Monday, June 21, 2004

A few more thoughts on SpaceShipOne

Now that I've had time to digest the news of the successful flight a little bit, a number of interesting questions pose themselves. What, in fact, are SpaceShipOne's estimated performance parameters? By that, I mean what are the theoretical limits to what it can do?

Let's compare SpaceShipOne to the old X-15, which made 199 flights between 1959 and 1968. The X-15 was dropped from the belly of its B-52 mothership at an altitude of 45,000 feet. The world altitude record for aircraft--just over 67 miles--was set by Joseph A. Walker Aug. 22, 1963. The world speed record for aircraft--Mach 6.7--was set by Pete Knight Oct. 3, 1967. SpaceShipOne is dropped from the belly of its mothership at an altitude of 50,000 feet, has reached an altitude of 62.5 miles and has approached speeds of close to Mach 3.5 during its ascent.

Simply stated, we don't know what SpaceShipOne is capable of, because privatly-held Scaled Composites has been fairly tight-lipped about their project. As well they should be, since they're in competition with several other teams for the $10 million X-Prize. But we can speculate, and indeed I shall. SpaceShipOne's previous flight topped 40 miles in altitude, and this flight topped 62 miles. Unless Scaled Composites is really pushing the ship's capabilities, I expect the X-15's record of 67 miles to fall shortly after the two qualifying flights to claim the X-Prize are completed. Having come this far, I'd be surprised if Burt Rutan couldn't coax another five miles or so of altitude out of his bird. The speed record is more of a challenge--that would mean doubling SpaceShipOne's top speed. But again, we don't know what SpaceShipOne's theoretical top speed actually is. These are still test flights, after all. If they open the throttle up all the way, who's to say they won't break the Mach 4 barrier? We don't know how much fuel the hybrid engine uses. The X-15 was the first plane ever to break the Mach 3 barrier, and went past Mach 4, 5 and 6 with the development of newer, more powerful engines. On its very first space flight, SpaceShipOne already topped Mach 3, so it is starting out somewhat ahead of the game from where the X-15 began--and at $30 million development cost, is significantly cheaper to fly than the X-15 as well.

We don't know a lot of things (something I seem to be repeating quite a bit) including maximum carrying capacity, although we do know it is at least equal to the weight of a pilot plus two passengers. But it could possibly be more. I also find myself wondering about SpaceShipOne's range--if, instead of immediately feathering the wings up to slow down and turn around, what if they continued in a ballistic trajectory for a while? What if they didn't turn around, and instead re-entered the atmosphere downrange? Could they launch in a trajectory that allows them to glide into Denver? The East Coast? Rutan's already spoken about "scaling up" the design and capability, so what are the prospects of a hypersonic spaceliner? Sure, space tourism is a nice start, but it's pointless to end things there. Scaled Composits could develop a hypersonic liner that carried, say, 30 passengers coast-to-coast or across the Atlantic or Pacific in an hour or so, while at the same time taking them into space, giving them the experience of weightlessness, well, that would be a winner on all levels. You'd still get tourism, sure, but you'd also capture a segment of the affluent business market--those movers and shakers who have to get from here to there, but want to have some adventure while doing so. A hypersonic space liner would give them a legitimate excuse.

I suspect Rutan is already thinking these things. Heck, it's pretty obvious from interviews with him that he's thinking orbit as well. If he's successful (and at this point I see no reason to doubt him) then pretty much every nation on Earth will be able to afford its own manned space program for just a little more than the cost of a state-of-the-art fighter jet. China is spending hundreds of millions, if not billions, on a long-range plan to land Taikonauts on the moon, solely for the prestige involved. The political ramifications of cheap (relatively speaking), universal space access are enormous. Scaled Composits is a small, innovative company with modest private backing. Can you imagine the potential if Boeing or Lockheed-Martin gets beind this? The market doesn't exist yet, but it would develop quickly. Very quickly, indeed.

Before any of that happens, thought, they'll need to fix SpaceShipOne. It seems that something went bump during the ascent, and there was obvious damage around one of the landing wheels when it touched down. Thank goodness nothing worse happened. But this will likely delay the X-Prize attempt by several weeks, at minimum.

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