Week Ending September 16, 2000
One of the big issues we're dealing with right now is filters for all the rovers' cameras. For Pancam, we're pretty
much set. Pancam has a filter wheel for each camera, which means that each time we take a Pancam picture we can
choose from among eight filters. The filter sets in the wheels are mostly different for each camera, and with two
Pancams we get a total of fourteen different filters. That's a lot. We picked a bunch of good filters for Pancam
a couple of years ago, and we're going to pretty much stay with them. None of the other cameras have filter wheels,
though, so for each of them we have to pick one filter and stick with it. There are actually ten cameras on each
rover: Two Pancams, two navigation cameras, four "hazard avoidance" cameras (two in the front and two in the back,
to watch out for obstacles), the Microscopic Imager, and a sun camera for navigation. We've got about one more week
to pick the filters for all of them, so we'll be doing a lot of work over the next several days to investigate
different possible filter choices and, we hope, to pick the best ones.
Week Ending September 10, 2000
We're in the part of the project where dozens of important design decisions are made every week. The biggest
decision of this past week is that we're probably going to build new Pancams for the 2003 mission, rather than using
the ones that we already built for 2001. The 2001 cameras are great, but they require a fair amount of electrical
power to keep them warm at night. We're going to be building a whole lot of new cameras that don't require heat
anyway -- cameras for navigation, and for detecting hazards. And as long as we're building so many, it doesn't take
much additional effort to replace the Pancams we have now with new ones that'll work just as well (or even better).
In the process we save electrical power, which will mean the mission will last longer. But it feels just a little
sad to put aside those cameras that we worked so hard on for 2001.
Week Ending September 3, 2000
Our main focus this past week has been on the two newest pieces of our payload: The Microscopic Imager and the RAT
(a.k.a. the Rock Abrasion Tool). The biggest issue lately has been figuring out how to make them work together. The
RAT will grind away a circular area of rock, and then we'll use the Microscopic Imager to look at it and see what's
inside the rock. The RAT needs to be able grind away an area as big as the MI's field of view. The bigger this is
the more we'll see, but if it's too big, the RAT has to be pretty big and heavy to get the job done. After
considering everything together, we came out with a RAT that grinds an area 47 millimeters in diameter, and a camera
field of view that's 42 millimeters across its diagonal -- giving us 5 millimeters of wiggle room in case we can't
position the camera as accurately as we'd like. Just one of the hundreds of design decisions we've got to make before
we're ready to start building more hardware.
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Week Ending August 27, 2000
This is an incredibly hectic time... which is why it has been two weeks since we've even been able to summarize here
what's been going on! We're at the beginning phases of this project now, dealing with what seems like a million details
of rover and mission design. The big event coming up in a couple of months is the mission's Preliminary Design Review,
or PDR. (We love acronyms in this business.) The PDR is where we have to show that we don't have any show-stoppers in
front of us... that there's a clear path from where we are to having a detailed design that will really work. So the
big jobs now, before the PDR, are figuring out exactly what the whole rover and payload have to do, and then making
the design decisions that will make it possible. Probably the biggest decision of the past two weeks was that we've
decided to focus the Microscopic Imager just by moving the rover's arm, rather than putting a complicated little
focusing mechanism into the camera. But that's just one decision among very many. We have a long, long way to go...
Week Ending August 13, 2000
Another wild week. On Thursday, NASA announced that they plan to send not one but two rovers to Mars in 2003, both
carrying identical copies of the Athena payload. This is great for the science, since it means we'll be able to land
the rovers in two very different places, doubling the science without doubling the cost.
In the near term, though, it means we have a lot more work to do! We thought we were done building some of our
toughest instruments. Not so. Now we have to get started on another Mini-TES, another Pancam, another Mössbauer,
and so forth. The experience we gained building the first set should help immensely, and we're hoping to avoid some
of the little "adventures" we had the first time around. But it's going to be a long haul.
Week Ending August 6, 2000
It's hard to imagine news that could be much better than what we've heard in the past week. We're back in business
again. After six months of uncertainty about our fate, NASA has now decided to fly the Athena payload to Mars on a
big, capable rover. We launch in the summer of 2003, and we land in January of 2004. See last week's press release
for more details. So now we're back to work. Several of the instruments we built for the cancelled '01 lander should
be ready for this rover: Pancam, Mini-TES, and the Mössbauer are all good to go. But we need to do a new APXS, we
have to work out the design details for the our Microscopic Imager, and we have to essentially invent the Rock
Abrasion Tool (a.k.a. the RAT) from scratch. And there's more. Not only has NASA decided to fly us, but they may
decide to fly two copies of everything... on two rovers! If that happens, the rovers will both be launched in '03,
and they'll land on Mars within a few weeks of one another. And, obviously, if that happens we'll have to build more
copies of everything. At least we shouldn't have to wait long for this decision... it may come within the next few
days. Stay tuned.
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No mission updates for the month of July, 2000.
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