Wednesday, September 16, 2009

Take Five for Cool

Maybe it's just a machinery geek thing, but this is just way cool.

I think the Space Shuttle, as it flies its last few missions, will have a mixed record in history: it is unable to achieve anything beyond a low Earth orbit; it has a pretty limited payload capacity; it has proven quite complex and expensive; and it has suffered two catastrophic failures. But it has been a most useful exercise technically, not least because it has shown us the limits of what kind of cost savings might be realized by re-using spacecraft and parts. It has played a pivotal role in building and supplying the International Space Station, our first real permanently-manned outpost in space. It has done really miraculous things with the Hubble Space Telescope, providing, after its initial delivery into space, two extensive repair missions. These have not only greatly increased our knowledge of how to accomplish technical things in space, but they have allowed HST to vastly increase our knowledge of the universe in which we life, and of which we are a part. And it has kept us in space, which is no small thing when budgets are tight and the average [not] Joe (the [not] Plumber) cannot begin to grasp the benefits to such expenditures.

And apart from all that, it's just freakin' cool. Setting aside the pummeling awe of the liftoff (which must accelerate the craft to over 17,000 mph to achieve orbit), the deceleration and free-fall from orbit back to landing never fails to put a lump in my throat. The Apollo moon missions required the crews to perform precise engine burns to escape the Earth's gravity and place the spacecraft on a precise trajectory that would insert them in orbit at the always-moving moon (and back again when the moon visit was done). Similarly, the shuttle's return to Earth is a one-shot deal. It's not so hard to exit the orbit per se, but exiting it such as to arrive at the specified landing site requires a little forethought. These things seem to have very few ways to go right and an almost infinite number of ways to fuck up--and most of those would spell catastrophe. In my profession--which is like the grade school version of space flight--one always has the go-around as an option, even if we almost never need to use it. And we have lots of tools available to us to alter our flight path along the way if we don't like how things are going (which is exactly why a go-around is so rarely needed). But the Shuttle comes in "dead stick," coasting. There is no propulsion available, so there's almost no way to fix things if the descent is not right. And to make it worse, the thing falls like a rock. A big jet like mine doesn't glide very well, but it'll glide a hell of a lot better than the Space Shuttle.

The cameras pick the craft up miles up in the atmosphere, while it's still falling at supersonic speed. Then, accompanied by a couple sonic booms as it becomes subsonic, it begins a wide, gentle falling arc, a maneuver which lines it up with the runway centerline. I'm sure there's some kind of electronic / instrument guidance in use here, but I don't know what it is. You can hear the controller telling the craft that, presumably, their flight path is correct as they make their wide, descending "heading alignment circle." We hear the transmissions "On at the 180" and "On at the 90," the radio business being, like our own, a dry, technical business. The video often shows the pilot's window view of the runway once s/he has the craft lined up, and the view out is so very different from what I've looked at my whole working life. My immediate, instinctive thought when they show that picture is "Dude, you're screwed; go around!" It's a much steeper path than any normal airplane could fly. But the Shuttle comes down so steeply because it's the size of a DC-9 but has the wing area of a fighter jet. And because it has so much drag; and so the round out--the flare for landing--must also be judged properly, since with that much drag the airspeed will fall off very quickly when one lifts the nose. Begin the flare too early and you'll land short--with no means of remedying the error. Flare too late and you may hit very hard.

Every time I see the footage of the pseudo-plane returning from the blackness of space I'm reminded of what an accomplishment it all is, from the design and construction of this hand-built miracle of a machine, to the rarified, almost magical nature of its mission, to the intensive training and great skill and dedication of those who work with it and all the vast ground forces needed to make the program actually work; it's something that puts our culture in the best light, I think. It shows that we can still dream big, that we can make sacrifices for things that may benefit us only far down the road--that may not benefit us at all directly. In its very essence it is the product of a respect for science and a quest for knowledge and a dedication to hard work.

That's good, good stuff on anyone's resume.

Here's the wannabe version:


Jon said...

It is cool to watch the shuttle every time it comes down. I do realize that it is an extremely complex machine, but I think that one of its downfall has been that NASA has never been able to fly it with any regularity. I think that until they can take off on a regular schedule, with no hold ups, space flight will never be an everyday thing. As it is now, if it rains or the wind is too strong or some part the size of my hand fails it stops the mission. There are thousands if not millions of parts that can fail. It needs to become easier. I know that is a dumb thing to say, but you know what I mean. You just can't count on it going to space on a given day. Maybe the next spacecraft will be less likely to have these problems, but I doubt it. I will also continue to enjoy watching it.

wunelle said...

I think your point is a good one, but I'm more guarded about the conclusion. It was just a blink of an eye ago that powered flight itself was impossible, and now we have all manner of it, from little personal aircraft to A-380s and zillions of specialized fighting machines. And that's just a hundred years.

Of course, within that hundred years we were on the moon and back, and we've done much less spectacular-seeming things since.

But while I think the learning curve is steep here, I think we'll eventually make space flight not so near-impossible. I don't know how it will happen, but I'm confident it will. Whether we jet off to other stars or not remains to be seen. But I think we'll explore our solar system within the next hundred years or so. (I guess we're doing it now, but unmanned.)

Mike said...

Great videos! The shuttle is still an amazing piece of machinery even though it is now VERY dated! Heck even with the upgrade the CPUs onboard are something like 486mhz, which is completely obsolete by today's standard. Yet, it's still awesomely amazing!