The SSES and the Division of Planetary Sciences both regard this -- like the proposed privatization of the Deep Space Network -- as a serious mistake, despite their support for competitive bidding for most other outer planet missions.

For Europa Orbiter is an unusually complex and technically advanced mission, which JPL because of its long experience in planetary missions is uniquely well equipped to handle, and which it has already designed in large measure.

To quote the DPS: "Reopening the program's status at this point risks losing the progress made to date in developing new technologies for outer Solar System missions, while substantially increasing the cost of a mission in which large investment has already been made, perhaps to the point of making it impractical to fly."

The SSES also listed its preferred initial set of outer Solar System missions in chronological order: first the Pluto flyby, then Europa Orbiter, then the "Comet Nucleus and Sample Return" mission -- a slightly jazzed-up version of the cancelled "Deep Space 4", in which a craft using solar-powered ion engines will rendezvous with a comet nucleus, land on it or dispatch a small lander to it, retrieve several intact frozen core samples of it and fly back to Earth with them, providing far better scientific information than the small sample of comet dust collected at high speed by the Stardust probe.

Fourth would come some kind of Titan lander or airship mission, whose form will remain undefined until Cassini and its Huygens Titan probe have given us a much better understanding of that still mostly mysterious organic-rich world.

But Europa Orbiter -- given its unusually high cost and difficulty -- seems to be the stumbling block in all this, especially if NASA sticks to its current determination to launch it in 2008 even at the cost of the Pluto probe.

The SSES has requested "an interim report from the Europa Study team, commissioned by [NASA Headquarters] to investigate alternative and cheaper ways of achieving Europa science objectives," at its December meeting.

One very likely course of action would be for NASA to give up its current plan to launch the Orbiter directly from Earth to Jupiter, and instead send it to Jupiter indirectly by making three consecutive gravity-assist flybys of Venus.

This would lengthen its flight time from 3 years to 6 1/2 years; but it would also allow its weight to be doubled without any increase in launch vehicle size, which makes the longer flight time a relatively trivial cost.

Also, JPL trajectory expert Martin Lo claims to have developed a technique that would allow the Orbiter, once it brakes itself into orbit around Jupiter, to maneuver itself into orbit around Europa using "gravitational fuzzy boundaries" and "Lagrange effects" -- which have already been used to put Japan's Hiten spacecraft into orbit around the Moon with a very small fuel expenditure, and which Lo claims would so drastically cut the mission's total fuel needs that its dry weight could be increased by about 30 percent.

Either or both of these techniques would allow a very great decrease in the amount of revolutionary new miniature electronics technology that the mission would need -- and they would also allow it to carry much more radiation shielding, thus also greatly decreasing its need for new radiation-proof solid-state electronics.

NASA's Europa Orbiter Program Executive Kurt Lindstrom tells me that NASA will finalize any such possible plans to cheapen the mission by the end of the year.

But even so, it's a difficult mission -- and NASA may well end up either having to substantially delay it (which, as with Mars SmartLander, may well be the best course of action), or replace it with a cheaper mission (such as a Jupiter orbiter with Europa flybys) that would provide much less scientific information about Europa.

At any rate, the next SSES meeting in December is looking rather fateful at this point. By then, NASA's overall plans for trying to cope as well as possible with its current financial crisis will have been set -- and we'll know how much money Congress will cut out of NASA's science budgets in response both to the Space Station's woes and the shrinking surplus.

Also, two subcommittees of the SSES will report their recommendations at that time -- one on any changes that need to be made to its suggested sequence of outer Solar System missions, and the other to suggest a new set of cheap missions to study the inner worlds: the Moon, the climate of Mars, and especially the hellish hard-to-explore world of Venus.

One preliminary suggestion is that Venus landers -- though not orbiters and atmospheric entry probes -- are impractical at Discovery Program costs, but that any such cheap Discovery Venus missions should also try to send "technology demonstration packages [which might also provide some science data] to Venus' surface", in preparation for the harder and more costly missions that will come at some point.

These two subcommittees are now scheduled to provide interim written reports in mid-September. Again, all I can advise readers at this turbulent time is to stay tuned.

Part  One - Two - Three - Four

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NASA BUDGET

Space Science Row Exposes NASA Budget Friction
Cameron Park - July 25, 2001
While not all the details are yet available, a significant collision seems to be developing between the U.S. House of Representatives and the Senate on how to modify President Bush's proposed NASA budget for the coming fiscal year of 2002.

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