Category Archives: Physics

The Van Allen Probes Turns 5 Today

Five years ago today, the Van Allen Probes were launched into orbit to begin their study of the trapped radiation belts first predicted by and then discovered by Dr. James Van Allen with the first US satellite, Explorer 1.  Fundamental Technologies in Lawrence, KS, where I do my space science research, is the Science Operations Center for the RBSPICE instruments on the two twin Van Allen Probes spacecraft.  Through my work at FunTech, my wife and I had the honor and privilege of being invited to the Kennedy Space Center to witness our spacecraft leave the planet.

We were at Cocoa Beach for three nights where during the day we interacted with visitors to the Kennedy Space Center where we had a large display assembled sharing information about the mission, its objectives, and its importance to improving our understanding of space weather.  As invited guests, we were given the opportunity to witness the launch from the same grandstands in which the families of the Apollo astronauts watched their husbands, brothers, and sons blast off on their epic voyage to the Moon.  It was an awe-inspiring, thrilling, and ultimately frustrating experience.

We had three nights and therefore three opportunities to get the Van Allen Probes off the planet, but on the first night, a launch was not even attempted.  Engineers had discovered a flaw in one of the RD-180 engines in Huntsville, AL, the same type of engine that powered the Atlas V rocket underneath our spacecraft.  The engines for our launch vehicle were inspected and found to be fine, so we were back on for night number two.

The launch window opened at 0430 which meant that we needed to arrive at Kennedy by 0030 to meet the shuttle busses that would take us to the viewing stands.  Once at the viewing location, we had a magnificent view of our launch vehicle standing on its pad and illuminated by the brightest lights you can imagine.  The atmosphere at the viewing site was thick with tension, anticipation, and mosquitoes.  Lots of mosquitoes! During the long countdown, several speakers gave talks about the mission, which we all knew about already, and details about the launch sequence and timeline, which many of us did not know.    What was truly special is that Maj. Gen. Charles Frank Bolden, Jr., Director of NASA, came out to address us and witness the launch with us.

At 0400, we reached the T-4 minute hold.  This was a preplanned hold during which final checks on the launch vehicle, the two Van Allen Probes spacecraft, and the launch conditions were made.  Talk about tense and exciting!  Movies always make the launch readiness poll sound over dramatic and you come away thinking, “Surely it’s not really that tense.”  Yes it is; it really is.  As each system was called out, the person responsible for that system would call out either “Go!” or “Go, Flight!”  I get goosebumps even now just thinking about that moment.

The Flight Director eventually got around to calling out, “Range.”  The response was a pause, and then an utterly disheartening, “No go, Flight. No go.”  That brought everything to an immediate halt.  When there’s a range fault, it could mean that there’s someone in the restricted space in the air or ocean that’s fouling the range, or it’s an instrumentation failure.  Many of our thoughts in the grandstands was that if it were a bunch of boaters out where they shouldn’t be, there might be violence done that day.  As it turned out, it was the fault of a transponder on the launch vehicle that couldn’t maintain a frequency lock on the downrange radar.

All launch vehicles are actively tracked.  A radar site doesn’t simply passively track them, they actively communicate with the launch vehicle to monitor the rocket’s attitude and trajectory with great precision.  The reason for this is that if a rocket begins to stray from its designated trajectory and begin headed inland where it may fall on a populated area, the vehicle will be destroyed instantly.  The last thing NASA wants is for a US missile to land and explode in a US city.

So with no launch on the second night, we all went back to our hotel rooms, caught what sleep we could before going back to the Visitor’s Center and our booth to do more public outreach in the afternoon.  That night, we all got up again and went back to Kennedy at 0030 to give the launch one more try.  Again with the speeches.  Again with the explanations.  Again with the waiting, the tension, the anticipation, and swarms of mosquitoes.  Once again, we reached the T-4 minute hold.  Once again, we listened nervously to the launch readiness poll.

“Hydraulics.”

“Go!”

“Water.”

“Go!”

“Range.”

And after a long pause, “Go, Flight!”

There was an uproar of cheers!  It was as our team had just won the World Series!  Everyone was jumping, clapping, and cheering, but the poll wasn’t over yet.

“Weather.”

“…No go, Flight.  Weather is no go.”

It was a soul-crushing moment.  All the anticipation, all the excitement was dissipated in an instant. The weight of all of the work that had gone into making the Van Allen Probes, its array of instruments, and all of the software to control the spacecraft and their instruments crashed down upon us.  For many of us, myself included, this was our first time, perhaps the singular time in our lifetimes, of getting to witness a rocket launch, and certainly the singular time we would be able to watch from such a historically significant location.  There were tears.  I’m not ashamed to admit it.

My wife and I along with my fellow colleagues flew home.  There was still work that needed to be done on other missions, and the Fall semester had started, so I had to get back to the classroom.  It wasn’t a fun trip back, and I moped around campus that Monday.  The Van Allen Probes obviously did launch successfully, but not until the Thursday of the week after we were there.  My newborn daughter and I were up at 0300 to watch the launch on NASA TV, and again I wept. This time happy to see our spacecraft finally on their way during a flawless launch.

Five years later, the two spacecraft are still going strong and providing truly unique perspectives and data on the working of the Earth’s trapped radiation belts, the ring current, and space weather in general.  We’re still the Science Operations Center for RBSPICE, and we’re still finding out new things about our near-Earth space environment.  It’s been a great five years, and here’s hoping for at least a couple more.

You can learn more about the Van Allen Probes mission and the RBSPICE instrument by following the links below:

http://vanallenprobes.jhuapl.edu/

http://rbspice.ftecs.com/

You can see my gallery of photos from our time down at the Kennedy Space Center and Cocoa Beach here:

https://www.flickr.com/photos/xorpheous/albums/72157631262396530

AGU14 – Day 1

If you jump in muddy puddles, you must wear your boots. Yeah, well, I don’t have boots. What I do have are two pairs of completely soaked socks, a pair of shoes that might dry out by March, and two very cold and tired feet! …I need wellies, or at least galoshes. It drizzled and rained all day long, which made getting from one building of the Moscone Center to another a bit of a miserable experience. Inside the sessions was quite a different matter, though.

There were several good talks about the behaviour of the magnetosphere and observations by the Van Allen Probes, but today the two most interesting talks I attended were about Mars. The first was about ancient lakes and outflows on the eastern portion of Valles Marineris. The presenter showed evidence on how the outflow from Eros Chaos was directed with estimations on the approximate time the area was drained based on the cratering density on the surface. By this time, it’s no surprise that there was abundant liquid water on the surface of Mars in the distant past, but it’s fun to see people starting to evaluate how that surface water flowed across the surface and how long it would have been present.

The other Mars talk I attended had the clickbait-style title, “How to snowboard on Mars”. What the talk was really about was providing an explanation of how numerous small gullies form on the sandy slopes of some ridge lines on Mars. At first glance, these gullies look remarkably like snowboard tracks. So… Aliens? No, dry ice. As the ice sublimates, the freshly formed vapour lifts the slab of ice off the surface slightly and serves as a lubricant allowing the slab to slide down the slope with enough energy to gouge out a furrow in the sandy surface. This phenomenon has been replicated with dry ice in the Mojave Desert. See the article on NASA’s website for more details.

AGU14 – Day 0

So yeah, this old FORTRAN guy is using a zero-index reference like those snooty C guys. The American Geophysical Union 2014 Fall meeting (AGU14) doesn’t officially start until tomorrow, but registration is open today and there are a couple of mission-specific meetings. The one I’m responsible for attending and engaging in meaningful participation is the Voyager SSG. Five hours of exploring the future direction of our greatest and most productive robotic mission ever. BRING IT!

In the meantime, I continue to work on bringing the Advanced Composition Explorer’s (ACE) Electron Proton Alpha Monitor (EPAM) data production fully up to date. The basic Level 2 rate data are ready for consumption, but more refined Level 3 fluxes and energy spectra are still on their way. Thankfully, the hotel wifi doesn’t block VPN connections. At least I got the pretty pictures (aka color spectrogram plots) up for viewing.

ACE/EPAM PHA-derived hourly-integrated species-resolved fluxes for 2014

I’ll update this post throughout the day. …more to come!

Evening Update
What a cool day! Five hours of listening to space science lectures doesn’t get most people excited, but wow, there were some very cool things discussed! How much turbulence is there in the Local Interstellar Medium, or even along the heliopause? Is our heliosphere’s tail bifurcated? There were some neck-level questions being asked about the outer reaches of our solar system, and all this leads into the preparation for the 2015 Senior Review. The Voyagers have plenty of hydrazine to last a long time, provided we can keep it from freezing, but the mission-limiting factor is power and money. The power issue centers on the 18 W needed to power the gyros during a fault protection event. The money issue is up to the Senior Review board, but it looks like the Voyager team has a lot of seriously important work ahead of them exploring a region of space that we’ve never seen before, and likely won’t visit again in our lifetimes.

GDC 2013 – Of Swag, HTML5, and Quaterions

Thursday started all light and fluffy, after my steak and eggs at Mel’s and my Asteroids fix. I’m still irked that Prof. Fleming bested my score on Asteroids. I have to correct that. The first session of the day was a postmortem, Class Game Postmortem – X-COM: UFO Defense, by Julian Gollop, now of Gollop Games, but originally with his brother, Nick, at Mythos Games. Postmortems are usually rather dry, but Julian did a good job not only of describing what went well and what went poorly with the development and design process, but he also gave a great summary of the history of the title, it’s evolution over time, and its present state. Very neat. GDC-2013_03-26-13_012 It seems that the Game Development industry is beginning to realize that it needs to embrace and preserve its history before it starts to slip away from them. Space science found itself in this same situation not too long ago, except we waited way too long and nearly lost the Pioneer data to the mists of time, and other datasets were lost. Thankfully, there appears to be a pretty strong movement with in GameDev to preserve its history, its stories, it’s vintage hardware, and its classic games and software. Good game play never gets old, which is quite evident by the line that always forms around the Asteroids and Mortal Combat games.

The big new take-away for me for the week, outside of the mathematics and physics insights mentioned in previous posts, is the growing utility of HTML5 as a gaming platform. There are an increasing number of utilities to assist game development for HTML5 including the wonderful little 2D physics engine Box2D. Those of you in the GameDev program at JCCC will be happy to know that Unity and GameMaker have HTML5 exporters! There are a number of games already on the next using this tech, including the Mars Curiosity games and interactives I mentioned in yesterday’s post.

CrowdedExpoHall_smIn between sessions, I did manage to cruise through the Expo Hall again. The crowds on the floor this year are insane! I still didn’t find anything super awesome, but there are a number of interesting tidbits. LED flashlights seem to be the thing this year, so I got a small red LED light for the observatory and a few white light ones. There were more decks of playing cards being offered. How can I refuse playing cards? I can’t, nor can I refuse poker chips of which there were several styles as well. I’ll continue to look for more today.

I did manage to squeeze in another physics-related session in the afternoon, and yes, there was more talk about collision detection and resolution, optimizing AABB broad-phase checks, and ways to mitigate tunneling and other undesirable effects resulting from high angular velocities. The solution was staggeringly simple, clamp the angular velocity to a maximum value. Of course, this grates on my sensibilities with my background in computational physics since it results in a non-physical limitation to the simulation, but it’s a great solution for game physics. The talk, GPU Rigid Body Simulation, by Erwin Coumans of Bullet Physics (yes, it’s free), also gave me more insight to the usefulness of quaterions. Not only are quaterions useful for affecting rotations, but it’s also useful for representing rotational position in a far more compact way. I feel a major rewrite of the PHYS 191 course coming.

The day ended with a great meal with some great folk. A few of the folks I’ve met through IndyCar and Twitter live here in San Francisco, so we got together last night to share great food and great conversation. Two members of our quartet had spent a couple weeks down in Florida to see the 12 Hours of Sebring, an Atlas V rocket launch, and the IZOD IndyCar Series season-opener at St. Petersburg, so they had plenty of stories to share. It was a wonderful evening of rocket ships and race cars. Seriously, does it get any better?? No. No it doesn’t.

GDC 2013 – NASA Saves The Day

It’s Expo Hall Day! YAY SWAG! Ok, I guess I didn’t have much time to gather too much swag today. Odd given that I only went to a couple of sessions, one of which was a let-down. After breakfast, we headed back over to the Video Game History Museum and got our old-school game fix on. I played better today than I did yesterday and set the high score on Asteroids, although I’m sure it didn’t survive the morning. Russ Hanna kicked my butt at Centipede and Richard Fleming bested me at the driving game Turbo. ARG! How do I lose to Fleming at a driving game??? Trip wire to activate the coin switch on the back side of a coin-op arcade game. If there were dragons in the game, sure I could see it, but driving? …ugh. I suck. I bit of geek pride was that I had to show the others how to trip the microswitch on the back of the coin acceptor to register credits instead of actually having to put a quarter in the slot. Seriously, did you guys not grow up in the 80s? How do you not know how to do this?

In past years, the first event on Wednesday was a keynote address by a legend in the game industry such as Shiguri Miyamoto or Hideo Kojima. Last year, they opted for a different format in which select presenters are given a brief amount of time to pitch their talks. It’s an interesting format, and it did get me to check out some sessions that I wouldn’t have otherwise, but on the whole, it was an hour of pointless idleness. This year I chose to be idle somewhere else, like the upstairs in the museum playing Asteroids. The Expo Hall opened at 10am, and we started in our systematic way, start at one end and leave no area unexplored. I didn’t spend a whole lot of time in the expo hall, only an hour, but I did need a supplementary bag! Going back for more today. The t-shirt count is up to seven, and sure to climb by the end of the conference on Friday. I haven’t run across anything especially interesting yet, mainly just the standard pens, pads, and other such trinkets.

The first session I attended after our lunch break was a talk on the lessons learned about the role of code, data, and tools during the development of Assassin’s Creed III – Homestead. While I thought that would be interesting, it really wasn’t. The presenter spent more time on fancifying his slides rather than crafting an intelligently organized presentation. JeffNorris Oh, well. The next session, and last of the day, was by Jeff Norris and Victor Luo from the Jet Propulsion Laboratory with the cheesy title, “We Are The Space Invaders”. I had fully expected the talk to simply be “We have 3D models of spacecraft, and you should use them in your game.” This has been NASA’s standard MO in the past, but this talk was amazing. Jeff and Victor demonstrated how NASA was using the Unity game engine to create interactive tools and games for the public, including a downloadable game for the XBox 360, and it actually looked good! Unfortunately, I don’t have a 360 so I can’t check it out, but if you do, search for Mars Curiosity. There should be a Kinetic game that you can download for FREE. Cool. The other point they made was that the game industry understands user interfaces and controls to a much greater extent that many rocket scientists. (duh) Given that, they’ve been working on ways to utilize more game-like controls into their spacecraft and rover control systems. One impressive demonstration was a video showing a group of 5th grade kids playing a motion recognition game on the Xbox, then taking those skills they learned in less than a minute in a game and using them to control a $5M robonaut. Mind you, they didn’t control a simulation of the robot, they were in actual control of the real multi-million dollar piece of hardware after 45 seconds of training, and they were controlling it with skill and dexterity! NASA took those lessons and started applying them to other less humanoid applications. The next demonstration they showed was super impressive. Using motion-capture technology on an operator’s hand, they are able to expertly control the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE). Best of all, they did the demonstration, not with an animation, but remotely with the actual two-story tall robot! Jeff Norris applied the controls live during the GDC talk and those commands were sent to and obeyed by the ATHLETE robot at JPL. It was brilliant!!

TimeForAPint_smThe last GDC event of the day was the Awards Show. This comes in two parts, the Independent Games Festival and the Game Developer’s Choice Awards. It’s always a good time and it’s neat to see what new things people are exploring in games. Two games that I plan on checking out when I get back are FTL: Faster Than Light, and the Game of the Year Journey. Journey is visually interesting, but I’m not clear as to why it was so much better than every other game. I guess I’ll have to play it to find out. Well, that’s it for a long day. Guess it’s time for a pint!