Viewing page 6 of 63

This transcription has been completed. Contact us with corrections.

3

The S/C deployment and separation from the Orbiter appeared identical to the SMS visual scene.  The crew feels that the SMS visual model was a mandatory training requirement. It allowed the crew to develop the coordination necessary to complete the extensive post-deploy photo documentation.  Additionally, it prepared the crew for the forward cockpit scene of the separation maneuver; i.e., at OMS ignition the S/C was visible in front of and above the Orbiter.  If the crew had never previously seen the relative motion of the Orbiter S/C separation, it might have been cause to question the OMS burn attitude.

Hughes made a late change during training to have the crew select free drift at D-01:40 if performing a push-off pin deploy with no insight into pin position.  This change was formalized as a standard MCC call during nominal pre-deploy ops. If the time will always remain D-01:40, it should be included in the checklist and deleted as a MCC real-time call.

PAM DEPLOYMENTS - SBS/TELSTAR

The 41-D crew deployed the Satellite Business Systems (SVS) satellite on flight day 1 and the Telstar satellite for the AT&T Corporation on flight day 3.  In every aspect of the deployment operations, the activities were completely nominal.

ASE/SCA Modifications.  Subsequent to the 41-B mission, the Payload Assist Module (PAM) Airborne Support Equipment (ASE) and Sequence Control Assembly (SCA) were modified to add manual inhibits to certain hazardous functions. Previous flights had operated under waiver of the requirement for three inhibits inline with hazardous activities.  Two new switch functions were added to the Standard Switch Panel (SSP), and the SCA software was modified to make Mechanical Sequence and Spin Sequence two distinct, crew-initiated functions. The STS 41-D mission was the first flight incorporating these changes.  These manual inhibits and some consolidation in the on-board PAM CRT displays resulted in deploy procedures which were slightly different from those used on previous PAM deploy missions.  The 41-D crew felt that the PAM deployments were easy to control and monitor and that the updates to the hardware and software represented desirable improvements.

Deploy Operations Overview.  PAM/spacecraft operations began shortly after orbit insertion with the SBS health check.  Until approximately 1 month prior to flight, we were planning on STDN coverage only, and the crew had been asked to try to accomplish the SBS health check over the Dakar site at roughly MET 1 + 40.  For the record, the as-run timeline would have supported the health check at Dakar AOS, although TDRS low-data rate was available at the time for 41-D.  Post-insertion sunshield closing was normal for both spacecraft.  Motor currents, closing times, and sunshield motion were exactly as expected.

The SBS and Telstar deployment activities occurred on time and were normal in every respect.  In flight, as in training, all five crewmembers were involved in the deploy operations.  MS2 was the crewmember with chief responsibility for the PAM deploys and was positioned in the CDR seat.  MS1 was the other prime deploy crewman and operated the standard switch panel.  This arrangement has become the ops normal configuration for PAM deploys. The PLT was the crewman responsible for Orbiter support for the deployments.  The CDR and MS3 were responsible for the photo documentation requirements which, in the case of 41-D, were considerable.