Wednesday, November 12, 2014

Media Event at NASA's Marshall Space Flight Center (Part 3)

Welcome to Part 3 of my experience at NASA's Marshall Space Flight Center Media Event. If you've missed Part 1 or Part 2, be sure to check them out. Great info.

I need this sign. For reasons.
After leaving the avionics testing area - after what felt like too short a time, but really wasn't - the group headed to see some seriously cool stuff dealing with propulsion. How cool? How does 'Nuclear Thermal Propulsion' sound? Yes...it was as cool as one can imagine.

Just what is nuclear thermal propulsion? Let's take a step back for a moment and discuss what rocket engines do: In order to propel a ship/probe/satellite, something needs to to 'push' against the craft. How exactly does one do that in space where there's nothing to push against? You bring the 'pushing stuff' with you in the form of fuel (also known as reaction mass). In very simple terms (really - this is an overly-simplified explanation), the amount of 'push' is a function of the speed at which the reaction mass exits the engine...and the mass of the craft. The faster that the reaction mass exits the engine, the quicker the craft is accelerated. But there are limits to the speed at which traditional chemical rockets (both liquid and solid varieties) can expel their reaction mass.

Engineer explaining testing the nuclear thermal rockets
A nuclear thermal rocket engine works by using the heat from a nuclear reactor to excite hydrogen and expel it from the nozzle. The hydrogen exits at a much higher velocity than do traditional chemical fuels; however, since it's the lightest element, it has less "push" per atom. But that's OK - it's VERY efficient. So, if one wants to get somewhere and speed is NOT of the essence, then a nuclear thermal rocket might fit the bill. Hydrogen is the most abundant element in the universe, is stable, and can be produced in-situ. This is a huge benefit over traditional chemical rockets that require more complicated fuels. Moreover, the amount of reaction mass needed to get the craft to its destination is vastly reduced over chemical rockets. This means less overall mass of the vehicle - an all-around win. Want to read a more in-depth explanation of nuclear thermal rockets? Wikipedia is your friend - click here.

An actual iodine thruster.
But all the advancements aren't in big rockets - oh, no. In fact, some of the most impressive engineering is going into smaller thrusters meant for cubesats. One of those is an iodine thruster. Doesn't sound too exciting, does it? Oh, but it is. Historically, cubesats have very little maneuvering capability or ability to change their orbit to any meaningful degree (perhaps a few m/sec delta-v). The iodine thruster, though, is a game changer. It mounts to a standard cubesat frame and promises to give more than 1,000 m/sec delta-v). What does that mean? Just that cubesats deployed from Low Earth Orbit (LEO) can transfer themselves to a higher...or more inclined...or more eccentric...orbit on their own. Think of the cool possibilities!

There were so many awesome things to see and learn in the propulsion and avionics areas, I could've spent all day there. I sure hope the engineers and scientists enjoyed having us there as much as I enjoyed seeing their work.

NASA engineer explaining the innovative solar cell layout.
The last stop before we headed off to a press conference discussing SLS was to see some more additive manufacturing, and examples of some fine engineering concepts from young engineers from several NASA centers. I didn't get a chance to spend much time with these extremely smart people, which was a shame...but I did get some excellent takeaways. Firstly, one team is working on autonomous programming that would allow cubesats to team up to combine disparate functions into a working unit greater than the sum of its individual parts. Another team devised a simple, but very effective, solar cell arrangement to ensure small satellites constantly receive adequate sunlight without the need for cumbersome orientation hardware. These are but two examples of phenomenal work coming out of young NASA engineers.

Lastly, we were part of a press briefing for Orion's first flight - EFT-1, scheduled to launch from Kennedy Space Center on December 4, 2014, atop a Delta IV-Heavy. Though it was, in large part, a rehash of the info I'd heard at the NASA Social at the Michoud Assembly Facility in September, excitement was heightened knowing that launch is rapidly approaching. I won't revisit the information here, but suffice it to say that EFT-1 is a big, BIG deal, and you'll be hearing more about it in the days ahead.

Though I'm a proponent of a cooperative global space program, I can't help but feel some national pride knowing that all of these super smart people are part of NASA. I know, childish...right? But there's something inspirational about seeing the Stars and Stripes hanging in a work area, or painted on a rocket, or stitched on the flight suit of one of the brave astronauts that are helping to make us a multi-planet species. I'm ready for SLS. I'm ready for Orion. I'm ready to go to Mars. Let's light this candle!

** I would like to thank the wonderful people in NASA's Public Affairs Office for allowing us this privileged access.**