Lunar Dust December 30, 2006
Posted by Brian Pfeifer in Future Development, NASA.add a comment
As NASA attempts to transform the President’s Vision for Space Exploration into a reality, researchers focus their attention solving the practical problems of living and working on the surface of the Moon and mars. One such research topic is Martian and lunar dust. Apollo astronauts complained of respiratory problems that may have been caused by breathing in the fine particles of lunar dust. Unlike most Earth-bound dust, the lunar variety tends to form sharp points that scratch lenses, helmet visors and other sensitive surfaces. While Apollo astronauts never spent much time on the surface, NASA’s current plans call for crews spending six-month rotations at a permanent lunar outpost. That’s more than long enough for the tiny particles to get into gears and bearings and gum up any mechanical system we try to use.
Any astronaut activity is bound to kick up some dust in the low gravity that will land exactly where we don’t want it. There is also evidence to show that sunlight can add enough energy to cause some lunar dust to levitate above the surface. As if this wasn’t bad enough, lunar dust is electro-static. That is, it sticks to iron, or anything that can generate a static charge. In the bone-dry vacuum of space, that’s surprisingly easy to do.
When we get to Mars, astronauts will find a different, but just as challenging dusty environment to deal with. We don’t yet know if Martian dust is electro-static, but it looks like it will be corrosive, and contains chemicals known to harm humans. Plus, the high-speed Martian winds can kick up impressive dust storms. During the summer, some grow until they engulf the entire planet. These mega-dust storms will reduce visibility just like a blizzard on Earth. They will grind away at lenses and any exposed sensitive equipment, and dust will penetrate any exposed mechanical system.
It’s not all doom and gloom.
Most aeronautical engineers build spacecraft in immaculate clean rooms. Workers must clean printed pages of excess toner before they can bring them into the clean room. It’s hard to believe that such vehicles would last long on the dusty surfaces of the Moon and Mars. Even so, the twin robotic geologists, Spirit and Opportunity have long outlasted their initial 90 warranties on Mars. They’ve operated so long, that film makers and book authors couldn’t wait until they broke down to tell their stories. The first round of books and movies about the plucky machines came out last year. They are showing signs of wear and tear, but it looks like the temperature swings on the red planet is as much to blame as the ever-present dust. At one point, Opportunity spent a month stuck in a sand dune. Every day, it spun its wheels to gain another inch of forward travel. During the struggle, the wheels became half buried in the dune, but the dust never managed to clog the well designed and built wheels.
In fact, we have a great deal of experience building and operating complex equipment in dusty and toxic environments here on Earth. Mines and deserts, chemical plants and nuclear reactors have all provided an invaluable education in harsh operation conditions. Most of this equipment is far more robust than the average economy car, and requires regular maintenance, but it works well. Perhaps we should bring some of these designers into the development of robust equipment for the Moon and Mars.
Tomorrow I’ll review some of the technologies NASA is exploring to mitigate risks to astronaut health and equipment from lunar dust.
EVA4 Success December 19, 2006
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Christer Fugelsang and Robert Curbeam are back inside the space station’s Quest airlock after shepherding the P6 solar array back into its storage box. The 31 bay solar array refused to fold up properly when commanded to retract earlier this week. During Saturday’s spacewalk Suni Williams and Curbeam shook the stuck array allowing controllers to retract a few more bays. Since it was a task added to an already long spacewalk the astronauts did not have time to get the entire array put away, but they were successful enough for managers to justify adding today’s spacewalk.
Christer remained on the Z1 truss where he could shake the array, while Beamer stood atop the station’s robotic arm where he could poke at the problem with needle-nose pliers and other tools. The duo’s work was important for future assembly missions as the array must be completely retracted so that the entire array may be moved out to the end of the port side truss later next year. Of course, if retracting the solar array was this difficult, we can expect redeployment after the move to be just as challenging.
Beamer and Suni Rock! December 17, 2006
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When sail powered whaling ships found themselves locked in ice, they attempted to break free by rocking the vessel from side to side. They would line the entire crew up on along one rail of the ship, and on command the sailors would race to the other side. By running back and forth across the deck from port to starboard and back again they generated a large rolling motion.
I’ve been waiting for the ISS crew to make use of the same technique. During yesterday’s spacewalk, Robert Curbeam (Beamer) and Suni Williams completed rewiring the station and all of their other tasks early. This gave them time to check out the stuck P6 solar array. In a carefully coordinated action, they shook the blanket box while controllers retracted the array one bay at a time. They did not complete the job, but it worked well enough for Mission control to extend the Shuttle mission by an extra day so Beamer in Christer Fuglesang can suit up and finish the job.
With this headache out of the way STS-116 crew will leave the ISS in the planned configuration. After two rewiring spacewalks the P4 solar is providing additional power in its associated ammonia cooling loops are working. When the S4 Solar arrays are installed they will be ready for work. This will set the stage for the addition of more modules and will support a larger crew contingent. The larger the crew, the more valuable the station becomes.
Finicky Roman Blinds in Space December 16, 2006
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Anyone who owns roman blinds knows they don’t always fold smoothly when they’ve been left closed for too long. The creases no longer fold evenly, and the cords are easily tangled. Astronauts aboard the International Space Station are learning this lesson the hard way. The P6 solar array has 30 accordion like folds and several guide wires, not unlike a roman blind. Halfway through the process of folding up the device, a guide wire snagged on a stainless steel swivel grommet. You can see a good photo of the problem area on Space.com.
How do you fix a finicky roman blind? The first step is usually to close it and open it again, causing the creases to unfold and then refold, hopefully in the right place. That’s exactly what they tried to do on the ISS. That didn’t help. So what do you try next to fix your stubborn curtain? You jiggle it, of course. So the astronauts used motors on the array to twist it back and forth a few times, hoping to release the caught wire, but to no effect. So what’s the next step? You take a hard look at your roman blind, and decide whether to jiggle it some more, or poke at it a bit. That’s exactly what ground controllers are discussing right now. At the end of today’s space walk, Bob Curbeam and Suni Williams will take a look at the problem area and take some photographs for engineers on the ground. Then the managers will get together and decide if they need to add a fourth spacewalk to fix the problem, or if some other solution will present itself.
We often think of spaceflight a being as complicated as, well, rocket science. Sometimes the astronauts are faced by problems like this that any homeowner intuitively understands. At your next Christmas party, be sure to smugly tell other guests that you know as much about fixing the station’s solar array problem as any NASA engineer.
A Complicated Mission Gets More Complicated December 14, 2006
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Yesterday, astronauts aboard the ISS and Shuttle Discovery attempted to retract one wing of the P6 solar array. The 31 bay power-generating array has been mounted atop the Z1 truss for the past six years and must be refolded into its original container. After virtually jiggling the system, mission managers decided to leave it only half retracted. It’s far enough to allow the newer and much larger P4 solar arrays to track the sun, but eventually it must be completed retracted so astronauts can relocate the device on the end of the port side truss structure.
This turn of events is no surprise to mission planners. In preflight interviews the both astronauts and managers admitted that after remaining on orbit for such an extended period of time, the hardware may not operate smoothly. In fact, contingency plans already exist for space walkers to winch they system closed manually. Unfortunately, there’s a snag, literally. The cables that help fold the array are stuck. Mission planners will take the next few days to decide the best way to tackle the problem.
Jim Bell and the Cornell Martians December 8, 2006
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I finally got to hear Jim Bell speak about the Martian rovers, Spirit and Opportunity, and the wonderful images they returned from the Red Planet. Jim is a professor at Cornell University as is Steve Squires. The university has also furnished many other MER team members, a few of which attended Jim’s lecture.
Afterwards, and after getting Jim’s signature on my copy of his book, Postcards From Mars, I spoke with John, one of the other Cornell Martians. John wrote some of the software that stitches the small photos together into the breathtaking panoramic views we’ve come to expect.
According to John an important dirt side computer failed this morning and for some reason it fell to him to break out the screwdrivers and repair the thing. He’s a software engineer, and tinkering with hardware is not his favorite pastime. So he’s lying on the floor with parts strewn all over when Steve Squires pops into the room. Steve sees the state of affairs and quips, “That’s just what you want to see, mission critical hardware in pieces.” John replied, “and the scary thing is that the guy with the screwdriver is a programmer.”
It’s good to hear that the MER team is still having fun with the project. What’s really impressive is that the team is still doing anything besides researching old data. The rovers were only designed to survive three months on Mars, and they’re still going strong after thirty months.
Humans on a Muddy Red Planet December 7, 2006
Posted by Brian Pfeifer in Future Development, NASA, News and politics.add a comment
Mars Global Surveyor may be lost, but its data is still yielding new and surprising results. Photographs the spacecraft took seven years apart indicate recent activity by water on the Red Planet.
“These observations give the strongest evidence to date that water still flows occasionally on the surface of Mars,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program, Washington.
This is both great news and troubling news for those who want to colonize Mars. Obviously water and power are the two most critical resources required by any long-term base of operations. If liquid water is available at or just below the surface, then it will be fairly easy to extract. After all, we do that on earth all the time. My own house is fed by a well.
The more troubling side is it also makes it much more likely that life currently exists on Mars. On Earth, everywhere we find water, we find life. So if life once evolved on Mars, perhaps billions of years ago when the planet was both warmer and wetter, then any remnants are most likely to be living in these water deposits.
Current life on Mars is bad for colonists for two reasons. First there’s the possibility of contaminating the earth or it’s colonists with alien microbes. Secondly, we have a legal obligation to protect alien life from Earthly contamination. Before NASA launches a planetary probe, the vehicle undergoes a serious disinfection regime. This helps ensure that we won’t send any bacteria that could survive and contaminate the target planet. If life is discovered in these wet spots on Mars, we may need to quarantine large areas of the planet to protect them from us. In fact we may have to create Martian preserves surrounding the most useful resources on the planet.
These moist locations do give us the best targets for searching out Martian life. If found, it will cause a debate about what we can and should do on a muddy Red Planet.
European Union Invades the ISS December 6, 2006
Posted by Brian Pfeifer in ESA, NASA.add a comment
No, it’s not a hostile takeover, but when STS-116 docks with the International Space Station, ESA will have more astronauts on board than the Russians have. Thomas Reiter, from Germany, has been aboard the ISS for the past six months conducting experiments for European scientists and pitching in with maintenance tasks. The Shuttle Discovery is scheduled for launch on Thursday evening, and it will be carrying Christer Fuglesung, from Sweden.
This marks the first time ESA has had two astronauts in orbit, let alone visiting the ISS. If you think the Swedes are excited about their first astronaut, wait till you see what’s ESA has in store for the upcoming year. Scheduled for the middle of 2007, ESA plans to launch the Jules Verne, their first ATV. The ATV, or Automated Transfer Vehicle is an unmanned cargo carrier launched aboard the Ariane 5 from French Guiana. The ATV will deliver nine metric tons of dry food, fuel, oxygen, and equipment to the ISS. But that’s not all. During the fourth quarter NASA is scheduled to install ESA’s Columbus laboratory module. Columbus can support ten standard ISS payload racks. At least four ESA astronauts are also scheduled to visit the orbital space station during the course of the year.
If all goes as planned, the European Union will prove itself as a full partner and a space faring people.
Deep Impact Asteroid Mining December 5, 2006
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On July 4, 2004, the comet named Tempel 1 suffered large meteoric impact creating a new crater estimated to be the size of Roman Coliseum. The explosive event propelled 250,000 tonnes of water plus large quantities of other minerals into space. This was no cosmic accident, but rather a carefully planned scientific experiment. The deep impact mission consisted of two spacecraft, an 800 lb comet seeking impactor, and the instrument laden flyby vehicle. Its goal was to uncover the internal structure of comets, our periodic visitors from the outer solar system.
When Deep impact was first proposed it was rejected because engineers did not believe we could hit a target as small and fast as a comet nucleus. Now that the technique is proven effective, other impactor missions have been proposed for a wide range of extra-terrestrial bodies. Of special interest is the idea of using this as a method of conducting a sample return mission. A high velocity impactor is fired into a moon, or asteroid, and a second vehicle flying close behind scoops up the ejecta and brings it home. This eliminates the need for sample return missions to land and launch a second time, and saving fuel, time, avoiding one of the more dangerous phases of such a mission.
This technique could also be applied to asteroid mining. Traditional mining methods will face serious challenges on asteroids. With their low gravity, simply lifting a shovel full of dirt and dumping it into a container becomes an incredibly challenging task. Drills on Earth require a constant supply of water to cool the drill and lubricate the shaft. Without any atmosphere liquid water would rapidly boil off on asteroids. Some dry drills are being developed for taking core sample on the Moon and Mars, but Apollo astronaut Jack Schmitt will tell you how tricky they are.
An impactor approach to asteroid mining could simplify the process greatly. Deep Impact struck with the force of 4.5 tonnes of TNT. That’s a lot of energy. Follow an impactor with collector vehicle and you have a quick method of strip-mining an asteroid. Even if large-scale material collection proves impossible, it would certainly work for prospectors trying to discern the composition of an asteroid before committing the resources needed for a full-scale mining operation.
Jim Bell Draws Record Crowd December 3, 2006
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Who is Jim Bell? He’s the Head of photography for the Mars rovers, and the author of Postcards From Mars. On Thursday, he was scheduled to speak at the Ithaca Sciencenter, and show off his slides from Mars. I hopped in my car and zipped down there. When I approached it center, I could see the parking lot was already full, so I parked on a deserted side street and walked over. I thought it was odd that some people appeared to be pulling out of the parking lot minutes before the talk was scheduled to start. Confused, I went inside and was met by more locals streaming out of the building.
That’s when a helpful staff member approached and informed me that the 110-seat auditorium was over capacity. It was so over-filled that they were turning people away and had already scheduled a repeat performance the following week. From the number of attendees milling about outside the room, I suspect that next week’s talk will be just as full.
Mars is still exciting. My wife just gave me a copy of Bell’s gorgeous book for my birthday. I’m used to viewing images from Mars on my desktop computer, and the large format photos in Postcards from Mars absolutely blew me away. I have yet to sit down and read the text because I keep flipping through to foldout pages.
I am very pleased to see that those who poured their heart and soul into Spirit and Opportunity are receiving public recognition for their efforts. These men and women transformed our vision of the Red Planet, and blazed a trail for other explorers to follow.
