OUTLAW GRAVITY!

Vice President Quayle is head of the National Space Council, and as such he appointed a 27-member panel to search for tech-nologies that could cut costs and advance space technology. In June the group, comprising many former Apollo project par-ticipants, came back with an answer that knocked the Luddites and sham-environmentalists speechless: develop nuclear powered space ships if you want to go to Mars by 2015.

Well, I don't want to go to Mars, and I think by 2015 robotics and computer technology will have developed sufficiently to spare humans the round trip of 300 to 400 days under the stress of weightlessness and exposure to strong radiation. And not just spare them, but outperform them.

For distances in space, fuel tanks and solar collectors do not just become absurdly large, they become impossible.

Nuclear propulsion would be ionic, expelling charged particles rather than hot gases to move forward. lt would not only sig-nificantly cut the time of a Mars mission (from 400 to 320 days for the round trip), but depending on what is to be accomplished, it is probably getting close to the border where nuclear power is the only solution.

I do not have the propulsion data, but for on-board power sour-ces the limits are shown in the figure (based on "Nuclear electric power in space," IEEE Spectrum, Dec. 1984). The vertical axis is the power available, the horizontal its duration. Nuclear is limited only from below, in that it would not make sense to use a nuclear reactor below 10 kW. Radioisotopes (providing heat, which is con-verted to electricity by a thermocouple) can be used only for very low levels of the order of 1 watt or less (would power a light visible only in the dark).

Chemical sources (batteries, fuel cells) are limited by weight along the curve indicated; beyond it, they would crowd out the payload with their demand for propulsion energy.

For solar, the limitation curve is due not only to the increasing weight of the collectors, but also to the increasing size, even if the collectors can be folded for launch, for this will affect the maneuverability of the craft (by rotational inertia even in a vacuum). Though the duration of solar is limitless, it cannot achieve a high enough power level.

Thus, the use of nuclear power in space will become inevitable.

But this poses no problems for the noisy Green priests, who can-not be confused by the facts. Natural laws? They have enough clout in Congress to repeal them.