We’ve never had a disaster on re-entry before. The launch has always been more worrisome because you’ve got thousands of tons of fuel ready to blow up if something goes wrong, so that’s always looked at as a time of more hazard than any other. But re-entry is a big transition from all that speed back down to the ground. You put your pressure suit on and you have your visors closed so if there’s any loss of pressure, you will be protected within your suit. Everybody calls it the pumpkin suit because of its orange color. I give it the Ohio pronunciation–the “punkin” suit.
At this point in the flight, you’re back in your seat, strapped in–shoulder straps, seat belt, the whole bit. You have some back and forth on the intercom, but there’s not much conversation because you don’t want to interfere with what the flight commander or the pilot may be receiving in the way of instructions from the ground. And they may have instructions for the crew, so you don’t say much during re-entry. This is a time period where the flight commander and the pilot who are up on the flight deck are running the flight, and the rest of us are just riding through it.
In re-entry, you fire the retrorockets to slow down, and then gravity starts easing you back down toward Earth. When you come into the upper part of the atmosphere, you hit all this friction because you’re going so fast–five miles per second–and that decelerates you. On Saturday’s flight, they were coming back into the atmosphere at about 200,000 feet. They’d lost a third of their orbital speed; they were down to about 12,000 miles an hour, according to reports.
At this point, who knows what happened? I have no idea.
I would say this, though: I think NASA will be able to pin this together pretty well, because they have hundreds–maybe even several thousand–telemetry channels, which are radio signals of everything onboard. All that information is being sent down to the ground all the time. That’s what the people are monitoring in the control center. So they’ll have a complete record, and I think they’ll be able to define on a timeline what failed first, and where the problem started.
I know this tragedy is all very negative, but it’s amazing we’ve come this far with this many manned flights. Out of more than 150 flights, we’ve only had two failures in space that lost life. That doesn’t make it any less terrible for the people involved or less terrible now, but I don’t think this should end the program or anything like that. We’re learning too much that will benefit mankind.
The first time I went up in space, I had two things happen. One, the automatic control system went out and I had to control the spacecraft manually. And the second thing was a signal that came down to two ground stations that the heat shield was loose. So NASA decided that instead of firing the retrorocket pack that slows you down up there, and throwing it away in space and re-entering with a clean heat shield, I would re-enter with the retrorocket pack strapped onto the body of the spacecraft. The theory was that it would hold the heat shield in place. So I made a very spectacular re-entry because that retro pack was burning off during re-entry and there were big flaming chunks of it flying past the window. I couldn’t be certain whether it was the heat shield or the retro pack. All I could do was keep on working, as I did all the way through.
Whether the crew of this flight had any warning, it’s hard to tell until we know more about what happened. But I imagine they kept on working.
