Fourteen years ago this week we were doing our final preparations on Columbia and the ground systems, getting ready to enter launch countdown (LCD).
With launch scheduled for January 16, the 3-day countdown was to begin Monday, 1/13. After dusting off vehicle and ground systems (and ourselves!) last week following our 9-day holiday period vacation, we were conducting several final tests that weren’t in the launch procedure but needed to be done as close to it as possible. On the schedule was installing the ordnance items, pressurizing the hypergolic system, checking out the space suits the crew would use if a spacewalk became necessary, doing some crew equipment and Spacehab installations, and closing the aft compartment of the Orbiter. Assuming this all went well, we’d have the 2-day weekend off just before LCD.
Ordnance installation and hypergolic fuel system pressurization were major hazardous operations requiring the pad to be cleared of non-essential personnel. And once done, they put the vehicle in a somewhat higher hazard level so we did them as late as practical. Access to the pad was more tightly controlled afterward. Dozens of explosives were used on the Shuttle and ground, mainly in separation sequences. The solid rocket boosters needed to be separated from the mobile launch platform, the SRBs from the external tank, the Orbiter from the ET, etc. All were done with ordnance firings. Installing them and verifying proper connections was an extremely precise skill. Our guys were the best at it.
Pressurizing the hypergolic propellants was necessarily done late in the pad flow to expose the least number of folks to that state following the pressurization. Hyper propellants—ones that ignite spontaneously when combined vs. needing an ignition source—were actually loaded well before the holidays. Hypers are stored at room temperatures, unlike the cryogenic liquid hydrogen and oxygen in the ET, but need to pressurized with nitrogen and helium gasses to get proper flow rates. Hypers were used in the thrusters, the auxiliary power units in the hydraulic system, and OMS engines.
Closing the aft compartment may not sound like a big deal, but it took several days to inspect each and every system, remove protective covers and access platforms, clean things up, and do other detailed work. It was an arduous process. It usually turned up a few items that needed to be addressed before we could have full confidence we were ready to go. We allotted 4½ days to fully inspect and prepare the multi-level aft compartment.
Checking out the space suits was fairly straightforward. Communications, power, and breathing systems were checked, as were all parts of the suits themselves. There were no scheduled EVAs in Columbia’s research mission, but we always provided two suits in case it became necessary. Every crew practiced an EVA to close and latch the payload bay doors if they wouldn’t close automatically. The Orbiter couldn’t reenter with those doors ajar!
We also did some “early stow” inside the Spacehab—experiments that weren’t time critical, different supplies, etc. Sounds easy—but remember the vehicle is vertical at the pad, and so is the Spacehab. Getting into it from the Crew Module was both tricky and ingenious. It involved a Rube Goldberg contraption consisting of tripods, hoists, wire rope, bosun’s chair, and nerve. The technician would be sitting in the chair, lowered down into the module via the wire and hoist system, dangling in free air all while installing stuff in lockers on the sidewalls. Easy, huh? In our jargon, the MVAK, the Module Vertical Access Kit, was neat to watch but a nightmare for the guys. But it was also the best thing we had to get the job done vertically. By the way, it would be left in place after using it this week. It would be used again during launch countdown to stow the late, time critical experiments – live worms, frozen samples, etc.
All this work went as scheduled so we had Saturday and Sunday off. Monday morning, however, we’d enter our Launch Countdown procedure and really act like launch was coming!
Next time, why does it take three days to launch the Shuttle?