Several interesting new tidbits I've recently run across about this mission (in addition to the two I mentioned earlier):
(1) All its possible landing areas seem to have a very thin layer of dry soil over the underlying permafrost -- only 4-6 cm thick in most places. This presents problems for one desired science goal: using the MECA and TEGA to analyze chemical gradients with depth in the soil layer -- they may have to settle for only one or at most two scoops of soil before they get to the ice, instead of the hoped-for three.
For this reason, the planners are now placing greater emphasis on analyzing the permafrost itself on this mission -- but that, in turn, presents problems. Permafrost is very hard stuff, and Deborah Bass' blog ( http://phoenix.lpl.arizona.edu/features/we...eborah_bass.php
, Nov. 13 and 21 entries) reports the problems they've been having designing the scoop to properly handle it. The robotic arm by itself, even with the digging tines fastened to its scoop, isn't nearly strong enough to rake up an adequate pile of the stuff without taking days -- during which any shreds of ice it manages to detach will probably sublimate away before enough can be accumulated for the scoop to pick them up. Thus the decision to add the Icy Soil Acquisition Device -- a rotating "ice shredder wheel"-- to the rear of the scoop to both quickly detach shreds and kick them straight into the scoop.
(2) The best description of the reasons for the choice of "Region B" as the overall landing region is at http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1328.pdf
-- which can be summarized by saying that it's scientifically as good as the other two regions, and somewhat safer.
(3) Bass' Aug. 27 entry talks about the measures being taken to keep chemical contamination of the site by the thrusters' hydrazine within acceptable bounds. (Note that the Vikings reported no problems from this.)
(4) The Dec. 8 entry talks about the fact that the lander will be swaying rapidly during its parachute descent, which may somewhat blur the descent images (as it might have on Polar Lander).
(5) Each MECA wet chemistry cell will finish its analysis by dropping two chemical pellets into the water: an acid one to reveal any carbonates, and another to reveal both sulfates and soil oxidants.
(6) Besides the meteorology measurements made by the lidar and temperature and pressure sensors on the MET experiment, and the periodic air analyses done by the mass spectrometer, the "TECP" probe on the arm scoop to measure soil electrical and thermal conductivity (which has a heated prong surrounded by temperature sensors) can double as a hot-wire anemometer, and an air humidity sensor is also built into the TECP. There are also strings dangling from the thin mast carrying the MET temperature sensors to serve as photographable wind sensors, like the windsocks on Pathfinder's mast.
QUOTE (Spacely @ Apr 19 2006, 11:40 PM)
Didn't see this elsewhere on the boards. The AO for Mars Scout '11/'12 went out on Monday.http://www.marstoday.com/news/viewsr.html?pid=20314
Anyone have any info on the types of proposals we can expect?
ARES and MARVEL will be resubmitted, with only minor changes; but I haven't yet been able to find out whether SCIM will be. Bruce Campbell is also resubmitting his Mars Scout SAR orbiter, now christened "Eagle" ( http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2188.pdf
). Ames Research Center is trying to one-up Langley and its ARES with "MATADOR", another Mars airplane that might actually be able to survive its final landing ( http://www.aviationnow.com/avnow/news/chan...ATADOR11174.xml
) Bruce Banerdt is submitting some kind of single lander focusing on geophysics, and somebody else is submitting some kind of Phoenix-like lander with a mini-rover. Finally, besides ARES, the Langley center was planning to submit an atmospheric orbiter ("MARS": http://www.spaceref.com/news/viewsr.html?pid=18893
) -- but the new plans for a big 2013 atmospheric orbiter may upset the chances for both that one and MARVEL.
Update: SCIM will
be resubmitted in 2011 ( http://www.space.com/missionlaunches/06012...e_capsules.html
). I regard it as a major contender, especially given the new delay in the flat-out surface Mars sample return mission.
A Bit more on MATADOR at http://research.hq.nasa.gov/code_s/nra/cur...MT/winners.html
"Lawrence Lemke / Ames Research Center
MATADOR: a Mars Advanced Technology Airplane for Deployment, Operations, and Recovery"
"Current Mars airplane missions typically begin by deploying the aiplane in a nose-down attitude, involve a dive below the cruise altitude in order to establish flight speed and end with an uncontrolled crash into the planet's surface. This proposal is to demonstrate technology which would improve this scenario by allowing controlled deployment of the folded wings at the beginning of flight without a negative altitude excursion and which would allow controlled impact of the aircraft into the planet's surface at the end of flight in a nose-high, low-energy approach which will leave the airframe in a condition to relay on-board data to an overhead spacecraft.
"The technology to accomplish this consists of a delta planform fuselage to contribute intrinsic pitch stability to the folded airplane at high angles of attack and a cold gas reaction control system under control of the autopilot to provide direct thrust vectors, independent of flight speed. This demonstration will be accomplished through a work plan to design, construct, and flight test an unpiloted aerial vehicle, named MATADOR.
"MATADOR is a blended wing-body rocket powered aircraft of 4m wingspan designed for steady-state flight on Mars at 4km above datum at 0.6 Mach and 0.6 Cl. The 3-year work plan calls for 2 high altitude flight test demonstrations of MATADOR to be conducted by carrying the airframe to approximately 30km altitude with a helium balloon and releasing it to begin flight. In addition, the plan calls for a series of ground impact tests in which the incidence angle and velocity and surface slope and roughness parameters will be experimentally investigated to determine their effect on the ability of the airplane to survive and function for the purposes of data communication."