One of my interests as a kid was space exploration and rocket launches. I grew up during the exciting days of the \u201cspace race\u201d in the 1960’s, when the Soviets and the USA were competing to outdo each other in putting men into space and making machines sail to Mars or Venus (or even to the outer planets, such as the Pioneer 10 mission in 1972). Teachers would bring TV’s into classrooms on days when a manned Mercury or Gemini mission was to be launched, and we would interrupt our boring history or english classes to \u201cjoin the countdown\u201d at Cape Canaveral in Florida. <\/p>\n
Thus I became something of a space geek, reading up as much as I could about the US and Soviet space programs. Since my father worked for a defense contractor (Bendix Aerospace) that made stuff for certain NASA rockets and satellites, he would occasionally chat a bit with me about the latest space shots. (He didn’t really like to do it too much, though, as it sort-of put him on my level, or vice versa. My father had an old-school \u201cI’m the boss and you’re the kid\u201d parenting mentality. But not to complain, as he was relatively gentle about it, he wasn’t a tyrant. Nonetheless, he was definitely not like today’s parents, who want to be \u201cfriends\u201d with their kids \u2013 and we’re now seeing just how well THAT turned out.)<\/p>\n
So I was recently looking at some YouTube videos of rocket launches, reveling in the clipped, precise communications going on between the ground controllers and technicians, and the hushed sense of anticipation and danger that eventually gave way to the goose-bumping final countdown and the crescendo of excitement as the rocket came to life, with booming sounds and steaming clouds and fire. Then came the slow, majestic ride into the skies, getting faster and faster, farther and farther away, with the techies putting in their occasional commentary such as \u201croger, three engines, nominal burns, initiate roll sequence\u201d to maintain the pretense that the whole affair was under control. It still thrills me after all these years.<\/p>\n
The well-known sidebar on YouTube offers a variety of variations on the theme that you are interested in, and the rocket launch sidebar inevitably offers a selection of fantastic failures, rockets that blew up on the ground or half way into orbit. So I watched a few of them (staying away from that ill-fated Challenger Space Shuttle launch; to me, watching that is a bit like viewing pornography, a cheap thrill that later makes you feel sullied and uncivilized). And all the explosions and flame reminded me of something that may be easier for a techie like myself to realize and appreciate: a rocket launch is really a controlled explosion, and rockets themselves are not that much different in design and character from a bomb. <\/p>\n
The average layperson who watches a rocket launch on the news or in a movie doesn’t usually sense this. The rocket puts out a lot of flame and smoke, but everything usually goes well, nothing gets blown up. But once in a while, things do blow up. And then you realize that anyone who would put themselves in a rocket is strapping themselves to a bomb, a very powerful bomb, right under their butt. Those first astronauts and cosmonauts were brave guys indeed. As as we later found out courtesy of the Space Shuttle, things have not changed much in the 50 years since Yuri Gagarin and Alan Shepard first ascended into the heavens on these flaming chariots.<\/p>\n
But space travel is progressing, if more slowly than we expected when I was that kid in fifth grade staring fixedly at the black and white TV screen as Walter Cronkite and other news journalists joined in with the \u201c10-9-8-7-\u201d chant. So now we already have a few billionaire \u201cspace tourists\u201d like Dennis Tito, and both government and private industry groups are planning to expand those ranks within the next few years. For example, Boeing is developing a space capsule called the CST-100<\/a> in conjunction with a company called Space Adventures, with the intent of to flying some hobbyist astronauts to orbital space along with the professional NASA people. \u201cWe hope, come 2015, we’ll be able to start flying some paying passengers” on the CST-100, said Tom Shelley<\/a>, president of Space Adventures. A number of other companies are working on schemes for offering both sub-orbital trips (such as the \u201cstanding room only\u201d Tyco Brahe mini-rocket<\/a>) and full orbital rides to tourist-adventurers, and hope to bring the cost down from about $30 million to around \u00bd million within five years. <\/p>\n I just hope that these space tourism enterprises are ethical enough to publicize the risks involved. They should require anyone wanting to blast into space to watch some launch explosion videos, such as this one<\/a> and this one<\/a>. I hope they make it clear to all potential customers: you are putting your one precious life on top of a bomb. If all goes as planned, this bomb will not go boom, but will release its energy over 2 minutes (versus 2 microseconds or so for a bomb). If something goes awry, which is known to happen, the bomb will suddenly burst and you will probably die in an instant. (And that doesn’t even count the risks in space and getting back home from space — remember the destruction of the Columbia<\/a> on re-entry). <\/p>\n I looked up some energy calculations as to get a rough sense of the forces involved. The energy needed to get 1500 kg spaceship (approximately like the early Mercury 1-person capsule) into earth orbit is around 4.9 x 10 ^ 10 Joules, based on an average of about 3.3 x 10^7 Joules needed per kilogram to launch to low orbit. For a 13000 kg CST-100 ship with 7 people: 3.3 x 10^7 Joules x 1.3 x 10^4 \u2192 4.4 x 10^11 Joules. The biggest conventional bomb used in WW2 released (RAF’s Grand Slam, used to destroy viaducts and submarine pens) released about 2.7 x 10^10 Joules, and a small atomic bomb (say 10 kilotons TNT equivalent, slightly smaller than the first Hiroshima bomb) releases about 4.2 x 10^13 Joules. So, the one-person capsule needs a rocket with the power of almost 2 Grand Slam bombs or about 1\/1000 of an atom bomb; the bigger CST-100 needs around 16 Grand Slams-worth, or about 1\/100 of a nuke. Given all the damage that an atomic bomb can do, one-thousanth of it is clearly more than enough to instantly shred and incinerate you and your little stagecoach to the stars.<\/p>\n Well . . . modern civilization is all about putting more and more energy at human fingertips. A young, strong caveman could throw a 3 pound stone or javelin at about 30 to 50 mph, and could build a slingshot to get a quarter pound pebble up past 100 mph. Horses could propel you up to around 40 mph; then came railroads in the 18th century, which could get you up to around 100 mph. Today, an average person can push a few thousand pounds of metal and plastic over an interstate at 70 mph, or buy a plane ticket and have their 180 pound body wisked along at around 500 mph (many do both on the same day, without any fanfare). <\/p>\n But when it goes bad, though, the consequences of modern energy harnessing can be much greater than a caveman might experience if he slipped while making his throw, or his slingshot’s bow snapped. Horse accidents could break your bones (and admittedly could kill or cripple you if you land the wrong way), but often you could walk away with just some bruises. Train accidents were worse, involving more uncontrolled force packed in a small place; plane crashes and car crashes today can be even worse still. Still, it’s not too surprising that someday (soon), people will want to escape the earth’s bounds. But good luck with keeping all that energy in the right place at the right time, and dealing with what happens when things go wrong.<\/p>\n P.S. \u2013 <\/p>\n