A Camera's Eye View from the Shuttle

Standing outside my office building, the Operations and Checkout (O&C) building, I watched the shuttle Columbia launch mission STS-94 from KSC Launch Pad 39A on Tuesday afternoon, July 1. Usually that would signal the end of the work of most KSC personnel for a shuttle mission. However, for five of my co-workers and me from Experiment Integration, our work had a long way to go - seventeen days, in fact, of around-the- clock science operations. We all immediately headed for Orlando International Airport to fly to Huntsville, Alabama, home of the Marshall Space Flight Center (MSFC), where the payload science operations were being controlled while the mission was in flight. All of the engineers, scientists, and mission managers for the experiments on board the Microgravity Science Laboratory (MSL) were there to instruct and to consult with the astronaut crew while the experiments were being performed. We had worked with these people for the last year and a half on STS-83 and STS-94, and we were going to MSFC to assist them with the knowledge we gained while integrating and testing the MSL experiment hardware during pre-launch processing.

My five co-workers each worked one shift of around-the-clock monitoring with a specific experiment team. However, my duties were not dedicated to one team. Instead, my mission was to help troubleshoot any problems that occurred with the Spacelab carrier or experiment systems. This was the sixth mission that I had traveled to MSFC to support on-orbit, so I had a lot of experience in working with experiment teams to resolve problems using alternate methods of operations and the tools in the shuttle's In-Flight Maintenance (IFM) Tool Kit.

With any luck, I don't have much to do for the whole mission. That makes the time pass pretty slowly for me each day, but I would rather all the experiments work perfectly than have to troubleshoot problems with everything. For this mission, the former was almost the case. We only had a few problems to resolve, and here is the story of the most significant one.

The Electromagnetic Containerless Processing Facility (TEMPUS), a German Space Agency-provided experiment facility, has two camera positions that could view the metal samples they were melting and studying inside their furnace. At first, both cameras were working normally, but after only a few hours of operation, the top-view camera became intermittent and then quit altogether. We put together a troubleshooting plan over the course of several days to try some easy fixes, such as powering things off and back on to see if they were being affected by other hardware, and then resetting the cameras to see if that would fix the problem. Another thing we tried was looking at the camera output on the on-board monitor instead of through the satellite downlink to see if it was operating properly in the on-board environment. But none of these things helped.

In order to continue with their other science operations, the TEMPUS team rearranged their activities so that all the operations that needed the top-view camera would occur in the second half of the mission. That gave us a few more days to put together a plan for a more invasive troubleshooting plan that would need to get approved by personnel at MSFC, as well as Shuttle Mission Control at the Johnson Space Center. We believed that there may have been a problem involving the sync signal that was being provided to the top-view camera. A sync signal is required for a camera to operate, and a sync signal can be provided externally, in this case by Spacelab, or internally, by the camera itself. I came up with a scheme to access a couple of cables in a fairly convenient location where we could switch the sync signal to the top-view camera with the sync signal that was going to the properly operating front view camera.

When we finally got the astronaut crew to do this procedure on-board, we could tell that the problem was related to the camera and not the external sync signal. The second part of my plan was to plug in some jumper wires that would bypass the external sync and allow the camera to operate on internal sync. Lo and behold, it worked. All this effort told us that the electronics that process external sync in that top view camera had degraded. The only disadvantage of operating the camera this way was a small line that ran through the video image because it was no longer on the same sync as the rest of the Spacelab video system, but it was infinitely better to have this small annoyance than no picture at all. The TEMPUS team was elated, and they went on to complete all of their planned activities.

When you successfully work your way through a problem, it sure feels good. But when you work your way through a problem with a team of people including international scientists and engineers during a shuttle mission, it feels really great.

At the conclusion of STS-94, my five co-workers and I all went back to KSC where we have already started work on the next and probably final Spacelab mission, STS-90, the Neurolab mission, which is scheduled for launch in April of 1998. That one will be focused on life sciences instead of microgravity science. Back to work...see ya.