SpaceX Falcon Heavy Demo - Discussion and Speculation

[Jim]

Is this to be taken as, Dragon is more active that most other satellite payloads or more active than other Dragon-like spacecraft?  I would be surprised to hear that Dragon is more active than, say, Orion is.

More active than most encapsulated payloads.

[Negan]

Is this to be taken as, Dragon is more active that most other satellite payloads or more active than other Dragon-like spacecraft?  I would be surprised to hear that Dragon is more active than, say, Orion is.

More active than most encapsulated payloads.

Why is that? Is it because of the payload Dragon carries?

[Lars-J]

Can we all stop this? While theoretically possible (to put a Dragon in a fairing), it just isn't going to happen.

The cost of producing a one-off solution just for this makes it very impractical.

And can we keep this a serious mission discussion thread and cut out the party thread nonsense? (Tesla Model S as cargo) 

[Johnnyhinbos]

Dragon usually gets umbilicals, see the very old picture from 2012:
http://www.universetoday.com/wp-content/uploads/2012/05/staticfire-2012.jpg

That would be pretty hard to supply through the fairing. It can be re-routed, sure but requires a ton of work to get the lines through the adapter and out at the side of F9. Not sure how that would work without compromising the certification.

To play devil's advocate, couldn't those feeds be taken from the PAF just like a regular satellite?

[Jim]

To play devil's advocate, couldn't those feeds be taken from the PAF just like a regular satellite?

Dragon doesn't do it that way, so redesign trunk and Dragon?  And it still needs air internal to it.

[Negan]

The cost of producing a one-off solution just for this makes it very impractical.

Agreed. Just as impractical as using a dedicated FH to do a full on demo of the circumlunar mission before the crewed one.

[Jim]

Agreed. Just as impractical as using a dedicated FH to do a full on demo of the circumlunar mission before the crewed one.

No, that is very practical and likely may happen.

[Negan]

Agreed. Just as impractical as using a dedicated FH to do a full on demo of the circumlunar mission before the crewed one.

No, that is very practical and likely may happen.

Who's going to pay for it?

[whitelancer64]

Agreed. Just as impractical as using a dedicated FH to do a full on demo of the circumlunar mission before the crewed one.

No, that is very practical and likely may happen.

Who's going to pay for it?

SpaceX. totes obvs.

[cscott]

If we're wagering, count me in the "Dragon-shaped mass simulator" camp.  They have plenty of "Dragon outer mold line" units -- for example, the drop test items -- and it may be worthwhile to slap some PICA-X on one of those and launch it in either a free-return lunar orbit (for bragging rights) or more likely a high-elliptical orbit (like Orion's test) in order to validate the heat shield design.  You might stuff some avionics in there to validate the star tracker/navigation/radios etc, like they did with the dragoneye component.

If it's essentially a mass simulator that just happens to have dragon's OML, then you don't need to play games with umbilicals, etc.  In fact, there's no reason to have a trunk or even to launch dragon nose-side-up: if the structures guys are happier, you could attach the payload adapter to the "docking ring" (simulator). It's "just" a mass simulator (from the FH side).

[bstrong]

I don't understand what practicality has to do with it. It seems to me that it should all come down to cost (assuming a desire to do a test mission and the availability of a Dragon). If designing and qualifying an adapter is cheaper than flying a separate mission, any rational business will design the adapter, even if it is inelegant, unsightly, and impractical.

The only question for me is whether they actually have a Dragon available and have the bandwidth to prepare it in in time for the demo mission without impacting Commercial Crew. My guess would be that they do not.

[Jim]

. If designing and qualifying an adapter is cheaper than flying a separate mission, any rational business will design the adapter, even if it is inelegant, unsightly, and impractical.

It is not just the adapter, it is the umbilical.  And then there is the aeroloads on the Dragon or lack of them.

[bstrong]

. If designing and qualifying an adapter is cheaper than flying a separate mission, any rational business will design the adapter, even if it is inelegant, unsightly, and impractical.

It is not just the adapter, it is the umbilical.  And then there is the aeroloads on the Dragon or lack of them.

I get that it is more than just the adapter. I was oversimplifying for brevity. My point was based on interpreting your comments as "it would be an extremely large amount of work" rather than "it would be impossible." It could require an awful lot of one-off work and still be cheaper than another FH launch. Even if it was the same cost, or even a little more expensive, it would have the advantage of getting done a lot sooner than they will likely have manifest availability for a separate launch.

I would go so far as to say that if a lunar demo mission is actually necessary, this is the only way I can see them possibly hitting their stated schedule. And they usually announce schedules that are extremely optimistic, but not known at the time to be actually impossible. In short, though there are obviously technical challenges, there are potentially very good business reasons to do the work to overcome them. So long as you have a Dragon available, which they probably don't.

[Negan]

The cost of producing a one-off solution just for this makes it very impractical.

Actually the solution could also be useful for interplanetary missions. Launching Dragon in a fairing could help with planetary protection protocols.

[Jim]

I would go so far as to say that if a lunar demo mission is actually necessary, this is the only way I can see them possibly hitting their stated schedule.

No, it would not fulfill the all needs of a lunar demo.  There still would be the need to fly Dragon 2 on a FH unencapsulated and on the standard Dragon adapter. So a Dragon on FH Demo is actually negative work.

[Jim]

The cost of producing a one-off solution just for this makes it very impractical.

Actually the solution could also be useful for interplanetary missions. Launching Dragon in a fairing could help with planetary protection protocols.

Not really, heat shields don't have to be sterile.  It would be cleaned by aeroheating during ascent and during Mars entry.

[ElGuapoGuano1]

I would trust Jim on this one. I know I would like to see the Falcon Heavy demo throw a dragon around the moon as well. But it just doesn't seem like it's in the cards. Also 60 days past August (best case scenario) Shouldn't this thread be renamed "late 2017"?

[leetdan]

Can an adapter be built to physically mount a Dragon+trunk inside a fairing?  Yes.  Would such a test yield relevant information in spite of the different aero loads, CG, moment, mass, etc?  Questionable at best, and especially doubtful considering SpaceX isn't going down this path.

[bstrong]

Can an adapter be built to physically mount a Dragon+trunk inside a fairing?  Yes.  Would such a test yield relevant information in spite of the different aero loads, CG, moment, mass, etc?  Questionable at best, and especially doubtful considering SpaceX isn't going down this path.

Is ascent really the riskiest part of the lunar mission (assuming Dragon has been qualified on F9)? I would have thought reentry targeting, heat shield working at lunar velocities, and comms and GNC working above LEO would be the ones most in need of demonstration, but what do I know.

I agree that this won't happen (for reasons of Dragon availability), so I'll stop arguing now. I just get annoyed when people don't include cost as an important factor in the decision, as I can assure you that in a for-profit business, it most assuredly is.

[Jim]

1.  Is ascent really the riskiest part of the lunar mission (assuming Dragon has been qualified on F9)? I would have thought reentry targeting, heat shield working at lunar velocities, and comms and GNC working above LEO would be the ones most in need of demonstration, but what do I know.

2.  I agree that this won't happen (for reasons of Dragon availability), so I'll stop arguing now. I just get annoyed when people don't include cost as an important factor in the decision, as I can assure you that in a for-profit business, it most assuredly is.

Costs are a big reason it isn't going to happen.

Fly a small demonstrator spacecraft that isn't a Dragon, it would be cheaper than all the one off mods.  Heat shield doesn't need a flight test.

Even if it were to fly, that does't mean a dedicated demo isn't going to or needs to happen.