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Comment by mikeash | Hacker News Reader

This "anomaly" caused hundreds of millions of dollars in losses, and was an unprecedented failure mode. It doesn't surprise me at all that it disrupted the launch schedule for the better part of a year (edit: actually the lesser part of a year, about four months total if they launch soon). If they manage to return to flight this month, it strikes me as rather quick.

I wonder if supercooled propellants are really worth it. It seems like a huge risk in exchange for a small performance increase. Hopefully this will be the last vehicle loss they suffer from it.

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My understanding is it effectively reduces launch costs by ~25% by getting ~30% more mass to LEO. Really if it increases risks of failure by less than 10% it's probably worth it for unmanned rockets.

PS: High launch costs set up a cost escalation as satellites are so expencive they can't fail. Which means launches need a really high success rate. If you could get 10,000kg to LEO for say 1 million but had a 40% failure rate you would see a very different approach with much lower overall costs.

With this explosion, there was a ~$200 million satellite destroyed as part of a ~$60 million launch. We'll probably see much cheaper payloads to go along with cheaper launches eventually, but for right now the payload loss dominates, so you have to look at that as well.

For this particular problem, the risk to the payload will be eliminated by not attaching it for the static fire. Any risk during the actual launch would still affect the payload, though.

Payloads are insured, most likely SpaceX itself takes most of the loss.

The insurer took the loss on the satellite, SpaceX took the loss on the vehicle/launch contract, and the pad equipment.

Insurance isn't magic money. The cost of the satellite is recouped through premiums charged to companies launching satellites. It becomes part of the cost of launching one way or another. If gain X has cost Y, Y still factors into the tradeoff even if it's insured.

To put it in concrete terms, if insurers decide that SpaceX is significantly more dangerous to its payloads, then launch insurance for satellites using SpaceX rockets will become significantly more expensive.

Not sure what you're getting at with the condescending tone. My point is that the satellite owner did not realize a $200m loss; SpaceX being at least partially self-insured, from what I've read, is more likely to take a hit. There were 85 launches in 2016, one rocket blowing up is not going to significant change the landscape (heh).

Disclaimer: I don't know shit about the space industry, so don't waste your time.

We're discussing the tradeoffs involved in making launches cheaper but more risky. My point here is that insurance is irrelevant to that tradeoff. One way or another, the payload owners are ultimately paying for that risk.

"small performance increase"

FT can get 30% more mass to LEO. That is a pretty big performance increase, especially considering that it enables SpaceX to carry the maximum payload of v1.1 in expendable configuration and still land the FT rocket. Even if we assume that half of that performance boost came from the other improvements, 15% is a significant increase.

That's the seductive side of design tradeoffs with rockets.

Shaving just a little weight (especially on the 2nd stage) or squeezing out just a little more performance can have dramatic differences in mass to LEO.

The question is how much this will increase overall operational cost. Up until this year or so, it has seemed that SpaceX has been willing to compromise on performance to get lower overall operational cost and reliability.

I'm a bit worried that they've started to go the other way with some of the improvements they've made this year.

Following STS-51-L (i.e., the Space Shuttle flight on which Challenger exploded on ascent), the Space Shuttle fleet was grounded for a bit over two-and-a-half years. This is quick (OTOH, this is unmanned!).

After the Ariane 5 first-launch failure, it was well over a year before it flew again.

It disrupted the schedule for 3 months, not for "the better part of a year". Otherwise you are making a fair point (but SpaceX seem to believe that it is worth it and that they will iteratively fix all these issues without losing customer trust).

Huh, I was sure it was in June. Actually September 1st. I guess it just feels longer to me. Thanks for pointing that out.

This fault wasn't due to the introduction of supercooled LOX, though. They've been doing that for a while. The change here was to the tanking schedule so that it could better withstand a last-minute hold. As it stands, they're back to any hold during tanking leading to a launch scrub.

Once the redesigned tanks come in, it's likely that they'll go right back, because little holds aren't uncommon.

They'd been doing it for about nine months before this explosion. It wasn't the proximate cause, but it was a major change to the vehicle, one which is highly unusual in rocketry, and without that change, the proximate causes for the explosion wouldn't have happened. Without supercooled propellants, there wouldn't have been the need for faster tanking (because the fuel can just be at ambient temperature, and the LOX maintains temperature by boiling), and even if there were, the LOX wouldn't have been cold enough to solidify.

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