56

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 only being moved from one docking port of the station to another the crews retreat to their vehicles in fire / leak / toxic atmosphere emergencies the crews ...


43

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 can't otherwise see because the helmet is in the way, they can't turn their head, they can't leave the seat, or similar. For example, if you try to look up, ...


33

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, that launched Mar 2, 2019 and docked to the PMA/IDS on the ISS. Then they did the in flight abort, Jan 19, 2020 with the C205 capsule. Then they flew the Demo-2 ...


27

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 if there was a freak accident in which the ISS needed to be evacuated and no space craft was available? For example, suppose two human-qualified vehicles are ...


17

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" is that it was a demonstration flight, not an operational flight. How is the recent one different? It is not a demonstration flight, it is an operational ...


11

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 is the proposed Gray Dragon mission. This would carry two astronauts around the Moon and back, with no ability to orbit when it got there. It would require the ...


7

There are a few necessary activities and schedule considerations that contributed to needing 18 hours between undock and entry. Sleep Loading the Crew Dragon with returning (“down-mass”) gear, readying the capsule for undocking and maneuvers, and prepping the astronauts themselves is a full day of work, even for the three U.S. astronauts that were on the ISS....


6

We'll ignore the 18 hours spent in orbit between Endeavour's undocking and the actual beginning of descent; I don't know what the crew were doing during that period, but it wasn't really part of the return-to-Earth process. I'm basing this answer on the times given Demo-2 return timeline posted on the NASA ISS blog on August 2, 2020, which as of this writing ...


6

To answer the first question: Crew Dragon would reenter safely. Otherwise there wouldn't be a button in the Pyros section labeled "Jettison nose cone."


6

Propulsive landing was the original plan for the Dragon 2, back when the Dragon 2 was also intended to maybe be used for Moon landings (Grey Dragon) and Mars landings (Red Dragon), where there is no or not enough atmosphere for parachutes. Plus, it would help commonize (is that a word?) knowledge between Falcon 9, Starship, and Dragon. However, both of those ...


5

There WAS a different concept for returning folks from orbit in emergencies that was considered, called MOOSE, but it never got out of the planning stages.


5

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-splashdown.html So propulsion must be useful in some contingency even that close to splashdown. But I won't speculate on what contingencies were considered. Edit: On ...


4

This 2014 post in the NASASpaceflight forums shows how it worked for the parachute test capsules. We know that the system was changed some since then, but the most basic things (i.e. what goes where) are likely to be the same. In that post's pictures, you can clearly see that the drogues are fired from the top hatch (yellow in your picture) and lines run ...


4

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 them will be less efficient than if they were directly in the desired direction. They burn real quick, which means more force that the station has to absorb, ...


3

Short answer: Three cargo and five crew vehicles. Gwynne Shotwell answered this Specifically, Shotwell revealed that SpaceX intends to build three reusable Cargo Dragon 2 capsules, one of which is already completed and in Florida preparing for its December 2nd CRS-21 launch debut. On the crew side of things, SpaceX will build “three more” Crew Dragon ...


3

The prior flights where Demo flights, and had test pilots as crew. Crew-1 had "regular" astronauts from NASA and other agencies. They are all crewed, why is it different? Test pilots vs Passengers. Think a commercial flight, you won't load up passengers on the first manned tests, you do test pilots and some test crew and such. Then you do the paid ...


3

On Earth, under a 1G gravity field, dust, crap, mites, etc fall to the ground. You can vacuum and clean as much as you want, but the damn stuff gets everywhere. And vehicles like this have lots of nooks and crannies. Remove gravity, inject lots of shake, rattle, and roll of launch, then orbital maneuvers, all sorts of unexpected bits and pieces will pop up ...


3

Yes, the FAA does in fact still certify parachute packers ('parachute riggers' is the specific term), who receive ratings based on the types of parachutes they are trained to pack. However, the FAA certifications (there are two levels, senior/entry-level and master) that are offered are typically used for packing skydiving parachutes, rather than for space ...


2

Crew Dragon with Falcon Heavy can theoretically be sent to a lunar free return trajectory, so pretty much any apogee could be done. As for just a Falcon 9, it's hard to know for certain. Putting in a desired orbit of 2000 km with the NASA Performance Vehicle Calculator, I got the following plots. Note that 9000 km is the launch mass of Crew Dragon. The ...


2

Yes and no. If it failed to close, it would damage the systems somewhat. There is a way to manually eject the nose cone, which is what would be done in such a situation. Presumably this would limit reuse and increase the risk, but not ultimately be as risky as having an unclosed nose cone. Note that Crew Dragon reentering with no nose cone is pretty similar ...


2

It is important to remember that we are talking about multiple separate spaceships with multiple separate crews docked together. We have the ISS, which has a crew. We also have the two "halves" of the ISS, i.e. the Russian segment and the international segment, and likewise we have the international complement to the ISS crew and the Russian ...


1

I won't answer specifics of the Dragon design. It's up to SpaceX to answer that if they choose to; other parties that reviewed that data are bound contractually and by law to not reveal proprietary information. The original NASA human systems integration requirements (HSIR) as given to SpaceX did not specify separate requirements for eyeballs-in and ...


1

Elon Musk can explain. “The reason we decided not to pursue (powered landings) heavily is it would have taken a tremendous amount of effort to qualify that for safety, particularly for crew transport,” Musk said. “And then there was a time when I thought that the Dragon approach to landing on Mars, where you’ve got a base heat shield and side-mounted ...


1

Thank you to David Hammen: The Velocity of Spacex's Livestream telemetry data is described by ECEF coordinates (earth-centered, earth-fixed). ECEF Wikipedia The equation for orbital velocity used above is valid only for ECI coordinates. ECEF coordinates are used preferrably in Satellite navigation, because it offers precise values without having to choose a ...


1

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) that the Draco maneuvering thrusters use. In fact, they use the same propellant storage tanks, with different pressurization lines and fuel valve systems. Dumping ...


1

The launchpad where SpaceX now launches its missions dor instance Crew Dragon mission is pad Kennedy Space Center Launch Complex 39. A lot of missions like Apollo missions Saturn V, Space Shuttles, Falcon 9, and finally Falcon Heavy. This pad built-in 1967 was acquired by SpaceX in 2014. When SpaceX acquired the pad they had to work with the structure ...


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