – aboard the Zvezda and Tranquility Modules. Similar to what was available aboard the Space Shuttle, astronauts fasten themselves to the toilet seat and the removal of waste is accomplished with a vacuum suction hole.
Liquid waste is transferred to the Water Recovery System, where it is converted back into drinking water (yes, astronauts drink their own urine, after a fashion!). Solid waste is collected in individual bags that are stored in an aluminum container, which are then transferred to the docked spacecraft for disposal.
Food aboard the station consists mainly of freeze-dried meals in vacuum-sealed plastic bags. Canned goods are available, but are limited due to their weight (which makes them more expensive to transport). Fresh fruit and vegetables are brought during resupply missions, and a large array of spices and condiments are used to ensure that food is flavorful – which is important since one of the effects of microgravity is a diminished sense of taste.
To prevent spillage, drinks and soups are contained in packets and consumed with a straw. Solid food is eaten with a knife and fork, which are attached to a tray with magnets to prevent them from floating away, while drinks are provided in dehydrated powder form and then mixed with water. Any food or crumbs that floats away must be collected to prevent them from clogging the air filters and other equipment.
Hazards:
Life aboard the station also carries with it a high degree of risk. These come in the form of radiation, the long-term effects of microgravity on the human physique, the psychological effects of being in space (i.e. stress and sleep disturbances), and the danger of collision with space debris.
In terms of radiation, objects within the Low-Earth Orbit environment are partially protected from solar radiation and cosmic rays by the Earth’s magnetosphere. However, without the protection of the Earth’s atmosphere, astronauts are still exposed to about 1 millisievert a day, which is the equivalent of what a person on Earth is exposed to during the course of a year.
As a result, astronauts are at higher risk for developing cancer, suffering DNA and chromosomal damage, and diminished immune system function. Hence why protective shielding and drugs are a must aboard the station, as well as protocols for limiting exposure. For instance, during solar flare activity, crews are able to seek shelter in the more heavily shielded Russian Orbital Segment of the station.
As already noted, the effects of microgravity also take a toll on muscle tissues and bone density. According to a 2001 study conducted by NASA’s Human Research Program (HRP) – which researched the effects on an astronaut Scott Kelly’s body after he spent a year aboard the ISS – bone density loss occurs at a rate of over 1% per month.
Similarly, a report by the Johnson Space Center – titled “Muscle Atrophy” – stated that astronauts experience up to a 20% loss of muscle mass on spaceflights lasting just five to 11 days. In addition, more recent studies have indicated that the long-term effects of being in space also include diminished organ function, decreased metabolism, and reduced eyesight.
Because of this, astronauts exercise regularly in order to minimize muscle and bone loss, and their nutritional regimen is designed to make sure they the appropriate nutrients to maintain proper organ function. Beyond that, the long-term health effects, and additional strategies to combat them, are still being investigated.
But perhaps the greatest hazard comes in the form of orbiting junk – aka. space debris. At present, there are over 500,000 pieces of debris that are being tracked by NASA and other agencies as they orbit the Earth. An estimated 20,000 of these are larger than a softball, while the remainder are about the size of a pebble. All told, there are likely to be many millions of pieces of debris in orbit, but most are so small they can’t be tracked.
These objects can travel at speeds of up to 28,163 km/h (17,500 mph), while the ISS orbits the Earth at a speed of 27,600 km/h (17,200 mph). As a result, a collision with one of these objects could be catastrophic to the ISS. The station is naturally shielded to withstand impacts from tiny bits of debris and well as micro-meteoroids – and this shielding is divided between the Russian Orbital Segment and the US Orbital Segment.
On the USOS, the shielding consists of a thin aluminum sheet that is held apart from the hull. This sheet causes objects to shatter into a cloud, thereby dispersing the kinetic energy of the impact before it reaches the main hull. On the ROS, shielding takes the form of a carbon plastic honeycomb screen, an aluminum honeycomb screen, and glass cloth, all of which are spaced over the hull.
The ROS’ shielding is less likely to be punctured, hence why the crew moves to the ROS whenever a more serious threat presents itself. But when faced with the possibility of an impact from a larger object that is being tracked, the station performs what is known as a Debris Avoidance Manoeuvre (DAM). In this event, the thrusters on the Russian Orbital Segment fire in order to alter the station’s orbital altitude, thus avoiding the debris.
Future of the ISS:
Given its reliance on international cooperation, there have been concerns in recent years – in response to growing tensions between Russia, the United States, and NATO – about the future of the International Space Station. However, for the time being, operations aboard the station are secure, thanks to commitments made by all of the major partners.
In January of 2014, the Obama Administration announced that it would be extending funding for the US portion of the station until 2024. Roscosmos has endorsed this extension but has also voiced approval for a plan that would use elements of the Russian Orbital Segment to construct a new Russian space station.
Known as the Orbital Piloted Assembly and Experiment Complex (OPSEK), the proposed station would serve as an assembly platform for crewed spacecraft traveling to the Moon, Mars, and the outer Solar System. There have also been tentative announcements made by Russian officials about a possible collaborative effort to build a future replacement for the ISS. However, NASA has yet to confirm these plans.
In April of 2015, the Canadian government approved a budget that included funding to ensure the CSA’s participation with the ISS through 2024. In December of 2015, JAXA and NASA announced their plans for a new cooperative framework for the International Space Station (ISS), which included Japan extending its participation until 2024. As of December 2016, the ESA has also committed to extending its mission to 2024.
The ISS represents one of the greatest collaborative and international efforts in history, not to mention one of the greatest scientific undertakings. In addition to providing a location for crucial scientific experiments that cannot be conducted here on Earth, it is also conducting research that will help humanity make its next great leaps in space – i.e. mission to Mars and beyond!
On top of all that, it has been a source of inspiration for countless millions who dream of going to space someday! Who knows what great undertakings the ISS will allow for before it is finally decommissioned – most likely decades from now?
An artist’s conception of the Lucy spacecraft (left) flying by the Trojan Eurybates, and Psyche (Right) Psyche, the first mission to the metal world 16 Psyche.
Credits: SwRI and SSL/Peter Rubin
It’s a New Year, with new challenges and new opportunities! And NASA, looking to kick things off, has announced the two new missions that will be launching in the coming decade. These robotic missions, named Lucy and Psyche, are intended to help us understand the history of the early Solar System, and will deploy starting in 2021 and 2023, respectively.
While Lucy’s mission is to explore one of Jupiter’s Trojan asteroids, Psyche will explore a metal asteroid known as 16 Psyche. And between the two of them, it is hoped that they will answer some enduring questions about planetary formation and how the Solar System came to be. More than that, these mission represent historic firsts for NASA and human space exploration.
NASA’s Discovery Program, of which Lucy and Psyche are part, was created in 1992 to compliment their larger “flagship” programs. By bringing scientists and engineers together to design missions, the Discovery Program’s focus has been to maximize scientific research by creating many smaller missions that have shorter development periods and require less in the way of operational resources.
Artist’s concept of the Lucy spacecraft flying by Eurybates, one of the six diverse and scientifically important Trojans it will study. Credit: SwRI
The Lucy mission is scheduled to launch in October of 2021, and is expected to arrive at its first destination (a Main Belt asteroid) in 2025. It will then set course for Jupiter’s Trojans, a group of asteroids that are trapped by Jupiter’s gravity and share its orbit. These asteroids are thought to be relics of the early Solar System; and between 2027 and 2033, Lucy will study six of them.
In addition to being the first mission to explore Jupiter’s Trojan population, Lucy is also of historic importance because of the number of asteroids it will visit. Throughout the course of its mission, it is will investigate six Trojans, which is the total number of Main Belt asteroids that have been studied to date. The nature of these six asteroids is also expected to tell us much about the early history of the Solar System.
As Harold F. Levison – the principal investigator of the Lucy mission from the Southwest Research Institute (SwRI) in Boulder, Colorado – explained during a NASA call-in briefing:
“One of the surprising aspects of this population is their diversity. If we look at them through telescopes on the Earth, we see that they are very different from one other in their color, in their spectra. And so, we believe that’s telling us something about how the Solar System formed and evolved… This diversity in these objects, we believe, are due to the fact that they actually formed in very different regions of the Solar System, with very different physical characteristics. And something occurred in the history of the Solar System where these objects started off at very different distances, but during the formation and evolution of the Solar System, they got moved around and placed in these stable reservoirs near Jupiter’s orbit.”
Illustration of the Lucy spacecraft’s orbit around Jupiter, which will allow it to study its Trojan population. Credit: SwRI
The six Trojans that Lucy is intended investigate were selected because the diversity of their physical characteristics show that they are from different locations throughout the Solar System. As Levison put it, “These small bodies really are the fossils of planet formation, and that’s why we named Lucy after the human ancestor known as Lucy.”
In addition, Lucy will build on the success of missions like New Horizons and OSIRIS-REx., which includes using updated versions of instruments they used to explore Pluto, the Kuiper Belt, and the asteroid Bennu -i.e. the RALPH and LORRI instruments and the OTES instrument. In addition, several members of the New Horizons and OSIRIS-REx science teams will be lending their expertise to the Lucy mission.
Similarly, the Psyche mission will of be immense scientific value since it will visit the only metal asteroid known to exist. This asteroid measures about 210 km (130 mi) in diameter and is believed to be composed entirely of iron and nickel. In this respect, it is similar to Earth’s metallic core, as well as the cores of every terrestrial planet in the Solar System.
It is for this reason why scientists believe it may be the exposed core of a Mars-sized planet. According to this theory, 16 Psyche experienced several major collisions during the early history of the Solar System, which caused it to shed its rocky mantle. The robotic probe will launch in 2023 and is expected to arrive by 2030 – after receiving an Earth gravity-assist maneuver in 2024 and a Mars flyby in 2025.
By measuring its composition, magnetic field, and mapping its surface features, Lucy’s science team hopes to learn more about the history of planetary formation. As Lindy Elkins-Tanton – the Principal Investigator of Psyche and the Director of the School of Earth and Space Exploration at Arizona State University – said during the NASA call-in briefing:
“Humankind has visited rocky worlds and icy worlds and worlds made of gas. But we have never seen a metal world. Psyche has never been visited or had a picture taken that was more than a point of light. And so, its appearance remains a mystery. This mission will be true exploration and discovery. We think that Psyche is the metal core of a small planet that was destroyed in the high-energy, high-speed, first one-one-hundredth of the age of our Solar System. By visiting Psyche we can literally visit a planetary core the only way humanity can… Psyche let’s us visit inner space by visiting outer space.”
Not only are planetary cores thought to be where magnetic fields originate (which are necessary for the emergence of life), but they are entirely inaccessible to us. The very edge of Earth’s outer core is roughly 2,890 km (1790 mi) from our planet’s surface. But the deepest humanity has ever dug has been to a depth of 12 km (7.5 mi), which took place at the Kola Superdeep Borehole, in Russia.
In addition, within the Earth’s core, temperature and pressure conditions are estimated to reach 5700 K (5400 °C; 9752 °F) and 330 to 360 gigapascals (over three million times normal air pressure). This makes exploring the core of our planet (or any other planet in the Solar System, for that matter) completely impractical. Hence why a robotic mission to a world like Pysche is such an opportunity.
And since Psyche is the only rounded body of metal that is known to exist in the Solar System, the asteroid is as improbably as it is unique. And since no missions have ever taken place to explore its surface, and no pictures exist that can tell us what its surface features would look like, the Psyche mission is sure to shed some serious light on what a metal world looks like.
“What do we think it might look like?” asked Tanton. “Does it have surface sulfur lava flows on its surface? Is it covered with towering cliffs created when solidifying metal shrank and the exterior of the body broke into fault? Is its surface a combination of iron metal and green mineral crystal as iron meteorites are? And what does an impact crater in metal look like? Could its edges or its metal flashes become frozen in the cold of space before they fell back on the surface. We don’t know.”
Jim Green, NASA’s Planetary Science Director, expressed enthusiasm for the Discovery 13 and 14 missions in a recent NASA press release:
“These are true missions of discovery that integrate into NASA’s larger strategy of investigating how the solar system formed and evolved. We’ve explored terrestrial planets, gas giants, and a range of other bodies orbiting the sun. Lucy will observe primitive remnants from farther out in the solar system, while Psyche will directly observe the interior of a planetary body. These additional pieces of the puzzle will help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained – and what the future may hold.”
Lucy and Psyche were chosen from five finalists that were selected for further development back in September 2015. These in turn were chosen from 27 mission concepts that were submitted back in November of 2014. Examples of past and present Discovery missions include the Kepler space probe, the Dawn spacecraft, the Mars Pathfinder, and the InSight lander (which is scheduled to launch in 2018).
The Soyuz MS-01 spacecraft launches from the Baikonur Cosmodrome on July 7, 2016 bringing a new crew to the International Space Station. Credit: (NASA/Bill Ingalls)
There are a group of unsung heroes at NASA, the people who travel the world to capture key events in our exploration of space. They share their images with all of us, but most of the time, it’s not just the pictures of launches, landings, and crucial mission events that they capture. They also show us behind-the-scenes events that otherwise might go unnoticed, and they also capture the true personalities of the people behind the missions and events.
From exciting beginnings of rocket launches and rocket tests to the sad losses of space exploration icons, these photographers are there take these images that will forever remind us of the glories and perils of spaceflight and the joys and sadness of human life.
NASA photographers Bill Ingalls, Aubrey Gemignani, Joel Kowsky, Connie Moore, and Gwen Pitman chose some of their favorites images from 2016, and below are just a few. As Ingalls told us, “These are the favorite images created by our HQ photo team, not from the entire agency. There are many more talented photographers at the NASA centers producing some amazing work as well.”
In this 30 second exposure taken with a circular fish-eye lens, a meteor streaks across the sky during the annual Perseid meteor shower as a photographer wipes moisture from the camera lenses Friday, August 12, 2016 in Spruce Knob, West Virginia. Photo Credit: (NASA/Bill Ingalls)
The team from the Juno mission celebrate after they received confirmation from the spacecraft that it had successfully completed the engine burn and entered orbit of Jupiter on July 4, 2016 in mission control of the Space Flight Operations Facility at the Jet Propulsion Laboratory in Pasadena, CA. Juno will orbit the planet for 20 months to collect data on the planetary core, map the magnetic field, and measure the amount of water and ammonia in the atmosphere. Credit: (NASA/Aubrey Gemignani)
The United Launch Alliance Atlas V rocket carrying NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft lifts off on from Space Launch Complex 41 on Sept. 8, 2016 at Cape Canaveral Air Force Station in Florida. OSIRIS-REx will be the first U.S. mission to sample an asteroid, retrieve at least two ounces of surface material and return it to Earth for study. The asteroid, Bennu, may hold clues to the origin of the solar system and the source of water and organic molecules found on Earth. Photo Credit: (NASA/Joel Kowsky)
Annie Glenn, Widow of former astronaut and Senator John Glenn, pays her respects to her late husband as he lies in repose, under a United States Marine honor guard, in the Rotunda of the Ohio Statehouse in Columbus, Friday, Dec. 16, 2016. Credit: (NASA/Bill Ingalls)
Piers Sellers, former astronaut and deputy director of the Sciences and Exploration Directorate at NASA’s Goddard Space Flight Center, speaks at NASA’s Earth Day event, Friday, April 22, 2016 at Union Station in Washington, DC. Sadly, Sellers passed away on Dec. 23, after battling cancer. Credit: (NASA/Joel Kowsky)
The Soyuz TMA-20M spacecraft is seen as it lands with Expedition 48 crew members NASA astronaut Jeff Williams, Russian cosmonauts Alexey Ovchinin, and Oleg Skripochka of Roscosmos near the town of Zhezkazgan, Kazakhstan on Wednesday, Sept. 7, 2016. Credit: (NASA/Bill Ingalls)
Following his year in space on board the International Space Station, astronaut Scott Kelly spoke during an event at the United States Capitol Visitor Center, on May 25, 2016, in Washington. Credit: (NASA/Bill Ingalls)
The second and final qualification motor (QM-2) test for the Space Launch System’s booster is seen, Tuesday, June 28, 2016, at Orbital ATK Propulsion Systems test facilities in Promontory, Utah. During the Space Launch System flight the boosters will provide more than 75 percent of the thrust needed to escape the gravitational pull of the Earth, the first step on NASA’s Journey to Mars. Credit: (NASA/Bill Ingalls)
NASA astronaut Peggy Whitson gets her hair cut on Nov. 14, 2016 at the Cosmonaut Hotel in Baikonur, Kazakhstan, a few days before launching to spend about six months on the International Space Station. Credit: (NASA/Bill Ingalls)
Click on each of the images to see larger versions on Flickr. You can see the entire selection of these favorite photos from 2016 on the NASA HQ Flickr page.
NASA’s Opportunity rover scans around and across to vast Endeavour crater on Dec. 19, 2016, as she climbs steep slopes on the way to reach a water carved gully along the eroded craters western rim. Note rover wheel tracks at center. This navcam camera photo mosaic was assembled from raw images taken on Sol 4587 (19 Dec. 2016) and colorized. Credit: NASA/JPL/Cornell/Ken Kremer/kenkremer.com/Marco Di Lorenzo
NASA’s Opportunity rover scans around and across to vast Endeavour crater on Dec. 19, 2016, as she climbs steep slopes on the way to reach a water carved gully along the eroded craters western rim. Note rover wheel tracks at center. This navcam camera photo mosaic was assembled from raw images taken on Sol 4587 (19 Dec. 2016) and colorized. Credit: NASA/JPL/Cornell/Ken Kremer/kenkremer.com/Marco Di Lorenzo
On the brink of 4600 Sols of a profoundly impactful life, NASA’s long lived Opportunity rover celebrates the Christmas/New Year’s holiday season on Mars marching relentlessly towards an ancient water carved gully along the eroded rim of vast Endeavour crater – the next science target on her heroic journey traversing across never before seen Red Planet terrains.
“Opportunity is continuing its great 21st century natural history expedition on Mars, exploring the complex geology and record of past climate here on the rim of the 22-km Endeavour impact crater,” writes Larry Crumpler, a science team member from the New Mexico Museum of Natural History & Science, in a mission update.
Indeed, New Years Day 2017 equates to 4600 Sols, or Martian Days – of boundless exploration and epic discovery by the longest living Martian rover ever dispatched by humanity to survey the most Earth-like planet in our solar system.
One can easily imagine our beloved Princess Leia gazing quite proudly upon the feistiness and resourcefulness of this never-give-up Martian Princess rover – climbing steeply uphill no less – nearly 13 YEARS into her 3 MONTH mission!!
“Not a boring flat terrain, but heroically rugged terrain,” says Crumpler.
“Hopefully the brakes are good! For a rover that originally landed 12 years ago on what amounts to a flat parking lot, the current terrain is about as different and rugged as any mountain goat rover could handle.”
Indeed she is 51 times beyond her “warrantied” life expectancy of merely 90 Sols roving the surface of the 4th rock from the Sun during her latest extended mission. (And this time round, the clueless Washington bean counters did not even dare threaten to shut her down – lest they suffer the wrath of a light saber or sister Curiosity’s laser canon !!).
Check out the glorious view from Opportunity’s current Martian holiday season exploits in our newest photo mosaics created by the imaging team of Ken Kremer and Marco Di Lorenzo.
“Opportunity has begun the ascent of the steep slopes here in the inner wall of Endeavour impact crater after completion of a survey of outcrops close to the crater floor. The goal now is to climb back to the rim where the terrain is less hazardous, drive south quickly about 1 km south, and arrive at the next major mission target on the rim before the next Martian winter,” Crumpler elaborated.
On Christmas Day 2016, NASA’s Opportunity rover scans around vast Endeavour crater as she ascends steep rocky slopes on the way to reach a water carved gully along the eroded craters western rim. This navcam camera photo mosaic was assembled from raw images taken on Sol 4593 (25 Dec. 2016) and colorized. Credit: NASA/JPL/Cornell/Ken Kremer/kenkremer.com/Marco Di Lorenzo
After surviving the scorching ‘6 minutes of Terror’ plummet through the thin Martian atmosphere, Opportunity bounced to an airbag cushioned landing on the plains of Meridiani Planum on January 24, 2004 – nearly 13 years ago!
Opportunity was launched on a Delta II rocket from Cape Canaveral Air Force Station in Florida on July 7, 2003.
NASA’s Opportunity rover scans ahead to Spirit Mound and vast Endeavour crater as she celebrates 4500 sols on the Red Planet after descending down Marathon Valley. This navcam camera photo mosaic was assembled from raw images taken on Sol 4500 (20 Sept 2016) and colorized. Credit: NASA/JPL/Cornell/ Ken Kremer/kenkremer.com/Marco Di Lorenzo
The newest 2 year extended mission phase just began on Oct. 1, 2016 as the six wheeled robot was stationed at the western rim of Endeavour crater at the bottom of Marathon Valley at a spot called “Bitterroot Valley” and completing investigation of nearby “Spirit Mound.”
She is now ascending back up to the top of the crater rim for the southward trek to ‘the gully’ in 2017.
“Opportunity is making progress towards the next science objective of the extended mission,” researchers leading the Mars Exploration Rover (MER) Opportunity mission wrote in a status update.
“The rover is headed toward an ancient water-carved gully about a kilometer south of the rover’s current location on the rim of Endeavour Crater.”
Endeavour crater spans some 22 kilometers (14 miles) in diameter.
Opportunity has been exploring Endeavour since arriving at the humongous crater in 2011. Endeavour crater was formed when it was carved out of the Red Planet by a huge meteor impact billions of years ago.
“Endeavour crater dates from the earliest Martian geologic history, a time when water was abundant and erosion was relatively rapid and somewhat Earth-like,” Crumpler explains.
“So in addition to exploring the geology of a large crater, a type of feature that no one has ever explored in its preserved state, the mission seeks to take a close look at the evidence in the rocks for the past environment. Thus we are trying to stick to the crater rim where the oldest rocks are.”
But the crater slopes ahead are steep! As much as 20 degrees and more – and thus potentially dangerous! So the team is commanding Opportunity to proceed ahead with caution to “the gully” which is the primary target of her latest extended mission.
The rover has even done “quite a bit of exploratory driving in an effort to attain a good vantage point for finding a path through a troubling area of boulder patch and steep slopes ahead. The concern was whether the available routes to avoid the boulders were all too steep to traverse, in which case we would have to forgo the current ‘Extended Mission 10’ (EM10) route and backtrack to find a different route to our main objective, the ‘gully.’”
“The slopes here exceed 20 degrees and the surface consists of flat outcrops of impact breccias covered with tiny rocks that act like ball bearings,” Crumpler writes. “Anyone who has attempted to walk on a 20 degree slope with a covering of fine pebbles on hard outcrop can attest to the difficulty. Opportunity has been operating at these extreme slope for several months. But going down hill is one thing, And going back up hill is another entirely.”
NASA’s Opportunity rover discovers a beautiful Martian dust devil moving across the floor of Endeavour crater as wheel tracks show robots path today exploring the steepest ever slopes of the 13 year long mission, in search of water altered minerals at Knudsen Ridge inside Marathon Valley on 1 April 2016. This navcam camera photo mosaic was assembled from raw images taken on Sol 4332 (1 April 2016) and colorized. Credit: NASA/JPL/Cornell/ Ken Kremer/kenkremer.com/Marco Di Lorenzo
As of today, Sol 4598, Dec. 29, 2016, Opportunity has taken over 215,900 images and traversed over 27.12 miles (43.65 kilometers) – more than a marathon.
See our updated route map below.
The rover surpassed the 27 mile mark milestone early last month on November 6 (Sol 4546).
The power output from solar array energy production is currently 414 watt-hours, before heading into another southern hemisphere Martian winter in 2017.
Meanwhile Opportunity’s younger sister rover Curiosity traverses and drills into the lower sedimentary layers at the base of Mount Sharp.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
13 Year Traverse Map for NASA’s Opportunity rover from 2004 to 2016. This map shows the entire 43 kilometer (27 mi) path the rover has driven on the Red Planet during nearly 13 years and more than a marathon runners distance for some 4600 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 – to current location at the western rim of Endeavour Crater. After descending down Marathon Valley and after studying Spirit Mound, the rover is now ascending back uphill on the way to a Martian water carved gully. Rover surpassed Marathon distance on Sol 3968 after reaching 11th Martian anniversary on Sol 3911. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone – and searched for more at Marathon Valley. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer/kenkremer.com
Artist concept of the Mars Ice Home. Credit: NASA.
At first glance, a new concept for a NASA habitat on Mars looks like a cross between Mark Watney’s inflatable potato farm from “The Martian” and the home of Luke’s Uncle Owen on Tatooine from “Star Wars.”
The key to the new design relies on something that may or may not be abundant on Mars: underground water or ice.
The “Mars Ice Home” is a large inflatable dome that is surrounded by a shell of water ice. NASA said the design is just one of many potential concepts for creating a sustainable home for future Martian explorers. The idea came from a team at NASA’s Langley Research Center that started with the concept of using resources on Mars to help build a habitat that could effectively protect humans from the elements on the Red Planet’s surface, including high-energy radiation.
The Mars Ice Home concept. Credit: Clouds Architecture Office, NASA Langley Research Center, Space Exploration Architecture.
Langley senior systems engineer Kevin Vipavetz who facilitated the design session said the team assessed “many crazy, out of the box ideas and finally converged on the current Ice Home design, which provides a sound engineering solution,” he said.
The advantages of the Mars Ice Home is that the shell is lightweight and can be transported and deployed with simple robotics, then filled with water before the crew arrives. The ice will protect astronauts from radiation and will provide a safe place to call home, NASA says. But the structure also serves as a storage tank for water, to be used either by the explorers or it could potentially be converted to rocket fuel for the proposed Mars Ascent Vehicle. Then the structure could be refilled for the next crew.
A cutaway of the interior of the Mars Ice Home concept. Credit: NASA Langley/Clouds AO/SEArch.
Other concepts had astronauts living in caves, or underground, or in dark, heavily shielded habitats. The team said the Ice Home concept balances the need to provide protection from radiation, without the drawbacks of an underground habitat. The design maximizes the thickness of ice above the crew quarters to reduce radiation exposure while also still allowing light to pass through ice and surrounding materials.
Team members of the Ice Home Feasibility Study discuss past and present technology development efforts in inflatable structures at NASA’s Langley Research Center. Credits: Courtesy of Kevin Kempton/NASA.
“All of the materials we’ve selected are translucent, so some outside daylight can pass through and make it feel like you’re in a home and not a cave,” said Kevin Kempton, also part of the Langley team.
One key constraint is the amount of water that can be reasonably extracted from Mars. Experts who develop systems for extracting resources on Mars indicated that it would be possible to fill the habitat at a rate of one cubic meter, or 35.3 cubic feet, per day. This rate would allow the Ice Home design to be completely filled in 400 days, so the habitat would need to be constructed robotically well before the crew arrives. The design could be scaled up if water could be extracted at higher rates.
The team wanted to also include large areas for workspace so the crew didn’t have to wear a pressure suit to do maintenance tasks such as working on robotic equipment. To manage temperatures inside the Ice Home, a layer of carbon dioxide gas — also available on Mars — would be used as in insulation between the living space and the thick shielding layer of ice.
“The materials that make up the Ice Home will have to withstand many years of use in the harsh Martian environment, including ultraviolet radiation, charged-particle radiation, possibly some atomic oxygen, perchlorates, as well as dust storms – although not as fierce as in the movie ‘The Martian’,” said Langley researcher Sheila Ann Thibeault.
The 18-segment gold coated primary mirror of NASA’s James Webb Space Telescope is raised into vertical alignment in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on Nov. 2, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com
The 18-segment gold coated primary mirror of NASA’s James Webb Space Telescope is raised into vertical alignment in the largest clean room at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, on Nov. 2, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com
NASA GODDARD SPACE FLIGHT CENTER, MD – The James Webb Space Telescope (JWST) is now deemed “sound” and apparently unscathed, engineers have concluded, based on results from a new batch of intensive inspections of the observatory’s structure, after concerns were raised in early December when technicians initially detected “anomalous readings” during a preplanned series of vibration tests, NASA announced Dec. 23.
After conducting both “visual and ultrasonic examinations” at NASA’s Goddard Space Flight Center in Maryland, engineers have found it to be safe at this point with “no visible signs of damage.”
But because so much is on the line with NASA’s $8.8 Billion groundbreaking Webb telescope mission that will peer back to nearly the dawn of time, engineers are still investigating the “root cause” of the “vibration anomaly” first detected amidst shake testing on Dec. 3.
“The team is making good progress at identifying the root cause of the vibration anomaly,” NASA explained in a Dec 23 statement – much to everyone’s relief!
“They have successfully conducted two low level vibrations of the telescope.”
“All visual and ultrasonic examinations of the structure continue to show it to be sound.”
Technicians work on the James Webb Space Telescope in the massive clean room at NASA’s Goddard Space Flight Center, Greenbelt, Maryland, on Nov. 2, 2016, as the completed golden primary mirror and observatory structure stands gloriously vertical on a work stand, reflecting incoming light from the area and observation deck. Credit: Ken Kremer/kenkremer.com
Starting late November, technicians began a defined series of environmental tests including vibration and acoustics tests to make sure that the telescopes huge optical structure was fit for blastoff and could safely withstand the powerful shaking encountered during a rocket launch and the especially harsh rigors of the space environment. It would be useless otherwise – unable to carry out unparallelled science.
To carry out the vibration and acoustics tests conducted on equipment located in a shirtsleeve environment, the telescope structure was first carefully placed inside a ‘clean tent’ structure to protect it from dirt and grime and maintain the pristine clean room conditions available inside Goddard’s massive clean room – where it has been undergoing assembly for the past year.
NASA’s James Webb Space Telescope placed inside a “clean tent” in Nov. 2016 to protect it from dust and dirt as engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland transport it out of the relatively dust-free cleanroom and into a shirtsleeve environment to conduct vibration and acoustics tests to confirm it is fit for launch in 2018. Credit: NASA/Chris Gunn
NASA’s James Webb Space Telescope is the most powerful space telescope ever built and is the scientific successor to the phenomenally successful Hubble Space Telescope (HST).
The mammoth 6.5 meter diameter primary mirror has enough light gathering capability to scan back over 13.5 billion years and see the formation of the first stars and galaxies in the early universe.
The Webb telescope will launch on an ESA Ariane V booster from the Guiana Space Center in Kourou, French Guiana in 2018.
“The James Webb Space Telescope is undergoing testing to make sure the spacecraft withstands the harsh conditions of launch, and to find and remedy all possible concerns before it is launched from French Guiana in 2018.”
However, shortly after the vibration testing began technicians soon discovered unexpected “anomalous readings” during a shake test of the telescope on Dec. 3, as the agency initially announced in a status update on the JWST website.
The anomalous readings were found during one of the vibration tests in progress on the shaker table, via accelerometers attached to the observatories optical structure known as OTIS.
“During the vibration testing on December 3, at Goddard Space Flight Center in Greenbelt, Maryland, accelerometers attached to the telescope detected anomalous readings during a particular test,” the team elaborated.
So the team quickly conducted further “low level vibration” tests and inspections to more fully understand the nature of the anomaly, as well as scrutinize the accelerometer data for clues.
“Further tests to identify the source of the anomaly are underway. The engineering team investigating the vibe anomaly has made numerous detailed visual inspections of the Webb telescope and has found no visible signs of damage.”
“They are continuing their analysis of accelerometer data to better determine the source of the anomaly.”
The team is measuring and recording the responses of the structure to the fresh low level vibration tests and will compare these new data to results obtained prior to detection of the anomaly.
Work continues over the holidays to ensure Webb is safe and sound and can meet its 2018 launch target. After thoroughly reviewing all the data the team hope to restart the planned vibration and acoustic testing in the new year.
“Currently, the team is continuing their analyses with the goal of having a review of their findings, conclusions and plans for resuming vibration testing in January.”
Webb’s massive optical structure being tested is known as OTIS or Optical Telescope element and Integrated Science. It includes the fully assembled 18-segment gold coated primary mirror and the science instrument module housing the four science instruments
OTIS is a combination of the OTE (Optical Telescope Assembly) and the ISIM (Integrated Science Instrument Module) together.
“OTIS is essentially the entire optical train of the observatory!” said John Durning, Webb Telescope Deputy Project Manager, in an earlier exclusive interview with Universe Today at NASA’s Goddard Space Flight Center.
“It’s the critical photon path for the system.”
The components were fully integrated this past summer at Goddard.
The combined OTIS entity of mirrors, science module and backplane truss weighs 8786 lbs (3940 kg) and measures 28’3” (8.6m) x 8”5” (2.6 m) x 7”10“ (2.4 m).
The environmental testing is being done at Goddard before shipping the huge structure to NASA’s Johnson Space Center in February 2017 for further ultra low temperature testing in the cryovac thermal vacuum chamber.
The 6.5 meter diameter ‘golden’ primary mirror is comprised of 18 hexagonal segments – looking honeycomb-like in appearance.
And it’s just mesmerizing to gaze at – as I had the opportunity to do on a few occasions at Goddard this past year – standing vertically in November and seated horizontally in May.
Each of the 18 hexagonal-shaped primary mirror segments measures just over 4.2 feet (1.3 meters) across and weighs approximately 88 pounds (40 kilograms). They are made of beryllium, gold coated and about the size of a coffee table.
All 18 gold coated primary mirrors of NASA’s James Webb Space Telescope are seen fully unveiled after removal of protective covers installed onto the backplane structure, as technicians work inside the massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland on May 3, 2016. The secondary mirror mount booms are folded down into stowed for launch configuration. Credit: Ken Kremer/kenkremer.com
The Webb Telescope is a joint international collaborative project between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).
Webb is designed to look at the first light of the Universe and will be able to peer back in time to when the first stars and first galaxies were forming.
It will also study the history of our universe and the formation of our solar system as well as other solar systems and exoplanets, some of which may be capable of supporting life on planets similar to Earth.
Up close side-view of newly exposed gold coated primary mirrors installed onto mirror backplane holding structure of NASA’s James Webb Space Telescope inside the massive clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland on May 3, 2016. Aft optics subsystem stands upright at center of 18 mirror segments between stowed secondary mirror mount booms. Credit: Ken Kremer/kenkremer.com
Watch this space for my ongoing reports on JWST mirrors, science, construction and testing.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Ken Kremer/Universe Today reflecting in and about the golden mirrors of NASA’s James Webb Space Telescope which will peer back 13.5 Billion years to unravel the mysteries off the formation of the early Universe and tell us how our place in the Universe came to be. Credit: Ken Kremer/kenkremer.com
All six members of the Expedition 50 crew aboard the International Space Station celebrated the holidays together with a festive meal on Christmas Day, Dec. 25, 2016 Image Credit: NASA
All six members of the Expedition 50 crew aboard the International Space Station celebrated the holidays together with a festive meal on Christmas Day, Dec. 25, 2016. Image Credit: NASA
As we celebrate the Christmas tidings of 2016 here on Earth, a lucky multinational crew of astronauts and cosmonauts celebrate the festive season floating in Zero-G while living and working together in space aboard the Earth orbiting International Space Station (ISS) complex – peacefully cooperating to benefit all humanity.
Today, Dec. 25, 2016, the six person Expedition 50 crew of five men and one woman marked the joyous holiday of Christ’s birth by gathering for a festive meal in space – as billions of Earthlings celebrated this Christmas season of giving, remembrance and peace to all here on our home planet.
This year is an especially noteworthy Space Christmas because it counts as Expedition 50. This is the 50th crew to reside on board since the space station began operating with permanent occupancy by rotating crews all the way back to 1998.
The Expedition 50 crew currently comprises of people from three nations supporting the ISS – namely the US, Russia and France; Commander Shane Kimbrough from NASA and flight engineers Andrey Borisenko (Roscosmos), Sergey Ryzhikov (Roscosmos), Thomas Pesquet (ESA), Peggy Whitson (NASA), and Oleg Novitskiy (Roscosmos).
Here a short video of holiday greetings from a trio of crew members explaining what Christmas in Space means to them:
Video Caption: Space Station Crew Celebrates the Holidays Aboard the Orbital Lab. Aboard the International Space Station, Expedition 50 Commander Shane Kimbrough and Peggy Whitson of NASA and Thomas Pesquet of the European Space Agency discussed their thoughts about being in space during the holidays and how they plan to celebrate Christmas and New Year’s in a downlink. Credit: NASA
“Hello from the Expedition 50 Crew! We’d like to share what Christmas means to us,” said Expedition 50 Commander Shane Kimbrough.
“For me it’s a lot about family,” said Expedition 50 Commander Shane Kimbrough. “We always travel to meet up with our family which is dispersed across the country. And we go home to Georgia and Florida … quite abit to meet up. Always a great time to get together and share with each other.”
“Although its typically thought of a season to get things, we in our family think about the giving aspect. Giving of our many talents and resources. Especially to those less fortunate.”
Kimbrough arrived on the complex in October, followed a month later by Whitson and Pesquet in November.
They were all launched aboard Russian Soyuz capsules from the Baikonur Cosmodrome in Kazakhstan.
Aboard the International Space Station, Expedition 50 Flight Engineer Peggy Whitson of NASA sent holiday greetings and festive imagery from the cupola on Dec. 18, 2016. Credit: NASA.
And Peggy Whitson especially has a lot to celebrate in space!
Because not only is Whitson currently enjoying her third long-duration flight aboard the station – as an Expedition 50 flight engineer. Soon she will become the first woman to command the station twice ! That momentous event happens when she assumes the role of Space Station Commander early in 2017 during the start of Expedition 51.
“In addition to family, there is another very important aspect to being on the ISS,” said Whitson.
“That is seeing the planet as a whole. It actually reinforces I think, that fact that we should live as one people and strive for peace.”
“I second the comments already made. I grew up in a family of 25 cousins,” said ESA’s Thomas Pesquet. “The only time we could catch up was around Christmas time…. So I always looked forward to that, although this year I can’t be with them of course … and will think of them.”
“I am making the most of this opportunity to look at the Earth. Reflect about what Christmas means to us as individuals and to the world in general. And we will have a good time on board the ISS and share a Christmas meal together.”
Aboard the International Space Station, Expedition 50 Flight Engineer Peggy Whitson of NASA sent holiday greetings and festive imagery from the Japanese Kibo laboratory module on Dec. 18, 2016. Credit: NASA
The crew is enjoying a light weekend of work and a day off tomorrow, Dec. 26.
After that they begin preparing for a pair of spacewalks in the new year by Kimbrough and Whitson – scheduled for Jan. 6 and 13. The crew is checking the spacesuits by testing the water among other activities.
The goal of the excursions is to “complete the replacement of old nickel-hydrogen batteries with new lithium-ion batteries on the station’s truss structure,” says NASA.
Research work also continues.
“Whitson, who is spending her second Christmas in space, and Pesquet drew blood, urine and saliva samples for the Fluid Shifts study. That experiment investigates the upward flow of body fluids in space potentially causing lasting vision changes in astronauts.”
NASA astronaut Peggy Whitson floats through the Unity module aboard the International Space Station. On her third long-duration flight aboard the station, Whitson will become the first woman to command the station twice when she assumes the role during Expedition 51. Credit: NASA
Among other activities, the crew is also unloading 4.5 tons of internal and external cargo, gear and fresh food – including six lithium-ion batteries – from Japan’s sixth H-II Transfer Vehicle (HTV-6), which recently arrived at the ISS on Dec 13.
A Cygnus cargo spacecraft named the SS Rick Husband is being prepared inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center for upcoming Orbital ATK CRS-6/OA-6 mission to deliver hardware and supplies to the International Space Station. Cygnus is scheduled to lift off atop a United Launch Alliance Atlas V rocket on March 22, 2016. Credit: Ken Kremer/kenkremer.com
SpaceX also hopes to resume Dragon cargo launches sometime in the new year after they resolve the issues that led to the destruction of a SpaceX Falcon 9 on Sept. 1 during fueling operations at pad 40 on the Cape.
Special Guest:
Mathew Anderson is the author of “Our Cosmic Story” available on Amazon in January, 2017. He wrote “Our Cosmic Story” in interest from his years studying science giants like Brian Greene, Neil deGrasse Tyson, Richard Dawkins, and from past figures like Carl Sagan. This book is a big picture view of our world, its diverse life and civilizations, and the chance for life and civilizations elsewhere in the cosmos.
As a special treat, for a limited time, our listeners will have the opportunity to receive an advance electronic copy of Mathew’s books. Join us today to learn how to get your copy!
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This self-portrait of NASA's Curiosity Mars rover shows the vehicle at the "Big Sky" site. Credit: NASA/JPL-Caltech/MSSS
Following is the final excerpt from my new book, “Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos.” The book is an inside look at several current NASA robotic missions, and this excerpt is part 3 of 3 posted here on Universe Today, of Chapter 2, “Roving Mars with Curiosity.” You can read Part 1 here, and Part 2 here. The book is available in print or e-book (Kindle or Nook) Amazon and Barnes & Noble.
How to Drive a Mars Rover
How does Curiosity know where and how to drive across Mars’ surface? You might envision engineers at JPL using joysticks, similar to those used for remote control toys or video games. But unlike RC driving or gaming, the Mars rover drivers don’t have immediate visual inputs or a video screen to see where the rover is going. And just like at the landing, there is always a time delay of when a command is sent to the rover and when it is received on Mars.
“It’s not driving in a real-time interactive sense because of the time lag,” explained John Michael Morookian, who leads the team of rover drivers.
The actual job title of Morookian and his team are ‘Rover Planners,’ which precisely describes what they do. Instead of ‘driving’ the rovers per se; they plan out the route in advance, program specialized software, and upload the instructions to Curiosity.
“We use images taken by the rover of its surroundings,” said Morookian. “We have a set of stereo images from four black-and-white Navigation Cameras, along with images from the Hazcams (hazard avoidance cameras), supported by high-resolution color images from the MastCam that give us details about the nature of the terrain ahead and clues about types of rocks and minerals at the site. This helps identify structures that look interesting to the scientists.”
Using all available data, they can create a three-dimensional visualization of the terrain with specialized software called the Rover Sequencing and Visualization Program (RSVP).
“This is basically a Mars simulator and we put a simulated Curiosity in a panorama of the scene to visualize how the rover could traverse on its path,” Morookian explained. “We can also put on stereo glasses, which allow our eyes to see the scene in three dimensions as if we were there with the rover.
In virtual reality, the rover drivers can manipulate the scene and the rover to test every possibility of which routes are the best and what areas to avoid. There, they can make all the mistakes (get stuck in a dune, tip the rover, crash into a big rock, drive off a precipice) and perfect the driving sequence while the real rover remains safe on Mars.
“The scientists also review the images for features that are interesting and consult with the Rover Planners to help define a path. Then we compose the detailed commands that are necessary to get Curiosity from Point A to Point B along that path,” Morookian said. “”We can also incorporate the commands needed to give the rover direction to make contact with the site using its robotic arm.”
When Curiosity’s Navigation Cameras (Navcams) take black-and-white images and send them back to Earth each day, rover planners combine them with other rover data to create 3D terrain models. By adding a computerized 3D rover model to the terrain model, rover planners can understand better the rover’s position, as well as distances to, and scale of, features in the landscape. Credit: NASA/JPL-Caltech.
So, every night the rover is commanded to shut down for eight hours to recharge its batteries with the nuclear generator. But first Curiosity sends data to Earth, including pictures of the terrain and any science information. On Earth, the Rover Planners take that data, do their planning work, complete the software programing and beam the information back to Mars. Then Curiosity wakes up, downloads the instructions and sets to work. And the cycle repeats.
Curiosity also has an AutoNav feature which allows the rover to traverse areas the team hasn’t seen yet in images. So, it could go over the hill and down the other side to uncharted territory, with the AutoNav sensing potential hazards.
“We don’t use it too often because it is computationally expensive, meaning it takes much longer for the rover to operate in that mode,” Morookian said. “We often find it’s a better trade to just come in the next day, look at the images and drive as far as we can see.”
A view of the Space Flight Operations Facility at the Jet Propulsion Laboratory, where all the data going both to and from all planetary missions is sent and received via the Deep Space Network. Credit: Nancy Atkinson.
As Morookian showed me the various rooms used by rover planning teams at JPL, he explained how they need to operate over a number of different timescales.
“We not only have the daily route planning,” he said, “but also do long-range strategic planning using orbital imagery from the HiRISE camera on the Mars Reconnaissance Orbiter and choose paths based on features seen from orbit. Our team works strategically, looking many months out to define the best paths.”
Another process called Supra-Tactical looks out to just the next week. This involves science planners managing and refining the types of activities the rover will be doing in the short term. Also, since no one on the team lives on Mars Time anymore, on Fridays the Rover Planners work out the plans for several days.
“Since we don’t work weekends, Friday plans contain multiple sols of activities,” Morookian said. “Two parallel teams decide which days the rover will drive and which days it will do other activities, such as work with the robotic arm or other instruments.”
The data that comes down from the rover over the weekend is monitored, however, and if there is a problem, a team is called in to do a more detailed assessment. Morookian indicated they’ve had to engage the emergency weekend team several times, but so far there have been no serious problems. “It does keep us on our toes, however,” he said.
The rover features a number of reactive safety checks on the amount of overall tilt of the rover deck and the articulation of the suspension system of the wheels, so if the rover is going over an object that is too large, it will automatically stop.
Curiosity wasn’t built for speed. It was designed to travel up to 660 feet (200 meters) in a day, but it rarely travels that far in a Sol. By early 2016 the rover had driven a total of about 7.5 miles (12 km) across Mars’ surface.
This image shows a close-up of track marks left by the Curiosity rover. Holes in the rover’s wheels, seen here in this view, leave imprints in the tracks that can be used to help the rover drive more accurately. The imprint is Morse code for ‘JPL,’ and aids in tracking how far the rover has traveled. Credit: NASA/JPL-Caltech.
There are several ways to determine how far Curiosity has traveled, but the most accurate measurement is called ‘Visual Odometry.’ Curiosity has specialized holes in its wheels in the shape of Morse code letters, spelling out ‘JPL’ – a nod to the home of the rover’s science and engineering teams – across the Martian soil.
“Visual odometry works by comparing the most recent pair of stereo images collected roughly every meter over the drive,” said Morookian. “Individual features in the scene are matched and tracked to provide a measure of how the camera (and thus the rover) has translated and rotated in 3 dimensional space between the two images and it tells us in a very real sense how far Curiosity has gone.”
Careful inspection of the rover tracks can reveal the type of traction the wheels have and if they have slipped, for instance due to high slopes or sandy ground.
Unfortunately, Curiosity now has new holes in its wheels that aren’t supposed to be there.
Rover Problems
Morookian and Project Scientist Ashwin Vasavada both expressed relief and satisfaction that overall — this far into the mission — Curiosity is a fairly healthy rover. The entire science payload is currently operating at nearly full capability. But the engineering team keeps an eye on a few issues.
“Around sol 400, we realized the wheels were wearing faster than we expected,” Vasavada said.
The team operating the Curiosity Mars rover uses the Mars Hand Lens Imager (MAHLI) camera on the rover’s arm to check the condition of the wheels at routine intervals. This image of Curiosity’s left-middle and left-rear wheels is part of an inspection set taken on April 18, 2016, during the 1,315th sol of the rover’s work on Mars. Credit: NASA/JPL-Caltech/MSSS.
And the wear didn’t consist of just little holes; the team started to see punctures and nasty tears. Engineers realized the holes were being created by the hard, jagged rocks the rover was driving over during that time.
“We weren’t fully expecting the kind of ‘pointy’ rocks that were doing damage,” Vasavada said. “We also did some testing and saw how one wheel could push another wheel into a rock, making the damage worse. We now drive more carefully and don’t drive as long as we have in the past. We’ve been able to level off the damage to a more acceptable rate.”
Early in the mission, Curiosity’s computer went into ‘safe mode’ several times, as Curiosity’s software recognized a problem, and the response was to disallow further activity and phone home.
Specialized fault protection software runs throughout the modules and instruments, and when a problem occurs, the rover stops and sends data called ‘event records’ to Earth. The records include various categories of urgency, and in early 2015, the rover sent a message that essentially said, “This is very, very bad.” The drill on the rover’s arm had experienced a fluctuation in an electrical current – like a short circuit.
“Curiosity’s software has the ability to detect shorts, like the ground fault circuit interrupter you have in your bathroom,” Morookian explained, “except this one tells you ‘this is very, very bad’ instead of just giving you a yellow light.”
Since the team can’t go to Mars and repair a problem, everything is fixed either by sending software updates to the rover or by changing operational procedures.
Curiosity’s drill in the turret of tools at the end of the robotic arm positioned in contact with the rock surface for the first drilling of the mission on the 170th sol of Curiosity’s work on Mars (Jan. 27, 2013) in Yellowknife Bay. The picture was taken by the front Hazard-Avoidance Camera (Hazcam). Image credit: NASA/JPL-Caltech.
“We are just more careful now with how we use the drill,” Vasavada said, “and don’t drill with full force at the beginning, but slowly ramp up. It’s sort of like how we drive now, more gingerly but it still gets the job done. It hasn’t been a huge impact as of yet.”
A lighter touch on the drill also was necessary for the softer mudstones and sandstones the rover encountered. Morookian said there was concern the layered rocks might not hold up under the assault of the standard drilling protocol, and so they adjusted the technique to use the lowest ‘settings’ that still allows the drill to make sufficient progress into the rock.
But opportunities to use the drill are increasing as Curiosity begins its traverse up the mountain. The rover is traveling through what Vasavada calls a “target rich, very interesting area,” as the science team works to tie together the geological context of everything they are seeing in the images.
Finding Balance on Mars
While the diversion at Yellowknife Bay allowed the team to make some major discoveries, they felt pressure to get to Mt. Sharp, so “drove like hell for a year,” Vasavada said.
Now on the mountain, there is still the pressure to make the most of the mission, with the goal of making it through at least four different rock units – or layers — on Mt. Sharp. Each layer could be like a chapter in the book of Mars’ history.
A portion of a panorama from Curiosity’s Mastcam shows the rugged surface of ‘Naukluft Plateau’ plus part of the rim of Gale Crater, taken on April 4, 2016 or Sol 1301. Credit: NASA/JPL-Caltech/MSSS
“Exploring Mt. Sharp is fascinating,” Vasavada said, “and we’re trying to maintain a mix between really great discoveries, which – you hate to say — slows us down, and getting higher on the mountain. Looking closely at a rock in front of you means you’ll never be able to go over and look at that other interesting rock over there.”
Vasavada and Morookian both said it’s a challenge to preserve that balance every day — to find what’s called the ‘knee in the curve’ or ‘sweet spot’ of the perfect optimization between driving and stopping for science.
Then there’s the balance between stopping to do a full observation with all the instruments and doing ‘flyby science’ where less intense observations are made.
“We take the observations we can, and generate all the hypotheses we can in real time,” Vasavada said. “Even if we’re left with 100 open questions, we know we can answer the questions later as long as we know we’ve taken enough data.”
Curiosity’s primary target is not the summit, but instead a region about 1,330 feet (400 meters) up where geologists expect to find the boundary between rocks that saw a lot of water in their history, and those that didn’t. That boundary will provide insight into Mars’ transition from a wet planet to dry, filling in a key gap in the understanding of the planet’s history.
he Curiosity rover recorded this view of the Sun setting at the close of the mission’s 956th sol (April 15, 2015), from the rover’s location in Gale Crater. This was the first sunset observed in color by Curiosity. The image comes from the left-eye camera of the rover’s Mast Camera (Mastcam). Credit: NASA/JPL-Caltech/MSSS/Texas A&M University.
No one really knows how long Curiosity will last, or if it will surprise everyone like its predecessors Spirit and Opportunity. Having made it past the ‘prime mission’ of one year on Mars (two Earth years), and now in the extended mission, the one big variable is the RTG power source. While the available power will start to steadily decrease, both Vasavada and Morookian don’t expect that to be in an issue for at least four more Earth years, and with the right “nurturing,” power could last for a dozen years or more.
But they also know there’s no way to predict how long Curiosity will go, or what unexpected event might end the mission.
The Beast
Does Curiosity have a personality like the previous Mars rovers?
“Actually no, we don’t seem to anthropomorphize this rover like people did with Spirit and Opportunity,” Vasavada said. “We haven’t bonded emotionally with it. Sociologists have actually been studying this.” He shook his head with an amused smile.
Vasavada indicated it might have something to do with Curiosity’s size.
“I think of it as a giant beast,” he said straight-faced. “But not in a mean way at all.”
Curiosity appears to be photobombing Mount Sharp in this selfie image, a mosaic created from several MAHLI images. Credit: NASA/JPL-Caltech/MSSS/Edited by Jason Major.
What has come to come to characterize this mission, Vasavada said, is the complexity of it, in every dimension: the human component of getting 500 people to work and cooperate together while optimizing everyone’s talents; keeping the rover safe and healthy; and keeping ten instruments going every day, which are sometimes doing completely unrelated science tasks.
“Every day is our own little ‘seven minutes of terror,’ where so many things have to go right every single day,” Vasavada said. “There are a million potential issues and interactions, and you have to constantly be thinking about all the ways things can go wrong, because there are a million ways you can mess up. It’s an intricate dance, but fortunately we have a great team.”
Then he added with a smile, “This mission is exciting though, even if it’s a beast.”
“Incredible Stories From Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos” is published by Page Street Publishing, a subsidiary of Macmillan.
Author Nancy Atkinson at JPL with a model of the Curiosity Rover.
