Nerves were once again being wracked around the world as Discovery and her crew of seven prepared for the dangers of entry interface – the first since flagship Columbia was lost at the same point of the mission.
Preparations had been on schedule, but low cloud at the landing strip have called off the first attempt. Discovery’s second attempt has also been called off.
“We’ve been working this pretty hard as I’m sure you can imagine from our silence down here,” Johnson Space Center’s Mission Control Center called up to Discovery. “We just can’t get comfortable with the stability of the situation for this particular opportunity so we are going to officially wave you off for 24 hours.”
Discovery’s first chance to land on Tuesday is at 10:08 UK time on Tuesday, with alternative sites in California and New Mexico should Florida’s weather remain unfavourable.
The crew awoke to Dexy’s Midnight Runner’s ‘Come on Eileen’ and began to power up systems required by Discovery for re-entry.
“I think Discovery is in absolutely great shape,” said Discovery Commander Eileen Collins in a news conference Sunday. “Iâ€™m pretty confident about re-entry, Iâ€™m thinking about the landing.”
The K-Band antenna was stowed back into the cargo bay – and the payload bay doors were closed at 6am UK time.
Tomorrow, after an Auxiliary Power Unit is fired up, Mission Control at the Johnson Space Center will give a go for de-orbit burn. Discovery will then fire her Orbital Manoeuvring System engines for three minutes to slow the spaceship down.
Entry interface will then occur 30 minutes later, as gravity starts to pull on Discovery’s body, dragging her down as she races into Earth’s atmosphere at 17,000 mph.
Arriving over Central America at a speed of Mach 20, Discovery will conduct two roll reversal, on to the left and one to the right, to lose speed.
With plasma trailing from her entry and super hot gasses glowing all around her, 25 minutes will have elapsed from the point of entry interface to a velocity of less that mach 2.5.
Slowing all the time, Discovery will break down from the speed of sound just over two minutes later, sounding her arrival at KSC with two sonic booms that will be heard for miles around.
Such is the noise, locals have been warned what to expect, with a report in the local paper, Florida Today.
“The reason why there’s two booms with the shuttle, instead of one with military jets, is because the nose breaks the sound barrier before the tail does,” NASA’s Bill Johnson said. “The orbiter’s the size of an airliner, and fighter jets aren’t that long.”
“It’ll wake you up in the morning,” added longtime Melbourne resident Robert Trice said. “If you’re not a hard sleeper, it’ll sure wake you up.”
Less than a minute after returning out of the speed of sound, Discovery will begin the HAC turn, taking a large circle to line up with the runway.
Dropping out of the sky several times faster than a normal aircraft, Discovery will glide down to the runway before lifting her nose with the landing gear down to touch Earth for the first time since she left the pad on July 26.
With brakes and a drag parachute, Discovery is set to wheel stop on the runway.
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