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by grmarcil 3188 days ago
The point is with a rocket, if you can't land at your original destination, you probably don't have the capability to safely land anywhere else. Maybe I'm overlooking a scenario you have in mind, but IMO you're looking at two classes of problems:

1) Problem during launch. There's been one successful use of a launch escape system in rocketry history[1], and such a system has never been developed for a shuttle type craft.

2) Problem after entering orbit. Cutting your orbital flight short isn't going to change the fact that you still have to survive re-entry stresses and have a working vertical landing system.

[1](https://en.wikipedia.org/wiki/Launch_escape_system#Usage)
1 comments
justin66 3188 days ago
> 1) Problem during launch. There's been one successful use of a launch escape system in rocketry history[1], and such a system has never been developed for a shuttle type craft.

I'm not sure if you're aware, but this is a feature of the latest version of SpaceX's capsules. I'm sure it would exist for their larger vehicles.

edit: although I'm just not sure what you'd do during an abort with all that fuel that larger vehicle holds...

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mikeash 3188 days ago
I'm not so sure. The Dragon 2 integrates a launch escape system by using the same engines that are also intended for propulsive landing (which is now probably off the table for good, but that was the idea). The BFR ship won't have near enough TWR when fully loaded for its landing engines to double as launch escape engines, and I see no evidence of any other engines.

The fact that the BFR ship serves as both second stage and capsule combined, whereas the Dragon 2 is just a capsule with a separate second stage to put it into orbit, makes the problem a lot harder. I bet that the system for the BFR will consist of "don't explode."

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justin66 3188 days ago
> which is now probably off the table for good, but that was the idea

Oh, that's interesting. What makes you say so?

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mikeash 3188 days ago
Apparently I'm remembering an official statement!

https://spaceflightnow.com/2017/07/19/propulsive-landings-ni...

The reason seems to be a combination of NASA not being interested in propulsive landing (and they're funding most of Dragon 2) and deciding to go all-out on BFR instead of refining Dragon 2 further.

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justin66 3187 days ago
Thanks for sharing, that is news to me! I need to review their inventory at some point when I have a few minutes...
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