thoth@tellab2.UUCP (Marcus Hall) (07/06/84)
The Apollo Service Module also was exempt from the RSS requirements,
although there was a battle between KSC and the Air Force about this.
The following is excerpted from _M_o_o_n_p_o_r_t, A NASA publication that
outlines the history of the Apollo program (pp. 188-190). I know that
this doesn't directly apply to the shuttle, but it seems to follow a
recent discussion so please excuse the deviation.
... The dispute began in March 1962, when Houston requested a
waiver -- spacecraft engineers did not want the astronauts carrying a
destruct package with them to the moon. ... in May 1963, Houston again
asked to fly the Apollo spacecraft (including the S-IVB stage) without a
destruct capability. Engineers cited the possibilities of an errant
signal triggering the systems or of an explosion during docking. The
Air Force stood firmly by the requirements of the range safety manual:
"Both engine shutdown and destruct capability are required for each
stage of the vehicle."
... calculations indicated that an explosion of the three
launch-vehicle stages, triggered by the range safety officer, would also
destruy the lunar and service modules with their propellants. (In the
meantime the launch escape system would have pulled the astronauts'
command module away from the explosion.) Their plan emplowed a shaped
charge on the front end of the S-II stage to explode the S-IVB stage.
The results were inconclusive, however, and the Air Force stressed the
possibility of a spacecraft falling back onto the Cape. ...
The Air Force countered LOC's calculations with a July presentation
on a liquid explosive, Aerex. ...
... [November 1963] North American would prepare a destruct system
for the service module. The spacecraft could fly early tests without
the destruct capability since the service module tanks would contain
little fuel. The decision, however, did not bring the matter to a
close. Marshall and KSC officials were visibly upset in March 1964 when
North American Aviation presented five spacecraft destruct systems, none
of which incorporated the designs of the Saturn stage destruct system.
When von Braun and Debus raised the issue at an Apollo Review Board,
Mueller, head of Manned Space Flight, asked the KSC chief to seek
elimination of the destruct requirements. ... KSC stressed among other
things the weight penalty. A 120-pound service module destruct system
would require nearly 7500 more newtons of thrust or a reduction in the
weight of the S-IC stage. When Mueller submitted a formal request for
waiver in September, General Davis directed the Range to go along.
marcus
..!ihnp4!tellab1!tellab2!thoth