Red Dragon confirmed!!

[cantab]

5 minutes ago, Oafman said:

I'm no engineer, but I would have thought that adding a rocket which launches out of the middle of the Dragon would be such a huge change to the original craft, that it would be inaccurate to describe it as a modified version of the same. 

Yo dawg, I heard you like to rocket, so I put a rocket in your rocket so you can rocket while you rocket.

[sevenperforce]

5 minutes ago, Oafman said:

I'm no engineer, but I would have thought that adding a rocket which launches out of the middle of the Dragon would be such a huge change to the original craft, that it would be inaccurate to describe it as a modified version of the same. 

Not...really?

I mean, it depends, but if you're merely removing the docking hatch and bolting a tube into the center of the cabin area, you can really put anything inside.

6 minutes ago, Oafman said:

As for the SSTO, apparently low Mars orbit requires 4.1km/s Deltav from the surface. I can't see how the Dragon could ever manage that, along with sufficient TWR, even if you filled the whole thing with fuel.

Conveniently, the Dragon's TWR is tripled on Mars. Hydrazine+NTO can have a vacuum ISP of 339 s with the right nozzle; 4.1 km/s thus requires a mass ratio of 2.5:1. Should be entirely realizable.

[tater]

The tube would effectively be a tube with a different hatch than the normal docking ring/hatch. Clearly a redesign, but D2 does already have a circular hole on top.

[Nibb31]

43 minutes ago, sevenperforce said:

The Dragon 1 already has the option of flying pressurized or unpressurized (final bullet, page 6 here). The Dragon V2 will have the same capability: it can fly with unpressurized cargo, pressurized cargo, or pressurized with crew.

Dragon's unpressurized cargo requirement for COTS is for the trunk. It isn't designed to fly unpressurized cargo inside. How would you get it out ?

43 minutes ago, sevenperforce said:

Page 5 of the House Subcommittee Statement by Garrett Reisman states, "Crew Dragon carries sufficient breathable gas stores to allow for a safe return to Earth in the event of a leak of up to an equivalent orifice of 0.25 inches in diameter. As an extra level of protection, the crew will wear SpaceX-designed spacesuits to protect them from a rapid cabin depressurization emergency event of even greater severity. The suits and the vehicle itself will be rated for operation at vacuum." So yeah, it's vacuum-hardened already.

Yes, it can survive a contingency depressurization event, but that doesn't mean that all systems are currently hardened for long duration exposure to vacuum. Unless you add radiators, there is no way to dispense the heat generated by the onboard systems.

43 minutes ago, sevenperforce said:

Like I said, Dragon V2 is over-designed for these express purposes. It will not need substantial redesign for its Martian debut.

It will need new navigation and communication systems, new power systems, a new trunk, provisions for planetary protection, an automated hatch, a mechanism to deploy whatever it has to deploy.

That is a substantial redesign already.

43 minutes ago, sevenperforce said:

Well, it would be a completely new craft inside the Dragon body to be sure, but the Dragon V2 itself would still be substantially the same.

Yes, only if you look at the outer mold line.

It will be as much a production Dragon as a NASCAR Ford Mustang is a production Ford Mustang.

2 hours ago, kerbiloid said:

Sorry, but how then they intend to get out for EVA? Probably, there is no airlock chamber.

Dragon has never intended to be EVA capable.

[sevenperforce]

4 minutes ago, Nibb31 said:

Dragon's unpressurized cargo requirement for COTS is for the trunk. It isn't designed to fly unpressurized cargo inside. How would you get it out ?

Presumably by pressurizing it and then opening the hatch. The contract at the provided link states that the full up or down capacity can be fully depressurized.

5 minutes ago, Nibb31 said:

Yes, it can survive a contingency depressurization event, but that doesn't mean that all systems are currently hardened for long duration exposure to vacuum. Unless you add radiators, there is no way to dispense the heat generated by the onboard systems.

What's the current coolant design?

7 minutes ago, Nibb31 said:

It will need new navigation and communication systems, new power systems, a new trunk, provisions for planetary protection, an automated hatch, a mechanism to deploy whatever it has to deploy.

That is a substantial redesign already.

New navcom, yes, but the existing trunk is just fine, the hatch is already automated, and the deployment mechanisms, planetary protection provisions, and auxiliary power systems are really just part of payload.

[Findthepin1]

17 minutes ago, Nibb31 said:

Dragon has never intended to be EVA capable.

If they eventually send people to Mars in it, how will they get out of the ship?

[tater]

Since they say the RD is a variant D V2 anyway, I can only presume that the base requirements are already redesigned for that mission, so I think saying it needs to be redesigned from D2 is a given, and all the obvious issues can be assumed.

RD would pretty much require a larger side hatch as you need to get out wearing a suit, for example.

[SSgt Baloo]

4 minutes ago, Findthepin1 said:

If they eventually send people to Mars in it, how will they get out of the ship?

[Nibb31]

5 minutes ago, Findthepin1 said:

If they eventually send people to Mars in it, how will they get out of the ship?

Nobody ever intended to send people to Mars in a Dragon. It isn't designed for that.

[sevenperforce]

9 minutes ago, tater said:

Since they say the RD is a variant D V2 anyway, I can only presume that the base requirements are already redesigned for that mission, so I think saying it needs to be redesigned from D2 is a given, and all the obvious issues can be assumed.

RD would pretty much require a larger side hatch as you need to get out wearing a suit, for example.

The SpaceX suits will be compressive rather than overpressure-based.

[Nibb31]

20 minutes ago, sevenperforce said:

Presumably by pressurizing it and then opening the hatch. The contract at the provided link states that the full up or down capacity can be fully depressurized.

Yes, if it flies empty with the trunk at max payload, which would be a bit of a waste, but is possible if they really need to send up a 3-ton piece of unpressurized equipment. How would you even get unpressurized cargo out of the Dragon cabin at the ISS ?

20 minutes ago, sevenperforce said:

What's the current coolant design?

Currently, the trunk walls act as a radiator. That won't possible once on the ground.

20 minutes ago, sevenperforce said:

New navcom, yes, but the existing trunk is just fine, the hatch is already automated, and the deployment mechanisms, planetary protection provisions, and auxiliary power systems are really just part of payload.

The trunk with the fins doesn't fit inside a payload fairing, which we have established, is going to be a requirement for planetary protection. Planetary protection is more of a process/quality/certification thing, but it requires development of ground systems, clean rooms and procedures that SpaceX probably doesn't have to deal with in its current payload processing facilities. Power systems are part of the spacecraft, not the payload.

[sevenperforce]

7 minutes ago, Nibb31 said:

How would you even get unpressurized cargo out of the Dragon cabin at the ISS ?

Like I said, presumably by pressurizing it and opening the hatch. Even unpressurized cargo in the trunk is typically brought out and then brought within an airlock if it is intended for use inside the ISS. The only reason to fly pressurized is if the cargo cannot be vacuum-hardened.

8 minutes ago, Nibb31 said:

Currently, the trunk walls act as a radiator. That won't possible once on the ground.

Once on the ground, the Martian atmosphere provides air-cooling to components.

9 minutes ago, Nibb31 said:

The trunk with the fins doesn't fit inside a payload fairing, which we have established, is going to be a requirement for planetary protection. Planetary protection is more of a process/quality/certification thing, but it requires development of ground systems, clean rooms and procedures that SpaceX probably doesn't have to deal with in its current payload processing facilities. Power systems are part of the spacecraft, not the payload.

I doubt the payload fairing will be required for planetary protection, but even if it is, the fins on the trunk are only there to provide stability during LES, which this wouldn't need. And power systems for the new navcom can be added separately in the form of payload.

[Nibb31]

2 minutes ago, sevenperforce said:

Even unpressurized cargo in the trunk is typically brought out and then brought within an airlock if it is intended for use inside the ISS. The only reason to fly pressurized is if the cargo cannot be vacuum-hardened.

Unpressurized cargo is only for use outside the ISS.

 

 

[kerbiloid]

4 minutes ago, sevenperforce said:

Martian atmosphere provides air-cooling

The second Dragon will bring a large fan... As the pressure is 0.001-0.01 bar.

[tater]

39 minutes ago, sevenperforce said:

The SpaceX suits will be compressive rather than overpressure-based.

Still need the PLSS.

[Kryten]

SpaceNews has some more details about the agreement;

http://spacenews.com/spacex-announces-plans-for-dragon-mission-to-mars/

notably there's a post-mission review just 60 days after landing. That should answer how this thing is intended to survive on Mars long term; it isn't.

[ModZero]

6 hours ago, tater said:

Regarding planetary protection... what would happen on any (distant) manned Mars landing? If someone coughs while suiting up is going on (even assuming the suits were isolated from the crew cabin before that process) then that's contamination, as would be just exposing the suits to the crew cabin. 

Honestly, it seems to me once people are involved contamination needs to be assumed.

While corporations are well known for how well they keep their promises, Emily Lakedwalla asked: 

Also, pretty much everyone is (finally) using the term "crewed" this time, it would be super-nice if this really nice forum would take note of that as well.

[tater]

Words change meaning. If a word is always used to mean one thing now, then it doesn't matter what it meant before. "Awful" means very bad, right? It used to mean inspiring awe/wonder. No one uses it that way now. "Cute" used to mean shrewd/perceptive. "Manned" means peopled/crewed, or in this forum, sometimes kerbaled. 

Gender neutral pronouns would surely also be needed... but they are all cumbersome---the singular "they," for example (I'm with Pinker on this). I sometimes switch randomly between he and she for that reason, but when a perfectly good word is already effectively neutral I'm not overly concerned. Interestingly, "man" started as the neutral, with wer (male) and wif (female) and the gendered versions. Even my use of "female" must similarly be wrong, because it contains "male"... what to do! 

Edited April 28, 2016 by tater

[Frybert]

Lets keep this on the topic of SpaceX sending a Dragon vehicle to mars, and not the words we use to describe if there are people on board or not. We really do not need to be going there.

[ModZero]

25 minutes ago, tater said:

Even my use of "female" must similarly be wrong, because it contains "male"... what to do! 

Look, actually, you can see quite a few hints, from quite a few places, about what to do: use the word "crewed". You'll live. EOT from me, before things get very silly indeed.

EDIT: and don't use the word "female" when you refer to women, or you're going to be made fun of on the Internet.

Edited April 28, 2016 by ModZero

[KSK]

52 minutes ago, ModZero said:

Look, actually, you can see quite a few hints, from quite a few places, about what to do: use the word "crewed". You'll live. EOT from me, before things get very silly indeed.

It's a crude solution but it works.

 

I'll get my coat...

[B787_300]

Keep it on topic of the landing please.

 

Also @Nibb31 the only thing that needs to be added for comms is a UHF radio that is COTS.  (Electra by L3 Communications)  everything else is just nice things.  At this time SpaceX does not have a payload or any science that they want to do on Mars (that has been announced).  

Also with a PMR 60 days after landing this is not supposed to last for very long on the surface therefore Power and thermal is not much of an issue.  

Also planetary protection for going to mars is just a simple sterilization process that SpaceX is not bound to follow (the scientists would like it but the Russians have not sterilized some of their mars landers). And a sterilization is a simple thing to do (and no it does not have to be in the fairing to not get recontaminated)

[tater]

The problem with planetary protection is that in the case of this unmanned mission, the point is presumably both to not contaminate Mars generally, and to not contaminate any possible experiments specifically (should there be any explicitly looking for signs of life). As for manned missions, as I said, it gets considerably more complex. The more form-fitting (alleviating the pressurized joints issues) suit designs would necessarily be put on by the crew inside the spacecraft/hab*... would airlock designs than have to include sterilization both directions? Has that been in the DRA?

*Some designs I have seen have the astronaut climbing in from the back, with the suit outside, then presumably someone wipes down the PLSS inside?

[AngelLestat]

This link has more info I guess:  take a look.
http://www.parabolicarc.com/2016/04/27/spacex-working-nasa-sending-dragon-spacecraft-mars/

 

[fredinno]

16 hours ago, Streetwind said:

Here is an actual primary source for the "no money changed hands" claim that spaceflightnow reported on. Quoting the relevant paragraph:

"Among the many exciting things we’re doing with American businesses, we’re particularly excited about an upcoming SpaceX project that would build upon a current 'no-exchange-of-funds' agreement we have with the company. In exchange for Martian entry, descent, and landing data from SpaceX, NASA will offer technical support for the firm’s plan to attempt to land an uncrewed Dragon 2 spacecraft on Mars."

This also sheds a bit of light about what science payloads will fly on this mission: basically, none. At least no official NASA ones. The Dragon V2 itself *is* the science payload.

SpaceX has a vested interest in testing martian EDL, because they have plans to do it a lot. The world's premier authority on Mars EDL, with more landed missions than any other organization, is NASA. So while SpaceX could test things themselves, or rely on laboratory studies (not really acceptable when you want to ferry humans), a collaboration with NASA is a prime opportunity. Nowhere else can they find more know-how about getting it right the first try (just remind yourself what a Hail-Mary maneuver Curiosity actually was). SpaceX wants that know-how. With a destination as infrequently accessible and expensive to reach as Mars, their usual approach of just throwing stuff repeatedly until it sticks is a suboptimal approach.

And what does NASA get in return? They get to see all the results of SpaceX's experiment. NASA has been studying how to land larger payloads on Mars for decades now. The biggest payload landed to date is maybe 1/7th of an empty Dragon V2, and probably 1/10th of the configuration that will end up landing on Mars. Progress has been incremental at best, and even the newest ways NASA is studying today could take maybe two or three tons more than before. And suddenly, there's this commercial company that says "hey guys, we think we have a way we can land an order of magnitude more mass on Mars than anyone has ever attempted, and we also think this method scales at least another order of magnitude beyond that. Can you help us out a bit? We'll share everything." Of course NASA jumps on that. They have no funds for anything even remotely like that (which is why Red Dragon won't carry any science payloads), but here they're getting it essentially for free, in a "you scratch my back and I'll scratch yours" type of deal. Undoubtedly they're as excited about the opportunity as SpaceX is. And since it's an unfunded agreement with a commercial partner, Congress can't even meddle in their affairs in this case.

 

Oh, and an amusing bit of fan speculation from the SpaceX subreddit... what if NASA, repeatedly criticized for having no proper path forward beyond SLS and Orion and its limited capabilities, is intentionally not bothering to plan one, because they already know all the details of MCT and what it can do for them?   I mean, it's quite unlikely to be true, since NASA's strategic plans work on somewhat different timescales than the short time that the MCT project will have had a useful form even internally. But this partnership here outlines pretty well what a few logically minded people have been saying for years: a.) SpaceX isn't going to Mars without NASA, or in competition with NASA, but rather as a collaborative effort; and b.) NASA stands to gain just as much from this partnership as SpaceX does, getting access to new technologies and capabilities that fill gaps in the agency's own. Mark my words: I will buy a hat for the express purpose of eating it if the first MCT flight isn't a NASA mission!

 

Quote

Here is an actual primary source for the "no money changed hands" claim that spaceflightnow reported on. Quoting the relevant paragraph:

"Among the many exciting things we’re doing with American businesses, we’re particularly excited about an upcoming SpaceX project that would build upon a current 'no-exchange-of-funds' agreement we have with the company. In exchange for Martian entry, descent, and landing data from SpaceX, NASA will offer technical support for the firm’s plan to attempt to land an uncrewed Dragon 2 spacecraft on Mars."

This also sheds a bit of light about what science payloads will fly on this mission: basically, none. At least no official NASA ones. The Dragon V2 itself *is* the science payload.

And what does NASA get in return? They get to see all the results of SpaceX's experiment. NASA has been studying how to land larger payloads on Mars for decades now. The biggest payload landed to date is maybe 1/7th of an empty Dragon V2, and probably 1/10th of the configuration that will end up landing on Mars. Progress has been incremental at best, and even the newest ways NASA is studying today could take maybe two or three tons more than before. And suddenly, there's this commercial company that says "hey guys, we think we have a way we can land an order of magnitude more mass on Mars than anyone has ever attempted, and we also think this method scales at least another order of magnitude beyond that. Can you help us out a bit? We'll share everything." Of course NASA jumps on that. They have no funds for anything even remotely like that (which is why Red Dragon won't carry any science payloads), but here they're getting it essentially for free, in a "you scratch my back and I'll scratch yours" type of deal. Undoubtedly they're as excited about the opportunity as SpaceX is. And since it's an unfunded agreement with a commercial partner, Congress can't even meddle in their affairs in this case.

So this basically confirms my speculation. SpaceX is sending a ~6.4T brick to Mars. A very advanced brick, but still a brick, since it probably won't carry more than a few sensors and an HD camera.

Quote

SpaceX has a vested interest in testing martian EDL, because they have plans to do it a lot. The world's premier authority on Mars EDL, with more landed missions than any other organization, is NASA. So while SpaceX could test things themselves, or rely on laboratory studies (not really acceptable when you want to ferry humans), a collaboration with NASA is a prime opportunity. Nowhere else can they find more know-how about getting it right the first try (just remind yourself what a Hail-Mary maneuver Curiosity actually was). SpaceX wants that know-how. With a destination as infrequently accessible and expensive to reach as Mars, their usual approach of just throwing stuff repeatedly until it sticks is a suboptimal approach.

Except NASA doesn't really have a plan for Mars, the "Journey to Mars" is PR trash. NASA is forced to look like it is working towards Mars, but it will never use something like a Dragon V2 to Mars. Way too much capability for a robotic probe. Skycrane's 1T to Mars landing capacity is more than enough for any forseeable (non-manned) usage, including Sample Return and ISRU experiments.

Quote

Progress has been incremental at best, and even the newest ways NASA is studying today could take maybe two or three tons more than before.

Which is also about the same amount Dragon V2 would carry to Mars

Quote

Oh, and an amusing bit of fan speculation from the SpaceX subreddit... what if NASA, repeatedly criticized for having no proper path forward beyond SLS and Orion and its limited capabilities, is intentionally not bothering to plan one, because they already know all the details of MCT and what it can do for them?   I mean, it's quite unlikely to be true, since NASA's strategic plans work on somewhat different timescales than the short time that the MCT project will have had a useful form even internally. But this partnership here outlines pretty well what a few logically minded people have been saying for years: a.) SpaceX isn't going to Mars without NASA, or in competition with NASA, but rather as a collaborative effort; and b.) NASA stands to gain just as much from this partnership as SpaceX does, getting access to new technologies and capabilities that fill gaps in the agency's own. Mark my words: I will buy a hat for the express purpose of eating it if the first MCT flight isn't a NASA mission!

Fat chance. Congress won't allow it. Why would they? NASA has their own system.

 

 

16 hours ago, Nibb31 said:

You would be far better off with a specialized vehicle. You only need the heatshield and the SuperDracos. Pretty much all the rest of the vehicle is wasted mass and limits the capabilities. You would be better off without the pressure vessel and aeroshell in the first place. That would allow you to add as much science equipment as you want, solar panels, and ever deploy rovers. And in the end, you would end up with a lander that looks like Viking or MPL.

It allows you to reduce development costs, but the only way out of the V2 is via the tiny hatch. Not very good for science at all, and severely limits its capability.

16 hours ago, popeter45 said:

the only query i have about red dragon is contamination

all previous mars mission have been build in a massive clean room and sealed in a landing vessel to avoid contamination

as far a we know the dragon capsule is exposed to the elements at launch and from that could bring bacteria to the surface of mars in a much higher quantity then any previous mission

16 hours ago, Nibb31 said:

This is going to require a Falcon Heavy at least, probably with the Raptor upper-stage, and a Dragon V2, none of which have flown yet. The Dragon is going to need a lot of modifications, including navigation systems (currently GPS-based). And there is also the planetary protection problem that popeter45 evoked and will probably make it a non-starter when NASA gets involved.

I agree with everything you said, until this part. FH can carry 13.2 T to Mars (Transfer) in Expendable mode, more than enough for a Fully-loaded Dragon (and this won't be fully loaded). It might even be able to launch with Booster reuse.

And the planetary protection systems would likely be circumvented by a payload fairing. Centaur did it on the Atlas V.