Some such system may very well be added to the smaller Lander if it is launched in 2003. And it is also likely that the craft's landing legs will be made "more robust", so that it could better survive a touchdown on a boulder or slope.

But it will not use the alternative bouncing airbag-shielded "hard-landing" technique used by Mars Pathfinder -- it would be much too hard to modify the Lander for this, and the airbags would add much more weight.

The weight that will be added to the Lander, however, will require some reductions in its science experiment payload - although the 2003 Mars launch opportunity is better than the 2001 one, and will somewhat reduce these cuts.

These cuts are nowhere near decided yet -- it may even, perhaps, be possible for the Lander to retain the little "Marie Curie" minirover, a twin of Mars Pathfinder's "Sojourner", which it was scheduled to carry but which would now definitely have to be removed if the Lander was flown in 2001.

McCleese says that serious consideration is also being given to building and launching a second such Mars Surveyor lander at the 2003 opportunity -- with the two landers between them perhaps being able to carry not only the 2001 Lander's planned instruments, but some of the "in-situ" (on-site) experiments which were recently officially selected to be added to the 2003 Sample Return Lander.

Finally, there is the matter of the "Mars Micromissions" which have recently been added to the program -- little spacecraft, weighing only 200 kg, which will be carried as piggyback payloads on European Ariane 5 commercial launches, and then wait in geosynchronous transfer orbit for up to several months before firing their kick motors to head for Mars when a biannual launch window opens up.

The first of these -- scheduled to depart Earth orbit and head for Mars in 2003 -- is "Marsnet 1", a tiny communications satellite which will be put into an 800-km equatorial orbit around Mars.

The current plan calls for six more such satellites to be launched in pairs at the next launch windows, building up a network around Mars which will greatly increase the amount of data sent back by Mars landers, and will also allow far greater accuracy in navigating both surface landers and the Mars orbiters which will have to rendezvous with and retrieve sample return canisters in Mars orbit.

McCleese told SpaceDaily that consideration is now being given to speeding up the schedule for these by launching two Marsnets in 2003 instead of one.

These Mars Micromission spacecraft can also be used to carry small but useful science payloads to Mars, as orbiters, tiny surface probes -- like the unsuccessful Deep Space-2 penetrator probes which piggybacked on the Polar Lander, or even small balloons or gliders to carry out detailed Martian aerial reconnaissance.

While no decisions have been made, it is also possible that the Mars program may be sped up -- and that some of the early missions might try to recover the scientific data lost by the failure of Mars Climate Orbiter and Mars Polar Lander, but using new miniature scientific instruments.