21 September 2002
Mars Program Facing Collapse
by Bruce Moomaw
spacedaily

Los Angeles - Sept 21, 2002
At last week's meeting of the NASA Advisory Council -- held at the Jet Propulsion Laboratory -- there was a great deal of news about new developments in Mars exploration besides the revelations (already reported in "SpaceDaily") that the two U.S. rovers intended for launch in 2003 are still running into problems that may possibly delay arrival of one or both of them at Mars by as much as four years.

The remainder of the decade's program has run into additional problems -- not linked to the U.S., but to difficulties and likely program cancellations in the Mars projects of three different European nations, two of them partnered with the U.S.. And a whole series of additional factors -- including the massive cost of a Mars sample return mission -- are forcing the U.S. to radically revise its post-2009 Mars program, including the form of the first sample-return mission.

Taking them in order of planned launch date: first, the little "Beagle 2" hard-lander intended to be carried to Mars in 2003 aboard the European Space Agency's Mars Express orbiter has continued to run into serious problems which might force it to be removed from that mission. Beagle 2 is being built on a remarkably low shoe-string budget -- only 62 million U.S. dollars -- by a consortium of universities led by Colin Pillinger of Britain's Open University, with about half its funding from the British government.

Beagle's planned cost has been the source of complaints from the very start by those skeptical that a successful hard-lander -- especially one with such sophisticated surface experiments -- can be built and tested for such a super-low cost. The ESA came reasonably close to eliminating it from the mission during a review last spring -- and there have been some continuing problems since.

ESA's science chief David Southwood confirmed this in a press conference last week, saying that "The prime responsibility for Beagle is with the British government, and I believe that in recent weeks they have had to find more money" -- although he added that the ESA is "doing its utmost to make sure that Beagle will there on the launch pad with [Mars Express]."

At the NASA Advisory Council meeting, JPL's Mars project director Firouz Naderi confirmed an earlier report in "Die Zeit" that one of the main problems has been with Beagle's shock-absorbing airbags. To save mass and money, the little lander -- unlike America's Martian hard landers -- depends only on a parachute and airbags for its landing, rather than carrying a package of solid rockets to fire at the last second and remove a lot of its remaining descent speed. But, since a parachute can only remove a limited amount of descent speed in Mars' faint atmosphere, this means that Beagle will hit at over 100 km/hour -- and so its airbags must be particularly tough and rip-proof.

According to Naderi, some recent tests run of the airbags at JPL itself at ESA's request revealed a serious tendency for them to rupture. However, Southwood has since told SpaceDaily that Beagle's entry and landing subsystem "has since been redesigned to use the airbags as qualified", and that a new parachute design which is part of this has been successfully tested. He expressed confidence that Beagle 2 will indeed be fully completed and successfully tested by the deadline at the end of next January.

If Beagle actually should be cancelled for 2003, it's possible that it could be flown to Mars later, but at the moment there seems to be no other Mars-bound spacecraft in the near future on which it could piggyback. The possibility can't quite be ruled out that none of the three Mars landers planned for the 2003 opportunity will be launched, and that Mars Express (which continues to go smoothly) will be the only spacecraft sent to Mars next year -- but both NASA and the ESA insist that the odds are still very much against such a calamity.

By contrast, the sophisticated Mars Reconnaissance Orbiter ("MRO") which the U.S. plans to launch to Mars in 2005 -- including a super-high powered camera system to photograph 2 percent of Mars' surface with resolutions as small as 25 cm -- is going smoothly in its early development, and has recently undergone a successful Project Design Review. There is, however, a problem with the only one of its science instruments to be provided by a foreign country: the "SHARAD" subsurface radar sounder to be provided by Italy's "ASI" space agency.

The new government of Silvio Berlusconi has shifted Italy's emphasis from deep space science to Earth-oriented science satellites, with several consequences. For one thing, ASI will decide in the next few weeks whether it will provide copies of the two IR spectrometers ("VIRTIS" and "PFS") that are the crucial core of the science payload that would be carried by the ESA's proposed 2005 "Venus Express" orbiter.

Upon this decision rests the question of whether this mission -- a unique opportunity to do very detailed studies of Venus' atmosphere for only one-third of the usual cost of such a mission, using a near duplicate of Mars Express -- can be flown by ESA. If the mission is delayed until the next Venus launch opportunity in 2007, its cost will rise so much, due to the difficulty of keeping the various Mars Express equipment sources on line, that it will probably be cancelled.

Another consequence is that the ASI is now uncertain whether it will provide the SHARAD sounder which it had promised to MRO, which would follow up the "MARSIS" radar sounder on Mars Express with a shallower-depth but much higher resolution search for permafrost layers and pocket of liquid water up to 300 meters below Mars' surface.

Naderi told this reporter that ASI still says that it is highly probable that SHARAD will be provided; but the final decision, again, won't come until the end of September. If SHARAD is cancelled, there probably isn't time to provide any substitute instrument for MRO. (This, however, would still leave most of MRO's science payload intact.) But, as we'll see, this is actually the least important likely Mars-related cancellation by Italy.

The planned 2007 U.S. mission to Mars -- the first "Mars Scout" mission, selected (like the Discovery Program missions to other Solar System targets) from low-cost competitive proposals by various university and corporate teams -- continues to go well. 20 plausible proposals were submitted by the early August deadline, many of them very promising-looking.

Three or four finalists are to be announced on Dec. 4 for more detailed government-funded study, with the final choice to be made next August. The finalists include a wide variety of orbiters and landers, including several missions that would use the 2001 Mars Surveyor soft lander that was built but never launched.

Italy Set To Abandon Mars Program

There is nothing smart about our failure to develop a coherent yet flexible long-term plan for exploring Mars in the decades ahead

Meanwhile, the other two 2007 Mars missions -- to be flown by France and Italy in direct junior-partner connection with NASA's Mars program -- are also in very serious trouble.

Italy had promised to cooperate with the US in building "Marconi", a spacecraft to be put into a high-altitude, moderately elliptical orbit to serve as the first Mars comsat, receiving data from the various landers all over the Martian surface and relaying it back to Earth much more continuously and at much higher speed than could be done by the landers themselves or by the data relay packages on the other science-oriented Mars orbiters.

It was also considered possible that a modified copy of Marconi could be flown to Mars in 2009 as a major U.S.-Italian Mars science orbiter, probably utilizing synthetic-aperture radar to prove meters beneath the global blanket of wind-blown dust that hides so many of Mars' detailed ancient surface features from visual cameras. (These may include ancient watercourses or lakebeds.) But the ASI now says that -- while the final decision won't come until October or November -- it is very likely that the Marconi project will be cancelled completely.

This presents a serious problem for America's ability to relay back large amounts of data from its planned landers -- especially the sophisticated "Smart Lander" it plans for 2009, which would release a large, nuclear-powered "Science Mobile Laboratory" to crawl for over 20 kilometers across the surface for the next three years carrying out the most detailed scientific study of Mars yet.

The projected data return from the SML rover will be huge. (Indeed, the new surface-composition instruments it will need -- especially those looking for biochemical evidence of ancient life -- are so sophisticated that NASA now considers it necessary to initiate unusually early studies of instrument design by the scientific community, and maybe release of the official "Announcement of Opportunity" for MSL instrument proposals a year or two earlier than this is usually done for NASA scientific missions.) Also, MSL's controllers badly need to stay in constant touch with it for hours at a time in order to drive it such long distances daily.

NASA, however, is compensating for Italy's pullout with a new plan to redivert the money it had intended to spend helping Italy build Marconi and the 2009 orbiter, in order to build a single all-American Mars relay comsat for launch in 2009, just in time to assist the Smart Lander. (Even without this relay comsat, the science return from Smart Lander will be great -- but not nearly as great as it would otherwise be.)

Since the Smart Lander must in any case be attached to a smaller cruise stage to steer it from Earth to Mars, NASA is seriously considering attaching the 2009 American Mars comsat to the Smart Lander for that purpose, separating the two only on final approach to Mars.

The second American partner to get cold feet in 2007 is France, whose present role is actually a lot more central to the U.S. Mars program than is Italy's. The plan for the first Martian sample-return missions, up to now, has been for NASA to soft-land a spacecraft which would collect half a kilogram of surface material and launch it back into low orbit around Mars encased in a tiny satellite weighing only a few kilograms.

Meanwhile, a French-built spacecraft would brake into low orbit around Mars by a big detachable Mars-orbital insertion stage. After waiting up to a year to drift into the same orbital plane around Mars as the sample canister, it would carry out an automatic rendezvous and docking with the canister, tracking it at long range using a solar-powered radar beacon on the canister, then homing in for the final five kilometers using an optical system to locate the canister down to the last fraction of a meter.

The orbiter would then scoop the canister up in a hinged basket and load it into a small Earth-return capsule. After waiting for the appropriate Earth-return launch window, the French orbiter would then fire its own onboard engine to break out of Mars orbit and return to Earth, flying by Earth but ejecting the Earth-return entry capsule to land here.

That totally automatic rendezvous and docking with a tiny canister in orbit around another planet is, of course, one of the trickiest parts of this whole complex mission. And so the plan was for France to test-fly the orbiter in 2007, putting it into elliptical orbit around Mars with a smaller orbital-insertion stage than the actual sample-return orbiter would use, and then lowering the orbiter into a final low Martian orbit using the same onboard fuel that the actual sample-return orbiter would use to break out of Mars orbit and return to Earth.

This "Premier" mission would then eject a dummy sample canister and practice the final optics-guided rendezvous and docking with the canister several times, before letting the canister drift away to practice radar-tracking it at long range.

Nor would this be Premier's only function. Before arriving at Mars, it would release four small "Netlander" hard landers built by France's CNES space agency to land on different parts of Mars carrying surface cameras and a wide variety of geophysical and weather sensors, such as seismometers, magnetometers and ground-penetrating radar to look for local subsurface water (although they carry no surface-composition analysis sensors).

Setting up such a planet-wide network to make simultaneous seismic and weather measurements is one of the highest scientific priorities for Mars. The Premier orbiter would then spend two years relaying back their data to Earth at the same time that it was practicing rendezvous and docking in Mars orbit.

Finally, as a later and lower-priority task, it would lower its periapsis to just above the Martian atmosphere and study the planet in detail using a set of magnetic and upper-atmospheric instruments, a microwave limb sounder to study Martian weather, and -- if payload space allows -- one or two more competitively chosen instruments.

Unfortunately, the development of this complex spacecraft has (not surprisingly) been suffering from cost overruns. And so, as reported at the Advisory Council meeting, CNES is very likely to make major cuts in the mission. The full scope of these decisions won't be officially decided until October or November. The least serious course of action would be simply to delay Premier until 2009 -- but Naderi told SpaceDaily that it's somewhat more likely that it will be cancelled altogether.

Since CNES still very badly wants to fly the Netlanders to Mars, the likely course of action would be to drop them off them at Mars in 2009 on a much smaller and simpler flyby spacecraft, after which they would relay their data back using the other existing U.S. and European Mars orbiters.

This means cancellation of the science instruments on Premier itself, including those competitively chosen ones. (The Mars Scout competition also turned out four possible proposals for U.S. instruments to piggyback on Premier.) But obviously its implications for the U.S. sample return mission are by far more important -- if France pulls out of the project, NASA will have to develop its own sample-return orbiter, adding greatly to the project's already high cost.

The U.S. is already developing plans for a separate, all-American test of unmanned rendezvous and docking with a target as tiny as the sample canister. As part of the "New Millennium" program for test flights of experimental new technology to see how well it actually works in space, the "Space Technology 6" mission will fly three different technology tests in Earth orbit in 2004. And one of them -- to be flown on the Pentagon's XSS-11 satellite -- will involve that satellite repeatedly practicing automatic rendezvous and docking with a target as tiny as the Mars sample canister, for the benefit of both the U.S. military and NASA.

NASA's feeling is that this by itself would be adequate as a test of retrieval of the sample canister in orbit around Mars -- although it would prefer the Premier test to be run as well, as a test of an alternate tracking system. (The Space Technology 6 mission had already been selected and designed before CNES developed its qualms about flying Premier.) ST-6 will use a "LIDAR" laser range-finding system to locate the dummy sample canister at close range, whereas Premier -- if it flies -- would use a wide-angle camera system for the purpose.

Even without this final blow by France, however, it's been clear for a year that the U.S. Mars sample-return mission -- and indeed, the entire U.S. Mars exploration program after 2009 -- will have to be drastically revised.