LiveChat Roundup - 5/10/12

By Jim Gerard, NASA INSPIRE, KSC, FL

The INSPIRE weekly LiveChat commenced on Thursday, May 10, with presenter Frank Jones, an aerospace engineer from Langley Research Center. 41 were in attendance to hear Mr. Jones talk about his work as an Associate Director in Aeronautics at LaRC. His presentation divided into Simulation Services, Aircraft Services, Supported Projects and Robotics and Autonomous Systems.

Mr. Jones talked about LaRC's Concept-to-Flight Research, which allows engineers to take an idea from thought to practicality. An engineer can work out his design through computer simulation and modeling to reduce the amount of time needed for costly and dangerous test flights.

You can find out more about the work done at Langley by attending our special LiveChat next Tuesday at 3:00pm CT with Digital Learning Network specialist Karen Ricks. And then on Thursday at 8:00pm CT we'll hear from John Koelling, also from LaRC, who will update us on the future of Airspace Systems. Sign up now on the Discussion Board!

Toe Koozies

By Don Petit, Astronaut, ISS Expedition 30/31

It was time to get new socks. Mine had been worn for a week, and had reached their pull date. Groping in the bag of socks, I pulled out a pair of women's (small) ankle socks by mistake. Not wanting to fold them up and put them back, I decided to just try them on - maybe they would stretch. They covered my toes, but only reached just past the ball of my foot. I quickly concluded, "This will not work."

But that was based on my experience on Earth. It occurred to me that up here, you use your feet differently. In zero-g, you hook your feet under "handrails," thus shifting the load from the bottom to the top of the foot, just behind the toe knuckle. After about two months in orbit your feet molt, and like some reptilian creature the callused skin on the bottom of your foot sheds, leaving soft pink flesh in its place. In the weightless environment, calluses apparently have no use, at least on the bottoms of your feet. However, the tops of your feet become red-rubbed raw and gnarly. And the bottom calluses shed faster than the top calluses can grow. Perpetually raw and hypersensitive, your foot tops can use a bit of padding to ease the pain.

Serendipitously, I discovered that these short socks provide the necessary protection for toes and toe tops while leaving your heels out where they can breathe. They are the zero-gravity equivalent to flip-flops. The more that I wore them, the more I liked them. I have dubbed this new space fashion "toe koozies" - they are perfect for lounging around in a Node or the Cupola.

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J-2X Progress: Two Stands Occupied

By Bill Greene, MSFC, AL

It's been awhile since I've had the opportunity to update what we've been doing for the J-2X development test campaign. So, everyone is probably wondering where we stand. Well, if possession is nine-tenths of the law, then J-2X IS THE LAW for the NASA Stennis Space Center A-complex! Right now, the J-2X development effort has our PowerPack Assembly 2 in test stand A-1 and Engine 10001 has been reinstalled on test stand A-2.

Below are two pictures of the J-2X PowerPack Assembly 2 (known as PPA2) taken from different perspectives. In the second one, you can see that several pieces are coated with ice. That's obviously a picture with cryogenic propellants loaded in the ducts and turbomachinery. In other words, to use our local jargon, in the second picture PPA2 is chilled down.

Well, you saw in a previous blog article that we spun up the PPA2 and we demonstrated ignition of the gas generator. Beyond that, however, we've had a few hiccups. For the first test intended to get to mainstage operation, we didn't get very far. We effectively demonstrated again the spin start and ignition of the gas generator. Immediately beyond that, just a few tenths of a second in fact, the test shut down due to an issue on the facility side. As I've described before, the PPA2 is kind of an odd beast in that it's a half-engine and half-facility test article. In this case, a facility valve did not function the way that it was supposed to. It was sluggish. A subsequent investigation into the facility hydraulic system identified and fixed the issue so we were again all ready to go.

On the next test we got a little farther but just before getting to mainstage, we busted an engine-side redline limit and had to shut down early. The reason for that early cut was actually quite analogous to the early cut we had on our first attempt at a mainstage test for Engine 10001. We didn't quite understand the characteristics of the engine components and so, as we powered up the system, we were headed towards an operating point different than we'd intended. In other words, our calibration was a bit off. The redline system identified this situation and, properly, cut off the test before anything damaging might occur. While early cuts are sometimes a pain in the neck, we have those safety systems built in there for a reason. There is always a substantial and meaningful difference between a nuisance and something potentially worse.

Over the course of the next couple of PPA2 tests we once again proved that hydrogen is a pernicious rascal. This is something that has been proven on many former occasions throughout the history of rocket engine development. If you give hydrogen any opportunity to leak, any at all, it will. And sometimes, it will only leak when the system is chilled down so that when you're checking out the system before a test, when you're searching for potential leaks, you don’t see a thing. But then, when you are all set up and get the test going, ta-da, you suddenly have a fire. Why a fire? Because with a hydrogen leak around all the rest of the hot stuff going on with the test, a leak almost always becomes a fire. And, because pooled, un-burnt hydrogen is a potential detonation hazard, we also have devices all around the vicinity of the test article designed to make sure that any leaked hydrogen gets burnt. So, quite simply: hydrogen leak on engine test = hydrogen fire on engine test. The fires that we saw on these two tests were not on the "engine" half of the PPA2 test article per se. Instead, we got fires on the facility half. The emergency systems in place for such issues include cameras and temperature probes so that there was practically no damage and our hardware is just fine. But the fires did mean that we've accumulated only a limited amount of mainstage data so far.

Undaunted, we have investigated and, we believe, solved the issue and will once again be ready for testing in the near future.

On the other test stand, specifically stand A-2, the folks at the NASA Stennis Space Center have been darn busy. If you go back a couple of months in these blog articles you'll find a discussion about the next phase of testing for J-2X development engine 10001 (E10001 for short). In that article, I tell you all about the test stand passive diffuser and the engine nozzle extension that we’ll be testing. Well, the first thing that we had to do to make this next phase for E10001 possible was to modify the test stand. In order to make the passive diffuser function properly, you have to effectively seal off the top.

In the picture above you'll see what’s called the clamshell. This two-piece device rotates out of the way for access to the engine between tests but during a test wraps around the nozzle of the engine on the top side and connects to the diffuser on the bottom side. We'll use a rubber-ish seal in the gap between the clamshell and the nozzle to maintain the seal while accommodating movement of the nozzle during hot fire testing. Getting this thing designed, built, and into the stand was a heck of a lot of work. The folks who accomplished this deserve mucho kudos.

So, that's the test stand side. Next, there is the test article side, i.e., the engine itself. Because the nozzle extension is not structurally beefy enough to support the rest of the engine, the installation of the test article into the stand has to be performed in two steps. First, you install the main part of the engine and then, once that’s in place, you install the nozzle extension.

By the way, while it sounds easy enough to simply bolt the nozzle extension into place on the end of the nozzle, it's actually a bit more complicated. While both pieces are designed to be exactly round, nothing is truly exactly round, especially not pieces of hardware this large. We have to use special "rounding" tools during the mating process. It's sometimes amazing to think about all of the specialized tools and equipment that you need, in addition to the engine itself of course, just to make the engine work.

So, that's where we stand in terms of our development test campaign. As if southern Mississippi isn't hot enough in the summer, J-2X will soon be adding even more heat from two active test stands very, very soon and for several months to come. Elsewhere, FYI, we're working on various stages of fabricating and/or assembling J-2X development engines 10002 and 10003. They will be what follows PPA2 and E10001 into the test stands. In other words, there's lots of excitement yet to come.

Discuss this blog here: http://tinyurl.com/bloginspire

Hit the Books and Work on Your Car!

By Don Petit, Astronaut, ISS Expedition 30/31

Space is a desert unlike anything encountered on Earth. The human body is not configured to be able to survive in the cold, dark vacuum of this unearthly realm; creatures of this planet were never meant to go into space. We can only go there if we make machines to take and provide us with all the necessary things our bodies need to stay alive.

To survive and thrive in this machine-dominated environment, we need to know how those machines work and how to maintain them. This takes a strong background in technical subjects—mathematics, science, and engineering. These subjects are interesting, and for many people, mostly fun. But they can be difficult to master.

The theoretical basis for our machines must be understood, but we must also have the practical hands-on mechanical-electrical skills needed to keep them running and fix them when they break down. Crew members who work on their cars and do their own home repairs are well prepared for what is required when they venture into space. When something breaks on a spacecraft, you have to get your hands dirty.

If you want to fly into space and be a part of this new frontier, you must study and absorb the fundamentals of these subjects, and develop the hands-on repair skills needed to keep things running smoothly. As in any wilderness, be it on Earth or in space, if you should find yourself without the necessary technical knowledge and skills, you will be at the mercy of the elements. You will have compromised your ability to complete the mission, and perhaps even decreased your chances of survival.

Discuss this blog here: http://tinyurl.com/bloginspire 

LiveChat Roundup - 5/4/2012

By Jim Gerard, NASA INSPIRE Education Specialist, KSC, FL

Happy International Star Wars Day! May the Fourth Be With You!

That said, we had a great chat last night with Johnson Space Center engineer Stuart McClung, who heads up the Orion Parachute Development project at JSC. The 43 INSPIRE students had to be patient, as Mr. McClung had some firewall issues connecting with Blackboard Collaborate. So, as with most NASA projects, we set up our redundant fall-back plan and had Mr. McClung call in by telephone. If you watch the chat via the archive you may not even notice a difference. Once the telephone link was made, the presentation began.

While last weeks chat was about the Orion spacecraft as a whole, Mr. McClung focused in on the development and testing of the primary landing system - the parachutes. While the Space Shuttle orbits at 17500 mph (Mach 25), the returning Orion will hit the atmosphere at 25000 mph (Mach 35), and must be slowed to 17 mph when it hits the water. Deceleration down to Mach .5 will be done entirely by the atmosphere, converting the kinetic energy to thermal energy and dissipating that with the same ablative heat shield used in the Apollo spacecraft. The parachutes will do the rest of the work to give the astronauts on board a safe splashdown into the ocean.

Testing these parachutes has involved multiple drops from US Air Force C-130 and C-17 cargo planes. Not all were successful, but each failure provided data to refine the procedure to produce a safer and more reliable method of recovery. More drop test will finally lead to Experimental Test Flight 1 (EFT-1). Launched via Delta IV Heavy booster, an Orion capsule will orbit the earth twice at a low inclination to the equator, but high altitude to simulate the angle and velocity of the capsule returning from a deep space mission. This will prove the design, and enable NASA to push toward the day that astronauts will leave the earth aboard a US built and flown spacecraft.

Sign up now for two new chats next week! Tuesday night will host a chat with our INSPIRE winners of the RealWorld-InWorld Design Challenge, and on Thursday a chat from Langley Research Center on Computer Flight Control. Sign up on the Discussion Board!

Perigee "Super Moon" On May 5-6

By Dr, Tony Philips, Science @ NASA

The full Moon has a reputation for trouble.

It raises high tides, it makes dogs howl, it wakes you up in the middle of the night with beams of moonlight stealing through the drapes.

If a moonbeam wakes you up on the night of May 5th, 2012, you might want to get out of bed and take a look.  This May’s full Moon is a "super Moon,” as much as 14% bigger and 30% brighter than other full Moons of 2012.

A ScienceCast video explains the facts and fiction of "super-moons."

The scientific term for the phenomenon is "perigee moon." Full Moons vary in size because of the oval shape of the Moon's orbit. The Moon follows an elliptical path around Earth with one side ("perigee") about 50,000 km closer than the other ("apogee").  Full Moons that occur on the perigee side of the Moon's orbit seem extra big and bright.
Such is the case on May 5th at 11:34 pm Eastern Daylight Time when the Moon reaches perigee.  Only one minute later, the Moon will line up with Earth and the sun to become gloriously full.  The timing is almost perfect.
Okay, the Moon is 14% bigger than usual, but can you really tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon can seem much like any other.

The best time to look is when the Moon is near the horizon.  For reasons not fully understood by astronomers or psychologists, low-hanging Moons look unnaturally large when they beam through trees, buildings and other foreground objects. On May 5th, this “Moon illusion” will amplify a full Moon that's extra-big to begin with.  The swollen orb rising in the east at sunset will seem super indeed.

Folklore holds that all kinds of wacky things happen under the light of a full Moon.  Supposedly, hospital admissions increase, the crime rate ticks upward, and people behave strangely. The idea that the full Moon causes mental disorders was widespread in the Middle Ages. Even the word "lunacy," meaning "insanity," comes from the Latin word for "Moon."
The majority of modern studies, however, show no correlation between the phase of the Moon and the incidence of crime, sickness, or human behavior.  The truth is, the Moon is less influential than folklore would have us believe.
It's true that a perigee full Moon brings with it extra-high "perigean tides," but according to the National Oceanic and Atmospheric Administration this is nothing to worry about. In most places, lunar gravity at perigee pulls tide waters only a few centimeters (an inch or so) higher than usual. Local geography can amplify the effect to about 15 centimeters (six inches)--not exactly a great flood.
Super perigee Moons are actually fairly common.  The Moon becomes full within a few hours of its closest approach to Earth about once a year on average.   The last such coincidence occurred on March 19th, 2011, producing a full Moon that was almost 400 km closer than this one.  As usual, no trouble was reported.
That is, unless you count a midnight awakening as trouble.
If so, close the drapes on May 5th.  Otherwise, enjoy the super-moonlight.

FIRST Robotics Competition Championship 2012

By Amruth Uppaluri, 9th Grade, and Karthik Uppaluri, 10th Grade

The 2012 FIRST robotics championship which started on Wednesday, April 25th ended on Saturday, April 28th. The event was held in St. Louis, MO at the Edward Jones Dome where 30,000 participants, fans, mentors, families and friends joined to cheer teams from around the world. The dome rocked with fans who were screaming for their favorite alliance, while the weather outside was creating its own noise. Thunder, lightning, hail and pouring rain outside did not stop the robotics event from ending on a high note.

Our team, Team Plasma from Mesa, Arizona flew to St. Louis on Wednesday morning to attend this “SuperBowl of robotics” as one of the presenters stated. The teams who qualified were assigned to different sub groups named after famous scientists such as Newton, Archimedes, Curie and Einstein etc. We were in the Archimedes group.

This year’s FRC challenge was titled Rebound Rumble and featured a modified basketball court where 3 robots from each alliance ( Red & Blue ) competed to score points during a two-minute 15 second match. The game started in autonomous mode where robots shot the pre-loaded basketballs into the baskets. Then, drivers from each team remotely controlled their robots to pick up balls and score as many points as possible. Some robots played defense by trying to keep the others from accumulating basketballs and tossing them over to the other side.

Our hopes were high after the first day of competition as we were ranked 6th out of 100 teams in our group. The next day, Friday, was a little bit of a disappointment where we slipped to 21st place. On Saturday, the final day of competition, the top eight teams from each of the fields selected other top teams to form the alliances for the final championships. Unfortunately, we were not selected and finished 37th overall and are very proud of our accomplishment. The winning alliance was Team 180, S.P.A.M., Stuart, Fla.; Team 16, Bomb Squad, Mountain Home, Ark.; Team 25, Raider Robotix, North Brunswick, N.J. from the Galileo Division.

This years’ highest honor the Chairman’s Award was presented at the FRC Championships to Simbotics from St. Catherines, Ontario, Canada and was recognized as the team that best exemplified the purpose and goals of FIRST.

Each year this event is gaining worldwide attention as major sponsors are aligning themselves with this great organization. Companies such as Boeing, U.S. Air Force, NASA, Autodesk, General Motors, Microsoft, Google, Rockwell Automation, UL and others are some of the key sponsors of the USFIRST championships.