‘Flying Through a Neon Tube’
Every astronaut who goes up knows the risks he or she faces. And every astronaut has to assess that risk and come to terms with it. There is no astronaut in the nation who is not well aware of the delicate nature of the flight.
Launch and reentry are especially risky because everything has to go exactly right. Before my first flight, we trained for reentry separately, in simulation after simulation, for months.
Reentry begins with the de- orbit burn. When the shuttle is ready to come back to Earth, it fires a couple of small engines, and its speed reduces very slightly to about 17,000 mph. You feel a push, almost like a kick, when the engines ignite.
About a half-hour later, the craft reaches the top of the Earth’s atmosphere. At an altitude of about 400,000 feet, the atmospheric drag begins pulling at the shuttle, the wind resistance slowing you down, robbing the craft of its energy. That’s when the ride begins to change.
Now, you’re screaming through the atmosphere and the shuttle is colliding with molecules. All you see out the window is a bright orange and pink glow. Astronauts say it’s like flying through a neon tube; it looks as if flames are licking at you as you hurtle past. It’s extraordinarily dramatic -- more eerie than beautiful -- and it continues until you hit daylight.
During this part of reentry, the ride starts to get rougher. Now it’s noticeable that you’re going through air. You begin to feel the turbulence, and it begins to get loud.
You are strapped in, sitting up, as if you were on an airplane. But it’s familiar and unfamiliar at the same time because you are slowing down from Mach 25 -- 25 times the speed of sound -- to landing speed.
It’s not exactly scary because you’ve been trained and prepared for it. But you’re acutely aware that everything has to go right and that the shuttle has to fly a precise trajectory through the atmosphere. You’re screeching through the atmosphere and, at the same time, the shuttle itself is heating up and encountering more air resistance.
It’s like when you stick your hand out a car window: If you are going 10 mph you don’t feel very much, but if you’re going down the freeway at 65 mph, you do. Now imagine it at Mach 20. That dynamic pressure against the craft is enormous.
It was clear to me very quickly that the situation on the Columbia was serious. You can have a couple of seconds of communication dropout; that doesn’t mean too much. But a minute or two with no communication and no data? I knew right then that it was bad.
But the space program goes on. It must go on. It is an example of what we can achieve as a nation, what we can achieve as a people if we put our minds to it. It’s really an example of some of the best in us.
You can see the fascination and wonder that it inspires by looking into the eyes of kids. When I talk to them about space, I can see the stars in their eyes. They’re fascinated by it, they’re motivated by it, it speaks to something that is inside all of us: the human drive to explore. The human drive to understand. These are very powerful forces.
