Date: June 24, 2011
Title: One Giant Leap For Mission Design
Podcaster: Bob Hirshon
Organization: American Association for the Advancement of Science (AAAS)
Links: www.aaas.org
Description: Science Update host Bob Hirshon speaks with the SciBox team at the Johns Hopkins Applied Physics Laboratory. SciBox is a revolutionary mission planning tool that allows scientists to pack over five times more data gathering activity into a planetary exploration mission, while reducing planning costs. In other words, more science for less money.
Bio: Bob Hirshon is Senior Project Director at the American Association for the Advancement of Science (AAAS) and host of the daily radio show and podcast Science Update. Now in its 24th year, Science Update is heard on over 300 commercial stations nationwide. Hirshon also heads up Kinetic City, including the Peabody Award winning children’s radio drama, McGraw-Hill book series and Codie Award winning website and education program. He oversees the Science NetLinks project for K-12 science teachers, part of the Verizon Foundation Thinkfinity partnership. Hirshon is a Computerworld/ Smithsonian Hero for a New Millennium laureate.
Sponsor: The Education and Outreach team for the MESSENGER mission to planet Mercury. Follow the mission as the spacecraft helps to unlock the secrets of the inner solar system at www.messenger-education.org.
Transcript:
Hirshon:
Welcome to the 365 Days of Astronomy Podcast. I’m Bob Hirshon, host of the AAAS radio show and podcast Science Update.
Everyone has calendars and to-do lists. But imagine having to plan every single thing you’re going to do for the next year, beginning with, say, waking up on July 1st. You might write down “make coffee,” “make breakfast” and “brush teeth.” But of course, each of those actions takes dozens of smaller actions, like “insert coffee filter” and “measure three scoops of coffee into filter.” And even those actions require still smaller actions, like “extend forearm 12 centimeters” and “rotate wrist 27 degrees.” And of course, that’s just for one morning of one day.
This exercise gives you some idea of what mission planners have to do for planetary exploration. A spacecraft’s time near its destination is very short, and scientists want to squeeze in as much data gathering as they can. That means programming every second of the time in minute detail.
Traditionally, this has been the purview of dozens of programmers, each working on a subset of the mission. It occupied many thousands of person hours. And if the mission changed—say, an instrument malfunctioned, or a new opportunity for data gathering arose—well, then it was back to the drawing board.
But now a set of planning tools called SciBox, developed at the Johns Hopkins Applied Physics Laboratory, has streamlined the process. Tek Choo is the Lead Programmer for the project.
Choo:
It’s a software library and the library is specifically tailored for planning science operations, generically for any spacecraft or any instrument. The idea is to help us run a science operations center more efficiently.
Hirshon:
The first mission to use SciBox is the MESSENGER mission to the planet Mercury, which recently went into orbit around the planet and began collecting data with its suite of seven instruments. Choo explains that six of the seven instruments are fixed, so the entire spacecraft must be oriented correctly for them to take a measurement. At the same time, the proximity of the sun means the spacecraft must always keep the instruments in the shadow of its sun-shield. And the orbit is very eccentric. As a result, many spots on the planet can be observed only once or twice in the course of the one year mission.
Choo:
And MESSENGER science objectives are very ambitious; it has a lot of measurement activity that we need to fulfill. So we need to pack a lot of measurement activities in one year. So what SciBox allows us to do is pre-plan all of this and then pack all those schedules very tightly so we can get them done safely.
Hirshon:
In fact, they were able to pack them so tightly that they allowed far more observations than were originally planned.
Choo:
And, for example, the prior, in the proposal before they were thinking about using SciBox, they were thinking about maybe MESSENGER would get about 6000 images, and when we are using SciBox, we are able to squeeze about 80,000 images into the schedule, which is almost 12 or 14 times more images.
Hirshon:
They’re also collecting about 4 million spectra and issuing 250,000 commands to the spacecraft. According to Deputy Lead Developer Joshua Steele, SciBox didn’t merely allow them to calculate and test all these commands before the mission—it also allows them to quickly simulate new plans and see the results in less than two hours. That meant that in March, after Mercury Orbital Insertion, or MOI, the team could modify the plan.
Steele:
And as soon as MOI happened, and we got a new spacecraft ephemeris, which tells us where the spacecraft is, we were able to rerun the simulations and generate new schedules and within a matter of hours and get us ready for a few weeks later when we started taking science operations.
Hirshon:
Choo says SciBox also lets them adjust the mission to accommodate new ideas from the science team, even while the spacecraft is en route. For example, for MESSENGER, the team was interested in changing the spacecraft’s orbit entirely, which would mean creating and testing a whole new set of commands.
Choo:
And so in the past, this would not have been done as close to the orbital insertion because there is a lot of work to be done. But with SciBox we went as far as changing the orbital inclination, orbital period and even experimented with different altitude and orbital maneuver strategy to see which mission design would give us the best science return. And since SciBox can be run so quickly, we essentially get all the evaluation out within just a weekend run, and the scientist can then look at the result and pick the right design. And in fact because of that simulation, we changed the orbital design from 80-degree inclination to 82-degree inclination. And that is what we have now. Past missions would not have done it, because it just too much effort.
Hirshon:
The new orbit will allow them to take a closer look at the planet’s north pole, where they think there could be water ice.
Harri Nair is a programmer for SciBox. He says that in addition to accommodating the demands of the science team, SciBox also allows them to adjust to unexpected circumstances.
Nair:
There are always unforeseen events. Like the dishes that were getting the commands down go out for a couple of days, or there’s a saving event on the spacecraft or something like that. And when that happens, you don’t have 40 people scrambling, coming up with a new plan. You run the software again, and in two hours you’ve got a new set of sequences that optimizes the week ahead. That covers for that loss we just had. And that’s a huge advantage and really makes things a lot more efficient.
Hirshon:
In addition to the mission planning tools, SciBox also includes visualization tools, which Software Developer Lillian Nguyen says were used on the STEREO mission, designed to observe the sun. These tools take raw data and present it in more intuitive ways.
Nguyen:
So rather than seeing like an engineering value or, even worse, hex on the screen, you’ll see something like your car’s display, you know, you’ll see a temperature gauge or, you know, RPM gauge, you’ll see different gauges and dials. And it makes it apparent very quickly what’s going on.
Hirshon:
Programmer Mike Lucks explains that SciBox not only allows scientists to interpret incoming data, but also to generate reports to indicate mission progress.
Lucks:
SciBox has an elaborate set of reporting tools that can provide the scientists and the planners a detailed description of exactly what SciBox has planned. So that, to provide some insight into whether the plan satisfies the scientific objectives. And also to display what, after things have been received, whether what was received is consistent with what was planned and whether it satisfies the objectives. And there are also some graphical interactive tools that facilitate that.
Hirshon:
Josh Steele says that from the start, SciBox was designed to offer a general set of tools, useful for any mission, not just MESSENGER.
Steele:
That sort of underlies the whole software structure: SciBox itself is a more generic library, that we can put custom layers on top of, MESSENGER SciBox being one of them, the STEREO visualizer being another, JMRO being another, so the idea is we had this very well intended, well functioning big library underneath that we can put custom layers on top of that we can rapidly turn around.
Hirshon:
As a result, Choo says that many future missions will rely on SciBox to plan, simulate, adjust and analyze data collection, allowing them to squeeze more science out of every mission.
Choo:
Definitely you can get a lot more out of the spacecraft. You can see that when there are many instruments on the spacecraft, just the sheer amount of effort to coordinate to put all the instrument to co observation, it take a long time, and when you take a long time to iterate, you usually don’t get the most optimum result. And so you don’t get the, using up all the resources. Past missions even downlink empty bits to the ground because they just run out of time, because the schedule is too tight. With SciBox, we are hoping to use every bit that’s available to us and every pointing opportunity.
Hirshon:
Well, that’s all we have for you this time. Thanks for listening. For the 365 Days of Astronomy podcast, I’m Bob Hirshon.
End of podcast:
365 Days of Astronomy
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