Mike, thanks for taking time out of your busy day to share your insight about launching a space shuttle into space.
Well, thanks for having me. We're getting close to the launch of STS-121, another great mission, I expect, of the shuttle Discovery and her seven-man crew commanded by Steve Lindsey.
The launch window for this launch, and for all launches is very precise and often relatively short. How is the launch time determined?
It's a, it's a very complicated set of equations and determinations that go into an exact launch window. And so we have to launch at a particular time in order to catch up to the space station from below, as the space station is orbiting overhead of us.
So it's kind of like throwing a ball towards a speeding train and hoping to land the ball on the train. So we have to launch at a particular time to rendezvous with the station in orbit, and that, that set of equations says we really only have about a 10-minute period of time during which, on any particular day, we could launch and make it to the station.
How long will it take to get Discovery into space?
It takes the shuttle approximately 8-1/2 minutes to get to orbit. And if you think about it, we're accelerating a 4-1/2 million pound system from zero miles per hour to its orbital velocity of 17,500 miles per hour in those 8-1/2 minutes. So it's a heck of a ride for the astronauts. When you are in the firing room on launch day, we hear the terms "t minus" a lot during the countdown. What does the "t" stand for? I joined the space program about 20 years ago and I asked this question of my, of my elders in the program when I did join, and it turns out that T stands for test. Because it's not always related to time. It could be the start of a particular test in our Orbiter Processing Facility that isindependent of the time of day.
A question a lot of people want to know is will the shuttle perform the same on-orbit 'flip' this time around?
You'll recall on STS-114, Eileen Collins, our commander on that mission, did this flip maneuver for the first time in the history of the program.
We did it in order to inspect the belly of the orbiter and other surfaces, but in particular the belly, to see if there's any damage to the tiles that we had incurred during ascent. And so that is baseline for every mission now in the shuttle program. As we approach the space station, we will do this reverse pitch maneuver, it's called, and do a flip and photograph the orbiter from the International Space Station.
So it's a very, very prudent thing to do, and we do plan to do it on every mission from here on out.
Tell us about the roll of the commander and pilot. Do they actually 'fly' the space shuttle?
It's funny, the entire shuttle system is computer controlled from liftoff 'til we make it into orbit, so it's really like autopilot for the commander and the pilot. For the most part, it's all fully automated, and the commander and the pilot, while watching all systems very, very closely for good performance, essentially are hands off in letting the autopilot fly the orbiter into orbit.
Landing day is a bit different. Once we're over top of the Shuttle Landing Facility, the commander does take control of the orbiter and flies it in for its final approach and touchdown.
After this mission successfully concludes, when will Discovery fly again?
Well, Discovery will fly two times this year -- for STS-121 of course, on July 1, and her second flight this year is currently scheduled for Dec. 14. So after she lands, we'll take Discovery back to the Orbiter Processing Facility to begin her about three-month turnaround in the Orbiter Processing Facility, after which we take her to the Vehicle Assembly Building and mate her up with the external tank and solid rocket boosters for her next mission.
Mike, thanks again for stopping by.
For NASA Direct at the Kennedy Space Center in Florida, I'm George Diller.
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