4 ms·

It hasn't flown any missions, but Crew Dragon has had its launch pad abort tested: https://www.youtube.com/watch?v=wcHD9AmkxA0 https://www.youtube.com/watch?v=w

by coob 8y ago

It hasn't flown any missions, but Crew Dragon has had its launch pad abort tested: https://www.youtube.com/watch?v=wcHD9AmkxA0 https://www.youtube.com/watch?v=wcHD9AmkxA0

rory096 8y ago
Orion has also done a pad abort test, for what it's worth. https://www.youtube.com/watch?v=j68mszdhTmY https://www.youtube.com/watch?v=j68mszdhTmY
- cptskippy 8y ago
  Why does Lockheed's official video look like it was filmed by my uncle on his VHS camcorder?
  - dmix 8y ago
    Looks like someone is recording a video feed broadcast via a projector onto a dark wall with a cellphone or camera. Probably a cellphone from 8yrs ago.
    - moreira 8y ago
      Off-topic, but, a cellphone from 8 years ago is the iPhone 4. Isn't that crazy to think about?
      - cptskippy 8y ago
        We're way off topic at this point. I think the iPhone 4's video quality would be better.
        dmix 8y ago
        Regardless it's a video recording of a video being projected onto a wall. The cellphone quality is the least important part of my comment and has improved dramatically in quality on the average smart over 8yrs (iPhone tends to be leading edge and that phone was brand new at the time which not everyone has).
dogma1138 8y ago
Yes, but there is a difference between being tested and being used. On paper the Crew Dragon launch abort system is slightly better since it doesn't rely on an escape tower for launch pad abort but in reality it's not clear how much better and safer for the crew the whole thing would be.
- orbital-decay 8y ago
  I'm not sure if having eight high-pressure hydrazine engines (which must work in perfect sync) inches apart from the crew is safer than a classic launch escape tower with a single solid booster on top.
  - dmix 8y ago
    Do other types of rocket engines not need to be in perfect sync?
    - orbital-decay 8y ago
      A classic launch escape system doesn't. It has several exhausts, but it's a single booster.
  - LeifCarrotson 8y ago
    > eight high-pressure hydrazine engines (which must work in perfect sync) There's eight for redundancy, it's a fault-tolerant system.
    - rbanffy 8y ago
      There are 8 independent engines, IIRC, mounted two by two. I think they are controlled in pairs, one on each side of the craft so as to avoid an engine on one side not knowing its counterpart on the other side failed and forcing the capsule to spin instead of fly away from the faulty booster.
  - 7952 8y ago
    One advantage is that you avoid having to jettison the escape tower which would add some complexity and risk. Also, the engines are designed for use in space during a normal mission and to be recovered. So in that configuration the crew would still need to be located close to a hydrazine thruster as a part of a normal flight.

by coob 8y ago

It hasn't flown any missions, but Crew Dragon has had its launch pad abort tested: https://www.youtube.com/watch?v=wcHD9AmkxA0 https://www.youtube.com/watch?v=wcHD9AmkxA0

rory096 8y ago

Orion has also done a pad abort test, for what it's worth. https://www.youtube.com/watch?v=j68mszdhTmY https://www.youtube.com/watch?v=j68mszdhTmY

cptskippy 8y ago
Why does Lockheed's official video look like it was filmed by my uncle on his VHS camcorder?
- dmix 8y ago
  Looks like someone is recording a video feed broadcast via a projector onto a dark wall with a cellphone or camera. Probably a cellphone from 8yrs ago.
  - moreira 8y ago
    Off-topic, but, a cellphone from 8 years ago is the iPhone 4. Isn't that crazy to think about?
    - cptskippy 8y ago
      We're way off topic at this point. I think the iPhone 4's video quality would be better.
      - dmix 8y ago
        Regardless it's a video recording of a video being projected onto a wall. The cellphone quality is the least important part of my comment and has improved dramatically in quality on the average smart over 8yrs (iPhone tends to be leading edge and that phone was brand new at the time which not everyone has).

dogma1138 8y ago

Yes, but there is a difference between being tested and being used. On paper the Crew Dragon launch abort system is slightly better since it doesn't rely on an escape tower for launch pad abort but in reality it's not clear how much better and safer for the crew the whole thing would be.

orbital-decay 8y ago
I'm not sure if having eight high-pressure hydrazine engines (which must work in perfect sync) inches apart from the crew is safer than a classic launch escape tower with a single solid booster on top.
- dmix 8y ago
  Do other types of rocket engines not need to be in perfect sync?
  - orbital-decay 8y ago
    A classic launch escape system doesn't. It has several exhausts, but it's a single booster.
- LeifCarrotson 8y ago
  > eight high-pressure hydrazine engines (which must work in perfect sync) There's eight for redundancy, it's a fault-tolerant system.
  - rbanffy 8y ago
    There are 8 independent engines, IIRC, mounted two by two. I think they are controlled in pairs, one on each side of the craft so as to avoid an engine on one side not knowing its counterpart on the other side failed and forcing the capsule to spin instead of fly away from the faulty booster.
- 7952 8y ago
  One advantage is that you avoid having to jettison the escape tower which would add some complexity and risk. Also, the engines are designed for use in space during a normal mission and to be recovered. So in that configuration the crew would still need to be located close to a hydrazine thruster as a part of a normal flight.