. Earth Science News .
MARSDAILY.COM
Deciding Where To Land

Picking a spot in only half the problem. Getting down in one piece is the biggest problem. MSSS image of MPL's proposed descent that never happened
by Bruce Moomaw
 Cameron Park - Sept. 19, 2000
 As outlined in the first two parts of this series, there is now a general consensus among Mars researchers that the U.S. Mars program must be redesigned to emphasize careful scientific reconnaissance of the planet in order to find the best possible sites on (or under) its surface to look for evidence of either fossil or "extant" (present-day) life.

This will need to be undertaken before be dispatch unmanned missions to Mars that try to return samples in order to definitively find that evidence; since such missions will always be expensive and infrequent, and will return only a small amount of Martian material to Earth.

It will also be necessary to test many new technologies that we will need, but do not yet have, to enable effective Mars exploration.

Initially these new technologies include;

  • precise pinpoint landings
  • the ability for soft landers to detect and dodge dangerously rough terrain during their final landing sequence
  • aerocapture of future orbiters into Mars orbit by skimming through its upper atmosphere
  • deep drilling into Mars' surface using only a small amount of electrical power

Additional technologies beyond this include;
  • the ability to retrieve samples from such depths)
  • in-situ propellant production ("ISPP") of takeoff propellants from the Martian atmosphere itself to greatly reduce the cost and weight of sample-return landers,
  • and the ability to clean accumulated dust off solar panels to prolong a vehicle's life on the surface.

    Moreover, all of these -- except ISPP techniques using carbon dioxide -- will also be vital in the exploration of other Solar System worlds.

    Only after we have done most of this can can we start to reasonably think about flying sample return missions.

    But just what should the details of the new U.S. Mars program be?

    NASA is due to announce those details by the end of this year, and maybe by the end of October -- but, at July's Houston conference on "Concepts and Approaches for Mars Exploration", Geoffrey Briggs and Christopher McKay proposed such a program.

    Briggs is the head of the Ames Research Center's Center for Mars Exploration; McKay, also at Ames, has been a leading scientific advocate of biological Mars exploration over the past decade.

    Their proposal drew considerable interest, and it is likely that something close to it will eventually be chosen.

    Their program design does allow considerable flexibility in the precise sequence of future missions, to allow both for failures and for the virtual certainty that Mars will spring even more scientific surprises at us, as it did a few months ago with the discovery of possible recent eruptions of near-surface groundwater.

    A discovery which, according to "Aviation Week", is already having a major impact on the Mars program design, and which certainly led Briggs and McKay to make some changes. But obviously there are also some missions that must be flown before others.

    Generally speaking, Briggs and McKay think that Mars missions should be divided into three groups:

    • site reconnaissance to look for scientifically optimum landing sites,
    • technology test missions,
    • and a series of progressively more advanced Mars science missions not related to site reconnaissance.

    For the 2003 launch window, they definitely preferred the proposed Mars Surveyor Orbiter to the long-range rovers that were finally chosen.

    Their reason was that the orbiter (besides its own science benefits) was the best way to continue detailed mapping of Mars for landing site selection; it would also have carried a very high-resolution camera to greatly extend MGS' surface mapping, a near-IR spectrometer to map the distribution of scientifically important minerals in a wavelength region that MGS and the 2001 Surveyor Orbiter don't cover, and an instrument to repeat the very detailed weather mapping previously planned for the lost Mars Climate Orbiter.

    However, Briggs told TerraDaily that they have no serious objection to the selection of the current rover missions.

  • Continue to Part Two of this Report
    • SPACE.WIRE