Newsgroups: sci.space.policy
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Mission to Ceres
Date: Fri, 11 Aug 2000 16:22:54 GMT

In article <3993EE34.DAE8BB7C@estec.esa.nl>,
mkhan  <nospam@estec.esa.nl> wrote:
>> There is probably not a lot of point in doing anything other than
>> landing missions on asteroids.
>
>There is some interest in asteroid magnetic fields, but you have to get
>really close to perform the requisite measurements.

Likewise in X-ray, gamma-ray, etc. emissions and gravitational fields --
note that NEAR has more than just a camera on board.  Some of these things
work best from asteroid orbit, a la NEAR, but most of them can give you
*some* data from a flyby.

>As any such
>spacecraft is likely going to have a CCD camera payload onboard, the
>people operating that camera will be violently opposed to getting too
>close ... so you'll have a fine fight among the individual investigators
>(so what else is new ....).

I recall hearing that there were three distinct factions among the Giotto
investigators.  One group would get best science return from going through
Halley's tail, far enough away from the nucleus to have a reasonable
chance of survival.  Another would get best return from an impact on the
nucleus (i.e., they wanted to get as close as possible and didn't care
whether the spacecraft survived the encounter).  And the third faction,
composed solely of the camera people, wanted to pass fairly close to the
nucleus on the sunward side, to get good approach pictures with a
reasonable chance of surviving to get departure pictures too.  Needless to
say, the camera people won.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)