Nancy has been with Universe Today since 2004, and has published over 6,000 articles on space exploration, astronomy, science and technology. She is the author of two books: "Eight Years to the Moon: the History of the Apollo Missions," (2019) which shares the stories of 60 engineers and scientists who worked behind the scenes to make landing on the Moon possible; and "Incredible Stories from Space: A Behind-the-Scenes Look at the Missions Changing Our View of the Cosmos" (2016) tells the stories of those who work on NASA's robotic missions to explore the Solar System and beyond.
Follow Nancy on Twitter at https://twitter.com/Nancy_A and and Instagram at and https://www.instagram.com/nancyatkinson_ut/
The yellow dots represent simple craters containing permanent shadow. Credit: Lunar and Planetary Institute
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Ice on the moon or no ice? That is the question. It’s long been thought that water ice could be hiding in deep, dark craters near the Moon’s poles. However in October, 2008 Japan’s Kaguya spacecraft took the best look yet inside the Shackelton Crater at the lunar south pole and didn’t see anything resembling ice, dashing hopes for an abundant water source for future colonists on the moon. But now a team of researchers have re-analyzed data from NASA’s 1998 Lunar Prospector mission – the spacecraft that deliberately took a kamikaze nose-dive into the moon hoping to create a visible ice plume, which it didn’t. But researchers from Glasgow and Durham Universities in the UK say that a new look at old data shows polar craters that are shaded from the sun could have ice in concentrations of up to 10 grams for each kilogram of rock.
The Lunar Prospector’s Neutron Spectrometer (NS) instrument had detected large quantities of hydrogen around the Moon’s north and south pole, but the spacecraft’s crash into the surface didn’t create the plume of ice that scientists had hoped for to prove that ice was actually present.
The latest research of the Lunar Prospector probe’s data is being used to pinpoint likely locations of water ice. A map showing the north and south polar regions of the moon. The dark blue shaded areas represent the highest concentrations of hydrogen. Credit: Dr Vincent Eke, Durham University/NASA
“We used a newly developed technique to show that the hydrogen on the moon is concentrated into permanently shaded craters near to the lunar poles,” said Dr. Luis Teodoro, of Glasgow University’s physics and astronomy department. “Hydrogen, together with the oxygen that is abundant within moon rock, is a key element in making water.”
If water ice is actually there, it should be stable for billions of years on the moon provided that it receives no sunlight.
“If the hydrogen is present as water ice then our results imply that the top meter of the moon holds about 200 billion litres of water,” Teodoro added.
However the researchers also say that instead of being water ice, hydrogen may be present in the form of protons fired from the sun into the dusty lunar surface.
The research is of interest for NASA’s upcoming LCROSS (Lunar Crater Observation and Sensing Satellite), part of the Lunar Reconnaissance Orbiter to be launched in 2009, and another impactor mission. Dr. Richard Elphic, in the Planetary Systems Branch, NASA Ames Research Center, said “LCROSS aims to liberate water by impacting into permanently shadowed polar terrain where ice may exist, and our improved maps of hydrogen abundance can help LCROSS select a promising impact site.
“These maps will also help focus LRO’s search for possible polar ice by identifying hydrogen-rich locales.”
If the LCROSS mission doesn’t definitively answer the ice question, it’s very likely we won’t know if water ice is on the moon until we go there ourselves and dig.
Binary waves from black holes. Image Credit: K. Thorne (Caltech) , T. Carnahan (NASA GSFC)
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If you’re a PlayStation 3 fan, or if you just received one as a holiday gift, you may be able to do more with the system than just gaming. A group of gravity researchers have configured 16 PlayStation 3’s together to create a type of supercomputer that is helping them estimate properties of the gravitational waves produced by the merger of two black holes. The research team from the University of Alabama in Huntsville and the University of Massachusetts, Dartmouth, calls their configuration the Gravity Grid, and they say the Sony PlayStation 3 has a number of unique features that make it particularly suited for scientific computation. Equally important, the raw computing power per dollar provided by the PS3 is significantly higher than anything else on the market today.
PlayStation 3s have also been used by the Folding@Home project, to harness the PS3’s technology to help study how proteins are formed in the human body and how they sometimes form incorrectly. This helps in research in several diseases such as Parkinson’s, Alzheimer’s, cystic fibrosis, and even Mad-Cow disease. Front view of the cluster of PS3's. Credit: GravityGrid
The PS3 uses a powerful new processor called the Cell Broadband Engine to run its highly realistic games, and can connect to the Internet so gamers can download new programs and take each other on.
The PlayStation 3 cluster used by the gravity research team can solve some astrophysical problems, such as ones involving many calculations but low memory usage, equaling the speed of a rented super-computer.
“If we had rented computing time from a supercomputer center it would have cost us about $5,000 to run our [black hole] simulation one time. For this project we ran our simulation several dozens of times to test different parameters and circumstances,” study author Lior Burko told Inside Science News Service.
One of the unique features of the PS3 is that it is an open platform, where different system software can be run on it. It’s special processor has a main CPU (called the PPU) and six special compute engines (called SPUs) available for raw computation. Moreover, each SPU performs vector operations, which implies that they can compute on multiple data, in a single step.
But the low cost is especially attractive to university researchers. The Gravity Grid team received a partial donation from Sony, and are using “stock” PS3s for the cluster, with no hardware modifications and are networked together using inexpensive equipment.
Gravitational waves are “ripples” in space-time that travel at the speed of light. These were theoretically predicted by Einstein’s general relativity, but have never been directly observed. Other research is being done in this area by the newly constructed NSF LIGO laboratory and various other such observatories in Europe and Asia. The ESA and NASA also have a mission planned in the near future – the LISA mission – that will also be attempting to detect these waves. To learn more about these waves and the recent attempts to observe them, please visit the LISA mission website.
Are you ready for another Where In The Universe Challenge? Take a look and see if you can name where in the Universe this image is from. Give yourself extra points if you can name the spacecraft responsible for the image. As usual, we’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image, drink some eggnog, and provide your answer/guess in the comment section — if you dare! Check back tomorrow on this same post to see how you did. Good luck and enjoy the holidays!
UPDATE (12/25): The answer has now been posted below. If you haven’t made your guess yet, no peeking before you do!!
In this holiday edition of Where In The Universe, newborn stars, hidden behind thick dust in visible light, are revealed in infrared in this image of a part of the Christmas Tree Cluster from NASA’s Spitzer Space Telescope. Two instruments created this image, Spitzer’s Infrared Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) instruments.
Astronomers nicknamed this the “Snowflake Cluster,” the stars appear to have formed in regularly spaced intervals along linear structures in a configuration that resembles the pattern of a snowflake.
More info on this image.
Best wishes for the merriest of whatever holiday you may celebrate.
SpaceX DragonLab™ - a free-flying, fully-recoverable, reusable spacecraft capable of hosting pressurized and unpressurized payloads. Credit: SpaceX
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Two upstart commercial space companies have been awarded contracts by NASA for commercial cargo resupply services to the International Space Station. SpaceX, also known as Space Exploration Technologies received a contract for $1.6 billion while Orbital Sciences Corp. of Dulles, Va. has a contract valued at $1.9 billion. NASA has ordered 12 flights from SpaceX and eight from Orbital. In October, at this year’s International Symposium for Personal and Commercial Spaceflight, SpaceX Vice President of Marketing and Communications Diane Murphy said that the six- year-old company has it in their sights to be able to fly to the space station by 2009. For now, the contract is for cargo only, however SpaceX’s Dragon capsule and Falcon 9 rocket are human rated, and would be capable of delivering up to 7 crew members to the station. The Dragon could also be used as an escape vehicle. If SpaceX and Orbital can be successful in cargo re-supply, it could pave the way for a potential solution to the gap between the shuttle retirement in 2010 and when the Constellation program would be ready to fly, hopefully by 2015.
“The SpaceX team is honored to have been selected by NASA as the winner of the Cargo Resupply Services contract,” said Elon Musk, CEO and CTO, SpaceX. “This is a tremendous responsibility, given the swiftly approaching retirement of the Space Shuttle and the significant future needs of the Space Station. This also demonstrates the success of the NASA COTS program, which has opened a new era for NASA in US Commercial spaceflight.” Orbital's Cygnus module will be used for ISS resupply. Credit: Orbital
“We are very appreciative of the trust NASA has placed with us to provide commercial cargo transportation services to and from the International Space Station, beginning with our demonstration flight scheduled in late 2010,” said Mr. David W. Thompson, Orbital’s Chairman and Chief Executive Officer. “The CRS program will serve as a showcase for the types of commercial services U.S. space companies can offer NASA, allowing the space agency to devote a greater proportion of its resources for the challenges of human spaceflight, deep space exploration and scientific investigations of our planet and the universe in which we live.”
Orbital will use their module called Cygnus to deliver cargo, launched on their Taurus rocket.
These fixed-price indefinite delivery, indefinite quantity contracts will begin Jan. 1, 2009, and are effective through Dec. 31, 2016. The contracts each call for the delivery of a minimum of 20 metric tons of upmass cargo to the space station. The contracts also call for delivery of non-standard services in support of the cargo resupply, including analysis and special tasks as the government determines are necessary.
NASA has set production milestones and reviews on the contracts to monitor progress toward providing services. The maximum potential value of each contract is about $3.1 billion. Based on known requirements, the value of both contracts combined is projected at $3.5 billion.
These agreements do fulfill NASA’s need to for cargo delivery to the space station after the retirement of the space shuttle.
Soyuz docked with the ISS, in a photo taken during Monday's spacewalk. Credit: NASA
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International Space Station Expedition 18 commander Mike Fincke and flight engineer Yury Lonchakov, conducted a five-hour 38-minute spacewalk on Dec. 23, successfully installing an electrical probe on the Russian Pirs airlock module designed to track down problems with Russian Soyuz capsule. They also retrieved a space exposure experiment and mounted instrumentation on the Zvezda command module that will monitor disturbances in the ionosphere. But the spacewalkers encountered problems with a second experiment package, designed to expose biological samples to the space environment, to properly plug into the station’s power and data system. After extensive troubleshooting, Russian flight controllers ordered Fincke and Lonchakov to disconnect the Expose-R experiment and return it to the airlock.
Russian scientists hope data from the probe installed by Fincke will help explain malfunctions that have occurred as the Soyuz crew return module has attempted to separate from the space station.
During the past two re-entries through Earth’s atmosphere in April of this year and October 2007, the Soyuz descended too steeply, leading to faster and bumpier-than-usual rides for the crews and off-target landings.
Investigators believe the Soyuz capsule detached too late because a pyrobolt — an exploding connector that keeps the module attached to the space station — failed to detonate on time.
Much of the spacewalk was devoted to arranging connectors and cables for various probes and experiments, and ensuring the reliability of telemetry from the data-gathering equipment.
Yury Lonchakov during the Dec. 23 spacewalk. Credit: NASA
Fincke and Lonchakov discovered a problem with the data transmission of a device they installed on a small platform outside the station’s Zvezda module. The European Space Agency experiment was supposed to gather data on the effects of the space environment on a variety of materials.
They successfully placed another device on the same platform to measure the plasma environment around the station. The pair also removed a biological experiment known as Biorisk 2, which exposes biological samples to space.
It was Fincke’s fifth spacewalk, Lonchakov’s first and the 119th spacewalk conducted from the international space station. During the spacewalk, Fincke said in Russian. “It’s good to be out here again.”
U.S. Flight Engineer Sandy Magnus, the third member of the station’s Expedition 18, was inside the station helping coordinate the mission with centers in Houston and in Korolyov, Russia.
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A coalition of leaders working on the concept of a space elevator has joined forces to form the International Space Elevator Consortium (ISEC). The new independent group is designed to promote standards and foster research relating to the construction of an Elevator to Space at the global level. Founding members of ISEC include the Spaceward Foundation, the Space Elevator Reference, the Space Elevator Blog, EuroSpaceward and the Japan Space Elevator Association. Heading the new organization is Ted Semon of the Space Elevator Blog, who will serve as president. Michael Laine, president of the space elevator company Liftport is excited about the consortium. “I think it’s a great thing,” he said. “This has been in the works for months, and the need to bring the different organizations under one roof has been long overdue. All five of the major organizations have been acting independently, which made sense in the beginning, but now we need coordination and cooperation.”
“The Space Elevator is a project whose time has come,” said Semon. “With the challenges facing today’s global economy, it is clear that new industries and new ideas are needed to help our planet in the 21st Century. The Space Elevator can be a key positive contributor, from providing inexpensive nanotechnology material science breakthroughs that will make your car stronger and lighter, to the creation of new industries that offer opportunities for investment and job creation. The International Space Elevator Consortium devoted to its development can make this happen.”
According to the Consortium, the goal of ISEC is to promote the development, construction and operation of the Space Elevator as a revolutionary and efficient way to space for all humanity. The group will accomplish this through these key areas:
• Development of a unified plan and roadmap for the Space Elevator and the coordinated assignment of specific research topics
• Funding of research on technologies relevant to the Space Elevator
• Development of the international legal framework necessary for the operation of the Space Elevator
• Global public outreach and central information exchange on Space Elevator activities
“In the past, some things fell through the cracks because no one knew what anyone else was working on,” said Laine. “Some needed tasks didn’t get done because everyone assumed that someone else was working on it. What we’re going to do with the consortium is refine the tasks, and have a better coordinated effort.”
Laine is very excited about upcoming projects for the consortium, to be announced in the next few weeks. “They’ve got some good things coming,” he said. ISEC will be unveiling additional plans and details, including a board of directors, technical journals, university and industry relationships, research opportunities and scholarships. Memberships will be available on the individual, corporate, academic and governmental levels.
The ISEC is headquartered in the Los Angeles area, a center of the aerospace industry. The consortium is a non-profit organization devoted to the research and construction of an elevator to space. See the ISEC website for more information.
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In preparation of celebrating Spirit and Opportunity’s fifth anniversary on Mars in January, we’ve been talking with rover driver Scott Maxwell, getting updates on the two Mars Exploration Rovers and learning about what it really is like to drive the rovers. Today, Scott will share some of the highlights of the past five years, and his outlook for the future. But first, in the latest updates from Scott via Twitter, he says Spirit tried to back-up off of ‘Home Plate’ but encountered quite a bit of slippage. It looks like she’ll probably end up driving forward and taking the long way around the low plateau to the next target objects, a hill called Von Braun, and a crater-like feature nearby called Goddard. Meanwhile, Opportunity is studying “cobbles” or loose rocks at a region called Santorini, where she has been stationed during solar conjunction. Now that radio transmissions are improving, Oppy will start receiving commands from the rover drivers to hit the road again. The image above is a panoramic image of Santorini, put together by James Canvin at his website, Martian Vistas.
Scott has actually been with the MER mission for longer than just the five years since the rovers landed. He joined the team early on, about three-and-a-half years before the rovers launched. He was part of the development team, helping to write the software used to drive the rovers. Back then, did he ever fathom the rovers would last this long?
How to Drive a Mars Rover, Part 1 How to Drive a Mars Rover, Part 2
“I think back, to that time, and we did all that work where we sat in our cubicles, had meetings and argued with each other about the best way to program the software,” said Scott. “We slaved away working on the mission, never knowing if the mission would succeed or not. We did all that work just for the chance, the hope, that the rovers would be working on Mars for three months. And it was worth it.”
The rover planners include Rich Morris, Scott Maxwell, Sharon Laubach, Joseph Carsten, John Wright and Brian Cooper; and (front row) Tara Estlin, Paolo Bellutta and Ashley Stroupe. Credit: PBS
“And then to do all that work and have the rovers on Mars for five years, it’s like you’re playing a slot machine and you put in your quarter and pull the lever, and not only do a few quarters come out, they keep coming and coming and coming, and it fills up your cup, and overflows. That’s what it’s like to work on this mission.”
OK, Scott, now we want to know the highlights for you from the past five years. Certainly there’s at least one or two memorable moments!
“Certainly for me, there are two things I think of,” Scott said. “One is the first time I ever drove the rover. There was the period early on where we lost contact with Spirit. But then we were able to recover her. But that was a month into the mission where we thought it was only going to last three months, and it delayed the time until I got my first chance to drive her.”
“I still remember the day. We planned and planned and rehearsed the drive. I checked over the sequence a million times before sending it. Then I went home and I should have gone to sleep, but I couldn’t. I just laid there in my bed and stared at the ceiling, and couldn’t get past the thought that right then, at that moment, there was a robot on another planet, doing what I had told it to do. It was just an awesome feeling to imagine that, and that feeling has never left me. I still feel like that every time I drive the rover.”
Scott says it’s an incredible feeling to go outside and look up and see Mars in the sky, and on that red dot way out there is an object, placed there by humans, and humans are telling it what to do. “And I’m one of the people doing that. It’s an absolutely amazing feeling. I feel that way all the time.” Scott Maxwell, rover driver. Image courtesy Scott Maxwell
Its obvious Scott has a soft spot in his heart for Spirit, as another memorable aspect of the mission involves her, too. Scott tells the story so well and with such passion, I’ll just let him go:
“The other thing I always think about is that Spirit travels the 300 million miles to Mars, she gets to Mars, drives off the lander, and she’s gone all that way with the hope of finding evidence of past liquid water on Mars,” Scott said. “But instead, when she drives around, there’s nothing: just lava as far as the eye can see. She drives around the area and looks at rocks, and then drives over to Bonnevillle crater, which is her best chance of finding evidence of liquid water, thinking maybe if she goes down far enough into this crater there will be something there, but there’s nothing.”
“But way off in the east, there are a range of hills, the Columbia Hills, and (principal investigator) Steve Squyres says clearly the hills may be too far for us to get to, but maybe we can get some images that can tell us something. But Spirit takes off for those hills anyway, even though they are too far away, and never gives up and gets there; she actually makes it all the way to the bottom of the hills.”
“And then,” Scott continued, “she’s at the bottom of the hill, looking up at them, and it’s now twice as long as she should have survived and she has driven three times as far as she was supposed to be able to drive, and she’s tired and her wheels are sore, now is when the real challenge will begin. Now she won’t just be driving over flat terrain, like she was meant to drive on. She’s going to have to climb the hill, which is taller than the Statue of Liberty, and everyone thinks it’s way too tall for this poor little rover to climb. But she does it anyway.”
“She starts climbing up the hill and there are times when she can’t make any progress, so we have to turn her around and give up some of the altitude she’s won and go back and find another path, but she never gives up and goes all the way to the top of that hill that was just impossibly far away when she started.” A special effect image of Spirit sitting on Husband Hill. Credit: NASA/JPL/Cornell. Rover model by Dan Maas
“When we came into work that day and we saw that image of Spirit standing on top of Husband Hill with the beautiful panorama of the world around her –she stood there for a long time and took the images of the area around her — to me, that’s one of the achievements, not just of this mission, but of engineering excellence in our whole civilization, to be able to do that. To be able to go so far and do so many impossible things, that image just says all of that for me. I know what it took to get there and be able to take that image, and I feel the pride of being part of the team that made it happen. It is just an amazing experience.”
As incredible as the MER mission has been, we all know the rovers won’t last forever. Someday – and we don’t know when – the rovers will eventually quit working. It’s hard to think about life without the rovers, but has Scott given any thought to what mission he would like to work on next?
“It’s all downhill from here!” Scott laughed. “But, really there’s a lot of cool and exciting stuff going on at JPL. We’ve got another rover we’re working on, the Mars Science Laboratory, and I’ve been working on that. I’m also involved with ATHLETE, which is a 12-ft. tall six legged robot spider on roller skates that we are going to send to the moon. There’s always so much like that going on here at JPL, it’s just like being an engineer in Disneyland. You come to work and say, ‘What cool stuff can I work on today?’ It’s just awesome, and there’s just no end to it.”
Scott says he has nothing against orbiter missions, but to be honest they’re not top on his list. “I’m not putting them down,” he said, “but orbiters don’t really float my boat. I kind of get into rovers, I kind of relate to them, in a way. But you look at a mission like Cassini and it’s amazing! Cassini is finding liquid water spewing out of Enceladus, and dropping a probe onto Titan and getting the first view beneath the thick clouds that cover that moon! It’s just amazing stuff. So even though orbiters aren’t my thing, I might end up on one of them, too, you never know.”
Scott has definitely shown his worth with the rovers, so, even though the MSL launch has slipped to 2011, the rover fans out there are secretly hoping Scott will have a place on the MSL team when the time comes. Spirit heading off into the sunset. Special effects image by NASA/JPL/Cornell
But in the meantime, Spirit and Opportunity, the Energizer Bunnies of Mars exploration keep going and roving, and sending back loads of data and images.
Dust storm on Mars. Image credits: NASA/JPL-Caltech/MSSS
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What an incredible image of a storm on Mars! The Mars Reconnaissance Orbiter’s main assignment is to study the surface of the Red Planet, looking for clues about the history of water on Mars. But while photographing, analyzing and mapping, it also spends time each day pursuing intense weather on Mars. Sometimes, MRO is able to capture a storm in action, as in the above image of a dust front rising from a network of canyons. Often, the storms are spirals like giant tornadoes on Earth, sometimes forming huge fronts of churning dust like the “dust bowl” of the 1930s in the US. While we sometimes think of Mars as an almost “dead” world, there’s a lot of action going on in the atmosphere, and MRO is always searching for the Perfect Storm!
Dust storms on Mars are catalysts for cloud formation. The storms lift dust particles high into the atmosphere, and the particles serve as seeds for water-ice cloud formation. Water ice condenses onto the dust particles to form wispy, white clouds. Daily variations in Mars’ atmosphere are quite large, in part because there is no ocean, which serves as large heat storage capacity on the surface. The ground warms up quickly during the day and cools off equally as quick at night. Daily temperature variations of 100 C (180 F) are common, and that cycle of heating and cooling is reflected in atmospheric variations. “That energy propagates up, and when integrated to the high altitudes, it can make a big difference from day to night in the densities that we saw at a given altitude,” said MRO Project Scientist Richard Zurek. Storms as seen by the Mars Color Imager. Image credits: NASA/JPL-Caltech/MSSS
These images show whirlwinds on top of volcanoes. Thin veils of icy clouds dissipate into the atmosphere above the dust plumes. The orbiter has discovered that smaller storms on Mars can feed into larger storms. Dust devils seen by the HiRISE camera. Credit: NASA/JPL/University of Arizona
And of course, dust devils on Mars are a common occurrence in several areas, as they have been photographed by both the Mars Exploration Rovers, as well as Phoenix.
Scott Maxwell, using his 3-D simulation software. Courtesy Scott Maxwell
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The Mars Exploration Rovers have been traversing the surface of the Red Planet for almost five years now. But how exactly are the two rovers, Spirit and Opportunity, “driven” from Earth, about 150 million km away? Many of us might have visions of joysticks, similar to what are used for remote control toys, but it’s not like that at all. However, being a “Rover Driver” is one job where having experience with video games and simulation software looks good your resume! Scott Maxwell is one of fourteen rover drivers, or planners as they are also called, who last week gave us an update on Spirit and Opportunity’s status. Today, Scott provides the details of how to drive a Mars rover.
“The way we wished it would work,” said Scott in a phone interview from JPL, “is if we could have a joystick where if we pushed forward on the joystick the rover would go forward, or push back and the rover would stop. But, with lag time delays in the radio signals, you would push forward on the joystick and 10 minutes later the rover would get the signal to go. But on Earth, you won’t know if it worked for another 10 minutes after that because of the time it takes for the signal to get back to you.”
This would create a nightmare in logistics, planning and operations, because the drivers can’t “see” what the rover is doing in real time. So instead, the rover drivers work the Martian nightshift. Recent view from Opportunity's hazard camera. Credit: NASA/JPL/Cornell
“We take advantage that our solar powered rovers have to shut down for the night,” said Scott. “So as the sun is going down in the Martian sky, the rover is commanded to take pictures of the world around them and send it before they go to sleep. When we get that data back on Earth, we go to work. We take all the images and put them into a simulation. We have a 3-D simulation world — kind of like a video game — on our computers. Then, we have a simulated rover that we put down in that 3-D world and we drive that rover around instead.”
So in that 3-D world, the rover drivers can test every possibility, make all the mistakes (tip the rover, get stuck, drive off a precipice, crash into a big rock) and perfect the driving sequence while the real rovers are dozing securely and peacefully. This certainly has helped with the long life the rovers have led, as in five years the rover drivers have safely and successfully guided the rovers to drive in and out of craters, climb a challenging hill, and put on more mileage than anyone ever thought possible. The biggest driving calamity has been getting stuck in a sand dune, but now the driving team has a few tricks up their sleeves to avoid that (see Part 1).
So then, when the drivers perfect the commands inside the simulation and hone the exact sequence of movements for the rover, they upload those commands and send it to the real rover. Then as the sun is coming up on Mars, the rover wakes up, receives a communications uplink from Earth, processes the commands and it goes to work while the rover drivers go to sleep. “At the end of the rover’s day, it sends us more pictures and data, and we start the cycle all over again,” Scott said. Rover test bed. Credit: JPL
If there’s a particularly difficult situation, such as how much tilt can the rover withstand without tipping over, a test rover can go through the same sequences in a simulated Mars environment out in JPL’s Mars Yard.
Back in 2004 during the “prime mission,” the first three months of the mission (the original length of time the rovers were slated to last) everyone who worked with MER lived on Mars time. Since the two rovers are on opposite sides of the planet, that meant operations going on 24 hours a day. And since a Mars day is 40 minutes longer than Earth’s day, that meant a perpetually shifting sleep/wake cycle, a difficult situation where your body continually feels “jet-lagged.” But now that the mission has been ongoing for such a long time, the planners operate in a more Earth-normal mode and even take some weekends off. But still, a planner’s eight- hour shift can start anywhere from 6:00 a.m. to noon.
So what’s an average drive for the rovers? “It varies widely,” Scott said, “but an average drive is in the neighborhood of a few meters.” Right now Spirit is struggling her way up the side of “Home Plate,” a low plateau, which for a rover is a steep hill. The crumbly soil gives out beneath her wheels as she makes the climb, making it difficult to drive father than a few centimeters in a day. Plus, Spirit is dealing with low power levels from dust-covered solar panels, providing limited energy for any big drives. Just after a recent dust storm, Spirit’s solar panels were producing only 89 watt hours, which is about the energy needed to run a small light bulb for an hour and half. Spirit's dusty solar panels. Credit: NASA/JP
But Opportunity’s power levels are much better, and she recently had drives as long as 216 meters, as she puts the pedal to the metal in an attempt to reach Endeavour Crater, about 12 km away.
Some of the rover drivers work mainly with one rover (Steve Squyres has said it’s easy to get attached to one rover or the other, depending which one you’re working with) but Scott goes back and forth between the two. “That’s in part because I’m a team lead, and part because I’m the kind of person who wants to run around and be part of everything all the time!” he said. When we talked with Scott last week, he was working with Spirit, and thought that this week he will probably do a drive or two with Opportunity.
Currently Spirit’s total odometry is at about 7,530 meters (over 4.6 miles), while Opportunity’s odometer reads almost 14,000 meters (about 9 miles).
WhiteKnightTwo at liftoff. Credit: FlightGlobal.com
Virgin Galactic’s WhiteKnightTwo (WK2) made its first test flight on Sunday, Dec. 21, a 59min shakedown flight of the twin fuselage aircraft at the Mojave Air and Space Port in California. WK2 climbed to a maximum altitude of 16,000ft (4,880m). “It reached an altitude 4,000ft above the original test plan’s maximum altitude,” said Virgin Galactic president Will Whitehorn. “That is how confident we are about the aircraft. Now we have to download all the data. There will be another flight early in the new year.” WK2 will carry Virgin’s SpaceShipTwo, the space plane that will bring passengers on suborbital flights, hopefully by 2011. FlightGlobal.com obtained exclusive video of the test flight, which can be viewed here.
The hour-long test flight of the four-engine WhiteKnightTwo used a skeleton flight crew. Previously last week, WK2 was taken out for four runs down the runway and a brief lifting of the nose gear on Dec. 20, and low-speed trips down the runway on Dec. 16 and 12.
Both WK2 and SS2 are being built by Scaled Composites of Mojave, CA, and Virgin Galactic has five SS2 rocket planes and two of the carrier crafts on order, with options on more. The WK2/SS2 combination will serve as the backbone for Sir Richard Branson’s suborbital spaceline company. The price per seat on the two pilot/six passenger suborbital SS2 is $200,000.
