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Comment by colebowl | Hacker News Reader

This may just be conjecture but it's always seemed like they are solving the wrong problem. Why aren't they looking for alternatives to parachutes which to me seem like an archaic way of doing things. In saying that, the number of different maneuvers required in landing the space shuttle definitely shows how hard this problem is.

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The tyranny of the rocket equation mostly - parachutes are light in comparison. They could use a burn to handle the deorbit or a but that would add more mass which requires adding more mass.

The "more modern" alternatives would be heavier and depend upon more systems. Even if dealing with futuristic assumptions like say electromagnetic in atmosphere flight and battery density/reactors good enough to handle reentey braking for a reduction of net reaction mass a parachute would have a place as a backup plan.

SpaceX originally planned to develop a [propulsive landing system](https://youtu.be/Cf_-g3UWQ04?t=90), but this was dropped due to several reasons:

* The additional risks of a relatively untested system * Starship development had begun, which would make Dragon obsolete

Propulsive landing of Dragon was therefore scrapped (and [Red Dragon](https://en.wikipedia.org/wiki/SpaceX_Red_Dragon), a plan to send uncrewed Dragons to the surface of Mars, along with it.)

Don't forget the biggest reason - the LES system used the same fuel as the propulsive landing system, and they only carried enough for one of the two. Which meant that landings after using the LES would require a parachute, and if you're carrying a parachute with you anyways why not just use it all the time?

Because landing on land allows for faster retrieval of the astronauts and cargo, and is better for the capsule.

It seems to me that the parachute(s) you need for LES wouldn't need to be as complex and capable as landing parachutes.

The LES parachute(s) will be firing at quite low speeds, so they don't need to be too strong. The LES parachute(s) also don't need to be nearly as reliable or give nearly as soft a landing.

Ejection seats in combat aircraft show the same tradeoff -- it's considered acceptable to have ejection seats that fail sometimes and sometimes cause a landing injury. Hopefully you never have to use it, and so even if it fails or injures you say 10% of the time, it's much better than certain death in a pad explosion or similar.

The propulsive landing is still potentially a backup option to a parachute failure in the future.

Q: Are thrusters programmed as backup if chutes fail to deploy properly?

A: Most likely, but this is contingent upon NASA review & approval

https://twitter.com/elonmusk/status/1104510803313487872?lang...

All that really needs to be recovered are the astronauts. A backup system could be devised where the astronauts bail out and come down on their own parachutes.

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