[meteorite-list] (Meteorite-list) Value of NEAR Shoemaker landing attempt

From: Sam Kimpton <bessel_at_meteoritecentral.com>
Date: Thu Apr 22 09:41:07 2004
Message-ID: <3A81BF09.D77090D3_at_europa.com>

I do not believe the Spacecraft will rebound of the surface of 433 Eros.

There are problems which will most likely impact (pardon the pun) the
survivability of the landing. One problem is the spacecraft's velocity.
Provided that the fuel supply is sufficient for the sustained that is
planned the NEAR Shoemaker spacecraft is estimated to touch down at a
velocity between 5 and 7 MPH. Add to this the unknown nature of the
exact touch-down point and the lack of landing gear and one is faced
with a pronounced likelyhood that the spacecraft will roll on contact
and assume an unfavorable attitude for relaying data from the asteroid's
surface.

This whole thing was not part of the origional flight plan. It was more
of an afterthought.
The mission objectives have been met. NEAR Shoemaker functioned
nominally in all respects and returned more data than origionally
anticipated. The descent to the surface provides a good opportunity to
develop and test software routines and procedures for approach and
landing during future mining and impact mitigation missions to
asteroids.
Even if the "landing" or "docking" is a failure it will only be so in a
partial sense. The experience will be of great value and will provide
much need information for the next attempt on some other body.

In addition the spacecraft will be integrating and sending images every
thirty seconds during the four hour descent and will provide graphic
data pertaining to 433 Eros' surface. Essentially this is a higher tech
rendition of what was accomplished with the Ranger Missions to the Moon.

The problem of planning the "landing" approach is much simpler in that
433 Eros has a
single axis of rotation. Can you imagine what this would be like in the
event that it became necesary to land on an object like Castalia which
has a non principal one?

The operation will not be carried on NASA TV owing to the attention
given by it to the
Shuttle mission. It will be carried on a seperate satelite. however I
do not have the details.

I will be watching none-the-less with great interest.

As for the questions regarding seemingly anomolous surface processes on
433 Eros such as fracturing of rocks and boulders, flat units of crater
infill, and mass wasting, could impact and radiative transport of the
regolith be the causative factor?

Food for thought.

Sam Kimpton
Director/Scientific Officer: Vernonia Peak Observatory
http://www.nwag.portland.or.us/
http://www.nwastronomygroup.org
Personal page: http://www.europa.com/~bessel/Impact/Impact.html
Received on Wed 07 Feb 2001 04:32:57 PM PST