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58 votes
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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 ...
Organic Marble's user avatar
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 ...
T.J. Tarazevits's user avatar
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 ...
geoffc's user avatar
  • 79.9k
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 ...
fred_dot_u's user avatar
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43 votes
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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 ...
Jörg W Mittag's user avatar
40 votes
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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 ...
geoffc's user avatar
  • 79.9k
38 votes

If Crew Dragon can dock autonomously, why is there a crew aboard when they change from docking port to another?

If the capsule were to fail to autonomously redock successfully, the crew would not be able to use it to return to Earth. Therefore, the crew rides in the capsule so that if does not redock ...
phil1008's user avatar
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34 votes
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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 ...
Russell Borogove's user avatar
33 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 ...
SF.'s user avatar
  • 55.1k
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, ...
geoffc's user avatar
  • 79.9k
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. ...
leftaroundabout's user avatar
30 votes
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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 ...
Uwe's user avatar
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28 votes
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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 ...
GremlinWranger's user avatar
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 ...
David Hammen's user avatar
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: ...
jwenting's user avatar
  • 593
23 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 ...
Antzi's user avatar
  • 12.7k
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 ...
John Aaron's user avatar
22 votes
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Eye Spy: Where are the other two (of six) vehicles docked to the ISS in this Maxar image (& what are they?)

Soyuz MS-25 and Cygnus-20 (NASA)
Steve Pemberton's user avatar
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 ...
Malky's user avatar
  • 309
20 votes
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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, ...
Johnny Robinson's user avatar
20 votes
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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 ...
Jörg W Mittag's user avatar
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" ...
Jörg W Mittag's user avatar
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 ...
geoffc's user avatar
  • 79.9k
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 ...
James Thorpe's user avatar
  • 1,315
14 votes

If Crew Dragon can dock autonomously, why is there a crew aboard when they change from docking port to another?

Every ISS crew member must always have a seat on a lifeboat available at any time. I'm pretty sure this is dictated by ISS Flight Rules, and I'm pretty sure there are members here that have access to ...
Jörg W Mittag's user avatar
13 votes
Accepted

Why do they make the astronauts sit in Crew Demo-2 for so long before launch?

All of the above, probably. Here are just a few of the things that must happen before liftoff. 35 minutes before liftoff, propellant loading starts on the Falcon 9 first and second stage. At this ...
Jörg W Mittag's user avatar
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 ...
PearsonArtPhoto's user avatar
  • 121k
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 ...
Rob's user avatar
  • 3,276
12 votes

Is Crew Dragon flawed? Is it just an improvisation with no future?

First of all, Crew Dragon can actually be reused. NASA has agreed to permit reuse of both rockets and the capsule after the second longer-term mission. Of some note, the capsule was always designed ...
PearsonArtPhoto's user avatar
  • 121k
12 votes

Effects On ISS Orbital Mechanics Resulting From Added Mass Of Dragon Capsule Visit

The orbital mechanics of satellites are independent from the mass of the satellite. As long as the sats mass is tiny compared to the mass of Earth. The total mass of the ISS is much larger than the ...
Uwe's user avatar
  • 49.2k

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