The Mars Surveyor Orbiter scheduled for 2001 is still expected to be launched next year, and will carry a gamma-ray spectrometer to map Mars' surface composition and look for ground ice. In addition a spectral IR camera is included on this orbitor to map minerals at very high resolutions and look for good landing sites for the sample return missions.

But McCleese flatly states that -- contrary to a recent report by "NASA Watch" -- there are no plans to build and launch a second orbiter at that same window.

He also tags as "unlikely" another report which has been making the rounds: that the Mars Surveyor lander originally set to be launched in 2001 might be re-equipped with the Mars Polar Lander's science instruments and launched on an unusual June 2002 launch window to repeat the Polar Lander's mission in early 2003.

This mission would require not only that the lander be very rapidly refitted with the changes necessary to improve its chances of a successful landing, but it would have to reach Mars by way of a gravity-assist flyby of Venus -- requiring that its temperature control systems be extensively modified.

Also, the 2001 lander is designed to land in the Martian near-equatorial regions, and would have to undergo further changes to allow it to survive the colder Martian polar regions.

It's much more likely -- though not certain -- that the 2001 Lander will be launched in 2003, probably to one of the two landing site candidates already picked for it. (see Mars 2001 Landing Sites Reduced To Two)

One of these is the mountainous highlands south of the Isidis Basin, and the other is the huge patch of hematite -- probably deposited by an ancient Martian lake -- discovered in the Sinus Meridiani region by the Mars Global Surveyor.

But it too will have to be extensively modified, even apart from the specific changes made to deal with the possible MPL failure causes identified by the Failure Review Board.

One of these -- which JPL now regards as absolute -- is the need for the spacecraft to transmit live engineering telemetry during its landing, so that the cause of any new failure can be precisely identified.

The craft may transmit this data directly to Earth, or send it to one of the Mars-orbiting spacecraft already planned to receive data from the Lander and relay it to Earth -- including the 2001 Orbiter, and the European "Mars Express" orbiter also scheduled for launch in 2003.

Indeed, the redesigned lander may do both at once.

Another, stranger possibility which is still being considered is to instead equip the lander with a "black box" package capable of surviving a high-speed crash onto Mars, and then later relaying back the data which it recorded during the landing attempt.

Such a package, however, would likely have to be significantly heavy in order to survive such a shock.

But the new communications equipment will add weight to the lander in any case -- especially since the lander will also have to have a new X-band radio link and dish antenna added to allow it to communicate scientific data directly to Earth after landing, in the event that all the relay orbiters fail.

This direct link was carried on the Polar Lander, but not on the 2001 Lander, since -- before the failure of the Mars Climate Orbiter -- it was thought that by then there would be two or three working Mars orbiter spacecraft capable of relaying the lander's data to Earth. Now we can only hope for one or two.

According to a JPL source all this new communications gear, by itself, "may add 30 kg to the craft's weight." And that "other changes will also be necessary."