eli5 What does the ‘abort’ handle in spacecraft cockpits actually do?



In many movies and media that depict real-life spacecraft, or near-future spacecraft that are logical progressions of real-life spacecraft, they show the abort handle or button or switch. What would happen in real-life if this handle was pulled during any given moment during space flight; takeoff, orbit, halfway to the moon, etc.?

In: Technology



The classic “abort handle” is for the launch abort, which obviously only works while you’re still connected to your carrier rocket. In that case, it activates a dedicated launch abort rocket and separates the spacecraft from the rocket. The small, but powerful abort rocket then pulls away the spacecraft from the rocket (and the imminent explosion which is usually the cause to use it). Then it usually activates the descent systems (e.g. attitude control so you’re right side up, and parachutes once you reach the correct altitude for them.

Couple videos from those systems in use:

[Soyuz pad abort](https://www.youtube.com/watch?v=nwtSWaHV_-4)
[Soyuz in-flight abort](https://youtu.be/c0l5QBmqQoI?t=223) (these 2 were real accidents with people on board!)

[Crew Dragon pad abort test](https://www.youtube.com/watch?v=wcHD9AmkxA0)
[Crew Dragon in-flight abort test](https://youtu.be/mhrkdHshb3E?t=1148)
[Apollo abort test](https://youtu.be/AqeJzItldSQ?t=93)

However, the handle isn’t the only way the abort can be activated, and it’s more likely that it’s activated by the flight computer sensing a failure.

It usually activates the escape rocket, which blasts the crew capsule away from the rocket. It is only usable for a certain window of the launch and then the escape rocket is jettisoned. It’s not available after that. There’s a different mechanism to blow exploding bolts on the hatch so the crew can get out quickly if the vehicle is still on the pad, then they get into a little cable cart that whips them away from the rocket. These are two completely separate systems with different specific windows of use.

It’s not like the ejector seat in a fighter plane that can be activated at any time.

Once you’re in space, just hope for the best. If still in orbit, an emergency re-entry may be possible, but there’s a whole process for that and it takes a while. You can’t just skedaddle back home all of a sudden.

It really depends on the space craft. In the case of Apollo and the Falcon 9 hitting the abort during launch fires explosive bolts and emergency thrusters that will kick the spacecraft away from the rocket. Which allows it to land safely. Now the abort button on say the lunar module if pressed would fire the accent stage thruster forcing the decent stage away from the accent stage allowing the lunar module to reach lunar orbit. There is really no abort during the trip to the moon. If a spacecraft has to return like Apollo 13 did you have to change the craft delta v to basically slingshot around the moon.

The abort modes are only used during launch. If there’s an emergency with the spacecraft on the launch pad or in flight that requires the capsule to come back to Earth immediately or if there’s something wrong with the booster, the abort handle or button will fire emergency rockets on the capsule that will pull it safely away from the booster. [You can see in this animation how that works](https://youtu.be/yVCbVRuDawk?t=64). Because the spacecraft is not yet in orbit, the capsule will then coast for a bit and then deploy its parachutes for a safe landing. In some rockets, like the Russian Soyuz, the abort rockets can be jettisoned after launch. In others, like the SpaceX Dragon, the emergency escape rockets are built into the capsule.

Typically though, the onboard computer will detect an emergency and activate the abort rockets automatically. The button or handle is more of a backup in case something happens that the computer doesn’t detect or if the computer doesn’t react fast enough.

The purpose of any ‘abort’ function in space is to jettison the crewed area from the spacecraft’s propellant, thereby reducing the crews chance of blowing up. The abort module would contain the minimum supplies, fuel, and equipment needed to return the crew to safety.

Depends on what the abort procedure is… During launch is the only real time it can save you, at that point the Lau Ch escape system would fire, pull you off the top of the rocket and away and then parachute down, in movies tho it can do anything needed for an abort like activating livevessles or return to home ect