Radiation Belt Storm Probe
- Nicky Fox
- Jim Stratton
The Radiation Belt Storm Probes (RBSP) Mission represents NASA's most comprehensive look at the Earth's Radiation Belt to date. Using identical probes in slightly different orbits, the RBSP Mission will give scientists an unprecedented look into the complex and hostile environment of our Radiation Belt. Most space craft turn off their instruments while passing through the Radiation Belt, but RSBP A & B will operate inside the "Belt" 24-7 throughout the life of the mission. After talking about the mission with experts Nicky Fox and Jim Stratton, it is clear that NASA EDGE could learn from the mission at large. NASA EDGE uses non-identical hosts operating in extremely different orbits for the vodcast! Maybe we should compare data.
CHRIS: Welcome to NASA EDGE.
BLAIR: An inside and outside look at all things NASA.
CHRIS: We’re at the Johns Hopkins University…
BLAIR: …Applied Physics Laboratory in Laurel, Maryland.
CHRIS: Getting a sneak peak behind the…
BLAIR: Radiation Belt Storm Probe mission.
CHRIS: Very good.
BLAIR: Or unofficially, Magnetospherence I & II.
CHRIS: You’re looking pretty tall today.
BLAIR: Well, it is a new year and as you know I vowed to be taller this year.
BLAIR: For 2011, I’m doing all my interviews sitting down because I’ve noticed you can’t tell how much taller the other person is when we’re sitting down. So, I figured instead of feeling inferior all the time interviewing all these people that are over 5 ft. 4 ½, I’d sit them down and then we’re on an equal playing field.
BLAIR: Or, when I can, use platforms or chairs. When I interview Nicky Fox, I will be using chairs. It will be fun.
CHRIS: Why are you dressed up in the clean room garb?
BLAIR: Chris, as you know, with hard work and diligence you have unique opportunities. And I did the legwork to get into the clean room.
CHRIS: This is pretty tight security here. How did you get permission to do that?
BLAIR: You’ve got to know the right people. You’ve got to fill out the right forms and do the hard work to get into the unique places.
CHRIS: I tell you what, you go interview Nicky Fox in the clean room and I’ll talk with Jim Stratton, who is the Mission Systems Engineer.
BLAIR: And I’ll see you on the other side.
BLAIR: Outside of the clean room.
CHRIS: All right.
BLAIR: Nicky, I’m a little concerned. I’ve noticed that you’re in your street clothes and I’m afraid you might be jeopardizing the integrity of this incredible mission. What gives?
NICKY: Well Blair, if we were actually in the clean room on the other side of this window then you would need to be dressed like that but we only let people who know what they’re doing on that side. You can just relax. You don’t need to be wearing all that stuff.
BLAIR: No, I knew that but this is more of a fashion statement. I’m sorry. I thought you’d make a similar one but we’ll just go with it as is.
BLAIR: We’re talking about a very important mission, and I wanted to talk about the unofficial name, if you don’t mind. I like to call the two satellites the Magnetospherence I & Magnetospherence II. Have you thought about changing the name for us?
NICKY: No. Actually, we like Radiation Belt Storm Probe, RBSP, and we love it.
BLAIR: Great. Why don’t you tell us; everything I’ve read about this mission says you’re taking these probes and you’re dropping them in a hostile environment of the radiation belts. Why is this necessary to understand space weather?
NICKY: As you say, we are putting them in the worse possible environment around the earth. We’re putting them in the region of space that most spacecraft try to avoid. The reason that we’re doing that is we need to really understand these regions so that when other spacecrafts do have to go through them, we can protect them better. Most instruments actually turn off when they go through the radiation belts. We have to be taking data. So, we have to build these really, really, well protected, well shielded spacecraft. That has a lot of impacts for space weather, as you say. The radiation belts are part of our infrastructure. We live and we work in them. And we have to understand them so we can better predict their effect on the earth.
JIM: We mostly have a tank around it to protect them. We have the luxury on RBSP that we have extra mass basically. The launch vehicle that we’re flying on, the Atlas 5, has more capability than we need for the spacecraft that we built. So, we’re able to put some very large heavy boxes on there to protect us from a lot of that radiation. We have filters on the inputs to all of our electronic circuits so if radiation comes through a wire and changes from a zero to a one, for example, our electronics are smart enough to ignore that.
NICKY: The data we will be bringing back will be telling us how these radiation belts change in response to everything that comes from the sun. The sun sends energy our way. We absorb it and our planet responds. So, the radiation belts can pump up and become very big and very hostile. They can go very small and become quiet. The same processes that cause those radiation belt changes are powering the aurora that you see overhead, that can cause issues with power grids and various other things here on earth; problems with GPS.
BLAIR: With Magnetospherence I & II, what kind of instruments are you going to place on those?
NICKY: Well, RBSP A & B are identical spacecraft and they have identical payloads of instruments. We have a full suite of particle instruments. We’re going to be taking measurements from very, very low energy plasmas right up to the incredibly high giga electron volt protons that you see mostly in the inner belt. In addition to that we have a full field of waves suite. We’re going to be looking at magnetic fields, electric fields, and all the waves that are associated with those. You can do very different science when the spacecraft are close together then when they’re further apart. For example, if you have one spacecraft going through an event, you can’t tell much about it if you don’t come back for another nine hours. You don’t know weather it is changing in time, or whether it’s getting bigger or how it’s really changing. The 2nd spacecraft coming through fairly quickly afterwards can tell you about the evolution of these events. When they’re actually far apart, you do sort of a cause and effect. What happens here and then how does it cause something to happen further in? We’ll be doing a full range of science as the separation of the two spacecraft changes. The reason you want identical; you don’t want a mother/daughter, you do want identical twins is that you really want to be using the same instruments to make sure you are studying the science and not seeing something that’s changed because you’re using a different instrument to sense it.
CHRIS: What are some of the major tests that you have to undergo to actually rate this spacecraft as space ready.
JIM: It starts at the component level really, the piece/part level. We build up the boxes. As the boxes go through their integration, we do a lot of electronic testing on the electronic boxes to make sure they’re functionally working the way they should. Then we do a lot of testing over temperature, so the absolute hottest and absolute coldest that the spacecraft will ever see and the boxes will ever see. We make sure everything works at those temperature extremes. We need to go through vibration testing on all those. But we also do a lot of functional testing, for example, when we’re trying to control the spacecraft with thrusters, that when we command this set of thrusters to come on that’s the right set of thrusters that come on.
JIM: And when the spacecraft is sensing where it is, it’s sensing where the sun is that it actually knows that up is up and down is down.
JIM: Phasing and alignment tests are a big part of it as well.
BLAIR: You talked about them being at different distances during the mission. How does that work?
NICKY: They actually trail one another. We will launch them, and the apogees or the furthest point away from the earth that they will see are slightly different. One is just a little bit closer to the earth than the other. That means that one will orbit faster. So, they will start off close together then this one will gradually drift away, then it will catch up and then go around again.
BLAIR: So you actually by plan are getting those different distances.
NICKY: Yes, it’s carefully planned to do that. In a perfect world, we would see a fabulous storm everyday. But, you know obviously that’s not going to happen. So, we try to design the mission to move around with enough quickness that we can be in all places to see storms but also not so quickly that you’re missing things in certain target regions.
BLAIR: I think this is absolutely a key mission in not only all the science you’re going to get but also in promoting magnetospherence use among the scientific community. I really think you need to consider the new names, or at least unofficially.
NICKY: I will certainly consider it, Blair. I promise.
BLAIR: Great. Awesome. You’re watching NASA EDGE, an inside and outside look at all things NASA.
NICKY: And before we go, can I have a pound of sliced turkey?
BLAIR: I don’t think I’m qualified to operate the slicer. I can hand it out but I can’t cut it.
Page Editor: Blair Allen