Comment by macspoofing | Hacker News Reader

Comment by macspoofing | Hacker News Reader

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>I sincerely hope that thanks to SpaceX the cost of launching telescopes to space will become small enough to allow multiple space-based telescopes (and radio telescopes).

I think people have unreasonable expectations as to what SpaceX can do. I'm sure there are efficiencies to squeeze out of the business, but it's largely from the ops, and infrastructure around the rocket, not the rocket design itself ... design that has not changed significantly in 50 years.

Rockets themselves are as simple as you can get. It's fuel and exhaust and cargo . That's it. Reusability is fraught with issues and no guarantees it's cost effective (maintenance is expensive, reliability suffers, and decreased cargo/revenue due to needing to carry extra fuel for return). But even if reusability pans out, you're not going to get one (or more) orders of magnitude reduction in launch costs from where we are today. You'll get a few percentage points, maybe a few tens of percentage points and that's it.

Oh, we are to get an order of magnitude of cost reduction per kg on an orbit. There are attempts to measure it: https://everydayastronaut.com/raptor-engine/

They need to prove it. Talk is cheap and corporate PR is not very reliable source of information.

SpaceX has been known to talk bullshit ... or more charitably, they have been known to mix aspirational language into their projections. Case in point, I saw a TED talk with the SpaceX CEO claiming that rocket-based passenger travel is just around the corner and will be faster and more efficient than airplane travel... a claim that on face value is just stupid, bordering on insane.

Coming "Soon"

And that is why spacex is doing so well. Europe, Russia and old US space contractors said same thing about falcon - and here we are

Investing $100M of your own money into a rocket company and then 18 years later taking NASA astronauts to the ISS is equally crazy.

Most people will remember the achievements and not the bold claims.

Using the same rocket ten times instead of once is an order of magnitude improvement. Why shouldn't it be possible to do even better than that?

>Using the same rocket ten times instead of once is an order of magnitude improvement.

Reusability is not a panacea. Space Shuttle was reusable but it was not cost-effective and there were no cost savings. Also, reliability suffered and maintenance became prohibitive. In fact, I think the consensus is that the entire program was a mistake.

>Why shouldn't it be possible to do even better than that?

Because reusability has to contend with factors like:

1) Turn around time. How quickly can you refurbish a rocket.

2) Maintenance costs. How expensive is it to recover and refurbish the rocket.

3) How many times can you reuse a rocket.

4) Failure rates. Does reusing a rocket compromise quality.

5) Decreased revenue per launch. Reusable rockets need to carry spare fuel meaning, that your cargo space is cut (and cargo is revenue), and your costs are higher, because you have to still 'pay' to ship that spare fuel along with cargo.

Factors like those may make it that even if there are cost-savings, that those cost savings are not orders of magnitude lower, but maybe something on the order of 10%-50% - which is nice, and you can disrupt the market and make a good business out of it, but it's not anywhere close to the claims that are made. And again, SpaceX has not shown in practice that they can get ANY savings from reusability.

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