Bad Simulation

''Arrivederci, au revoir, auf wiedersehen and adios,'' Allen radioed cheerily from Columbia's flight deck on 22 February 1996, as he and his crewmates lowered their visors and prepared for launch. ''We'll see you in a couple of weeks.'' Without further ado, and after a picture-perfect countdown, they thundered into space precisely on time at 8:18 pm. Unfortunately, the first portion of their ascent did not prove to be quite as perfect as NASA would have liked: a mere four seconds after liftoff, Allen and Horowitz spotted a potentially serious problem on their instrument panel.

One of the Shuttle's three main engines, it seemed, was running at a mere 40% thrust; far lower than the 104% it should have been pumping out in the seconds after launch. After checking with Mission Control, who confirmed that their telemetry indicated that all three were indeed performing normally at full power, the crew continued safely into orbit. Of course, if the (ultimately erroneous) instrument readout had been for real, it would have required Allen and Horowitz to perform an emergency landing back at KSC.

''We had a couple of moments there that we got a little adrenaline rush,'' Allen said later. ''I said [to Horowitz], 'This looks like a bad simulation run'.'' After achieving orbit, the crew divided into their respective shifts, and Blue Team members Chang-Diaz and Nicollier quickly set to work activating the TSS-1R support equipment in readiness for a planned deployment of the satellite early on 24 February. Before turning in at the end of his first shift, Hoffman also tested the reel motor and latching mechanism which secured the spherical satellite to its docking ring on top of the still-folded deployment tower.

By the afternoon of the 23rd, with less than 24 hours to go before deployment, the mission had encountered its first spate of problems: a computer relay, responsible for sending crew-issued commands to the satellite, experienced what appeared to be an electrical overload. Known as a Smart Flexible Multiplexer-Demultiplexer, or 'Smartflex', the relay had to be switched to a backup component; although the backup performed satisfactorily, Mission Control opted to spend several hours evaluating it before giving the go-ahead to begin TSS-1R deployment activities.

Next, a laptop computer on Columbia's aft flight deck encountered difficulties and was exchanged for a spare, which performed sluggishly. Nevertheless, in the early hours of the 24th, the methodical, step-by-step procedure to activate the experiments associated with the tethered satellite got underway. Firstly, the experiments were turned on individually, and then together, in an attempt to isolate the computer problems. By 8:00 am, all experiments were up and running and data was successfully transmitted through the Smartflex to the laptop and from thence to Mission Control in Houston.

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