The USS Frontier stood poised for takeoff. T-minus 31 seconds.
There were two countdown clocks. The L or launch clock represented the time in real terms before the shuttle launched; and the T clock also represented time, but had several built in holds where additional verifications could be made. If mission parameters allowed, built in holds could be extended, but launches to the International Space Station (ISS) can’t be extended because of the tight launch window. The launch window is limited to 10 minutes because of the 90 minute orbit of the ISS and the speed of the earth’s rotation at 1,470.3 km at the Kennedy Space Station in Florida, which puts the launch pads 1,000km east of the launch pads during the next orbit.
In 2011, NASA had suspended the shuttle space program following 135 missions from 1981, the last being STS-135 flown by Atlantis.
Now they stood poised to launch a new generation of shuttles and the USS Frontier was the pinnacle of that new craft. Like previous shuttle missions, it had been designed as a low orbital craft, but the new version could carry up to twelve astronauts as compared to eight on previous missions.
At 72 hours before launch there was a call to stations. At T-43 hours and counting a sequence of events kicked off. Space technicians began the final and facility closeouts for launch. Next up was a check of the backup flight systems. Flight software was then checked on the display systems, and backup flight system software was loaded into the orbiter’s general purpose computers. Next was the removal of the middeck and flightdeck platforms. Engineers then activated and tested the navigational systems, and completed preparations to load the power reactant storage and distribution systems, and they also completed the preliminary flight deck inspections.
At T-27 hours and holding, non-essential personnel were cleared from the area. It was the first built in hold and could last for four hours. Technicians began loading cryogenic propellants into the orbiter’s power reactant storage and distribution systems. At T-27 hours and counting, the fuel cell storage tanks continued to be pumped with cryogenic propellants.
At T-19 hours and holding, the hold could again last for four hours but could be extended and included procedures that included demating the orbiter’s midbody umbilical unit, cleaning and vacuuming the crew module and purging the external tank nosecone. At T-19 hours and counting final preparations were begun for the three main engines for main propellant intake and flight, filling of the launch pad sound suppression water tank, resumption of the orbiter and ground support equipment close-outs, and closing out the tail service masts on the mobile launcher platform.
At T-11 hours and holding, the hold could last from thirteen to fourteen hours and included weather briefings, engineering briefings, pad debris inspection and closeout, late stow of flight crew equipment, moving the rotating service structure to its ‘park’ position, activating the orbiter’s inertial measurement and communication systems, and performing the ascent switch list. At T-11 hours and counting there was an activation of the fuel cells, the blast danger area was cleared of non-essential personnel, and the orbiter’s purge air was switched to gaseous nitrogen.
At T-6 hours and holding, the hold could last up to two hours. Procedures at this point included a scrub that could last twenty four hours, a weather update for the launch director and mission management team, and once the launch team confirmed that there were no violations of launch criteria the orders were given to begin loading the external tank with propellants – 500,000 gallons of cryogenic propellants – and a chill-down of the propellant transfer lines. At T-6 and counting, the external tank is checked for frost and debris, then further checked for the presence of H2 at the orbiter, and a final filling of the external tank with its flight load of liquid hydrogen and liquid oxygen propellants.
At T-3 hours and holding, the hold lasting two and a half hours, the external tank loading enters stable replenishing, the performance of the inertial measurement unit preflight calibration, the alignment of the Merritt Island launch area tracking antennas, the flight inspection team walked up and down the launch tower inspecting the shuttle, followed by the closeout crew who configured the crew module for countdown and launch and assisted the crew in entering the orbiter, a televised weather briefing and a flight crew weather brief, and the astronaut support person enters the crew module to complete a comms check.
At T-3 hours and counting, the crew departs for the launch pad and as soon as they arrive they begin their entry into the orbiter via the White Room, closeout procedures in the White Room, a check of cockpit switch configurations, astronauts conduct air-to-ground voice checks with Launch and Mission controls, the orbiter’s crew hatch is closed and checked for leaks, the White Room closeout is completed, and the closeout crew retreats to the fallback area.
At T-20 minutes and holding, the hold lasting ten minutes, the NASA Test Director conducts final launch team briefings and completes inertial measurement unit preflight alignments. At T-20 minutes and counting, as the countdown resumes the orbiter’s onboard computers transition to launch configuration, commencement of the fuel cell thermal conditioning, the closure of the orbiter’s cabin vent valves, and the transition of the backup flight system to launch configuration.
At T-9 minutes and holding, the hold varying in terms of length and the final hold, a determination on the launch window, the flight recorders are activated, and final “go/no go” launch polls conducted by NASA Test Director, mission management and Launch Director. At T-9 minutes and counting, things begin to heat up. The automatic ground launch sequencer is started; at T-7 minutes 30 seconds, the retraction of the orbiter access arm; at T-5 minutes 0 seconds, the auxiliary power units start, and the arming of the solid rocket booster range safety safe and devices; at T-3 minutes 55 seconds the commencement of the orbiter’s aerosurface profile test and the main engine gimbal profile test; at T-2 minutes 55 seconds the retraction of the gaseous oxygen vent arm or ‘beanie cap’; at T-2 minutes 0 seconds the crew close and lock their visors; at T-50 seconds the orbiter transferred from ground to internal power; at T-31 seconds the ground launch sequencer is go for auto sequence start; at T-16 seconds activation of the launch pad sound suppression system; at T-10 seconds activation of the main engine hydrogen burnoff system; and at T-6.6 seconds the ground launch sequencer is go for main engine start.
Finally, at T-0 the ignition of the solid rocket boosters, explosive bolts releasing the boosters, and the shuttle launches from the launch pad. The USS Frontier climbed upward, soaring towards the heavens.
The three main engines were operating at 100 per cent thrust, the engines providing 1.2 million pounds of thrust and the boosters providing 6,600,000 pounds of thrust. Total thrust at liftoff was about 7.8 million pounds of thrust and to achieve orbit the shuttle had to go from 0 to a speed of 28,968 km an hour. At T plus 20 seconds, the Frontier rolled at 180 degrees at a 78-degree pitch, and at T plus 26 seconds the main engines were throttled down due to the maximum dynamic pressure. Shuttle Commander, Benjamin Stokes, spoke to Mission Control. “Go, for throttle up?”
Mission Control replied: “You are go for throttle up. Good luck, Ben.”
Seconds later, Stokes throttled the engines to 104 per cent power, and then disaster struck. Catastrophe!
In Mission Control there was shock and disbelief as technicians scrambled to check their systems. Memories of the Challenger disaster resurfaced because instead of the beautiful image of the Frontier rising upwards towards the heavens, all that hung in the still air and against the cold blue sky were long entrails of white smoke, and strangely enough the largest column of smoke formed a huge question mark against the sky.
It was eerie.