57
votes
Accepted
Evacuating the ISS but wait, there's only one Spacecraft?
By design that will never happen. There are always enough return seats for the crew.
This is exactly why
the whole crew of one of the visiting vehicles gets in it whenever it undocks, even when it is ...
- 177k
53
votes
After the Crew Dragon's success, does Boeing's Starliner still offer value?
Commercial Crew awarded two providers for dissimilar redundancy.
This is exactly why NASA decided to select two partners in the commercial crew effort. Having dissimilar redundancy is key in NASA’s ...
- 3,797
45
votes
Is Crew Dragon flawed? Is it just an improvisation with no future?
It seems like you are considering design for re-use as a flaw.
The Super Draco engines are kept since they can be reused. They need them for abort, so unless they ditch them, they cost payload mass ...
- 79.2k
44
votes
Why do Crew Dragon astronauts need to climb up one level using the stairs before ingress?
Scott Manley of the YouTube has a great video that addresses the extra level of the tower, located at the seven minute mark of a recent posting.
Verbatim transcript from the video:
So pad 39A is ...
- 1,870
43
votes
Accepted
What are these shiny wrist plates worn by astronauts in the SpaceX crew capsule
These are mirrors. Even SpaceX's slick spacesuits have limited mobility, especially when the astronauts are strapped into the seats. The mirrors allow them to see corners of the spacecraft that they ...
- 17.8k
40
votes
Accepted
What is the primary reason for SpaceX motion to have astronauts board Dragon before fueling up the rocket?
The Merlin-1D engines are now tuned to use the super cooled fuel and oxidizer. Thus you would be running the engines in an out of normal state, if not using it the same as all other launches with ...
- 79.2k
34
votes
Accepted
Would this chair support astronaut during launch in Crew Dragon
1.) Chairs needed to be custom molded / adjusted for the astronauts. There's stories of people sitting down in bathtubs of foam to create the perfect shape.
That is an extra comfort of the Soyuz ...
- 54.4k
34
votes
Accepted
How would astronauts brave a 19 hour trip to ISS inside Crew Dragon capsule?
After the initial launch into orbit, the crew will be weightless, which will make things a little more comfortable. The Crew Dragon isn't as cramped as you might think; it has room for 4 crew members ...
- 166k
33
votes
Why is the SpaceX crew-1 mission more important than the previous one (demo-1)?
The contract between SpaceX and NASA required two demo flights (and SpaceX voluntarily did the in flight abort, notice Boeing is not doing that).
They did an unmanned demo flight with Dragon C201, ...
- 79.2k
31
votes
Why does opening the Crew Dragon hatch take so long?
As I understand the livestream, the most important thing was pressure equalisation and subsequent leak checking.
I guess this could be done faster, but it's just not worth taking any risks on it. ...
- 3,585
30
votes
Accepted
Why would spacecraft docking to the ISS have a different atmospheric pressure?
The pressures of both the Dragon spacecraft and the ISS match the atmospheric sea level pressure of Earth, about 1 bar. But there are small inevitable tolerances of about some millibar or less. So ...
- 48.7k
28
votes
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 ...
- 20.9k
28
votes
Evacuating the ISS but wait, there's only one Spacecraft?
What would happen if there was a freak accident in which that the ISS needed to be evacuated and there was ONLY one space craft available?
Carrying that to an even greater extreme, what would happen ...
- 72.5k
27
votes
Why was the SpaceX abort test not initiated by real booster failure?
It was a real failure (albeit triggered externally rather than accidentally), just not the only failure that can happen. and it is the worst case of a series of the most likely failure scenarios: ...
- 593
23
votes
Why is it even desirable for a spacecraft to land without a parachute?
If you're just looking at it as a mass trade, then yes, you will definitely get a mass savings by replacing a portion of your propellant with a bag full of nylon. Depending on your speed, the nylon ...
- 58.4k
22
votes
Getting the SpaceX dragon crew rated
Two things.
Human-rating a rocket is a long, expensive process
See this questions for more informations What exactly does it mean to human-rate a rocket? As opposed to the escape system?
Every ...
- 12.6k
22
votes
What is the primary reason for SpaceX motion to have astronauts board Dragon before fueling up the rocket?
In addition to not wanting to change anything for crewed launches (as geoffc mentioned), adding crew to a fueled vehicle is a seriously dangerous move.
If you look at the AMOS-6 failure you'll see ...
- 340
21
votes
Accepted
Will a Dragon v2 ever bring 7 astronauts to the ISS?
NASA has only contracted for flights with 4 astronauts, since the complement of the station is a maximum of 7 in the long term. The limit of 7 has many reasons, but some are for sleeping ...
- 79.2k
20
votes
Why was the SpaceX abort test not initiated by real booster failure?
You seem to think they were testing in ideal conditions. That's as far from truth as you can get. The abort happened at the moment in flight with worst aerodynamical conditions (called maxQ), when ...
- 309
20
votes
Accepted
After Crew Dragon launch abort, was Falcon 9's detonation intentional?
They didn't blow it up. They simply knew it would break up. A rocket is a very frail thing. It can only maintain it's structural integrity in forces it was designed to handle. When the Dragon left, ...
- 4,854
20
votes
Accepted
How does Spacex Crew Dragon capsule deorbit?
Crew Dragon uses the regular Draco thrusters for the deorbit burn, and in fact for any burn during a regular flight. The Superdracos are only used for launch escape.
The main reason is that the ...
- 17.8k
17
votes
Why is the SpaceX crew-1 mission more important than the previous one (demo-1)?
The previous one was also crewed (two crew) but it was called "demo" for some reason - despite taking astronauts to the ISS.
The "some reason" that it was called "Demo" ...
- 17.8k
16
votes
Accepted
Why is it even desirable for a spacecraft to land without a parachute?
Note that this answer refers to the final flight version of the Dragon V2. The first powered landings will be using parachutes before the system is validated for powered-only landing (see this article,...
- 4,350
16
votes
How would astronauts brave a 19 hour trip to ISS inside Crew Dragon capsule?
Ironically, the Soyuz vehicle has been taking a 'faster' approach to the ISS of late. Used to be a 1-2 day mission, and the new faster approach (tested on Progress vehicles first) is only about 4 ...
- 79.2k
15
votes
Will a Dragon v2 ever bring 7 astronauts to the ISS?
When the space shuttle was in operation, it could carry as many as seven extra people, bringing the total population of the ISS up to ten. Three crew members is the standard permanent capacity of the ...
- 23.7k
15
votes
Why is it even desirable for a spacecraft to land without a parachute?
E. Musk has answered this multiple times in interviews. This comes down to the economics of it. They are putting this entire system together to haul cargo, and the reusable portion is there to ...
- 151
15
votes
When is the Dragon V2 abort system armed?
Now we've had the Crew Dragon In Flight Abort test, this can be answered more definitively. I've not found a stream where it's absolutely crystal clear, but in the NASASpaceFlight coverage, you can ...
- 1,315
13
votes
Accepted
What capabilities does Orion have that Dragon-V2 does not?
Orion is larger, has a life support rated for a few weeks, has a service module that will allow it real control around the Moon, and is rated for a return from the Moon.
The closest direct comparison ...
- 121k
12
votes
Could a modified Dragon reach Low Earth Orbit just using SuperDraco engines?
Dragon V2 (Crew Dragon) uses 8 SuperDraco engines with maximum of 73,000 N thrust each. So, in theory, it could produce enough thrust to lift about 50,000 kg off the pad at thrust-to-weight ratio (T/W)...
- 76.4k
12
votes
What is the primary reason for SpaceX motion to have astronauts board Dragon before fueling up the rocket?
What is the primary reason for SpaceX motion to have astronauts board Dragon before fueling up the rocket?
From what I understand though, it shouldn't be necessary - Falcon 9 and Dragon 2 have enough ...
- 3,256
Only top scored, non community-wiki answers of a minimum length are eligible