"Used" Dragons

[yg1968]

I took clongton's statement just a bit diffferently.  Not that there are not now, currently, two different models of Dragon.  There clearly are:  the crew Dragon currently flying on CRS-3 (which is a "Dragon v2" with upgraded power and avionics), and perhaps with others in the production pipeline (as we've seen) for future CRS flights); and the new SuperDraco-included Dragons that will be unveiled late this month, and will participate in the ground-abort test and launch-abort test in the coming months.

Dragon V2 is the docking and land-landing capable dragon initially intended for crew transport. CRS-3 dragon is upgraded but not a new main version. It have been called Dragon v1.5 on one occasion, but that seems a bit high a version number, since the only confirmed changes are improved power system that can provide much more power to payloads and more waterproof solutions for electronics boxes in the unpressurized but internal part of dragon. Perhaps the upgrades are much more extensive than what is confirmed -- It would probably be smart to "backport" much of the minor v1.x compatible changes intended for V2 back into v1.x cargo dragons to get them tested early, spread out the risks on more than one flight and avoid unnecessary parallel versions of subsystems.

edit: typos etc.

The 1.5 Dragon would be a cargo Dragon that lands on land with parachutes.

[docmordrid]

Let's not forget they're on the record for 2 types of propulsive landing; under 'chutes with a braking burn similar to Soyuz (but according to the conops video, a bit higher), and fully propulsive.

[InfraNut2]

SpaceX is not going to build 2 different Dragons. That goes against the fundamental design concept of the vehicle. Musk has stated many times that there will be only 1 spacecraft, with appropriate mods for mission definition (cargo v.s. crew).

I'm glad you seem to know that with such "certainty". Because it goes against all evidence so far.

When has he stated that "there will only be 1 spacecraft"?

It has been stated that Cargo Dragon will eventually have propulsive landing.

I think it obvious that Cargo Dragon will eventually have propulsive landing, (even if I am not certain whether I have heard it confirmed). It improves reusability and along with any other commonality, it reduces the overhead of producing/supporting different versions of things.

However, that does not mean that there necessarily will be a single version of dragon v2 (except for the interior). It is not obvious to me whether SpaceX will prefer keeping a berthing version for cargo to preserve the advantages of that or leave berthing to the competitors to reap the benefits of a single version.

In any case I fully expect anything not directly berthing or docking-mandated to be made identical eventually, even if they keep a berthing version.

[clongton]

SpaceX is not going to build 2 different Dragons. That goes against the fundamental design concept of the vehicle. Musk has stated many times that there will be only 1 spacecraft, with appropriate mods for mission definition (cargo v.s. crew).

I'm glad you seem to know that with such "certainty". Because it goes against all evidence so far.

When has he stated that "there will only be 1 spacecraft"?

It has been stated that Cargo Dragon will eventually have propulsive landing.

That is correct. As Dragon 2 crew comes on line, the cargo Dragons will already be transitioning to the same base spacecraft.

Like I said - there will eventually be a single base spacecraft which will take 2 different tracks at the end of assembly to become mission specific - either crew or cargo. All Dragons - crew and cargo - will default to propulsive landing. Sea-parachute landings will not be nominal for either spacecraft. They are the future backup recovery mode for both crew and cargo. I believe the transition has either already begun or will begin soon. It is paced to bring Dragon 2 crew on line first. Dragons 1/1.5 that are in the assembly pipeline will be completed to their original design specs but no new ones of that generation will be started once the transition is underway. At some point the first full Dragon 2 cargo spacecraft will start construction, and it will share the assembly process with its identical twin - Dragon 2 crew.

For those that keep asking me for source, I will only say that I can't begin to count the number of times Elon has stated that there is/will be no difference in the base spacecraft between cargo and crew. He has repeatedly said that Crew Dragon IS Cargo dragon, modified at the end of assembly for crew. Dragon was designed from the beginning for crew. Cargo Dragon is Crew Dragon minus crew equipment. That is a fundamental design intent of Dragon.

[A12]

CRS-3 splashdown successful. Another piece to be added to the inventory :-)

[guckyfan]

I took clongton's statement just a bit diffferently.  Not that there are not now, currently, two different models of Dragon.  There clearly are:  the crew Dragon currently flying on CRS-3 (which is a "Dragon v2" with upgraded power and avionics), and perhaps with others in the production pipeline (as we've seen) for future CRS flights); and the new SuperDraco-included Dragons that will be unveiled late this month, and will participate in the ground-abort test and launch-abort test in the coming months.

Dragon V2 is the docking and land-landing capable dragon initially intended for crew transport. CRS-3 dragon is upgraded but not a new main version. It have been called Dragon v1.5 on one occasion, but that seems a bit high a version number, since the only confirmed changes are improved power system that can provide much more power to payloads and more waterproof solutions for electronics boxes in the unpressurized but internal part of dragon. Perhaps the upgrades are much more extensive than what is confirmed -- It would probably be smart to "backport" much of the minor v1.x compatible changes intended for V2 back into v1.x cargo dragons to get them tested early, spread out the risks on more than one flight and avoid unnecessary parallel versions of subsystems.

edit: typos etc.

The 1.5 Dragon would be a cargo Dragon that lands on land with parachutes.

But it won't be different hardware. Just an intermediate step for safety. And I am quite sure that purely parachute landing on land would be very harsh. There will be a propulsive braking for the last few meters to soften touchdown. Purely parachute will be survivable but not desirable and not done intentionally.

[docmordrid]

SpaceX Dragon CCiCAP landings: 'chutes & rockets:

[Lars_J]

SpaceX is not going to build 2 different Dragons. That goes against the fundamental design concept of the vehicle. Musk has stated many times that there will be only 1 spacecraft, with appropriate mods for mission definition (cargo v.s. crew).

I'm glad you seem to know that with such "certainty". Because it goes against all evidence so far.

When has he stated that "there will only be 1 spacecraft"?

It has been stated that Cargo Dragon will eventually have propulsive landing.

If it has been stated, then you wouldn't mind posting a source, right?

This forum can be a cesspool of speculation that after being repeated a few times turn into "facts". So source it, please.

[Lars_J]

SpaceX is not going to build 2 different Dragons. That goes against the fundamental design concept of the vehicle. Musk has stated many times that there will be only 1 spacecraft, with appropriate mods for mission definition (cargo v.s. crew).

I'm glad you seem to know that with such "certainty". Because it goes against all evidence so far.

When has he stated that "there will only be 1 spacecraft"?

It has been stated that Cargo Dragon will eventually have propulsive landing.

That is correct. As Dragon 2 crew comes on line, the cargo Dragons will already be transitioning to the same base spacecraft.

Like I said - there will eventually be a single base spacecraft which will take 2 different tracks at the end of assembly to become mission specific - either crew or cargo. All Dragons - crew and cargo - will default to propulsive landing. Sea-parachute landings will not be nominal for either spacecraft. They are the future backup recovery mode for both crew and cargo. I believe the transition has either already begun or will begin soon. It is paced to bring Dragon 2 crew on line first. Dragons 1/1.5 that are in the assembly pipeline will be completed to their original design specs but no new ones of that generation will be started once the transition is underway. At some point the first full Dragon 2 cargo spacecraft will start construction, and it will share the assembly process with its identical twin - Dragon 2 crew.

For those that keep asking me for source, I will only say that I can't begin to count the number of times Elon has stated that there is/will be no difference in the base spacecraft between cargo and crew. He has repeatedly said that Crew Dragon IS Cargo dragon, modified at the end of assembly for crew. Dragon was designed from the beginning for crew. Cargo Dragon is Crew Dragon minus crew equipment. That is a fundamental design intent of Dragon.

Chuck, what is the point of attempting to argue things with you when you ignore evidence that contradicts your assumption?

Don't you have ANY comment about my reply to you that illustrated how the Dragon 2 drogue placement is incompatible with a CBM ring? Or are you going to ignore this as well?

[Llian Rhydderch]

I took clongton's statement just a bit diffferently.  Not that there are not now, currently, two different models of Dragon.  There clearly are:  the crew Dragon currently flying on CRS-3 (which is a "Dragon v2" with upgraded power and avionics), and perhaps with others in the production pipeline (as we've seen) for future CRS flights); and the new SuperDraco-included Dragons that will be unveiled late this month, and will participate in the ground-abort test and launch-abort test in the coming months.

Dragon V2 is the docking and land-landing capable dragon initially intended for crew transport. CRS-3 dragon is upgraded but not a new main version. It have been called Dragon v1.5 on one occasion, but that seems a bit high a version number, since the only confirmed changes are improved power system that can provide much more power to payloads and more waterproof solutions for electronics boxes in the unpressurized but internal part of dragon. Perhaps the upgrades are much more extensive than what is confirmed -- It would probably be smart to "backport" much of the minor v1.x compatible changes intended for V2 back into v1.x cargo dragons to get them tested early, spread out the risks on more than one flight and avoid unnecessary parallel versions of subsystems.

edit: typos etc.

I do understand the major distinction between the cargo Dragon and the new, soon-to-be-unveiled, crew Dragon.  I thought that Shotwell referred to the upgraded Dragon (new avionics and additional power for the NASA cargos) as "v2".  I could quite easily be wrong.  I know I was surprised to hear her say that as I had been aware of the major upgrades for crew that had been planned for a long time.

What is SpaceX formally referring to the particular model of cargo Dragon that just flew on CRS-3?

[Garrett]

It has been stated that Cargo Dragon will eventually have propulsive landing.

If it has been stated, then you wouldn't mind posting a source, right?
This forum can be a cesspool of speculation that after being repeated a few times turn into "facts". So source it, please.

Sometimes, things are stated many times on this forum because they are facts. At some point, it gets ridiculous to ask for sources for every bit of information.
Some users are more reliable than others. yg1968 is one of the more reliable posters.

But for the record, here is possibly the most well-known source: a quote from Shotwell transcripted by manboy from here: http://archive.thespaceshow.com/shows/2212-BWB-2014-03-21.mp3 :

"When will the cargo version of Dragon begin making propulsive landings?" "So the current version of Dragon lands in water on parachute descent, we are looking at landing it on land under parachute. As for propulsive landing that is for our new version, we call it V2 for Dragon and that's the primary vehicle, that's the vehicle for crew, and we will retrofit that for cargo."

[Lars_J]

Thanks, Garret, I appreciate you digging up the quote.

The "retrofit" wording does indicate that the Cargo Dragon will remain a separate line, though. (even though many or most components are shared)

[baldusi]

There's the issue of approx ops. The sensors are arranged differently, and the Docking port is not a bolt on kit on the CBM. My guess is that they have been designing the Crew considering a cargo version, and they'll try to maximize commonality, but they will have some differences. In particular, the top will be different.
But, if they get to reasonable reusability, it won't matter that much. But this 1.0 Dragons will find some other use, because they will have too expensive ops in comparison to 2.0.

[clongton]

Chuck, what is the point of attempting to argue things with you when you ignore evidence that contradicts your assumption?

It is not an assumption.
From Garrett:

But for the record, here is possibly the most well-known source: a quote from Shotwell transcripted by manboy from here: http://archive.thespaceshow.com/shows/2212-BWB-2014-03-21.mp3 :

"When will the cargo version of Dragon begin making propulsive landings?" "So the current version of Dragon lands in water on parachute descent, we are looking at landing it on land under parachute. As for propulsive landing that is for our new version, we call it V2 for Dragon and that's the primary vehicle, that's the vehicle for crew, and we will retrofit that for cargo."

The direct quote from Shotwell trumps your "evidence".
 
There will be one "base" Dragon design for both Crew and Cargo, Dragon v2. First use will be crew. Then Cargo will be backfitted to conform to v2. Between Dragon-Crew v2 and Dragon-Cargo v2 will be the time of transitioning Dragon-Cargo v1.5 to Dragon-Cargo v2, just like she said. In the end there will be only one Dragon design, Dragon v2. They will be completely identical until final outfitting. They will be final outfitted to be mission specific; crew or cargo.

[guckyfan]

"When will the cargo version of Dragon begin making propulsive landings?" "So the current version of Dragon lands in water on parachute descent, we are looking at landing it on land under parachute. As for propulsive landing that is for our new version, we call it V2 for Dragon and that's the primary vehicle, that's the vehicle for crew, and we will retrofit that for cargo."

I interpreted that as "we will retrofit V2 for cargo. But english is not my native language so I may be wrong.

How they would deal with the drogue chutes I don't know.

[clongton]

How they would deal with the drogue chutes I don't know.

I don't know the answer to that either, because the current arrangement would be difficult, as Lars has correctly pointed out. I am assuming that the drogue and parachute locations will need to be adjusted. There is much about Dragon v2 that we just don't know yet.

[swervin]

Does anyone know if the trunk is large enough to house a VF-200 VASIMR rocket, or a modified one? Besides the ridiculously high price of building one of those (I assume) -- perhaps a used Dragon would be a great test platform, should using the ISS as a test platform not work out.

If a Dragon can theoretically stay up for an extended period of time (i.e., DragonLab), then placing a right-sized VASIMR engine in the trunk may be useful. Obviously, the main problem would be the lack of enough solar power to power such a system, and I recognize that. Perhaps, modify to have larger solar panels? Pack the internal volume with a crap-ton of batteries?

But hey, here's to theorizing and not arguing about quotes and sources... . If theorizing re-uses of Dragon is not appropriate in this thread, then I won't be offended if this post disappears.

Cheers,
Splinter

[Dudely]

Read a quote from Elon saying Dragon 2 will be not have solar panels at all. Can't find it now.

[VulcanCafe]

I remember reading about no solar on Dragon v2 as well... I suspect the trunk will feature 'mission modules' including solar as needed. Just wild speculation on my part.

[Elmar Moelzer]

Read a quote from Elon saying Dragon 2 will be not have solar panels at all. Can't find it now.

I remember something about the crewed Dragon not having solar panels. If there is a cargo version of Dragon2 (which I personally find plausible), then it might still have solar panels.