Re: SPACE: Roton in New Scientist

Hal Finney (
Mon, 10 Aug 1998 12:05:10 -0700

> I understand, I thought it would take less fuel since the operation would be
> done in a vacuum. The idea is still there, for when we have the opportunuity
> to slow it down without using or bringing extra fuel, there would be more
> possibilities in a vacuum to do something like that, perhaps laser technology
> or some kind of waveform, using satellites.
> danny

Ironically, in the context of remote space exploration, slowing down by rockets is the old-fashioned way to go, and atmospheric braking is the hot new idea. The movie 2010 had a dramatic sequence showing aerobraking being used to put a manned spacecraft into orbit around Jupiter.

The current Mars observer has been using aerobraking to circularize its orbit, although the technique has not worked too well because of a problem with a somewhat broken solar panel attachment.

Aerobraking can potentially save considerable fuel in a mission to orbit another planet and no doubt it will continue to be used in the future. It would be somewhat backwards to use rockets in the one case where atmospheric braking is well established and understood, re-entry into Earth's atmosphere.