On October 4, 2016, Hurricane Matthew made landfall on southwestern Haiti as a category-4 storm—the strongest storm to hit the Caribbean nation in more than 50 years. Just hours after landfall, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color image. At the time, Matthew had top sustained winds of about 230 kilometers (145 miles) per hour. Credit: NASA Earth Observatory image by Joshua Stevens
As Hurricane Matthew approaches the east coast of Florida, the evacuation of hundreds of thousands of people is taking place in Florida and South Carolina. Forecasters say the conditions appear to be favorable for the storm to restrengthen after it caused major damage to western Haiti and eastern Cuba. Matthew is now heading toward Florida, bringing with it the potential for heavy rain, storm surges and hurricane-force winds. The expected maximum sustained winds could be 130 mph (210 km/hr), and it could be the strongest hurricane to hit the region in 11 years
The National Hurricane Center said “Matthew is moving toward the northwest near 12 mph (19 kph), and this motion is expected to continue during the next 24 to 48 hours. On this track, Matthew will be moving across the Bahamas through Thursday, and is expected to be very near the east coast of Florida by Thursday evening, Oct. 6.”
The image above was taken by NASA’s Terra satellite on October 4, 2016, showing the hurricane over the eastern tip of Cuba and the eastern-most extent over Puerto Rico. Reports say it was the strongest storm to hit the Caribbean nation in more than 50 years.
Cameras on board the International Space Station captured these views of Hurricane Matthew today (October 5) as the now Category 3 storm moved to the north of Cuba:
NASA’s Kennedy Space Center released a statement that they closed at 1 p.m. today due to the approach of the hurricane, with essential personnel preparing facilities for the storm’s arrival.
Stu Ostro, a senior meteorologist at The Weather Channel, tweeted a satellite image of the hurricane, which has gone viral, which some say shows a face with a fiery eye, teeth and a sinister smile.
WeatherUnderground is tracking the storm and as of 6:00 pm ET on October 5, this was the projected path of the storm. You can click the image (or this link) to get the current tracking data on WeatherUnderground.
Projected path for Hurricane Matthew as of October 5, 2016. Click for updated map on WeatherUnderground.com.
This animation of NOAA’s GOES-East satellite imagery from Oct. 3 to Oct. 5 shows Hurricane Matthew make landfall on Oct. 4 in western Haiti and move toward the Bahamas on Oct. 5.
NOAA said tropical storm or hurricane conditions could affect South Carolina and North Carolina later this week or this weekend, even if the center of Matthew remains offshore, adding that “it is too soon to determine what, if any, land areas might be directly affected by Matthew next week. At a minimum, dangerous beach and boating conditions are
likely along much of the U.S. east coast during the next several days.”
A picture of Earth taken by Apollo 11 astronauts. Credit: NASA
The moment that the Apollo-11 mission touched down on the Moon, followed by Neil Armstrong‘s famous words – “That’s one small step for [a] man, one giant leap for mankind” – is one of the most iconic moments in history. The culmination of years of hard work and sacrifice, it was an achievement that forever established humanity as a space-faring species.
And in the year’s that followed, several more spacecraft and astronauts landed on the Moon. But before, during and after these missions, a number of other “lunar landings” were accomplished as well. Aside from astronauts, a number of robotic missions were mounted which were milestones in themselves. So exactly what were the earliest lunar landings?
Robotic Missions:
The first missions to the Moon consisted of probes and landers, the purpose of which was to study the lunar surface and determine where crewed missions might land. This took place during the 1950s where both the Soviet Space program and NASA sent landers to the Moon as part of their Luna and Pioneer programs.
The Soviet Luna 2 probe, the first man-made object to land on the Moon. Credit: NASA
After several attempts on both sides, the Soviets managed to achieve a successful lunar landing on Sept. 14th, 1959 with their Luna-2 spacecraft. After flying directly to the Moon for 36 hours, the spacecraft achieved a hard landing (i.e. crashed) on the surface west of the Mare Serenitatis – near the craters Aristides, Archimedes, and Autolycus.
The primary objective of the probe was to help confirm the discovery of the solar wind, turned up by the Luna-1mission. However, with this crash landing, it became the first man-made object to touch down on the Moon. Upon impact, it scattered a series of Soviet emblems and ribbons that had been assembled into spheres, and which broke apart upon hitting the surface.
The next craft to make a lunar landing was the Soviet Luna-3 probe, almost a month after Luna-2 did. However, unlike its predecessor, the Luna-3 probe was equipped with a camera and managed to send back the first images of the far side of the Moon.
The first US spacecraft to impact the Moon was the Ranger-7 probe, which crashed into the Moon on July 31st, 1964. This came after a string of failures with previous spacecraft in the Pioneer and Ranger line of robotic spacecraft. Prior to impact, it too transmitted back photographs of the Lunar surface.
The Ranger 7 lander, which became the first US spacecraft to land on the Moon. Credit: NASA
This was followed by the Ranger-8 lander, which impacted the surface of the Moon on Feb. 20th, 1965. The spacecraft took 7,000 high-resolution images of the Moon before crashing onto the surface, just 24 km from the Sea of Tranquility, which NASA had been surveying for the sake of their future Apollo missions. These images, which yielded details about the local terrain, helped to pave the way for crewed missions.
The first spacecraft to make a soft landing on the Moon was the Soviet Luna-9 mission, on February 3rd, 1966. This was accomplished through the use of an airbag system that allowed the probe to survive hitting the surface at a speed of 50 km/hour. It also became the first spacecraft to transmit photographic data back to Earth from the surface of another celestial body.
The first truly soft landing was made by the US with the Surveyor-1 spacecraft, which touched down on the surface of the Moon on June 2nd, 1966. After landing in the Ocean of Storms, the probe transmitted data back to Earth that would also prove useful for the eventual Apollo missions.
Several more Surveyor missions and one more Luna mission landed on the Moon before crewed mission began, as part of NASA’s Apollo program.
Launch of Apollo 11 mission aboard a Saturn V rocket on July 16th, 1969. Credit: NASA
Crewed Missions:
The first crewed landing on the Moon was none other than the historic Apollo-11 mission, which touched down on the lunar surface on July 20th, 1969. After achieving orbit around the Moon in their Command Module (aka. the Columbia module), Neil Armstrong and Buzz Aldrin rode the Lunar Excursion (Eagle) Module down to the surface of the Moon.
Once they had landed, Armstrong radioed to Mission Control and announced their arrival by saying: “Houston, Tranquility Base here. The Eagle has landed.” Once the crew had gone through their checklist and depressurized the cabin, the Eagles’ hatch was opened and Armstrong began walking down the ladder to the Lunar surface first.
When he reached the bottom of the ladder, Armstrong said: “I’m going to step off the LEM now” (referring to the Lunar Excursion Module). He then turned and set his left boot on the surface of the Moon at 2:56 UTC July 21st, 1969, and spoke the famous words “That’s one small step for [a] man, one giant leap for mankind.”
About 20 minutes after the first step, Aldrin joined Armstrong on the surface and became the second human to set foot on the Moon. The two then unveiled a plaque commemorating their flight, set up the Early Apollo Scientific Experiment Package, and planted the flag of the United States before blasting off in the Lunar Module.
Buzz Aldrin on the Moon during the Apollo 11 mission, with the reflection of Neil Armstrong visible in his face plate. Credit: NASA
Several more Apollo missions followed which expanded on the accomplishments of the Apollo-11 crew. The US and NASA would remain the only nation and space agency to successfully land astronauts on the Moon, an accomplishment that has not been matched to this day.
Today, multiple space agencies (and even private companies) are contemplating returning to the Moon. Between NASA, the European Space Agency (ESA), the Russian Space Agency (Roscosmos), and the Chinese National Space Administration (CNSA), there are several plans for crewed missions, and even the construction of permanent bases on the Moon.
Hubble image of variable star RS Puppis (NASA, ESA, and the Hubble Heritage Team)
The Universe is a really, really big place. We’re talking… imperceptibly big! In fact, based on decades worth of observations, astronomers now believe that the observable Universe measures about 46 billion light years across. The key word there is observable, because when you take into account that which we cannot see, scientists think it’s actually more like 92 billion light years across.
The hardest part in all of this is making accurate measurements of the distances involved. But since the birth of modern astronomy, increasingly accurate methods have evolved. Aside from redshift and examining the light coming from distant stars and galaxies, astronomers also rely on a class of stars known as Cepheid Variables (CVs) to determine the distance of objects within and beyond our Galaxy.
Definition:
Variable stars are essentially stars that experience fluctuations in their brightness (aka. absolute luminosity). Cepheids Variables are special type of variable star in that they are hot and massive – five to twenty times as much mass as our Sun – and are known for their tendency to pulsate radially and vary in both diameter and temperature.
What’s more, these pulsations are directly related to their absolute luminosity, which occurs within well-defined and predictable time periods (ranging from 1 to 100 days). When plotted as a magnitude vs. period relationship, the shape of the Cephiad luminosity curve resembles that of a “shark fin” – do its sudden rise and peak, followed by a steadier decline.
The name is derived from Delta Cephei, a variable star in the Cepheus constellation that was the first CV to be identified. Analysis of this star’s spectrum suggests that CVs also undergo changes in terms of temperature (between 5500 – 66oo K) and diameter (~15%) during a pulsation period.
Use in Astronomy:
The relationship between the period of variability and the luminosity of CV stars makes them very useful in determining the distance of objects in our Universe. Once the period is measured, the luminosity can be determined, thus yielding accurate estimates of the star’s distance using distance modulus equation.
This equation states that: m – M = 5 log d – 5 – where m is the apparent magnitude of the object, M is the absolute magnitude of the object, and d is the distance to the object in parsecs. Cepheid variables can be seen and measured to a distance of about 20 million light years, compared to a maximum distance of about 65 light years for Earth-based parallax measurements and just over 326 light years for the ESA’s Hipparcos mission.
Calibrated Period-luminosity Relationship for Cepheids. Credit: NASA
Because they are bright, and can be clearly seen million of light years away, they can be easily distinguished from other bright stars in their vicinity. Combined with the relationship between their variability and luminosity, this makes them highly useful tools in deducing the size and scale of our Universe.
Classes:
Cepheid variables are divided into two subclasses – Classical Cepheids and Type II Cepheids – based on differences in their masses, ages, and evolutionary histories. Classical Cepheids are Population I (metal-rich) variable stars that are 4-20 times more massive than the Sun and up to 100,000 times more luminous. They undergo pulsations with very regular periods on the order of days to months.
These Cepheids are typically yellow bright giants and supergiants (spectral class F6 – K2) and they experience radius changes in the millions of kilometers during a pulsation cycle. Classical Cepheids are used to determine distances to galaxies within the Local Group and beyond, and are a means by which the Hubble Constant can be established (see below).
Type II Cepheids are Population II (metal-poor) variable stars which pulsate with periods of typically between 1 and 50 days. Type II Cepheids are also older stars (~10 billion years) that have around half the mass of our Sun.
Type II Cepheids are also subdivided based on their period into the BL Her, W Virginis, and RV Tauri subclasses (named after specific examples) – which have periods of 1-4 days, 10-20 days, and more than 20 days, respectively. Type II Cepheids are used to establish the distance to the Galactic Center, globular clusters, and neighboring galaxies.
There are also those that do not fit into either category, which are known as Anomalous Cepheids. These variables have periods of less than 2 days (similar to RR Lyrae) but have higher luminosities. They also have higher masses than Type II Cepheids, and have unknown ages.
A small proportion of Cepheid variables have also been observed which pulsate in two modes at the same time, hence the name Double-mode Cepheids. A very small number pulsate in three modes, or an unusual combination of modes.
History of Observation:
The first Cepheid variable to be discovered was Eta Aquilae, which was observed on September 10th, 1784, by English astronomer Edward Pigott. Delta Cephei, for which this class of star is named, was discovered a few months later by amateur English astronomer John Goodricke.
Hubble image of variable star RS Puppis, one of the brightest known Cepheid variable stars in the Milky Way galaxy. Credit: NASA/ ESA/Hubble Heritage Team
In 1908, during an investigation of variable stars in the Magellanic Clouds, American astronomer Henrietta Swan Leavitt discovered the relationship between the period and luminosity of Classical Cepheids. After recording the periods of 25 different variables stars, she published her findings in 1912.
In the following years, several more astronomers would conduct research on Cepheids. By 1925, Edwin Hubble was able to establish the distance between the Milky Way and the Andromeda Galaxy based on Cepheid variables within the latter. These findings were pivotal, in that they settled the Great Debate, where astronomers sought to established whether or not the Milky Way was unique, or one of many galaxies in the Universe.
By gauging the distance between the Milky Way and several other galaxies, and combining it with Vesto Slipher’s measurements of their redshift, Hubble and Milton L. Humason were able to formulate Hubble’s Law. In short, they were able to prove that the Universe is in a state of expansion, something that had been suggested years prior.
Further developments during the 20th century included dividing Cepheids into different classes, which helped resolve issues in determining astronomical distances. This was done largely by Walter Baade, who in the 1940s recognized the difference between Classical and Type II Cepheids based on their size, age and luminosities.
Limitations:
Despite their value in determining astronomical distances, there are some limitations with this method. Chief among them is the fact that with Type II Cepheids, the relationship between period and luminosity can be effected by their lower metallicity, photometric contamination, and the changing and unknown effect that gas and dust have on the light they emit (stellar extinction).
These unresolved issues have resulted in different values being cited for Hubble’s Constant – which range between 60 km/s per 1 million parsecs (Mpc) and 80 km/s/Mpc. Resolving this discrepancy is one of the largest problems in modern cosmology, since the true size and rate of expansion of the Universe are linked.
However, improvements in instrumentation and methodology are increasing the accuracy with which Cepheid Variables are observed. In time, it is hoped that observations of these curious and unique stars will yield truly accurate values, thus removing a key source of doubt about our understanding of the Universe.
Screenshots of the ignition of the crew escape abort motor 45 seconds into the flight. Credit: Blue Origin/John Gardi.
Blue Origin successfully conducted an in-flight test of the New Shepard crew escape system on Wednesday. A live webcast featured stunning views of the crew capsule blasting away from the rocket booster 45 seconds into the flight with a two-second burn, and then parachuting safely back down to the ground. “We’re speechless right now and absolutely rightfully so,” said launch commentator Ariane Cornell.
Adding to the excitement, the rocket booster unexpectedly also survived the test, returning intact and making a successful vertical landing back at Blue Origin’s West Texas facility. So, yes, we were wrong about it ending in ‘fiery destruction.’ Blue Origin founder Jeff Bezos had said computer simulations showed a minimal chance the booster could survive the stresses of “70,000 pounds of off-axis force delivered by searing hot exhaust,” from the capsule escape motor, and then successfully return and land vertically as it’s done previously.
Bezos was pumped about the outcome, tweeting “That is one hell of a booster,” and included this Vine video of the event:
This is the fifth launch and landing of this rocket, the fourth made just this year. The successful landing of the booster means the intact rocket will find a place of honor – perhaps in a museum or even as a lawn ornament at Blue Origin, as SpaceX did.
Here’s the webcast:
This is the fifth launch and landing of this rocket, the fourth made just this year. The successful landing of the booster means the intact rocket will find a place of honor – perhaps in a museum or even as a lawn ornament at Blue Origin, as SpaceX did.
The escape system is designed to safely separate the New Shepherd crew capsule from the rocket booster in the event of an anomaly during flight, protecting a future crew. The abort system performed as expected, as about 45 seconds after liftoff, the escape motor ignited underneath the crew capsule. The motor burned for two seconds and shot the capsule up and away from the rocket booster. After a bit of tumbling – which would have given any occupants inside a fairly wild ride –the capsule’s parachutes deployed, allowing it to land safely. It will be interesting to hear followup on the tumbling from Blue Origin’s engineers, to see how unexpected that might be.
Cornel said this was a nominal test, providing an “exhilarating but safe ride.”
Screen capture of New Shepard booster touching down. Credit: Blue Origin.
Once it was obvious the booster survived the blast from the escape system, it was fun and nail-biting to watch the booster reach the edge of space and then begin its descent. It used a series of braking maneuvers then just 8 minutes after launch as it approached the ground –still vertical — its BE-3 engine turned on and the landing legs deployed. The booster – looking only a little worse for wear — touched down gently.
Cornell said both the capsule and the booster will be retired, earning another turtle stencil.
Blue Origin stencils a tortoise on their vehicles after each successful flight. The tortoise is part of the company’s Coat of Arms. Credit: Blue Origin.
Blue Origin hopes to launch paying passengers into suborbital space by 2018 and today’s successful test means the company is on track to make it so.
Today’s successful test flight won praise from many in the industry. Eric Stallmer, presdient of the Commercial Spaceflight Federation congratulated the Blue Origin team and said, “Today’s fifth successful flight proved the New Shepard’s most critical safety features, innovative escape system technologies, and overall robustness of their system. It’s an exciting time to see these fantastic technological advancements and to witness the power of commercial industry.”
Screen capture of the New Shepard just before and after the abort motor ignition 45 seconds into the flight. Credit: Blue Origin/John Gardi.
Io and Europa cast simultaneous shadows on Jupiter on March 22nd, 2016. Image credit and copyright: Andrew Symes.
Missing Jove? The largest planet in our solar system is currently on the far side of the Sun and just passed solar conjunction on September 26th, 2016. October now sees Jupiter slowly return to the dawn sky. Follow that gas giant, as an interesting set of double shadow transits transpires in late October leading in to early November.
This particular cycle of double shadow transits involves the large Jovian moons of Europa and Ganymede.
The scene on October 24th at 23:55 UT. Image credit: Created using Starry Night Education software.
Europa and Ganymede double shadow transit season begins later this month, as both cast shadows on the Jovian cloud tops. This series of simultaneous shadow transits runs from October 17th to November 8th, and includes four weekly events.
The inner three large moons Io, Europa and Ganymede are in a 4:2:1 resonance. Europa orbits Jove once every 3.6 days and makes two circuits for Ganymede’s one. This means there’s a double shadow transit once every week in the current season:
The double shadow transit season of 2016. Created by author.
When can you first spy Jupiter, post solar conjunction? Catching this particular series of double shadow transits is challenging this time around, owing to the planet’s position low in the dawn twilight. The first event on October 17th starts with Jupiter just 16 degrees west of the Sun, and the cycle ends with Jove 38 degrees west of the Sun on November 8th.
Keep in mind, it is possible to track Jupiter up in to the daytime sky, post sunrise. To do this, you’ll need a ‘scope with a solid equatorial mount and good sidereal tracking. The trick is to lock on to Jupiter before sunrise and track it up in to the dawn sky. Be sure to physically block that dazzling rising Sun out of view behind a hill or building, and NEVER aim your telescope at the Sun!
Using this method opens up the possibility of nabbing a given double shadow event to longitudes due east of the quoted locales above.
The waning crescent Moon also passes 1.4 degrees NNE of Jupiter on October 28th, offering another chance to spy the gas giant in the dawn sky, using the nearby crescent Moon as a guide.
The Moon and Jupiter in the daytime skies on October 28th. Image credit: Stellarium.
And another interesting pairing is coming right up on the morning of Tuesday, October 11th, when Mercury passes just 0.8 degrees (48′) NNE of Jupiter. Both are only 12 degrees west of the Sun at closest approach, which occurs around 10:00 UT. Still, both will appear as an interesting pseudo-double star, with Mercury shining at magnitude -1.1 and Jupiter only half a magnitude fainter at -1.6.
You can even see Jupiter coming off of solar conjunction and headed toward dawn skies courtesy of SOHO’s LASCO C3 camera:
Jupiter (arrowed) exiting the 15 degree wide field of view of SOHO’s LASCO C3 camera on October 5th. Image credit: NASA/ESA/SOHO.
Callisto, the outermost large moon of Jupiter, ceased casting its shadow on Jupiter earlier this year on September 1st 2016. Callisto is the only large moon that can ‘miss’ the gas giant’s cloud tops. Callisto must be involved for a triple shadow transit to occur, and the moon resumes regularly casting its shadow on Jove on December 4th, 2019.
Callisto can also experience total solar eclipses similar to those seen from the Earth during the mutual eclipse season for Jupiter’s moons, albeit shorter in duration:
And don ‘t forget: we’ve got a spacecraft currently exploring Jupiter for the next year and a half: NASA’s very own Juno.
Be sure to check out the Jovian action over the next month, gracing a dawn sky near you.
Welding is complete on the largest piece of the core stage that will provide the fuel for the first flight of NASA's new rocket, the Space Launch System, with the Orion spacecraft in 2018. The core stage liquid hydrogen tank has completed welding on the Vertical Assembly Center at NASA's Michoud Assembly Facility in New Orleans. Credit: NASA/MAF/Steven Seipel
Welding is complete on the largest piece of the core stage that will provide the fuel for the first flight of NASA’s new rocket, the Space Launch System, with the Orion spacecraft in 2018. The core stage liquid hydrogen tank has completed welding on the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans. Credit: NASA/MAF/Steven Seipel
The first of the massive fuel tanks that will fly on the maiden launch of NASA’s SLS mega rocket in late 2018 has completed welding at the agency’s rocket manufacturing facility in New Orleans – marking a giant step forward for NASA’s goal of sending astronauts on a ‘Journey to Mars’ in the 2030s.
Welding is nearly complete on the liquid hydrogen tank will provide the fuel for the first flight of NASA’s new rocket, the Space Launch System, with the Orion spacecraft in 2018. The tank has now has now completed welding on the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com
This flight version of the hydrogen tank is the largest of the two fuel tanks making up the SLS core stage – the other being the liquid oxygen tank (LOX).
In fact the 130 foot tall hydrogen tank is the biggest cryogenic tank ever built for flight.
“Standing more than 130 feet tall, the liquid hydrogen tank is the largest cryogenic fuel tank for a rocket in the world,” according to NASA.
And it is truly huge – measuring also 27.6 feet (8.4 m) in diameter.
The liquid hydrogen tank qualification test article for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally after final welding was completed at NASA’s Michoud Assembly Facility in New Orleans in July 2016. Credit: Ken Kremer/kenkremer.com
The precursor qualification tank was constructed to prove out all the manufacturing techniques and welding tools being utilized at Michoud.
The first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine on July 22, 2016 after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com
SLS is the most powerful booster the world has even seen and one day soon will propel NASA astronauts in the agency’s Orion crew capsule on exciting missions of exploration to deep space destinations including the Moon, Asteroids and Mars – venturing further out than humans ever have before!
NASA’s agency wide goal is to send humans to Mars by the 2030s with SLS and Orion.
The LH2 and LOX tanks sit on top of one another inside the SLS outer skin. Together the hold over 733,000 gallons of propellant.
The SLS core stage – or first stage – is mostly comprised of the liquid hydrogen and liquid oxygen cryogenic fuel storage tanks which store the rocket propellants at super chilled temperatures. Boeing is the prime contractor for the SLS core stage.
The SLS core stage stands some 212 feet tall.
The SLS core stage is comprised of five major structures: the forward skirt, the liquid oxygen tank (LOX), the intertank, the liquid hydrogen tank (LH2) and the engine section.
The LH2 and LOX tanks feed the cryogenic propellants into the first stage engine propulsion section which is powered by a quartet of RS-25 engines – modified space shuttle main engines (SSMEs) – and a pair of enhanced five segment solid rocket boosters (SRBs) also derived from the shuttles four segment boosters.
NASA engineers successfully conducted a development test of the RS-25 rocket engine Thursday, Aug. 18 at NASA’s Stennis Space Center near Bay St. Louis, Miss. The RS-25 will help power the core stage of the agency’s new Space Launch System (SLS) rocket for the journey to Mars. Credit: Ken Kremer/kenkremer.com
The vehicle’s four RS-25 engines will produce a total of 2 million pounds of thrust.
The tanks are assembled by joining previously manufactured dome, ring and barrel components together in the Vertical Assembly Center by a process known as friction stir welding. The rings connect and provide stiffness between the domes and barrels.
The LH2 tank is the largest major part of the SLS core stage. It holds 537,000 gallons of super chilled liquid hydrogen. It is comprised of 5 barrels, 2 domes, and 2 rings.
The LOX tank holds 196,000 pounds of liquid oxygen. It is assembled from 2 barrels, 2 domes, and 2 rings and measures over 50 feet long.
The maiden test flight of the SLS/Orion is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) Block 1 configuration with a liftoff thrust of 8.4 million pounds – more powerful than NASA’s Saturn V moon landing rocket.
Although the SLS-1 flight in 2018 will be uncrewed, NASA plans to launch astronauts on the SLS-2/EM-2 mission slated for the 2021 to 2023 timeframe.
NASA’s Space Launch System (SLS) blasts off from launch pad 39B at the Kennedy Space Center in this artist rendering showing a view of the liftoff of the Block 1 70-metric-ton (77-ton) crew vehicle configuration. Credit: NASA/MSFC
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
The newly assembled first liquid hydrogen tank, also called the qualification test article, for NASA’s new Space Launch System (SLS) heavy lift rocket lies horizontally beside the Vertical Assembly Center robotic weld machine (blue) on July 22, 2016. It was lifted out of the welder (top) after final welding was just completed at NASA’s Michoud Assembly Facility in New Orleans. Credit: Ken Kremer/kenkremer.com
NASA's MSL Curiosity. NASA is the only agency to successfully place a lander on Mars. This self portrait shows Curiosity doing its thing on Mars. Image: NASA/JPL-Caltech/MSSS
We may be living in the Golden Age of Mars Exploration. With multiple orbiters around Mars and two functioning rovers on the surface of the red planet, our knowledge of Mars is growing at an unprecedented rate. But it hasn’t always been this way. Getting a lander to Mars and safely onto the surface is a difficult challenge, and many landers sent to Mars have failed.
The joint ESA/Roscosmos Mars Express mission, and its Chiaparelli lander, is due at Mars in only 15 days. Now’s a good time to look at the challenges in getting a lander to Mars, and also to look back at the many failed attempts.
A model of the Schiaparelli lander. The lander is part of the ExoMars mission. By Pline – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=26837226
For now, NASA has the bragging rights as the only organization to successfully land probes on Mars. And they’ve done it several times. But they weren’t the first ones to try. The Soviet Union tried first.
The USSR sent several probes to Mars starting back in the 1960s. They made their first attempt in 1962, but that mission failed to launch. That failure illustrates the first challenge in getting a craft to land on Mars: rocketry. We’re a lot better at rocketry than we were back in the 1960’s, but mishaps still happen.
Then in 1971, the Soviets sent a pair of probes to Mars called Mars 2 and Mars 3. They were both orbiters with detachable landers destined for the Martian surface. The fate of Mars 2 and Mars 3 provides other illustrative examples of the challenges in getting to Mars.
Mars 2 separated from its orbiter successfully, but crashed into the surface and was destroyed. The crash was likely caused by its angle of descent, which was too steep. This interrupted the descent sequence, which meant the parachute failed to deploy. So Mars 2 has the dubious distinction of being the first man-made object to reach Mars.
Mars 3 was exactly the same as Mars 2. The Soviets liked to do missions in pairs back then, for redundancy. Mars 3 separated from its orbiter and headed for the Martian surface, and through a combination of aerodynamic breaking, rockets, and parachutes, it became the first craft to make a soft landing on Mars. So it was a success, sort of.
A model of the Mars 3 lander with its petals open after landing. By NASA – http://nssdc.gsfc.nasa.gov/image/spacecraft/mars3_lander_vsm.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=14634254
But after only 14.5 seconds of data transmission, it went quiet and was never heard from again. The cause was likely an intense dust storm. In an odd turn of events, NASA’s Mariner 9 orbiter reached Mars only days before Mars 2 and 3, becoming the first spacecraft to orbit another planet. It captured images of the planet-concealing dust storms, above which only the volcanic Olympus Mons could be seen. These images provided an explanation for the failure of Mars 3.
This image from the Mariner 9 orbiter shows Olympus Mons above the dust storms that concealed much of the planet when it arrived at Mars in 1971. Image: NASA
In 1973, the Soviets tried again. They sent four craft to Mars, two of which were landers, named Mars 6 and Mars 7. Mars 6 failed on impact, but Mars 7’s fate was perhaps a little more tragic. It missed Mars completely, by about 1300 km, and is in a helicentric orbit to this day. In our day and age, we just assume that our spacecraft will go where we want them to, but Mars 7 shows us that it can all go wrong. After all, Mars is a moving target.
In the 1970s, NASA was fresh off the success of their Apollo Program, and were setting their sites on Mars. They developed the Viking program which saw 2 landers, Viking 1 and Viking 2, sent to Mars. Both of them were probe/lander configurations, and both landers landed successfully on the surface of Mars. The Vikings sent back beautiful pictures of Mars that caused excitement around the world.
The Viking 2 lander captured this image of itself on the Martian surface. By NASA – NASA website; description,[1] high resolution image.[2], Public Domain, https://commons.wikimedia.org/w/index.php?curid=17624
In 1997, NASA’s Martian Pathfinder made it to Mars and landed successfully. Pathfinder itself was stationary, but it brought a little rover called Sojourner with it. Sojourner explored the immediate landing area around Pathfinder. Sojourner became the first rover to operate on another planet.
Pathfinder was able to send back over 16,000 images of Mars, along with its scientific data. It was also a proof of concept mission for technologies such as automated obstacle avoidance and airbag mediated touchdown. Pathfinder helped lay the groundwork for the Mars Exploration Rover Mission. That means Spirit and Opportunity.
An artist’s conception of Spirit/Opportunity working on Mars. By NASA/JPL/Cornell University, Maas Digital LLC – http://photojournal.jpl.nasa.gov/catalog/PIA04413 (image link), Public Domain, https://commons.wikimedia.org/w/index.php?curid=565283
But after Pathfinder, and before Spirit and Opportunity, came a time of failure for Martian landing attempts. Everybody took part in the failure, it seems, with Russia, Japan, the USA, and the European Space Agency all experiencing bitter failure. Rocket failures, engineering errors, and other terminal errors all contributed to the failure.
Japan’s Nozomi orbiter ran out of fuel before ever reaching Mars. NASA’s Mars Polar Lander failed its landing attempt. NASA’s Deep Space 2, part of the Polar Lander mission, failed its parachute-less landing and was never heard from. The ESA’s Beagle 2 lander made it to the surface, but two of its solar panels failed to deploy, ending its mission. Russian joined in the failure again, with its Phobos-Grunt mission, which was actually headed for the Martian moon Phobos, to retrieve a sample and send it back to Earth.
In one infamous failure, engineers mixed up the use of English units with Metric units, causing NASA’s Mars Climate Orbiter to burn up on entry. These failures show us that failure is not rare. It’s difficult and challenging to get to the surface of Mars.
After this period of failure, NASA’s Spirit and Opportunity rovers were both unprecedented successes. They landed on the Martian surface in January 2004. Both exceeded their planned mission length of three months, and Opportunity is still going strong now.
So where does that leave us now? NASA is the only one to have successfully landed a rover on Mars and have the rover complete its mission. But the ESA and Russia are determined to get there.
The Schiaparelli lander, as part of the ExoMars mission, is primarily a proof of technology mission. In fact, its full name is the Schiaparelli EDM lander, meaning Entry, Descent, and Landing Demonstrator Module.
It will have some small science capacity, but is really designed to demonstrate the ability to enter the Martian atmosphere, descend safely, and finally, to land on the surface. In fact, it has no solar panels or other power source, and will only carry enough battery power to survive for 2-8 days.
Schiaparelli faces the same challenges as other craft destined for Mars. Once launched successfully, which it was, it had to navigate its way to Mars. That took about 6 months, and since ExoMars is only 15 days away from arrival at Mars, it looks like it has successfully made its way their. But perhaps the trickiest part comes next: atmospheric entry.
Schiaparelli is like most Martian craft. It will make a ballistic entry into the Martian atmosphere, and this has to be done right. There is no room for error. The angle of entry is the key here. If the angle is too steep, Schiaparelli may overheat and burn up on entry. On the other hand, if the angle is too shallow, it could hit the atmosphere and bounce right back into space. There’ll be no second chance.
The entry and descent sequence is all pre-programmed. It will either work or it won’t. It would take way too long to send any commands to Schiaparelli when it is entering and descending to Mars.
If the entry is successful, the landing comes next. The exact landing location is imprecise, because of wind speed, turbulence, and other factors. Like other craft sent to Mars, Schiaparelli’s landing site is defined as an ellipse.
Schiaparelli will land somewhere in this defined ellipse on the surface of Mars. Image: IRSPS/TAS-I
The lander will be travelling at over 21,000 km/h when it reaches Mars, and will have only 6 or 7 minutes to descend. At that speed, Schiaparelli will have to withstand extreme heating for 2 or 3 minutes. It’s heat shield will protect it, and will reach temperatures of several thousand degrees Celsius.
It will decelerate rapidly, and at about 10km altitude, it will have slowed to approximately 1700 km/h. At that point, a parachute will deploy, which will further slow the craft. After the parachute slows its descent, the heat shield will be jettisoned.
Schiaparelli’s Descent and Landing Sequence. Image: ESA/ATG medialab. Click here for larger image.
On Earth, a parachute would be enough to slow a descending craft. But with Mars’ less dense atmosphere, rockets are needed for the final descent. An onboard radar will monitor Schiaparelli’s altitude as it approaches the surface, and rockets will fire to slow it to a few meters per second in preparation for landing.
In the final moments, the rockets will stop firing, and a short free-fall will signal Schiaparelli’s arrival on Mars. If all goes according to plan, of course.
We won’t have much longer to wait. Soon we’ll know if the ESA and Russia will join NASA as the only agencies to successfully land a craft on Mars. Or, if they’ll add to the long list of failed attempts.
Rocket lifting from Space Launch Complex 40, located at Cape Canaveral Air Force Station in Florida. Credit: SpaceX
On Sept. 1st, 2016, aerospace giant SpaceX suffered a terrible setback when one of their Falcon 9 rockets inexplicably exploded during a fueling test. An investigation into the causes of the accident – which Musk described as being the “most difficult and complex failure” in the company’s history – was immediately mounted.
And while the focus of the investigation has been on potential mechanical failures – such as a possible breach In 2nd stage helium system – another line in inquiry also came to light recently. In this case, the focus was on the ongoing feud between SpaceX and its greatest competitor, United Launch Alliance (ULA), and whether or not that could have played a role.
Speculation about this possible connection began after three unnamed industry officials who were familiar with the accident shared details of an incident that happened a few weeks after the explosion. According to The Washington Post, these officials claimed that SpaceX had come across something suspicious during the course of their investigation.
On Sept. 1st, one of SpaceX’s Falcon 9 rocket’s exploded during a static firing test. The company is now facing a potential legal battle over the damage caused. Credit: SpaceX
After pouring over images and video from the explosion, SpaceX investigators noticed an odd shadow and then a white spot on the roof of building located close to their launch complex. The building is currently being leased by ULA to refurbish their Sensible Modular Autonomous Return Technology (SMART) rocket motors – a key component in the company’s new Vulcan rocket.
Located about one and half kilometers (1 mile) from SpaceX’s launch facilities, and has a clear line of sight on the launch pad. SpaceX dispatched an representative to check it out, who arrived at the building and requested access to the roof. A ULA representative denied them access and called Air Force investigators, who then inspected the roof themselves and determined that nothing of a suspicions nature was there.
While the incident proved to be inconclusive, it is the fact that it was not previously reported that is raising some eyebrows. And it is just another mysterious detail to come from an accident that remains largely unexplained. However, in all likelihood the incident was avoided to prevent embarrassment to either company, and to avoid fueling speculations about possible sabotage (which seems highly unlikely at this point).
In the meantime, SpaceX is still investigating the explosion with the help of NASA, the Federal Aviation Administration (FAA), the USAF’s 45th Space Wing. Musk commented on the ongoing investigation while attending the International Astronautical Congress in Guadalajara, Mexico.
Mangled SpaceX Falcon 9 strongback after prelaunch explosion destroyed the rocket and AMOS-6 payload and damaged the pad. Credit: Ken Kremer/kenkremer.com
In the midst of sharing the latest details of his vision to colonize Mars, Musk was quoted by The Washington Post as saying that the investigation is his company’s “absolute top priority.” As for the cause, he went on to say that they have “eliminated all of the obvious possibilities for what occurred there. So what remains are the less probable answers.”
Whether or not sabotage is a realistic possibility, this incident does serve to highlight the rivalry between SpaceX and ULA. Prior to 2014, ULA was the sole provider of launch services for the US Air Force, until a lawsuit from SpaceX compelled them to open the field to competition. Since then, both companies have been fighting – sometimes bitterly – to secure national security contracts.
It has also brought the issue of government oversight and accountability to the fore. On Sept. 29th, members of Congress Mike Coffman (R-Co) and Robert Aderholt (R-Al) sent a congressional letter to the heads of NASA, the US Air Force and the FAA expressing concerns about SpaceX’s recent accidents and the need for “assured access to space”.
In the letter, Coffman and Aderholt indicated that authority for investigating this and other accidents involving commercial space companies should be entrusted to the federal government:
“The investigative responses to both SpaceX failures raise serious concerns about the authority provided to commercial providers and the protection of national space assets. In both Falcon 9 explosions, NASA and the FAA granted primary responsibility for conducting the mishap investigation to SpaceX. Although subject to FAA oversight, it can be asserted the investigation lacked the openness taxpayers would expect before a return-to-flight.”
SpaceX Falcon 9 rocket explodes about 2 minutes after liftoff from Cape Canaveral Air Force Station in Florida on June 28, 2015. Credit: Ken Kremer/kenkremer.com
In other words, several Republican members of Congress hope to make SpaceX’s return to flight contingent on more stringent federal oversight. This may prove to be a source of inconvenience for SpaceX, which has stated that they intend to return to regular flights with their Falcon 9 rockets by November 1st.
Then again, increased federal oversight may also be beneficial in the long run. As is stated in the letter, both accidents involving SpaceX in the past few months occurred after the USAF signed off on the rockets involved:
“Both accidents occurred after the Air Force certified the Falcon 9 launch vehicle for U.S. national security launches, less than fifteen months ago. The certification, designed to subject the Falcon 9’s design and manufacturing process to a review of their technical and manufacturing rigor, appears to have fallen short of ensuring reliable assured US access to space for our most important payloads.”
Clearly, something is wrong if technical failures are not being caught in advance. But then again, space exploration is a hard business, and even the most routine checks can’t account for everything. Nevertheless, if there’s one thing that the Space Race taught us, it is that fierce competition can lead to mistakes, which can in turn cost lives.
As such, demanding that the federal authorities be on hand to ensure that safety standards are met, and that all competitors are being subjected to the same regulatory framework (without preference), might not be a bad idea.
The sign of a truly great scientific theory is by the outcomes it predicts when you run experiments or perform observations. And one of the greatest theories ever proposed was the concept of Relativity, described by Albert Einstein in the beginning of the 20th century.
In addition to helping us understand that light is the ultimate speed limit of the Universe, Einstein described gravity itself as a warping of spacetime.
He did more than just provide a bunch of elaborate new explanations for the Universe, he proposed a series of tests that could be done to find out if his theories were correct.
One test, for example, completely explained why Mercury’s orbit didn’t match the predictions made by Newton. Other predictions could be tested with the scientific instruments of the day, like measuring time dilation with fast moving clocks.
Since gravity is actually a distortion of spacetime, Einstein predicted that massive objects moving through spacetime should generate ripples, like waves moving through the ocean.
The more massive the object, the more it distorts spacetime. Credit: LIGO/T. Pyle
Just by walking around, you leave a wake of gravitational waves that compress and expand space around you. However, these waves are incredibly tiny. Only the most energetic events in the entire Universe can produce waves we can detect.
It took over 100 years to finally be proven true, the direct detection of gravitational waves. In February, 2016, physicists with the Laser Interferometer Gravitational Wave Observatory, or LIGO announced the collision of two massive black holes more than a billion light-years away.
Any size of black hole can collide. Plain old stellar mass black holes or supermassive black holes. Same process, just on a completely different scale.
Colliding black holes. Credit: LIGO/A. Simonnet
Let’s start with the stellar mass black holes. These, of course, form when a star with many times the mass of our Sun dies in a supernova. Just like regular stars, these massive stars can be in binary systems.
Imagine a stellar nebula where a pair of binary stars form. But unlike the Sun, each of these are monsters with many times the mass of the Sun, putting out thousands of times as much energy. The two stars will orbit one another for just a few million years, and then one will detonate as a supernova. Now you’ll have a massive star orbiting a black hole. And then the second star explodes, and now you have two black holes orbiting around each other.
As the black holes zip around one another, they radiate gravitational waves which causes their orbit to decay. This is kind of mind-bending, actually. The black holes convert their momentum into gravitational waves.
As their angular momentum decreases, they spiral inward until they actually collide. What should be one of the most energetic explosions in the known Universe is completely dark and silent, because nothing can escape a black hole. No radiation, no light, no particles, no screams, nothing. And if you mash two black holes together, you just get a more massive black hole.
The gravitational waves ripple out from this momentous collision like waves through the ocean, and it’s detectable across more than a billion light-years.
Arial view of LIGO Livingston. Credit: The LIGO Scientific Collaboration
This is exactly what happened earlier this year with the announcement from LIGO. This sensitive instrument detected the gravitational waves generated when two black holes with 30 solar masses collided about 1.3 billion light-years away.
This wasn’t a one-time event either, they detected another collision with two other stellar mass black holes.
Regular stellar mass black holes aren’t the only ones that can collide. Supermassive black holes can collide too.
From what we can tell, there’s a supermassive black hole at the heart of pretty much every galaxy in the Universe. The one in the Milky Way is more than 4.1 million times the mass of the Sun, and the one at the heart of Andromeda is thought to be 110 to 230 million times the mass of the Sun.
In a few billion years, the Milky Way and Andromeda are going to collide, and begin the process of merging together. Unless the Milky Way’s black hole gets kicked off into deep space, the two black holes are going to end up orbiting one another.
Just with the stellar mass black holes, they’re going to radiate away angular momentum in the form of gravitational waves, and spiral closer and closer together. Some point, in the distant future, the two black holes will merge into an even more supermassive black hole.
View of Milkdromeda from Earth “shortly” after the merger, around 3.85-3.9 billion years from now. Credit: NASA, ESA, Z. Levay and R. van der Marel (STScI), T. Hallas, and A. Mellinger
The Milky Way and Andromeda will merge into Milkdromeda, and over the future billions of years, will continue to gather up new galaxies, extract their black holes and mashing them into the collective.
Black holes can absolutely collide. Einstein predicted the gravitational waves this would generate, and now LIGO has observed them for the first time. As better tools are developed, we should learn more and more about these extreme events.
![The Viking 2 lander captured this image of itself on the Martian surface. By NASA - NASA website; description,[1] high resolution image.[2], Public Domain, https://commons.wikimedia.org/w/index.php?curid=17624](https://www.universetoday.com/wp-content/uploads/2016/10/608px-Viking2lander1.jpg)
