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36

TL;DR: The low technology readiness, the very, very low thrust, and the need for a catalyst bed means this was and still is the wrong technology for the intended purpose of a launch abort system and maneuvering in low Earth orbit. Low technology readiness SpaceX began working on Dragon V2 over five years ago. At that point, AF-M315E had a rather low ...


34

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 spacecraft. In NASA spacecraft, the seats were "one size fits all." One of the reasons is that the 'failsafe' modes of Soyuz - launchpad abort, ballistic reentry - ...


27

There are many different constraints that putting a time window around a launch attempt (even a pad abort) can help manage. Orbital constraints, facilities availability and many more. In the case of a Pad Abort, consider the flight path. Ignite the Super Dracos, get high enough for the parachutes to be effective, and land in the ocean just off the coast. ...


19

Yes, the ISS was a busy place recently. As you probably remember Cygnus had to wait for a week to proceed with its rendezvous to let Soyuz dock first. We can consider that a traffic jam in orbit. :-) The current Russian plans include docking MLM Nauka after deorbiting Pirs. And a bit later to add a spherical Uzlovoy Module (i.e. Hub Module or Nodal Module). ...


16

Horsh answered for the Russian side of the station very. But the question was more about the US side of the station. The US side of the station does need more ports. It looks like a fair bit of reconfiguration will be performed of the current modules to free up spots. (Edit: Early 2016 this reconfiguration was complete. CRS-7 with IDA-1 was lost on ...


16

Dragon is not the first manned spacecraft to launch without a fairing Mercury had a Launch Escape Tower bolted to the top. Gemini had ejection seats so no tower was needed Starting with Apollo, a small fairing cover was included as part of the LES. This cover detached with the LES during flight to reduce weight. With Soyuz all capsules have had a fairing ...


15

As the RUD event occurred during stage 1 flight the Dragon wouldn't having been travelling fast enough to need a heatsheild to survive reentry. (And from 44.5 km it hadn't really gone high enough to be said to be 'reentering', it never really left). The biggest danger to the dragon during the fall would be if it started tumbling. The conic structure of ...


15

The NASA contract for the CRS missions specified a new Dragon for each flight. That would explain why no Dragon has been reused on an ISS logistics mission. But that does not answer why SpaceX has not reflown any of the others, which they retain ownership of, post flight. SpaceX has proposed a commercial free flyer, where a Dragon would be launched with ...


14

Yes. According to SpaceX; PICA-X, which is SpaceX's proprietary derivative of the PICA (Phenolic Impregnated Carbon Ablator) heatshield designed by NASA, can withstand reentries from "Lunar and Martian Velocities". Martian velocities being even higher, of course. Source from SpaceX here. PICA itself was used on the Stardust spacecraft which reentered at a ...


14

Musk indicated that Dragon 2 could be reused "with minimal rework and fueling" about 10 times between overhauls. This is the target number but these are early days. The previous ablative shield was dumped in favor of a more advanced design. The goal then, for heat shield, engines and other major components would be at Least 10 flights, in theory. Regards ...


14

You forgot HTV, the Japanese vehicle that has a fairly large payload. It has a planned flight Aug 15, 2015. There are several more HTV flights planned on the manifest. Progress is due to fly again with cargo in early July 2015. Assuming the Russian space agency is able to resolve its issues that will help with the supply situation. Cygnus flying on Atlas ...


12

It's got to be hugely expensive to transport and erect a Falcon even if you don't intend to launch it. The potential for damaging part of the rocket in the test makes it even less attractive. Why use a real rocket if a truss suffices? After Apollo's first abort test from a low platform in the desert, they also did several in-flight abort tests by ...


12

Yes, by quite a bit. Right now the heaviest object soft landed on Mars is Curiosity, as you noted. The mass of it is 900 kg. The Red Dragon is 6400 kg, plus payload of up to 2000 kg (Maybe more for later flights) In fact, when successful, the Dragon will be more than the sum of every other object which attempted to soft landed on Mars. Each Viking massed ...


11

It's the Dragon logo! That's it! They changed it from this: to this: The logo was leaked to Reddit community /r/SpaceX a while back, and first appeared on the Dragon v2 test article. This is the first time it's making its appearance on a Dragon v1. My understanding for the change is that because Dragon v2 has no "wings" (extendable solar panels), they ...


11

As usual in this sort of thing, there's no single optimal answer because the capsule has to do a few different things, so the shape has to balance different requirements. A narrow cone angle gives less drag on ascent. A large broad base is required for deceleration on re-entry. A squat cylinder gives more convenient usable interior space. I believe the ...


11

Yes, that section is usually called trunk and it may contain unpressurized cargo - up to 14 m3 (compared to 10 m3 of pressurized payload) (source) You can see it being loaded with BEAM (Twitter post) And here is what seems like a real photo of the open section from the ISS (nasaspaceflight.com article)


10

The ISS orbital speed is 7.71 km/s or 27 756 km/hour. I'm sure the best thrust it could give the Dragox-X with the robotic arm is an order of 20km/h and with Dragon-X weighing roughly 8 tons with the payload, and ISS weighing 450 ton, less than 2% of that speed has been transferred to the station. That means its speed changed by 0.2km/hour, which is 2/...


10

I shall answer myself, since in wondering and writing about it, I think I know the answer. Probably not. The issue is that a Dragon capsule (Cargo version) only has Draco thrusters for maneuvering. These have a thrust of 90 lbs. That is just too little to make much of a difference. Now if they could thrust for hours, sure that would help, but of course ...


10

Aviation Week seems to be the best source right now. A few interesting bits: NASA is spending up to $30 million in support, mostly to help gain information for EDL on Mars. A photo might be taken using either ground-based sources, or orbital sources, to help the process. The specific plans will be outlined at the International Astronautical Congress in ...


9

The Manned Dragon capsule, the Dragon 2, is designed to be able to do a powered escape from a launch stack. That requires at least 1.1 Gees thrust (and ISTR a requirement of 3 Gees). Further, it's designed to perform a powered landing after escaping the launch stack. But it's also required to be able to detach in flight at any altitude, including LEO, and ...


9

SpaceX had a permit/environmental assessment for their Dragonfly test vehicle/series of tests. It included the full gamut of ground level tests (at least one completed, hover test on a crane (video) and then helicopter drops, propulsive landings, and then boosted hops. They have been very quiet about performing these tests for some reason. Of course, the ...


8

The CST-100 heat shield is replaced each flight because it is discarded as part of the landing process. The capsule has airbags, between the heat shield and bottom of the capsule. As the parachutes slow it down for landing, it discards the heat shield, inflates the airbags, and lands on the ground. Thus they can never reuse a heat shield, they throw it ...


8

The best I've been able to come up with is interior shots from the unveiling and of the test article (complete with test dummy), but I'd say the visual difference is a pretty compelling argument that at least the hull of the test vehicle isn't the one used in the unveiling: A still from the video of the unveiling, Elon climbing in: Test vehicle with test ...


8

This is such an expansive question that it is difficult to answer without writing an entire essay. The answer comes down to the systems engineering process and the mission requirements. As in all spaceflight missions, the payload needs to be protected, especially when a human is the payload. The shape will largely be derived from payload, aside from its ...


8

First of all, the difference in capacity is actually greater than you included. Dragon launches without a fairing, thus there is an increased capacity as a result of launching without the fairing. The exact mass isn't known. Okay, so what else might be different in the cargo capacity? Here's a few things: The Dragon might not be structurally capable of ...


7

There are many payloads that are large, and need transport to the station. Things the Shuttle used to provide. If you carried them pressurized, they would need to be sized to fit through the CBM port to get out of the Dragon, then through one of the airlocks (Quest or Russian side) to get out of the station. The Shuttle left some large line replaceable ...


7

Unpressurized volume is used to deliver payloads that will be used externally on the International Space Station (ISS), i.e. external cargo. It also holds the two Dragon's solar panels and about 14 cubic meters is available for other unpressurized cargo, or 34 cubic meters with extended trunk. One such example unpressurized cargo was the RapidScat that was ...


7

In addition to Geoff's answer: There was no requirement for the CRS spacecraft to provide ISS reboost. The two reboost methods available now (Progress, and the ISS' own engines on Zvezda) were seen as sufficient. NASA was working on a third method: they wanted to install a VASIMR ion engine to test it for reboost purposes. This plan was canceled in 2015. ...


7

The parachute configuration for abort was determined to require changes from the parachute configuration for a normal reentry. On a normal reentry, the parachutes have more time to deploy at a higher altitude. In an abort case, they need to be shot out with a mortar and deploy faster. This was tested in 2014 after being dropped from a helicopter. The test ...


7

The dragon capsule has limited painting on it because it has to stay in space for long periods of time and the addition of logos would affect the thermal performance of the exterior at that spot, possibly leading to a hot spot on that location. The sides of the launch vehicle however, don't get exposed long enough during the time they are active to really ...


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