Re:Astronauts escape malfunctioning Soyuz rocket
by coob on Thursday October 11, 2018 @08:42AM
(#18192990)
It hasn't flown any missions, but Crew Dragon has had its launch pad abort tested: https://www.youtube.com/watch?v=wcHD9AmkxA0
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Re:Astronauts escape malfunctioning Soyuz rocket
by dogma1138 on Thursday October 11, 2018 @08:57AM
(#18193092)
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.
Re:Astronauts escape malfunctioning Soyuz rocket
by orbital-decay on Thursday October 11, 2018 @10:18AM
(#18193725)
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.
Re:Astronauts escape malfunctioning Soyuz rocket
by dmix on Thursday October 11, 2018 @10:45AM
(#18193924)
Do other types of rocket engines not need to be in perfect sync?
Re:Astronauts escape malfunctioning Soyuz rocket
by orbital-decay on Thursday October 11, 2018 @11:15AM
(#18194164)
A classic launch escape system doesn't. It has several exhausts, but it's a single booster.
Re:Astronauts escape malfunctioning Soyuz rocket
by njarboe on Thursday October 11, 2018 @12:16PM
(#18194760)
The original plan for Crew Dragon was to have it land with rockets like a rocket should, instead of with parachutes. They also wanted to have a design that could also land on Mars. Safety first NASA didn't allow that plan. Not sure if rockets are still powerful enough to do a powered landing coming from orbit. I hope so and that tourists will have the option of returning that way even if NASA astronauts don't.
Re:Astronauts escape malfunctioning Soyuz rocket
by rory096 on Thursday October 11, 2018 @12:47PM
(#18195008)
They will not develop powered landing. SuperDraco or not, one of the main obstacles was the difficulty and risk of putting legs through the heatshield.
Smaller Dracos are used for in-orbit maneuvering. SuperDracos are now solely for launch abort. They could conceivably be used for an orbital maneuver requiring more delta-v than the fine-tuning the Dracos do, but at this point the only likely destination for Dragon is the ISS.
Re:Astronauts escape malfunctioning Soyuz rocket
by 7952 on Thursday October 11, 2018 @12:01PM
(#18194612)
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.
Re:Astronauts escape malfunctioning Soyuz rocket
by LeifCarrotson on Thursday October 11, 2018 @11:15AM
(#18194161)
> eight high-pressure hydrazine engines (which must work in perfect sync)
There's eight for redundancy, it's a fault-tolerant system.
Re:Astronauts escape malfunctioning Soyuz rocket
by rbanffy on Thursday October 11, 2018 @11:54AM
(#18194546)
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.
Re:Astronauts escape malfunctioning Soyuz rocket
by rory096 on Thursday October 11, 2018 @09:41AM
(#18193423)
Orion has also done a pad abort test, for what it's worth.
Re:Astronauts escape malfunctioning Soyuz rocket
by cptskippy on Thursday October 11, 2018 @10:34AM
(#18193842)
Why does Lockheed's official video look like it was filmed by my uncle on his VHS camcorder?
Re:Astronauts escape malfunctioning Soyuz rocket
by dmix on Thursday October 11, 2018 @10:48AM
(#18193951)
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.
Re:Astronauts escape malfunctioning Soyuz rocket
by moreira on Thursday October 11, 2018 @11:13AM
(#18194145)
Off-topic, but, a cellphone from 8 years ago is the iPhone 4. Isn't that crazy to think about?
Re:Astronauts escape malfunctioning Soyuz rocket
by cptskippy on Thursday October 11, 2018 @11:21AM
(#18194224)
We're way off topic at this point. I think the iPhone 4's video quality would be better.
Re:Astronauts escape malfunctioning Soyuz rocket
by dmix on Thursday October 11, 2018 @11:58PM
(#18199095)
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).