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It's an issue of safety margins. Just consider the airplane. - A two-engine plane can operate on just one engine - In the event of losing power or losing both
by cletus 8y ago
It's an issue of safety margins. Just consider the airplane.
- A two-engine plane can operate on just one engine
- In the event of losing power or losing both engines, a plane has a certain glide capability
- Runways are built allowing a certain amount of overshooting
- A bad approach allows you to circle back around and try again
- Planes can land and takeoff with significant winds and precipitation (including cross winds)
- A plane can actually land in a body of water (as happened on the Hudson).
Now compare the safety margins for a dead stop rocket reentering from space at Mach 30.
- skykooler 8y agoTo address your first point - the rocket has 3 sea-level engines on the spaceship stage, each of which has enough thrust to land the ship on its own if the other two fail. (This is partly a byproduct of it being much lighter during landing than takeoff as most fuel has already been burned.)
- alonmower 8y agoI think the issue with the current hoverslam solution is that the timing of the rocket relight is critical to the rocket hoverslamming (and not just regular slamming). I don't have the answer to this but imagine that if an engine fails to relight at the correct time there's a much smaller (or maybe non-existent?) margin of error. A plane on the other hand has two engines and can also generally just glide to the ground in the event that neither of them are working.