Week Ending September 24, 1999
This was a very bad week for Mars exploration. On Thursday, we got the news that the Mars Climate Orbiter
spacecraft had been lost during its orbit insertion maneuver. Apparently the spacecraft was sent too close to the
planet as a result of a navigation error. The friction with the martian atmosphere at that altitude -- only
about 57 kilometers above the surface -- would have been enough to destroy the spacecraft.
This is a setback for the Mars program, though not a crippling blow. One of the reasons that NASA is sending so
many spacecraft to Mars now is that it keeps the loss of any one spacecraft from causing serious damage to the
program. And when you do things as hard as flying missions to Mars, mistakes and accidents will happen. APEX
and Athena should not be impacted by the loss of MCO. But our hearts go out to the MCO Project family... we
know how hard they worked on their spacecraft and their instruments, and we know how deeply they feel this loss.
Week Ending September 17, 1999
We had a wild week, with lots going on. On APEX, the Mössbauer problem from last week was fixed, and we're
making good progress toward assembling the flight versions of both the Mössbauer Spectrometer and the Pancam
cameras. Over in Germany, the flight APXS instrument underwent the final refurbishment of its electronics, and
is now almost completely calibrated. We should ship it to JPL to be put onto the Marie Curie rover in just a few
weeks. On Athena, the big news of the week was the System Requirements Review... the first big formal review of
the Mars Sample Return Project. This is the review where you make sure you've got all your requirements straight
-- in other words, where show that you understand the job that you're supposed to do. It went well, and the next
big one will be the Preliminary Design Review, coming up in December.
Week Ending September 10, 1999
Little troubles here and there this week. The good news is that the engineering model for the APEX Mössbauer
Spectrometer has been delivered to JPL. The bad news is that it isn't working yet... or rather, that it isn't
talking properly to the rest of the APEX electronics. We don't think it's a big problem, mostly because we got
an earlier version of the Mössbauer to work just fine. But it's one of those things that you have to track down
and fix, which ought to keep some of the team busy for the next few days. Meanwhile, we've hit a little bump in
the road with the APXS, too, having to spend a week going in and changing some temperature-correction hardware
and software that we thought was working right months ago. This is the reason that you put margin in your schedule!
The instrument's doing fine overall, though, and we're still on track to deliver it to the Marie Curie rover early
next month.
Week Ending September 3, 1999
The Mars 2001 Project is making progress toward picking a landing site. Back in June, there was a landing site
workshop in Buffalo. Dozens of Mars scientists attended, and something like sixty or so possible sites were
discussed. Lots of these sites would have been good scientifically, but there's also the issue of lander
safety, which is essential. Since the workshop, the Mars Global Surveyor spacecraft (which is orbiting Mars
now) has put a lot of effort into taking high-resolution pictures of prospective sites. Many of them, it
turns out, are too rugged for the lander to be able to land safely. But some of them look pretty good, and it's
now down to a "short list" that MGS will inspect even more carefully over the next few months. The general
landing area needs to be picked by the end of the year. After that, there'll plenty of time to fine-tune the
location of the final site.
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Week Ending August 27, 1999
Lots of hard work this week. It's time to start getting our instruments ready to "talk" to the lander
once it's built... to exchange commands and data in the same way that they will when we get to Mars.
We had worked most of this out over the past several weeks, but there was one interface -- the one that
lets Pancam talk to the spacecraft -- that wasn't working. Several of the APEX electronics and software
hotshots hopped a plane to Denver early this week, and spent a very long day there with the Lockheed
Martin lander team tracking down the problem. They got it, and as of this week all of the APEX interfaces
to the spacecraft are tested and ready to go.
Week Ending August 20, 1999
APEX hardware is starting to come together very quickly now. The most important event of the week (and
one of the most important APEX events to date) was that Mini-TES has now been delivered. The instrument
was shipped from Santa Barbara to JPL, and is ready now to begin integration with the rest of the APEX
flight hardware once it arrives. The Pancam flight cameras are coming together quickly now, too, and
should look like real cameras within another few weeks. And calibration of the APXS instrument continues
in Germany... a months-long process that has been going on round-the-clock since June.
Week Ending August 6, 1999
Sorry about missing last week's report... things have been a little busy lately. Mini-TES has spent the
better part of the last two weeks in continued thermal vacuum testing in Santa Barbara, making sure
we've really chased down all the problems. As of this weekend, it looks like we've finally got it. The
big news of this past week came from the Mössbauer Spectrometer. Uwe and Bodo from Darmstadt brought
the first copy of the Mössbauer electronics to JPL this week, and when we hooked them up to the rest
of the APEX electronics, everything worked! It doesn't always happen that way...
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Week Ending July 23, 1999
This week we did our second big operations test with the FIDO rover. This one was in the "Mars yard":
a gigantic rock-filled sandbox at JPL. In two days of work, we simulated the first 12 martian days (or
"sols") of the Athena Rover's mission. Commanding the rover in the blind, we selected rocks for
investigation, and then drove the rover into the precise positions necessary to sample them. These tests
are crucial to learn how to operate the vehicle once we get to Mars, and they're also a ton of fun!
Week Ending July 16, 1999
We're deep into our test program. Mini-TES is still in the thermal vacuum chamber in Santa Barbara,
and we're working to confirm that the fix we made last week worked. The most important event of this
past week was that the Mössbauer spectrometer design has finally passed its vibration test in
Germany. This was a big deal, because a wire inside the instrument had broken the first couple of
times we tried it. The team in Darmstadt figured out a change that fixed the problem, and now we have
a design that we're confident will be able to withstand the rigors of launch.
Week Ending July 9, 1999
This week starts a new feature on the site: A summary of the major events of the past week. We're into
one of the exciting phases of APEX now, with flight hardware being built and tests underway.
The big event of this past week has been "thermal vac" testing of the Mini-TES flight instrument -- putting
it into a vacuum chamber in Santa Barbara and running it through the kinds of temperatures we'll see on
Mars. We got a little bit of a scare at first... the instrument was performing beautifully at warm
temperatures, but not nearly so well as it got colder. Some troubleshooting tracked the problem down,
though, and it was easily fixed by changing just one part - a resistor - in the electronics. All in all,
an elegant bit of sleuthing by the guys at Raytheon.
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