John and I watched a few minutes of a documentary on space flight the other day, long enough for him to be amused at early space suits
and for me to be jolted backwards. I was a Gemini kid, accustomed to early morning launches from Cape Canaveral. I don’t remember if I had any thoughts about growing up to be an astronaut, but surely I did. I had little plastic space capsules in my bedroom and imagined squeezing in, flicking switches above my head and watching the world below through a porthole. It was probably a toss-up between astronaut and Zorro, actually, if I’m remembering correctly. If I could have worn a mask and a black cape into space, it would have been a done deal.
Watching the film, reliving those 20 minutes of Alan Shepard’s first suborbital flight, I realized I was holding my breath at the end, in that same Apollo 13 why-am-I-doing-this way. Getting up there was one thing; coming down was a question. Even a fairly small object such as the Mercury capsule still has to deal with physics, with ram pressure of a body moving through a fluid medium, compressing the air in front and creating a lot of heat. It’s the coming down part that’s tricky.
We know now that space stuff arrives all the time, every day. And once a year or more, something large enough will explode in the upper atmosphere from the heat, producing 20 kilotons of energy (i.e., the Nagasaki atomic bomb).
Once every few centuries, on the other hand, something much bigger drops by. Something that would cause a lot of damage were it to survive intact to get within a few miles of the surface.
Which is what happened, most likely, on June 30, 1908, near the Tunguska River in Krasnoyarsk Krai, Russia, a pretty isolated area at the time. The most commonly accepted estimates are that it exploded roughly five miles above the surface in an explosion comparable to a thermonuclear weapon, a hydrogen bomb. It flattened 80 million trees.
This is one of those events that floats around in our collective consciousness. We’ve heard of it, sort of, somewhere. It fits in there with volcano eruptions and far-off earthquakes and famines and maybe even historical battles. Moving on, moving on.
It makes life seem tenuous this morning, but then, duh. I’d much rather think about Rear Admiral (Ret.) Shepard up there, the smartest of the seven original, the one chosen because he might have the best chance of fixing a problem should one have occurred. They delayed that launch for four hours, fussing and worrying, and finally Shepard forced the issue.
“Let’s light this candle,” he said, get it over with, life is always going to be tenuous, you can hide under the covers or you can fly. I may have to watch Apollo 13 again soon, hold my breath again. I’m still a Gemini kid, I realized, Zorro was just pretend.
New column online now