Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.
The life-cycle of a Sun-like star from protostar (left side) to red giant (near the right side) to white dwarf (far right). Credit: ESO/M. Kornmesser
If you want a picture of how you’ll look in 30 years, youngsters are told, look at your parents. The same principle is true of astronomy, where scientists compare similar stars in different age groups to see how they progress.
We have a special interest in learning how the Sun will look in a few billion years because, you know, it’s the main source of energy and life on Earth. Newly discovered HIP 102152 could give us some clues. The star is four billion years older than the sun, but so close in composition that researchers consider it almost like a twin.
Telescopes have only been around for a few centuries, making it hard to project what happens during the billions upon billions of years for a star’s lifetime. We have about 400 years of observations on the sun, for example, which is a minute fraction of its 4.6 billion-year-old lifespan so far.
Today, we take telescopic observations of the Sun for granted, but the technology only became available about 400 years ago. This picture shows the Sun in H-Alpha, on 01-07-2013, using a Lunt Solar LS60Scope/LS50 Hydrogen Alpha Solar filter. Credit: John Chumack
“It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives,” stated the European Southern Observatory.
ESO’s Very Large Telescope — guided by a team led by the University of Sao Paulo’s Jorge Melendez — examined HIP 102152 with a spectrograph that broke up the light into various colors, revealing properties such as chemical composition. Around the same time, they scrutinized 18 Scorpii, also considered to be a twin but one that is younger than the sun (2.9 billion years old)
So what can we predict about the Sun’s future? One thing puzzling scientists has been the amount of lithium in our closest stellar companion. Although the Big Bang (the beginning of the universe) created hydrogen, helium and lithium, only the first two elements are abundant in the Sun.
Periodic Table of Elements
HIP 102152, it turns out, also has low levels of lithium. Why isn’t clear yet, ESO notes, although “several processes have been proposed to transport lithium from the surface of a star into its deeper layers, where it is then destroyed.” Previous observations of young Sun-like stars also show higher levels of lithium, implying something changes between youth and middle age.
The elder twin to our Sun may host another discovery: there could be Earth-sized planets circling the star. Chemical properties of HIP 102152 show that it has few elements that you see in meteorites and rocky planets, implying the elements are “locked up” in bodies close to the star. “This is a strong hint that HIP 102152 may host terrestrial rocky planets,” ESO stated.
Better yet, separate observations showed that there are no giant planets close to the star — leaving room for Earth-sized planets to flourish.
A crater on Mercury at the edge of the larger Oskison crater located in the plains north of Caloris basin. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Permanently shadowed craters on the moon or Mercury are one of the most exciting locations to search for water. Because the walls of these craters protect certain spots inside from the rays of the sun, it’s quite possible for ice to lurk inside of there.
We’ve found ice on so-called airless worlds because of this trick of geometry. So how about exploring them? What’s the best way to do so?
The NASA Innovative Advanced Concepts office suggests using TransFormers to get inside these places. No, not the awesome robots you see in the movies, but still something that has a certain degree of complication: “multifunctional platforms that can change their shape and function”, according to the agency.
NASA’s TransFormers mission concept as it could be deployed on Mercury. Credit: NASA Innovative Advanced Concepts
Like the iconic science fiction heroes, however, the TransFormers would be able to unfold and change their shape. These machines could relay information between a rover and an orbiting satellite, or reflect solar energy on to a target (say, a solar-powered rover).
The challenge with putting a rover in a permanently shadowed crater is figuring out how to power it. Nuclear power sources have special handling considerations during preparation and launch that must be taken into account for safety reasons. Solar power, however, would not be possible in these craters given there is no sunlight.
Putting a TransFormer at the crater’s edge, however, could make the environment a friendly one for a rover powered by the sun. It could reflect light inside and provide a power source for the rover to keep moving.
Solar-panelled rovers are already used on Mars. Here, the Spirit rover’s solar panels were covered with dust until a gust of wind blew it off in 2006. Credit: NASA.
And once that rover starts running around, it would have immense scientific benefits, NASA stated.
“For example, water found in the permanently shadowed areas of craters on the Moon or Mercury can reveal clues about planetary formation and history, and could be used as a resource for astronauts,” the agency wrote.
This could even be extended to the Red Planet, which offers the enticing possibility of stumbling across life.
“Cave exploration on Mars offers the possibility of finding extraterrestrial life; furthermore, caves are time capsules preserving geochemical traces and may safely shelter future human explorers.”
A concept for windsurfing on Venus from the NASA Innovative Advanced Concepts office. Credit: NASA
A windsailing rover could use the high speeds and hot temperatures of Venus to a robotic explorer’s advantage, according to an idea funded by NASA’s Innovative Advanced Concepts program.
The rover would not only be able to move around Venus, but would also have electronics inside able to withstand the temperatures of 450 degrees Celsius (840 degrees Fahrenheit).
The rover, which is nicknamed Zephyr, would spend most of its time on Venus doing analysis on the ground. Whenever the science team wants to move some distance, however, it would deploy a sail that could bring it across the surface. One vision sees it sailing for about 15 minutes a day for about a month.
Artist’s conception of the atmosphere of Venus. Credit: ESA
“A sail rover would be extraordinary for Venus. The sail has only two moving parts-just to set the sail and set the steering position-and that doesn’t require a lot of power. There’s no power required to actually drive,” stated Geoffrey Landis, who is with NASA’s Glenn Research Center.
“The fundamental elements of a rover for Venus are not beyond the bounds of physics,” Landis added. “We could survive the furnace of Venus if we can come up with an innovative concept for a rover that can move on extremely low power levels.”
Atlantis begins the slow journey to Launch Pad 39A from the Vehicle Assembly Building (VAB) in preparation for the launch of STS-79 in 16 September 1996. This dramatic view looking directly down onto the shuttle stack atop the Mobile Launcher Platform (MLP) and crawler-transporter was taken from the VAB roof approximately 525 feet (160 meters) above the ground. In view are the Orbiter, orange External Tank and twin white Solid Rocket Boosters. Credit: NASA
If you’ve got a new use for the mobile launcher platforms NASA used for the shuttle program, the agency is all ears.
NASA invited government and commercial entities to submit their ideas for the platforms, which used to ferry the space shuttles and the Apollo rockets from the Vehicle Assembly Building to their launch pads.
Space shuttle Discovery on board one of the mobile launcher platforms. Credit: NASA
The ideal for NASA is to make them available for commercial launch activity. “Interested parties are requested to provide the following … estimated annual launch manifest, plans for retrofitting, storing, transporting, estimated schedule for acquiring use of the MLP(s), and the length of time the MLP(s) would be required for a particular activity,” the agency stated in a request for information.
Other options for the platforms could include modifying them for use in oil rigs, artificial reefs or even museum exhibits. Deconstruction is also being considered.
Each of the three platforms is two storeys tall, weigh 8.2 million pounds, with a platform of about 160 feet by 135 feet.
Safety in spaceflight comes from working the procedures in training so often that responses become automatic, says German astronaut Alexander Gerst, shown here during spacewalk training. Credit: NASA
Routines. They tell you when to get up in the morning, what to do at your day job and how to handle myriad tasks ranging from house cleaning to using a computer. Memorizing these procedures makes it a lot easier to handle things that come up in life.
In space, establishing routines is even more important because they will help guide your thinking during an emergency. That’s why astronauts spend thousands of hours learning, simulating and memorizing before heading up to space.
European Space Agency astronaut Alexander Gerst, who will fly to the International Space Station in 2014 during Expedition 40/41, gave Universe Today some insight on how it’s done.
Why train so often? According to Gerst, practicing an emergency procedure on the ground makes it easier to think clearly during a situation up in space. An astronaut’s reaction to any problem on station — a fire, a depressurization, toxic air — is to begin with the procedures. “They sink in and become a memorized response or a natural reaction,” he said. In a fire situation, for example, “Immediately when you hear the sound of the alarm, I will grab the nearest gas mask and the nearest emergency book and head to our control post, which is part of the emergency response.” (Chris Cassidy, a former Navy SEAL on station right now, had more to say to Universe Today in March about “muscle memory” during emergencies.)
European Space Agency astronauts Alexander Gerst (left) and Samantha Cristoforetti in Russian Orlan spacesuits during training in 2012. Credit: GCTC
What’s the biggest challenge? The complexity of the station. The American and Russian sides have different procedures and different equipment. There are three types of gas masks on station, for example, and three kinds of fire extinguishing systems. (According to Gerst, all but the most stubborn fires on station are extinguished after cutting ventilation and electricity to the affected area.) To address the complexity, the astronauts spend hours in the classroom discussing what to look for in the fire sensors, pressure sensors, ammonia sensors and other parts of the vehicle. The signatures look different for depressurizations, fires and other conditions in space and it’s key to know what they mean at a glance.
What happens during a simulation? After discussing what actions to take, it’s time to play them out. “We don’t light our modules on fire, but the trainers are creative in creating that [emergency] condition,” Gerst said. Sometimes smoke machines will be used during a fire simulation, for example, or the astronauts will simply be informed by instructors that there is a fire in a section of the station. As the astronauts go through the procedures, trainers keep an eye on them and give feedback. In more complex situations, 10 to 20 flight controllers can join in to simulate communications with Mission Control in Houston or its equivalent in Russia.
ESA astronaut Alexander Gerst (left) and NASA astronaut Gregory Reid Wiseman (middle) during training at NASA’s Johnson Space Center. Credit: ESA–S. Corvaja
What about dealing with emergencies in a smaller spacecraft? Astronauts can spend anywhere from hours to days on a Russian Soyuz getting to and from the station. If there’s a fire on board, the three people squashed inside the capsule wouldn’t have much room to deploy fire extinguishers. The response is essentially for astronauts to slam shut the visors on their spacesuits and vent the spacecraft. During a depressurization, the procedure is also to close the visor. “You don’t even have to get out of your seat to deal with the emergency, which makes it quite different,” Gerst said.
What about emergencies during a spacewalk? Astronauts spend hundreds of hours inside the Neutral Buoyancy Laboratory in Houston, a huge pool with a mockup of most of the International Space Station inside. They practice spacewalk procedures such as how to bring an unconscious crew member back to the airlock, or what to do if air leaks out of a spacesuit. Gerst credits this sort of training for helping out during a recent incident involving fellow ESA astronaut Luca Parmitano. In July, emergency procedures kicked in for real when Parmitano’s spacesuit sprung a water leak during a spacewalk. In a nutshell, the crew worked to bring Parmitano back inside as quickly as possible, which led to a safe (but early) end to the work. (Read Parmitano’s nail-biting first-hand account of the incident here.)
What’s the big takeaway? Gerst emphasizes that emergency training is a “huge topic”. He and Reid Wiseman recently got checked out for emergency procedures on the United States side of the station, only to fly to Moscow and then have to do the same thing for the Russian side in mid-August. And there’s other training to do as well — another huge topic is medical emergencies , which Gerst practiced in a German hospital in July.
The 2013 astronaut candidate class. Front row, left to right: Jessica Meir, Christina Hammock, Andrew Morgan. Back row (left to right), Anne McClain, Nicole Mann, Tyler (Nick) Hague, Josh Cassada and Victor Glover. Credit: NASA
Being selected to (potentially) go on a mission outside of Earth orbit has to be exciting. Assuming the astronaut title, however, brings some tough career choices.
“All of us were in our careers, and we were really in places where we started to be leaders in those careers. Now, our biggest responsibility is to learn from all these people around us, and from years and years of history at NASA so that when that baton does get passed to us, we’re ready to move forward.”
It was the first time NASA’s astronaut candidates — eight Americans, comprising four men and four women — spoke to journalists since their selection. NASA has been heavily promoting this group on Facebook, Twitter and other forms of social media, positioning these new employees in tune with the agency’s desire to retrieve asteroids and generally push on to exploration outside of Earth’s orbit.
The astronauts emphasized the years of effort it took to get to their positions today, with McClain adding it’s best to choose a career you’re passionate about just in case the odds aren’t in your favor. (To put this in perspective, the eight people selected were from more than 6,000 applicants, pegging anyone’s chance of getting in at far less than 1%).
Nevertheless, many of them have been working at it since childhood. Andrew Morgan, also a U.S. Army major, recalled writing to Apollo astronaut Alan Bean when Morgan was in fourth grade (making him about eight or nine years old at the time).
“I received several weeks later a letter in the mail. It was addressed from NASA and I was convinced that that was my acceptance as an astronaut candidate,” Morgan said as laughter came from the audience. “From that day forward, if I had to peg a point, it was that point. It was a letter from Alan Bean that made that difference for me.”
Some observers are saying the 2013 astronaut candidates could be the first to go beyond Earth orbit since the Apollo program. Above, Alan Bean — an inspiration to 2013 ASCAN Andrew Morgan — during Apollo 12. Credit: NASA
Getting selected was an 18-month process. From the thousands of applications, the top 120 were selected for initial interviews and medical screening and then brought down to a shortlist of 49 that had more detailed evaluations (including team-building exercises).
It was serious work, but there was time for a little fun along the way.
“We were asked to compose a tweet, a limerick or a haiku,” said Victor Glover (a lieutenant-commander in the U.S. Navy) of one writing test during the selection process. His, a limerick, poked fun at the extensive medical testing:
An artist’s conception of a space exploration vehicle approaching an asteroid. Credit: NASA
Eyes fixed, gazing off into space My mind in awe of the human race This is all dizzying to me Because I gave so much blood and pee Happy to be here (at) the colonoscopy place.
We won’t hear much from the astronaut candidates in the next two years as they learn the basics about how the space station works and undergo basic or supplemental flight training in T-38s. In the meantime, you can read more about the candidates on this NASA web hub.
A subsurface spacecraft prototype is deliberately slammed into 10 tonnes of ice in a rocket facility. Credit: European Space Agency/YouTube (screenshot)
If you want to get inside a planet or moon fast, the European Space Agency says lobbing a spacecraft at the surface might be a good approach.
This concept may sound like suicide. A recent prototype test, however, shows the spacecraft structure is mostly okay. Next step is figuring out what can survive on the inside.
ESA, like NASA and other agencies, isn’t afraid to test out new landing concepts if they suit better than the traditional ones (which use rockets and/or parachutes to land a spacecraft softly on the surface). Witness the Curiosity rover’s “seven minutes of terror” concept as a successful example.
Imagine that you want to look at water below the surface of Mars, or (like the people in Europa Report) you wish to plumb into the ice of Jupiter’s moon, Europa. One option could be a drill. Another one could be a subsurface spacecraft.
“One benefit over landers and rovers is that penetrators provide access to the subsurface without the need for additional drilling or digging,” ESA stated.
To test this out, engineers put 12 solid-propellant boosters on to a 44-pound (20 kilogram) prototype and fired it at almost the speed of sound at sea level: 1,118 feet a second (341 meters/second). (More technical details on the test).
The 1.5-second test, shown in the video, saw the prototype careening into 10 tonnes of ice at a deceleration of 24,000 times the force of gravity. Astronauts, by contrast, usually only withstand 3-4 g when going into space.
The scuffed and dented spacecraft was retrieved successfully, and now ESA is reviewing how well the internal structure held up in the chaos. They also plan to develop battery and communications systems that could somehow survive intact.
High-speed tests are not only useful for spacecraft landings, but also for meteor simulations.
Most meteors are comet dust striking at the atmosphere at speeds so high, they vaporiz in a blaze of light. This is a meteor from the Leonid shower in 2001. Credit: Bob King
An article in Wired recently covered the progress of the NASA Ames Vertical Gun range in its nearly 50 years of operation.
“Though it’s called a gun, the facility doesn’t look much like any firearm you’ve ever seen,” wrote Adam Mann. “The main chassis is a long metal barrel as thick as a cannon mounted on an enormous red pole that forks at the end into two legs.”
Sierra Nevada Corp.'s Dream Chaser just before tow tests at NASA's Dryden Flight Research Center on Aug. 2, 2013. Credit: NASA/Ken Ulbrich
Another kind of commercial spacecraft is almost ready to take flight, its backers say.
Sierra Nevada Corp.’s Dream Chaser recently finished four low- and high-speed ground tests at NASA’s Dryden Flight Research Center in Edwards, Calif., the same spot where the shuttle was put through its paces in early tests of its program. Several shuttle flights also landed at Dryden.
The Dream Chaser tow-and-release tests, which took place at speeds ranging from 10 to 60 miles per hour (16 to 96 kilometers per hour), examined items such as the flight computer, how the guidance performed, steering parameters and the flight surfaces.
“Watching Dream Chaser undergo tow testing on the same runway where we landed several space shuttle orbiters brings a great amount of pride to our Dream Chaser team,” stated Steve Lindsey, SNC’s Space Systems senior director of programs, who is also a former NASA astronaut.
“We are another step closer to restoring America’s capability to return U.S. astronauts to the International Space Station.”
The next step will be an approach and landing test, which should take place sometime in the third quarter of 2013.
SNC is one of three companies receiving money from NASA under the agency’s commercial crew program, whose goal is to move astronaut launches back to American soil in the next few years. The other competitors are SpaceX and Boeing. You can read a more in-depth look at their proposals here.
Artist's conception of the Kepler Space Telescope. Credit: NASA/JPL-Caltech
It’s unclear how the Kepler space telescope’s science operations will continue, if at all, as NASA weighs what to do with the crippled spacecraft. But the agency says not to count Kepler out yet.
What’s known for sure is NASA cannot recover the two failed reaction wheels that stopped Kepler from doing its primary science mission, which was searching for exoplanets (with a focus on Earth-sized exoplanets) in a small area in the constellation Cygnus.
“We do not believe we can recover three-wheel operation or Kepler’s original science mission,” said Paul Hertz, NASA astrophysics division director, in a telephone press conference with reporters Thursday (Aug. 15).
But the spacecraft, which is already working years past when its prime mission ceased in 2010, is still in great shape otherwise, added Charles Sobeck, Kepler’s deputy project manager.
As such, NASA is now considering other science missions, which could be anything from searching for asteroids to a technique called microlensing, which could show Jupiter-sized planets around other stars with the spacecraft’s more limited pointed ability. More information should be available in the fall on these points, once Kepler’s team reviews some white papers with science proposals.
A view of Kepler’s search area as seen from Earth. Credit: Carter Roberts / Eastbay Astronomical Society
There are limiting factors. The first is the health of the spacecraft, but it is so far listed as good (except for the two damaged reaction wheels). While radiation can degrade components over time, and a stray micrometeorid could (as a small chance) cause damage on the spacecraft, right now Kepler is able to work on something new, Sobeck said.
“We have it in a point rest state right now,” Sobeck said, referring to a state where the spacecraft uses as little fuel as possible. This will extend the fuel “budget” for years, although Sobeck was unable to say just how many years yet.
Another concern is NASA’s limited budget, which (like other government departments) has undergone sequestration and other measures as the U.S. government grapples with its debt. Kepler has an estimated $18 million budget in fiscal 2013, agency officials said, adding they would need to weigh any future science mission against those of other projects being done by the agency.
The public drama began on May 15, when NASA announced that a second of Kepler’s four reaction wheels — devices that keep the telescope pointed in the right direction — had failed.
Sizes and temperatures of Kepler discoveries compared to Earth and Jupiter
“We need three wheels in service to give us the pointing precision to enable us to find planets,” said Bill Borucki, Kepler principal investigator, during a press briefing that day. “Without three wheels, it is unclear whether we could continue to do anything on that order.”
Around the same time, Scott Hubbard — a consulting professor of aeronautics and astronautics at Stanford’s School of Engineering — wrote an online Q&A about Kepler’s recovery process. He emphasized the potential loss, although sad, is not devastating to the science.
“The science returns of the Kepler mission have been staggering and have changed our view of the universe, in that we now think there are planets just about everywhere,” he wrote.
“It will be very sad if it can’t go on any longer, but the taxpayers did get their money’s worth. Kepler has, so far, detected more than 2,700 candidate exoplanets orbiting distant stars, including many Earth-size planets that are within their star’s habitable zone, where water could exist in liquid form.” (You can read about some of Kepler’s more unusual finds here.)
In February 2013, NASA’s Kepler mission discovered a new planetary system that is home to the smallest planet yet found around a star like our sun, approximately 210 light-years away in the constellation Lyra. Credit: NASA/Ames/JPL-Caltech
NASA made several attempts to resurrect the wheels. On July 18, team members tested reaction wheel four, which spun in a counterclockwise direction but would not budge in the clockwise direction. Four days later, a test with reaction wheel two showed it moving well to the test commands in both directions.
“Over the next two weeks, engineers will review the data from these tests and consider what steps to take next,” mission manager Roger Hunter said. “Although both wheels have shown motion, the friction levels will be critical in future considerations. The details of the wheel friction are under analysis.”
Mission managers successfully spun reaction wheel 4 in both directions on July 25, an Aug. 2 update said. While warning that friction could affect the usability of the wheels in the long term, the team expressed optimism as more tests continued.
Artist’s conception of “Super-Earth” exoplanet Kepler-22b, which is about 2.4 times larger than Earth. Credit: NASA.
“With the demonstration that both wheels will still move, and the measurement of their friction levels, the functional testing of the reaction wheels is now complete,” Hunter wrote in the update, the last one to go out before Thursday’s press conference.”The next step will be a system-level performance test to see if the wheels can adequately control spacecraft pointing.”
That was expected to begin Aug. 8. You can read more technical details of the tests here. Those tests, however, showed that the friction built up beyond what the spacecraft could handle. Kepler entered safe mode, it was recovered, and it is now essentially in standby awaiting more instructions.
Meanwhile, probing the data Kepler produced thus far is still revealing new planetary candidates. The current count is now 3,548 — an increase from the approximately 2,700 quoted in May — even though Kepler was sidelined in the intervening time.
There’s also a follow-up spacecraft planned: the Transiting Exoplanet Survey Satellite, which is expected to start around 2017 or 2018. It will look for alien planets in the brightest and closest stars in the entire sky, in locations that are (in relative terms) close to Earth.
In February 2013, asteroid DA 2014 safely passed by the Earth. There are several proposals abounding about bringing asteroids closer to our planet to better examine their structure. Credit: NASA/JPL-Caltech
One scientific team has identified 12 “Easily Retrievable Objects” in our solar system that are circling the sun and would not cost too much to retrieve (in relative terms, of course!)
The definition of an ERO is an object that can be captured and brought back to a stable gravitational point near Earth (called a Lagrange point, or more specifically the L1/L2 points between the sun and the Earth.) The change in speed necessary in these objects to make them easily retrievable is “arbitrarily” set at 500 meters per second (1,641 feet/second) or less, the researchers stated.
Image of asteroid Vesta calculated from a shape model, showing a tilted view of the topography of the south polar region. This perspective shows the topography, but removes the overall curvature of Vesta, as if the giant asteroid were flat and not rounded. Credit: NASA
Catching the objects wouldn’t just be a technology demonstration, but also could shed some light into how the solar system formed. Asteroids are generally considered leftovers of the early days of the neighborhood; under our current understanding of the solar system’s history, a spinning disc of gas and dust gradually clumped into rocks and other small objects, which eventually crashed into each other and formed planets.
Also, steering these objects around has another benefit: teaching humans how to deflect potentially hazardous asteroids from smacking into the Earth and causing damage. As we were reminded about earlier this year, even smaller rocks such as the one that broke up over a portion of Russia can be hazardous.
Concept of NASA spacecraft with Asteroid capture mechanism deployed to redirect a small space rock to a stable lunar orbit for later study by astronauts aboard Orion crew capsule. Credit: NASA.
There are at least a couple of big limitations to the plan. The first is to make sure not to put the asteroid in a path that would hit the Earth. The second is that he L1 and L2 points are somewhat unstable, so over time the asteroid would drift from its spot. It would need a nudge every so often to keep it in that location.
For the curious, this is the complete list of possible asteroids: 2006 RH120, 2010 VQ98, 2007 UN12, 2010 UE51, 2008 EA9, 2011 UD21, 2009 BD, 2008 UA 202, 2011 BL45, 2011 MD, 2000 SG344 and 1991 VG.
