Category Archives: Space

We Don’t Need No Stinkin’ Air Breathers

Henry Spencer (who I expect will be at Space Access this year, after missing last year for the first time ever) explains (once again) why the future of space launch continues to lie with rockets, despite the superficial appeal of not having to carry oxidizer.

This is an important point that I’d never thought about explicitly:

The pure-rocket design was more than twice as heavy as X-30 at takeoff, because of all that LOX. On the other hand, its empty weight – the part you have to build and maintain – was 40% less than X-30’s. It was about half the size. Its fuel and oxidiser together cost less than half as much per flight as X-30’s fuel. And finally, because it quickly climbed out of the atmosphere and did its accelerating in vacuum, it had to endure rather lower stresses and less than 1% of X-30’s friction heating. Which approach would be easier and cheaper to operate was pretty obvious.

This implies that a rocket powered vehicle will have much better off-design (higher delta V, such as more altitude or higher inclination) performance than the air breather, because its dry mass that has to be given the additional velocity is much less. It also means that it will be cheaper to deorbit, and the thermal load will be less, for a given wing area (assuming that it has wings, which an air breather certainly would). I suspect that no matter what the technology level, air-breathing launchers are doomed to remain the equivalent of flying cars — interesting in theory, but never achieved in practice.

I Hope He Freezes In The Dark

Timothy Noah is cheering what he hopes is the upcoming demise of the nuclear power industry, in the wake of Obama’s closing off the Yucca Mountain option. I was never a big fan of Yucca Mountain — I think it a ridiculously overpriced solution to an hysterical non-problem. But for the money that they planned to spend on it, we could have come up with a safe and reliable launch industry, by using it as a market for storage on the moon.

Mind Boggling

How can any sane person support Ares/Orion with development costs like this?

I can’t tell if the “life cycle” ends with the first launch in 2015 or includes some X number of additional launches beyond that. Regardless, the numbers are impressive, even in these days of trillions:
/– Ares I only : $17B to $20B
/– Orion capsule only: $20B to $29B

And no, that doesn’t include ops costs. As “Red” notes in comments:

Something like this was already done at Cosmic Log, but it would be interested to translate that $20B + $29B (~$50B) in more understandable terms:

25,000 Lunar Lander Challenges
100 COTS programs
> 500 Lunar Prospectors
500,000 XCOR Lynx tickets
250,000 SS2 tickets
500 BA 330 modules, or 1000 years of half-year BA 330 module leases
1000 Falcon 9 launches (mix of regular and heavy)
>5000 Falcon 1 launches
2000 Google Lunar X PRIZEs
1000 smallsats averaging $50M

… etc … That’s assuming no discounts for bulk purchases … and if you want variety in your space program, take off a zero from each of the above and have them all …

On the other hand, an administration that just increased the deficit by a factor of four, to trillions, probably thinks fifty billion is just couch-cushion change.

Close Call

We were just missed by an asteroid this morning, with only three days warning, and well inside the orbit of the moon:

The rock, estimated to be no more than 200 feet wide, zoomed past our planet at an altitude of 40,000 miles at 1:44 p.m. universal time — or 8:44 EST.

Dubbed 2009 DD45, it was discovered only on Friday by Australian astronomers.

“…no more than 200 feet wide…”?

That’s plenty big enough to pack a hell of a wallop if it had hit off shore, likely wiping out much of the coastline of the surrounding continents. If it hit a populated area, it could have been easily mistaken for a nuke initially, perhaps setting off an international crisis, and even retaliation.

There is no excuse for how little prepared we are for these things.