Category Archives: Space

Space Policy

This anti-business piece is sort of a mess:

Indeed, legislation has been proposed in Congress since the UAG was formed that promotes the Council’s professed goals of expedition, streamlining, and commercial dominance, and it enjoys bipartisan support from lawmakers representing “states and districts where aerospace technology plays a significant role in the local economy,” according to an analysis from Daily Kos. This shared financial interest has brought together far-right, anti-science legislators like Ted Cruz and Lamar Smith in co-sponsorship with Democrats from states with aerospace-heavy economies. [Emphasis mine]

The premise is that space is supposed to be about science, but that has never been true. And as Mark Whittington pointed out on Twitter, it wasn’t Ted Cruz or Lamar Smith who were running ads blasting their opponents for supporting a mission to Europa.

The Stainless-Steel Starship

Elon explains.

I would note, though, that the idea of transpiration cooling has been around for a long time. It’s just never been implemented. But I guess what he’s saying has never been proposed before is the structure also serving as heat shield.

[Update a while later]

New Glenn has been redesigned. Looks like the upper stage is expendable.

Looks like they were inspired in part by Falcon 9. It’s interesting that we’re starting to see spacecraft designs converging, as aircraft designs did in the thirties.

The End Of Rockets?

No, Futurism:

All that essential, but not actually useful, extra weight jacks up the cost of a mission. Falcon Heavy launches cost $1.2 million USD per ton of payload. Again, that’s a crazy improvement from earlier missions, but that many zeros on a space mission mean these launches will stay out-of-reach for consumers or smaller companies.

No one outside of SpaceX knows what Falcon Heavy costs (and that depends on whether you mean average cost or marginal cost).

And then there is the environmental cost. These souped-up rockets use more fuel, and Falcon rockets rely on what’s basically kerosene and oxygen. Per launch, the carbon these missions spew isn’t that much. But if space flight frequency reaches the twice a month threshold that SpaceX is aiming for, experts think the overall carbon output could reach 4,400 tons a year. If every private space company chimes in with their own launch emissions, that number could climb dramatically.

Not everyone uses kerosene. Blue Origin (and ULA) plan to use liquid natural gas (mostly methane), which has much lower carbon content. And they both plan LOX/LH2 upper stages, whose exhaust is water. And even at a hundred times that amount, it would continue to be dwarfed by the airline industry.

There are also all the potential atmospheric impacts that we don’t understand very well. Burning rocket fuel emits soot and a chemical called alumina, and scientists have started to study how these molecules break down our ozone layer, something we’ve been working hard to restore over several decades.

Again, not all rocket fuel. Methane will produce almost no soot, and hydrogen none. And only solid rockets emit alumina, and only ULA plans to use them (OK, well, NASA will have them on SLS, if it ever flies, but it will hardly ever fly).

No, it will be a long time, if ever, before we need space elevators, even if they’re technical feasible and practical.

Missile Defense And Launch Costs

I did a thread on Twitter this morning.

[Update a couple minutes later]

Trump’s missile-defense strategy.

As I noted above, if the space segment is now feasible, it’s despite, not because of government launch policy for the past three decades (except possibly for COTS).