By Jim Gerard, INSPIRE Education Specialist, KSC, FL
The NASA Spacesuit, otherwise known as the Extravehicular Mobility Unit (EMU), is a complex machine whose sole purpose is to keep humans alive in the extreme environment of outer space. 49 members of the INSPIRE Online Learning Community were led through a presentation by spacesuit engineer Mallory Jennings from the Johnson Space Center. Ms. Jennings chatted to students about the parts of the EMU, including her specialty, the Portable Life Support System (PLSS). Students were then introduced to some new designs, and shown ways they are being tested. As usual, the chat ended with questions and answers.
Next week, LiveChat is taking a 'Spring Break', but will be back the following week on April 12, where I will talk to you about the History of the Space Shuttle. Sign up now on the Discussion Board!
Don't forget, if you missed the chat you can still view it in the archives by clicking the Live Chats link on the Connect page.
Discuss this blog here: http://tinyurl.com/bloginspire
Friday, March 30, 2012
A Flashing Success
By Don Petit, Astronaut, ISS Expedition 30/31
Flashing space station with beams of light as it passes overhead had never been successfully done—until yesterday.
It sounds deceptively easy. In an earlier post I wrote about the technical requirements. But like so many other tasks, it becomes much more involved in the execution than in the planning.
Early Sunday morning, at 01:27 our time, the San Antonio Astronomical Association, an amateur astronomy group, succeeded in flashing space station with a one-watt blue laser and a white spot light as we passed overhead. This took a number of engineering calculations. Projected beam diameters (assuming the propagation of a Gaussian wave for the laser) and intensity at the target had to be calculated. Tracking space station’s path as it streaked across the sky was another challenge. I used email to communicate with Robert Reeves, one of the association’s members. Considering that it takes a day, maybe more, for a simple exchange of messages (on space station we receive email drops two to three times a day), the whole event took weeks to plan.
I was ready with cameras for the early morning San Antonio pass and can report that it was a flashing success. Here’s one of the pictures to prove it.
Discuss this blog here: http://tinyurl.com/bloginspire
Flashing space station with beams of light as it passes overhead had never been successfully done—until yesterday.
It sounds deceptively easy. In an earlier post I wrote about the technical requirements. But like so many other tasks, it becomes much more involved in the execution than in the planning.
Early Sunday morning, at 01:27 our time, the San Antonio Astronomical Association, an amateur astronomy group, succeeded in flashing space station with a one-watt blue laser and a white spot light as we passed overhead. This took a number of engineering calculations. Projected beam diameters (assuming the propagation of a Gaussian wave for the laser) and intensity at the target had to be calculated. Tracking space station’s path as it streaked across the sky was another challenge. I used email to communicate with Robert Reeves, one of the association’s members. Considering that it takes a day, maybe more, for a simple exchange of messages (on space station we receive email drops two to three times a day), the whole event took weeks to plan.
I was ready with cameras for the early morning San Antonio pass and can report that it was a flashing success. Here’s one of the pictures to prove it.
Discuss this blog here: http://tinyurl.com/bloginspire
Wednesday, March 28, 2012
Our Fancy Coffee Machine
By Don Petit, Astronaut, ISS Expedition 30/31
During the flight of STS-126 in 2008, we carried up three refrigerator-sized pieces of equipment. One was a toilet for the NASA side of space station. There was already one on the Russian side, so this one gave us redundancy. In the past, when the toilet broke, all work had halted until we fixed it. No other single piece of equipment fell into this category of importance. The oxygen generator could break, and maybe in a day or two we would fix it; same with the carbon dioxide scrubber. But when the toilet broke—now that was serious.
The second piece of equipment we carried up was a small chemical plant. It contained a distillation apparatus, catalytic reactors, pumps, filters, and plumbing. It was a chemical engineer’s dream. The liquid effluent from the toilet was plumbed to the inlet of this machine.
The third piece of equipment was a new galley. It sported an injection port for filling our drink bags and rehydrating freeze-dried food with our choice of hot or room-temperature water. It also had a hot box for warming thermally stabilized meat pouches (canned meat without the can) and a small refrigerator—not for science samples, but for the crew’s food. The inlet to the galley was plumbed into the outlet of the chemical plant. This completed what we call our regenerative life support system. Simply put, what goes out one end is processed, reworked, and put back in the other end.
Water is an essential ingredient not just for us, but for all life forms that we recognize. And water is always in short supply on a spacecraft. There may be water shortages in some places on Earth, but spaceflight redefines the meaning of the word “desert.” Closing the water loop will therefore be essential technology when humans venture away from Earth for long periods of time. If the toilet fails on a mission to Mars, the crew will run out of water and die. Earth orbit, where spare parts and engineering knowledge are close by, is the ideal place to refine this technology and produce equipment that is truly robust. I call this engineering research; it is complementary to scientific research, and is one of the more important activities that we conduct on space station.
Nowhere on Earth do we recycle urine using portable machinery. Not in Antarctica, not on ships at sea, not in our driest deserts. We choose to let Earth do the recycling, not a machine. Our recycling system on space station is not a one-time demonstration, nor a test of astronauts’ ability to handle the “yuck factor.” It’s a day-in, day-out operation, designed as an integral part of the overall spacecraft water balance. With this technology, we are truly on the frontier, and we have serial number 001 of a complex machine. Of course it breaks down—constantly. And of course, we are always fixing it. Of course there is a steady stream of spare parts arriving from Earth. Any new technology is like this. The first crews arriving at Mars will thank us for our urine-stained hands.
Morning is a time for comfortable habits, and so it is on space station. Each morning I float out (“getting up” is obviously a gravity-centric expression) and do my daily routine. I can hear the rumbles of the chemical plant. It vibrates the deck rails and gives your feet a massage at the same time. Then I float over to the galley and make a bag of coffee. Kona is one of my favorites; I can feel the caffeine race to my brain and stimulate my thoughts. It occurs to me that our regenerative life support equipment is really just a fancy coffee machine. It makes yesterday’s coffee into today’s coffee.
Discuss this blog here: http://tinyurl.com/bloginspire
During the flight of STS-126 in 2008, we carried up three refrigerator-sized pieces of equipment. One was a toilet for the NASA side of space station. There was already one on the Russian side, so this one gave us redundancy. In the past, when the toilet broke, all work had halted until we fixed it. No other single piece of equipment fell into this category of importance. The oxygen generator could break, and maybe in a day or two we would fix it; same with the carbon dioxide scrubber. But when the toilet broke—now that was serious.The second piece of equipment we carried up was a small chemical plant. It contained a distillation apparatus, catalytic reactors, pumps, filters, and plumbing. It was a chemical engineer’s dream. The liquid effluent from the toilet was plumbed to the inlet of this machine.
The third piece of equipment was a new galley. It sported an injection port for filling our drink bags and rehydrating freeze-dried food with our choice of hot or room-temperature water. It also had a hot box for warming thermally stabilized meat pouches (canned meat without the can) and a small refrigerator—not for science samples, but for the crew’s food. The inlet to the galley was plumbed into the outlet of the chemical plant. This completed what we call our regenerative life support system. Simply put, what goes out one end is processed, reworked, and put back in the other end.
Water is an essential ingredient not just for us, but for all life forms that we recognize. And water is always in short supply on a spacecraft. There may be water shortages in some places on Earth, but spaceflight redefines the meaning of the word “desert.” Closing the water loop will therefore be essential technology when humans venture away from Earth for long periods of time. If the toilet fails on a mission to Mars, the crew will run out of water and die. Earth orbit, where spare parts and engineering knowledge are close by, is the ideal place to refine this technology and produce equipment that is truly robust. I call this engineering research; it is complementary to scientific research, and is one of the more important activities that we conduct on space station.
Nowhere on Earth do we recycle urine using portable machinery. Not in Antarctica, not on ships at sea, not in our driest deserts. We choose to let Earth do the recycling, not a machine. Our recycling system on space station is not a one-time demonstration, nor a test of astronauts’ ability to handle the “yuck factor.” It’s a day-in, day-out operation, designed as an integral part of the overall spacecraft water balance. With this technology, we are truly on the frontier, and we have serial number 001 of a complex machine. Of course it breaks down—constantly. And of course, we are always fixing it. Of course there is a steady stream of spare parts arriving from Earth. Any new technology is like this. The first crews arriving at Mars will thank us for our urine-stained hands.
Morning is a time for comfortable habits, and so it is on space station. Each morning I float out (“getting up” is obviously a gravity-centric expression) and do my daily routine. I can hear the rumbles of the chemical plant. It vibrates the deck rails and gives your feet a massage at the same time. Then I float over to the galley and make a bag of coffee. Kona is one of my favorites; I can feel the caffeine race to my brain and stimulate my thoughts. It occurs to me that our regenerative life support equipment is really just a fancy coffee machine. It makes yesterday’s coffee into today’s coffee.
Discuss this blog here: http://tinyurl.com/bloginspire
Tuesday, March 27, 2012
J-2X Progress: Getting All Spun Up
By Bill Greene, MSFC, AL
If you go back through the J-2X Development Blog articles, you’ll find one about the "Burp Test" that we conducted last July on J-2X development engine E10001. In that case, we ran a very short test where we activated the helium spin start system and we ignited the main chamber, very briefly, before we shut down the whole thing. Well, here we are about six months later and we're doing the equivalent thing on the J-2X PowerPack Assembly 2 (PPA2). Here is a video of the test:
Testing at night is always so much more dramatic.
For the PPA2, there is no main chamber to light, so this entire test was primarily focused on exercising the helium spin start system. The flames that you see are from flare stacks necessary to get rid of the hydrogen used in the test. Remember, the PPA2 is primarily a test article for turbomachinery and the gas-generator turbine-drive system. It doesn't make thrust. All of that hydrogen that gets pumped by the fuel turbopump has to be disposed of in a controlled manner other than in the production of thrust. So, we burn it off. The liquid oxygen is disposed of as well, but it doesn’t require anything quite so gaudy as flare stacks.
Interestingly, when hydrogen burns, it usually burns clear. The whole orange-flame thing is not something I entirely understand, but it always looks that way at night. There’s some propane in the flame used as kind of like a pilot light, but not enough to cause that much color. It could be that burning hydrogen at such a low mixture ratio (i.e., not enough oxygen immediately available so you get afterburning effects) is the cause of this as compared to the usual white hot rocket engine exhaust. It's also possible that it's stuff in the air or somehow water vapor effects, or disassociation effects, but I honestly don’t know. Any ideas from anyone else? I'd love to hear some theories. I do know that if you're standing anywhere where you can see the flame, you can feel the heat radiating from it. It's quite an impressive experience.
Beyond exercising the helium spin start system, what this test also did is prove out the test stand subsystems, the test stand and test article control systems, demonstrates that the gobs and gobs of instrumentation is hooked up, working properly, and feeding back reasonable data, and that the proper procedures are in place to conduct a safe test. Every facet listed is a big, big deal and has to work in conjunction with everything else.
The folks at the Stennis Space Center -- civil service, support contractors, and prime contractors alike -- all deserve kudos for pulling this off successfully and, really, with minimal technical issues. Way to go guys! This test is yet another in a long string of demonstrations of the power of collaboration and the overall dedication and excellence of the J-2X team. We're now ready to step into the meat of the test series and start putting the hardware through its paces. This is going to be exciting! Go J-2X!
Discuss this blog here: http://tinyurl.com/bloginspire
If you go back through the J-2X Development Blog articles, you’ll find one about the "Burp Test" that we conducted last July on J-2X development engine E10001. In that case, we ran a very short test where we activated the helium spin start system and we ignited the main chamber, very briefly, before we shut down the whole thing. Well, here we are about six months later and we're doing the equivalent thing on the J-2X PowerPack Assembly 2 (PPA2). Here is a video of the test:
Testing at night is always so much more dramatic.
For the PPA2, there is no main chamber to light, so this entire test was primarily focused on exercising the helium spin start system. The flames that you see are from flare stacks necessary to get rid of the hydrogen used in the test. Remember, the PPA2 is primarily a test article for turbomachinery and the gas-generator turbine-drive system. It doesn't make thrust. All of that hydrogen that gets pumped by the fuel turbopump has to be disposed of in a controlled manner other than in the production of thrust. So, we burn it off. The liquid oxygen is disposed of as well, but it doesn’t require anything quite so gaudy as flare stacks.
Interestingly, when hydrogen burns, it usually burns clear. The whole orange-flame thing is not something I entirely understand, but it always looks that way at night. There’s some propane in the flame used as kind of like a pilot light, but not enough to cause that much color. It could be that burning hydrogen at such a low mixture ratio (i.e., not enough oxygen immediately available so you get afterburning effects) is the cause of this as compared to the usual white hot rocket engine exhaust. It's also possible that it's stuff in the air or somehow water vapor effects, or disassociation effects, but I honestly don’t know. Any ideas from anyone else? I'd love to hear some theories. I do know that if you're standing anywhere where you can see the flame, you can feel the heat radiating from it. It's quite an impressive experience.
Beyond exercising the helium spin start system, what this test also did is prove out the test stand subsystems, the test stand and test article control systems, demonstrates that the gobs and gobs of instrumentation is hooked up, working properly, and feeding back reasonable data, and that the proper procedures are in place to conduct a safe test. Every facet listed is a big, big deal and has to work in conjunction with everything else.
The folks at the Stennis Space Center -- civil service, support contractors, and prime contractors alike -- all deserve kudos for pulling this off successfully and, really, with minimal technical issues. Way to go guys! This test is yet another in a long string of demonstrations of the power of collaboration and the overall dedication and excellence of the J-2X team. We're now ready to step into the meat of the test series and start putting the hardware through its paces. This is going to be exciting! Go J-2X!
Discuss this blog here: http://tinyurl.com/bloginspire
Friday, March 23, 2012
LiveChat Roundup: March 22, 2012
By Jim Gerard, NASA INSPIRE Education Specialist, KSC, FL
Imagine spending two weeks at Mars, and then flying home in only a couple of hours. Science fiction? Not if the Mars we are talking about is an Earth analog site and the home of the Mars Desert Research Station. The current crew of the MDRS is from Georgia Tech, and consists of 6 Tech students at the station and a team of 4 support students in Atlanta. Among them are three INSPIRE alumni, who were anxious to share their experience with their OLC colleagues. Last night, 51 INSPIRE students attended the LiveChat with the MDRS team.
Among those attending were four INSPIRE students who submitted experiments for the MDRS team to perform during their simulation. Hannah M. shared her plant growth experiment, and Abdiel G. shared for his team of Jacky Q and Paul P. about the several projects they proposed. One student, Alex D. was unable to attend but sent information about his experiment. These students then heard first hand how their experiments fared from the MDRS crew.
Besides the LiveChat, we have had daily updates from crew member Lisa Thornsberry. Here is her update from last night:
Discuss this blog here: http://tinyurl.com/bloginspire
Imagine spending two weeks at Mars, and then flying home in only a couple of hours. Science fiction? Not if the Mars we are talking about is an Earth analog site and the home of the Mars Desert Research Station. The current crew of the MDRS is from Georgia Tech, and consists of 6 Tech students at the station and a team of 4 support students in Atlanta. Among them are three INSPIRE alumni, who were anxious to share their experience with their OLC colleagues. Last night, 51 INSPIRE students attended the LiveChat with the MDRS team.
Among those attending were four INSPIRE students who submitted experiments for the MDRS team to perform during their simulation. Hannah M. shared her plant growth experiment, and Abdiel G. shared for his team of Jacky Q and Paul P. about the several projects they proposed. One student, Alex D. was unable to attend but sent information about his experiment. These students then heard first hand how their experiments fared from the MDRS crew.
Besides the LiveChat, we have had daily updates from crew member Lisa Thornsberry. Here is her update from last night:
We had so much fun today sharing our Mars simulation experience with the NASA INSPIRE students! Thanks for time and attention and your great questions! The hab crew would like to give a huge thank you to the INSPIRE program for its support. Also, thanks to our fantastic mission support team for making it possible!I hope you have enjoyed sharing in this experience with the Georgia Tech team!
Discuss this blog here: http://tinyurl.com/bloginspire
Thursday, March 22, 2012
By Don Petit, Astronaut, ISS Expedition 30/31
From my orbital perspective, I am sitting still and Earth is moving. I sit above the grandest of all globes spinning below my feet, and watch the world speed by at an amazing eight kilometers per second (288 miles per minute, or 17,300 miles per hour).
This makes Earth photography complicated.
Even with a shutter speed of 1/1000th of a second, eight meters (26 feet) of motion occurs during the exposure. Our 400-millimeter telephoto lens has a resolution of less than three meters on the ground. Simply pointing at a target and squeezing the shutter always yields a less-than-perfect image, and precise manual tracking must be done to capture truly sharp pictures. It usually takes a new space station crewmember a month of on-orbit practice to use the full capability of this telephoto lens.
Another surprisingly difficult aspect of Earth photography is capturing a specific target. If I want to take a picture of Silverton, Oregon, my hometown, I have about 10 to 15 seconds of prime nadir (the point directly below us) viewing time to take the picture. If the image is taken off the nadir, a distorted, squashed projection is obtained. If I float up to the window and see my target, it’s too late to take a picture. If the camera has the wrong lens, the memory card is full, the battery depleted, or the camera is on some non-standard setting enabled by its myriad buttons and knobs, the opportunity will be over by the time the situation is corrected. And some targets like my hometown, sitting in the middle of farmland, are low-contrast and difficult to find. If more than a few seconds are needed to spot the target, again the moment is lost. All of us have missed the chance to take that “good one.” Fortunately, when in orbit, what goes around comes around, and in a few days there will be another chance.
It takes 90 minutes to circle the Earth, with about 60 minutes in daylight and 30 minutes in darkness. The globe is equally divided into day and night by the shadow line, but being 400 kilometers up, we travel a significant distance over the nighttime earth while the station remains in full sunlight. During those times, as viewed from Earth, we are brightly lit against a dark sky. This is a special period that makes it possible for people on the ground to observe space station pass overhead as a large, bright, moving point of light. This condition lasts for only about seven minutes; after that we are still overhead, but are unlit and so cannot be readily observed.
Ironically, when earthlings can see us, we cannot see them. The glare from the full sun effectively turns our windows into mirrors that return our own ghostly reflection. This often plays out when friends want to flash space station from the ground as it travels overhead. They shine green lasers, xenon strobes, and halogen spotlights at us as we sprint across the sky. These well-wishers don’t know that we cannot see a thing during this time. The best time to try this is during a dark pass when orbital calculations show that we are passing overhead. This becomes complicated when highly collimated light from lasers are used, since the beam diameter at our orbital distance is about one kilometer, and this spot has to be tracking us while in the dark. And of course we have to be looking. As often happens, technical details complicate what seems like a simple observation. So far, all attempts at flashing the space station have failed.
Discuss this blog here: http://tinyurl.com/bloginspire
From my orbital perspective, I am sitting still and Earth is moving. I sit above the grandest of all globes spinning below my feet, and watch the world speed by at an amazing eight kilometers per second (288 miles per minute, or 17,300 miles per hour).This makes Earth photography complicated.
Even with a shutter speed of 1/1000th of a second, eight meters (26 feet) of motion occurs during the exposure. Our 400-millimeter telephoto lens has a resolution of less than three meters on the ground. Simply pointing at a target and squeezing the shutter always yields a less-than-perfect image, and precise manual tracking must be done to capture truly sharp pictures. It usually takes a new space station crewmember a month of on-orbit practice to use the full capability of this telephoto lens.
Another surprisingly difficult aspect of Earth photography is capturing a specific target. If I want to take a picture of Silverton, Oregon, my hometown, I have about 10 to 15 seconds of prime nadir (the point directly below us) viewing time to take the picture. If the image is taken off the nadir, a distorted, squashed projection is obtained. If I float up to the window and see my target, it’s too late to take a picture. If the camera has the wrong lens, the memory card is full, the battery depleted, or the camera is on some non-standard setting enabled by its myriad buttons and knobs, the opportunity will be over by the time the situation is corrected. And some targets like my hometown, sitting in the middle of farmland, are low-contrast and difficult to find. If more than a few seconds are needed to spot the target, again the moment is lost. All of us have missed the chance to take that “good one.” Fortunately, when in orbit, what goes around comes around, and in a few days there will be another chance.
It takes 90 minutes to circle the Earth, with about 60 minutes in daylight and 30 minutes in darkness. The globe is equally divided into day and night by the shadow line, but being 400 kilometers up, we travel a significant distance over the nighttime earth while the station remains in full sunlight. During those times, as viewed from Earth, we are brightly lit against a dark sky. This is a special period that makes it possible for people on the ground to observe space station pass overhead as a large, bright, moving point of light. This condition lasts for only about seven minutes; after that we are still overhead, but are unlit and so cannot be readily observed.
Ironically, when earthlings can see us, we cannot see them. The glare from the full sun effectively turns our windows into mirrors that return our own ghostly reflection. This often plays out when friends want to flash space station from the ground as it travels overhead. They shine green lasers, xenon strobes, and halogen spotlights at us as we sprint across the sky. These well-wishers don’t know that we cannot see a thing during this time. The best time to try this is during a dark pass when orbital calculations show that we are passing overhead. This becomes complicated when highly collimated light from lasers are used, since the beam diameter at our orbital distance is about one kilometer, and this spot has to be tracking us while in the dark. And of course we have to be looking. As often happens, technical details complicate what seems like a simple observation. So far, all attempts at flashing the space station have failed.
Discuss this blog here: http://tinyurl.com/bloginspire
Fresh Update from MDRS
By Lisa Thornsberry, Georgia Tech MDRS Crew 115
Today, Kyle, Jenny, and Jackie went on a three-hour EVA to make a map of the dirt roads surrounding the hab. They did this using an automatic packet reporting system (APRS), which connects our radio to a global positioning system (GPS) unit. The radio sends latitude and longitude information to a computer, which shows the location on a map. By updating their location several times a minute, the crew members were able to trace out their path on the map.
Question of the day: How long is a day on Mars?
Answer: 24 hours, 39 minutes, 35 seconds. A day on Mars is referred to as a "sol."
And don't forget to sign up for tonight's (Thursday March 22) LiveChat and hear from me and my crew! Go to the OLC Discussion Board and find the sign up topic folder. See you then!
Today, Kyle, Jenny, and Jackie went on a three-hour EVA to make a map of the dirt roads surrounding the hab. They did this using an automatic packet reporting system (APRS), which connects our radio to a global positioning system (GPS) unit. The radio sends latitude and longitude information to a computer, which shows the location on a map. By updating their location several times a minute, the crew members were able to trace out their path on the map.
Question of the day: How long is a day on Mars?
Answer: 24 hours, 39 minutes, 35 seconds. A day on Mars is referred to as a "sol."
And don't forget to sign up for tonight's (Thursday March 22) LiveChat and hear from me and my crew! Go to the OLC Discussion Board and find the sign up topic folder. See you then!
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