Mission Loss: Martian Chronicles II
Martian Chronicles II:
Three spacecrafts are now hurtling toward the Red Planet to look for evidence that it might once have been wet enough to sustain life. Orbital projections of where Europe’s Mars Express and the two NASA Mars Exploration Rovers (MER) are right now, can be continuously monitored over their half-year journeys. Experiments performed by the MERs will help to determine whether water might have once existed in volume on the red planet. The two Mars Exploration Rovers are targeting what imagery indicates might have been ancient dry lake beds and other geologically interesting sites in early 2004.
The Martian Chronicles series gives an inside view of what it takes for scientists to deliver a complex mars mission. The journal entries are from Cornell’s Steve Squyres, the Principal Investigator for the Mars Exploration Rovers’ scientific package called Athena. The chronicles begin sequentially from the beginning of July 1999, four years before launch, and will culminate in the dramatic landing of the twin rovers on Mars in January 2004. The expected mission time roaming the red planet is ninety days, from January to April.
The chronicles include an insider’s view of hardware tests and site selection to problem solving and science planning on the surface of Mars.
November 5, 1999
We had a tough week. After getting all the Pancam problems we knew about straightened out, we put the cameras back in the test chamber. Problem is, as soon as we cooled them down to martian temperatures (it was the first time we’d done this with the flight cameras), they both acted up, and in fact one of them stopped taking pictures altogether.
|Clamshell pod for MER shown in Kennedy storage.|
When they were warmed back up the bad one started working again, so we’re hoping it isn’t too serious. The whole thing reminded us of the problems we had with Mini-TES when we first took it to low temperatures back in August. We solved that one, and we’ll solve this one too… it’s all part of the game. In fact, within the last 24 hours, we may have found the problem. And if we’re right, it could be just a simple software fix to get everything working again. We’ll see…
November 19, 1999
Things have been crazy. The big news is that we’ve found and fixed the problems with Pancam. This wasn’t easy! It turns out that there were two separate problems. One was pretty simple to fix. The way our software was written, we’d try to take a picture very quickly after the camera was turned on. The electronics didn’t like this, and it was simple to put in a little delay that fixed that problem. The other problem, though, was much tougher to track down, and it took us more than a week to find it. The Pancam electronics team at JPL, with Enrique Villegas leading the way, nailed it after a lot of work, and we’re now back in business. Calibration starts again soon… but first we’re going to let the team rest up over the Thanksgiving weekend!
November 26, 1999
Pancam is fixed. What a relief! Everything now works just the way it’s supposed to, all the way down to the coldest temperatures we’ll see on Mars. On Monday of this week we’ll put the cameras back in the test chamber, fire them up, and start a week-long effort to complete all the tests we need to perform before flight.
The other big news this week is that half of the Mössbauer spectrometer has been delivered to JPL. Bodo Bernhardt brought the electronics board over from Germany at mid-week. This is the part that sits inside the lander; the sensor head, which is the part that’s out on the Robotic Arm, should arrive late next month.
The week ahead is a very big one, with the landing of Mars Polar Lander on Friday. The Mars ’01 lander is a lot like this one, so we’re going to be watching closely… holding our breath.
December 4, 1999
There’s been plenty of APEX and Athena progress this week, but the real news is about the Mars Polar Lander. As of this writing, our MPL friends still haven’t heard from their spacecraft. It’s a complicated machine, and there’s still a good chance that it’s up there, safe and sound, and waiting to phone home. All we can do now is wait and hope, and wish our friends the best of luck.
December 11, 1999
It has been a very, very bad week. All signs now suggest that the Mars Polar Lander has failed. This is terrible news for the Mars program, since MPL was going to be a great mission. It also looks like bad news for APEX. The Mars ’01 lander has nearly the same design as MPL. And at this point, we know that the MPL design failed, but we don’t know why. In the space business, when a vehicle has a problem you don’t understand, you ground it until you figure out what went wrong and you fix it. So for now, at least, the ’01 lander is grounded, and APEX is grounded with it.
December 18, 1999
|The Pancam CCD housing assembly. Here the Pancam CCD itself is covered by a protective piece of orange Kapton tape.|
This week was devoted to odds and ends as we get ready to wrap up for the holiday break. There’s been plenty of progress on all the APEX instruments: The motors and gearboxes for Pancam and Mini-TES are now all done, we’ve just finished some new "baffles" to keep light from scattering around too much inside the Pancam cameras, and the Marie Curie rover team is starting to build the covers that’ll protect theAPXS instrument from dust. It’s good progress, and all we really can do at this point is just keep going… and see what comes out of NASA’s review of the Mars Polar Lander failure.
January 1, 2000
The last couple of weeks have been pretty quiet due to the holidays. We’re still waiting to see what the new Mars program will look like after the loss of Mars Climate Orbiter and Mars Polar Lander. One piece of really good news is that NASA has appointed a blue-ribbon panel to look at what happened to the missions we just lost, and what to do about the future ones. It’s a very good group, chaired by Tom Young. Tom is a member of the NASA Advisory Council, a former director of Goddard Space Flight Center, and a former executive with the Martin Marietta corporation. He also played a big role in the Viking project back in the ’70′s, so he knows what it takes to be successful in exploring Mars. It’ll be very interesting over the coming weeks to see what kinds of changes this group comes up with.
January 14, 2000
NASA’s efforts to figure out how to restructure the Mars Exploration program continue. We still don’t know what it’s going to look like… only that it’s going to be different from that timeline you see over there to the left!
For now, we’re just focussing on getting the APEX [Athena Precursor Experiment] instruments done, so that they’ll be ready to fly when the opportunity comes. The Pancam mast is all assembled now, and early last week we deployed it for the first time… made it stand up just like we will right after landing. The cameras are finished now too, and we should have them on the mast within the next few weeks.
January 22, 2000
We’re still not sure what’s going to happen with the ’01 mission, but other than that we had a great week. The biggest news of the week is probably that the Mössbauer spectrometer sensor head passed its vibration test, and is now only about a week or so away from delivery. The other big accomplishment was that the Pancam mast has been put together, and we’ve put it through its first motion tests. The tests went beautifully… it was nice to see the hardware in action!
January 28, 2000
It has been an interesting week, to say the least! The APEX news is that we’ve finally wrapped up the testing of the Pancam cameras, and we’re now ready to start putting them on the mast.
|Each "eye" of the Pancam carries a filter wheel that gives Pancam its multispectral imaging capabilities.|
The big Mars news is that it sounds like there’s a slim chance that the Mars Polar Lander team may have heard from their spacecraft! It’s far from certain, but there’s at least a chance that the spacecraft was still alive weeks after it landed. Getting any data back from it looks like a real long shot, but it’d be great just to know it got onto the surface in one piece.
February 4, 2000
The Mössbauer Spectrometer is at JPL, and it works! Goestar Klingelhoefer flew the sensor head in from Germany early in the week, and spent several days getting it hooked up with the electronics. There were some problems at first, and by the middle of the week we were a little bit worried. A phone call to Ralf and Bodo in Mainz cleared things up, though… it was just a software problem that was easy to fix. A few minor changes, and the whole setup was working perfectly. This is a very big milestone for us, since it means that all the APEX instruments are now built and delivered to JPL. We still don’t know if we’re going to launch them next year or not, but we’re on track to do it if the opportunity comes.
February 11, 2000
We had a bit of a slow week for a change. With all the APEX instruments now delivered to JPL, our focus has turned to getting them hooked up together and tested. A lot of this past week was spent on software work. The next big event happens this coming week: our big "electromagnetic interference" (EMI) test. What we do in this test is put all the instruments and radio transmitters onto a mockup of the lander deck, and then operate them individually and together, checking to see that stray electromagnetic signals from one piece of hardware don’t mess up what another piece of hardware is trying to do. We’re hoping to find no unpleasant surprises!
February 18, 2000
We didn’t have a very good week. This was the week that we were planning to do our first big test of all the APEX hardware together. The test is called EMC, for "electromagnetic cleanliness". Basically, it means making sure all of the pieces work together without creating any electrical interference for one another. Problem was, we never really got to do all the testing we had hoped to do. Every piece of APEX hardware had been tested before this week, except for one cable that runs up the outside of the Pancam mast. Well, it turns out that that cable has some real problems with it, and the problems kept us from getting a lot of the testing done. We’ll be able to build a new cable and fix it, but it’s one of those setbacks you can hit at this stage of the game.