To expand on the point, while he didn’t include it, I told Leonard in email:
The other issue is not launch reliability, but schedule reliability. SpaceX has aborted launches of the Falcon 9 when one or more of the engines was indicating performance issues on ignition. Three times as many engines means a lot higher probability of having an issue with one of them. For example, while I don’t know what the ignition reliability of a Merlin D is, suppose it’s 99% (that is, there’s a one in a hundred chance of failure to perform up to spec on ignition). For nine engines, that means the probability of a Falcon 9 aborting on the pad due to an engine issue would be one minus 0.99 to the ninth power, or about 8% per flight, or about once every dozen flights (which doesn’t seem that far off from their record). I don’t know what their flight rules will be for the Heavy, but if they have the same rule that they can’t take off with an underperforming engine, the reliability for twenty-seven engines will be one minus 0.99 to the 27th power, or 24%. That is, if they’re only 0.99 reliable per engine, and require all engines operating properly to take off, they have about a one in four chance of aborting a Falcon Heavy every single flight. That says to me that either they think Merlin reliability is greater than that (which it could well be) or that they’ll relax the rules to allow engine out from liftoff, or perhaps both.
Regardless, here’s hoping for a successful flight in less than three months.
A first-hand account from Houstonian and amateur (but competent) meterorologist Eric Berger. This will certainly be the costliest storm in US history to date.
[Update a couple minutes later]
Michael Mann versus Joe Bastardi. One is a “climate scientist,” the other understands how weather works.
… had its first captive carry flight in years today. I disagree that the big test is whether it can launch on an Atlas V (though there may be aero issues). Its real big test, assuming successful drop tests, will be whether it can survive entry.
It could well be that 125 years is the maximum, with current body design, though we may develop alternative repair mechanisms. But as I always say, there are no laws of physics that require that we age, and ultimately, the only laws are physics.
Evolution is running like molasses, chewing up CPU, apparently because it’s choking on half a million emails in my “Junk” folder. And I can’t clean them out because, you know, half a million messages in my Junk folder. I’ve tried loading the folder into a browser tab in roundcube, but it can’t open it either. Any ideas how to go in on the server directly and clean things up there? vi would be a nightmare.
It’s not a giant rabbit (and the name will likely be retired after this storm). When he’s not reporting on space, Eric Berger (a Houston resident) covers tropical storms. He says the rain outlook is grim.
And it’s bad news for bad people around the world.
[Update a few minutes later]
Mexico’s largest shale field is now open for business. In theory, this should help the economy down there as well, and perhaps relieve the pressure to emigrate. But the place is still pretty corrupt.