28
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Accepted
Why did Crew Dragon switch to burst disks instead of multiple check valves?
It would be possible to design a check valve chain of high reliability of closing, but it would restrict flow and start to increase the risk of one valve sticking shut. You would probably also need ...
- 25k
8
votes
Accepted
Why does the Superdraco exhaust seem so under-expanded in this photo?
In this photo, the exhaust doesn't expand so much. The nozzle looks to be a bit longer. So they've played with various nozzles.
(cropped and adjusted for visibility)
And the Ars Technica article ...
- 130k
7
votes
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Why doesn't the crew dragon spacecraft of Polaris dawn mission appear to have a launch escape system?
The SuperDraco thrusters are there they are just not easily visible. Crew Dragon SuperDraco thrusters are difficult to see in most photos because of the covers in place to protect them. This photo of ...
- 5,914
6
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Does the Crew Dragon still have the launch abort fuel on board at landing?
Yes, fuel is still carried. Only 600 m before splashdown (2:12 in this video), "Dragon has safed all propulsion systems on board." https://www.space.com/spacex-crew-dragon-demo-2-...
- 12.3k
6
votes
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How could SpaceX’s crew Dragon land with abort thrusters in case of emergencies?
PearsonArtPhoto answers why it isn't done - generally NASA's very conservative approach to spacecraft safety, and hurdles it would set to get it implemented.
But assuming a miraculous change in NASA ...
- 56k
5
votes
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Dragon capsule thrust requirements
Dragon 2 (Crew Dragon) has two separate types of engines: the powerful SuperDraco thrusters (currently planned only for use in launch escape) and the much smaller Draco thrusters used for attitude ...
- 1,542
5
votes
Accepted
SuperDraco Engines in Crew Dragon spacecraft
Firstly, available space for engines isn’t really a problem. A spacecraft can be made exactly as big as the needed cargo space plus engines. Capsules only look tiny because you usually see them next ...
- 2,267
5
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How could SpaceX’s crew Dragon land with abort thrusters in case of emergencies?
There is no plan to do this, nor has there ever been an extensively studied plan. In theory it could be done, but NASA would want to certify it, and it is just better to spend more effort to make sure ...
- 122k
5
votes
Could the Crew Dragon be used to re-boost the ISS?
Theoretically, it could, but why use the larger, more expensive rocket engines when you could just use a less expensive, smaller draco engines?
Super Dracos are off axis, meaning that any thrust from ...
- 122k
5
votes
Accepted
What would happen during an inflight abort in a Falcon 9 if the booster engines did not shut down?
The abort system in the Falcon 9 removes the payload (Crew Dragon) from the second stage using the Super Draco engines. The second stage remains attached to the first stage. Mass of the fully loaded ...
- 461
3
votes
Why not Super-Draco in lunar lander?
To begin with, SpaceX bid Starship as their lunar lander. Starship used methalox as their propellant for their Raptor engines. However, Starship does need landing engines higher up on the hull for the ...
- 4,283
3
votes
Merlin 1D Engine
The Merlin Engine is a gas generator cycle engine which uses liquid Oxygen(LOX) and refined Kerosene(RP1) as its propellants.
The SuperDraco engine is a pressure fed cycle engine which uses mono-...
- 4,305
3
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Why does the Superdraco exhaust seem so under-expanded in this photo?
I think its clear the lack of a nozzle is the cause. As to the "why" I can think of a few reasons that might be partly responsible (other than it's just testing):
They are not designed to be used for ...
- 3,442
2
votes
SuperDraco Engines in Crew Dragon spacecraft
The SuperDraco engines themselves are quite compact. Liquid rocket engines consist of a relatively small combustion chamber and a nozzle which may be large or small in proportion depending on the ...
- 172k
2
votes
Why not Super-Draco in lunar lander?
First of all, the SuperDracos were designed from the start primarily as a launch escape system. Although using them for propulsive landing was explored extensively, it was never implemented.
For ...
- 1,542
1
vote
Dragon Superdracos: how much MMH/NTO propellant?
For the abort tests in early 2020, according to documents filed with the FAA over a year prior, the Dragon flew with 2565 kg of propellant (1590 kg of NTO and 975 kg of MMH), but only about half of ...
- 172k
1
vote
Does the Crew Dragon still have the launch abort fuel on board at landing?
Yes, the fuel for the launch abort system is kept during the duration of the flight, however it is not wasted.
The SuperDraco abort thrusters use the same combination of propellants (NTO and N2O2) ...
- 3,857
1
vote
Purpose of side holes on SuperDraco pods of DM-1 flight Dragon 2 capsule
I believe these are the flaps that open and close to reveal the openings for the SuperDracos. The SuperDracos allow Dragon 2 to separate from the rocket during aborts. I think they swivel so the ones ...
- 11
1
vote
Crew Dragon SuperDraco Engine Covers
The abort test was done several years ago. Quite a few changes have been made since. The covers on the Super Draco nozzles are quite recent, from what I've seen. The entire pod area now has a silver-...
- 723
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