Author Topic: SpaceX DragonFly Discussion Thread  (Read 375249 times)

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 5490
  • Canada
  • Liked: 1809
  • Likes Given: 1302
Re: SpaceX DragonFly Discussion Thread
« Reply #440 on: 05/10/2015 12:35 am »

Speaking of doing testing on actual (existing) flights, I wonder how hard it would be to begin using a model of Dragon 2 that is similar to the one just used in the pad abort test as the vehicle for later CRS missions. The thing already gets sent to LEO. It already undergoes an actual reentry. I realize some issues would be approaching ISS with that much hypergolic prop on board in a Dragon variant that has never been to ISS. Maybe the first of these would need to approach and berth with no prop for the SuperDracos. There is also the issue of getting approval of a landing site. Places that come to mind are Spaceport America, Mojave Desert around Edwards, maybe Kazakhstan, though were I Elon, I wouldn't want any chance of proprietary hardware falling into the wrong hands. Maybe even land the first ones on the ocean surface like Falcon stage 1 just to show it can be done.

This is just off the top of the head thinking, I realize there would be substantial issues to deal with. OTOH, it would be somewhat like using existing launches to test stage 1 landings. Thoughts?

Somehow the lack of a CBM hatch on the Dragon 2 (aka Dragon V2, crewed Dragon, Dragonrider, etc) make it very unlikely.

Online docmordrid

  • Senior Member
  • *****
  • Posts: 6334
  • Michigan
  • Liked: 4207
  • Likes Given: 2
Re: SpaceX DragonFly Discussion Thread
« Reply #441 on: 05/10/2015 02:58 am »
One would think that depends on the size of the cargo containers on a particular mission. If they're smaller than an IDA's hatch, why not?
DM

Offline guckyfan

  • Senior Member
  • *****
  • Posts: 7438
  • Germany
  • Liked: 2332
  • Likes Given: 2891
Re: SpaceX DragonFly Discussion Thread
« Reply #442 on: 05/10/2015 05:48 am »

The trunk is used to provide stability during the boost phase, not or only secondary during the coast phase.
I believe those things have not been discussed yet because the trunk with fins on abort was not known before.


Wrong, it is there for the coast phase.  It is not needed for the boost phase, the vehicle has active control.  If it was not needed for the coast phase, it would not fly at all much less have fins.

Thanks, I learned something. I wonder if I was the only one with that misunderstanding.

Offline cosmicvoid

  • Full Member
  • *
  • Posts: 154
  • Seattle 'ish
  • Liked: 45
  • Likes Given: 92
Re: SpaceX DragonFly Discussion Thread
« Reply #443 on: 05/10/2015 06:40 am »
Somehow the lack of a CBM hatch on the Dragon 2 (aka Dragon V2, crewed Dragon, Dragonrider, etc) make it very unlikely.

Not to mention lack of a grapple fixture.
Infiinity or bust.

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 5490
  • Canada
  • Liked: 1809
  • Likes Given: 1302
Re: SpaceX DragonFly Discussion Thread
« Reply #444 on: 05/10/2015 09:28 am »
Somehow the lack of a CBM hatch on the Dragon 2 (aka Dragon V2, crewed Dragon, Dragonrider, etc) make it very unlikely.

Not to mention lack of a grapple fixture.

Why would you need a grapple fixture when you have an IDA docking hatch.  ::)

Offline AncientU

  • Senior Member
  • *****
  • Posts: 6257
  • Liked: 4164
  • Likes Given: 6078
Re: SpaceX DragonFly Discussion Thread
« Reply #445 on: 05/10/2015 12:28 pm »
I wonder if they'll bother with tethered flight tests?

I probably would.

They probably won't.

The drop tests should validate precision control. Take-offs from the pad for parachute-assisted landings will validate take-off control. Hopping should round out the envelope.

Their testing boldness continues to increase as shown by just-completed pad abort where eight engine performance was demo'd 24 hrs before live launch from a pad they have fully booked.
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline baldusi

  • Senior Member
  • *****
  • Posts: 8356
  • Buenos Aires, Argentina
  • Liked: 2539
  • Likes Given: 8273
Re: SpaceX DragonFly Discussion Thread
« Reply #446 on: 05/10/2015 04:37 pm »

Speaking of doing testing on actual (existing) flights, I wonder how hard it would be to begin using a model of Dragon 2 that is similar to the one just used in the pad abort test as the vehicle for later CRS missions. The thing already gets sent to LEO. It already undergoes an actual reentry. I realize some issues would be approaching ISS with that much hypergolic prop on board in a Dragon variant that has never been to ISS. Maybe the first of these would need to approach and berth with no prop for the SuperDracos. There is also the issue of getting approval of a landing site. Places that come to mind are Spaceport America, Mojave Desert around Edwards, maybe Kazakhstan, though were I Elon, I wouldn't want any chance of proprietary hardware falling into the wrong hands. Maybe even land the first ones on the ocean surface like Falcon stage 1 just to show it can be done.

This is just off the top of the head thinking, I realize there would be substantial issues to deal with. OTOH, it would be somewhat like using existing launches to test stage 1 landings. Thoughts?

Somehow the lack of a CBM hatch on the Dragon 2 (aka Dragon V2, crewed Dragon, Dragonrider, etc) make it very unlikely.
CRS-2 actually allowed for IDA equipped vehicles. And I doubt that they'll will waste the uncrewed demonstration flight and thus it won't flight empty. I wouldn't be surprised if SpaceX actually wins a fat contract in CRS-2 (a likely outcome), they might offer an uncrewed Dragon v2 as a one-off mission. For CRS-2 it will offer cargo without the cost of crew time required for training and actual berthing operation, and it wouldn't conflict with any CBM CVV. It could also sand unpressurized cargo that's not well behaved in an abort situation. And it would allow to certify the propulsive (assited?) landing. Size limited unpressurized cargo might be manifested on a different flight.
Now, how does this affects DragonFly? Well, I believe that the cheapest opportunity to certify the Crewed Dragon for propulsive landing would be the Uncrewed Flight. But it would seem like they won't go that route and DragonFly might actually happen after it. Besides, they must have a mountain of certificates in development for water landing and redoing it for propulsive landing will take a while. And SpaceX wants that flag!
Thus, I would assume, that the next cheapest and safest way is to do the DragonFly program after Uncrewed Flight, and once all the kinks are out, they can negotiate a single Dragon v2 flight within their CRS-2 program, with the specific purpose of demonstrating the propulsive landing. It would also allow for a significant amount of downmass with a relatively gentle landing and could probably be in the hands of investigators at L+4hrs. Nothing that CST-100 Cargo wouldn't offer. But a nice thing to have if it doesn't cost anything.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: SpaceX DragonFly Discussion Thread
« Reply #447 on: 05/10/2015 05:25 pm »
I wonder if they'll bother with tethered flight tests?

I probably would.

They probably won't.

The drop tests should validate precision control. Take-offs from the pad for parachute-assisted landings will validate take-off control. Hopping should round out the envelope.

Their testing boldness continues to increase as shown by just-completed pad abort where eight engine performance was demo'd 24 hrs before live launch from a pad they have fully booked.
I don't expect them to fly tethered tests. But I certainly would as that's a lot cheaper than building a new expensive spacecraft.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline meekGee

  • Senior Member
  • *****
  • Posts: 14158
  • N. California
  • Liked: 14046
  • Likes Given: 1392
Re: SpaceX DragonFly Discussion Thread
« Reply #448 on: 05/10/2015 06:29 pm »
I wonder if they'll bother with tethered flight tests?

I probably would.

They probably won't.

The drop tests should validate precision control. Take-offs from the pad for parachute-assisted landings will validate take-off control. Hopping should round out the envelope.

Their testing boldness continues to increase as shown by just-completed pad abort where eight engine performance was demo'd 24 hrs before live launch from a pad they have fully booked.
I don't expect them to fly tethered tests. But I certainly would as that's a lot cheaper than building a new expensive spacecraft.

What they can do is start with T/w<1, and see how weight is controllably taken off the legs, without ever leaving the ground.

Then T/w>1 for a brief period / hover, staying within what the legs can take if they were to suddenly shutdown all engines.

At that point you're gotten quite a bit of information.

Then T/w>1 for a couple of seconds, getting to parachute height, so you can abort by parachute.  Might not be pretty, but better than crashing.

Then they can start using it go get lunch downtown without getting caught in traffic.
ABCD - Always Be Counting Down

Offline Zed_Noir

  • Senior Member
  • *****
  • Posts: 5490
  • Canada
  • Liked: 1809
  • Likes Given: 1302
Re: SpaceX DragonFly Discussion Thread
« Reply #449 on: 05/10/2015 07:09 pm »


Somehow the lack of a CBM hatch on the Dragon 2 (aka Dragon V2, crewed Dragon, Dragonrider, etc) make it very unlikely.
CRS-2 actually allowed for IDA equipped vehicles. And I doubt that they'll will waste the uncrewed demonstration flight and thus it won't flight empty. I wouldn't be surprised if SpaceX actually wins a fat contract in CRS-2 (a likely outcome), they might offer an uncrewed Dragon v2 as a one-off mission. For CRS-2 it will offer cargo without the cost of crew time required for training and actual berthing operation, and it wouldn't conflict with any CBM CVV. It could also sand unpressurized cargo that's not well behaved in an abort situation. And it would allow to certify the propulsive (assited?) landing. Size limited unpressurized cargo might be manifested on a different flight.
Now, how does this affects DragonFly? Well, I believe that the cheapest opportunity to certify the Crewed Dragon for propulsive landing would be the Uncrewed Flight. But it would seem like they won't go that route and DragonFly might actually happen after it. Besides, they must have a mountain of certificates in development for water landing and redoing it for propulsive landing will take a while. And SpaceX wants that flag!
Thus, I would assume, that the next cheapest and safest way is to do the DragonFly program after Uncrewed Flight, and once all the kinks are out, they can negotiate a single Dragon v2 flight within their CRS-2 program, with the specific purpose of demonstrating the propulsive landing. It would also allow for a significant amount of downmass with a relatively gentle landing and could probably be in the hands of investigators at L+4hrs. Nothing that CST-100 Cargo wouldn't offer. But a nice thing to have if it doesn't cost anything.

What you suggest seems doable with a restricted cargo manifest. However don't think NASA will go for it.

Offline TomH

  • Senior Member
  • *****
  • Posts: 2938
  • Vancouver, WA
  • Liked: 1868
  • Likes Given: 909
Re: SpaceX DragonFly Discussion Thread
« Reply #450 on: 05/11/2015 02:24 am »
What you suggest seems doable with a restricted cargo manifest. However don't think NASA will go for it.

Perhaps at a lower price. NASA gets some cargo up at a lower price, SpaceX gets some remuneration.  I could see the first CST-100 doing this and the first Dragon2 doing it sans prop for the SDracos. Later, after several manned Dragon2s have visited ISS, another unmanned with small sized cargo could be used for the first retropulsive landing. May as well get a little more out of these flights if they're going to ISS anyway.

Offline TomH

  • Senior Member
  • *****
  • Posts: 2938
  • Vancouver, WA
  • Liked: 1868
  • Likes Given: 909
Re: SpaceX DragonFly Discussion Thread
« Reply #451 on: 07/28/2015 05:05 am »
Chris' article indicates that the first unmanned Dragon2 will carry cargo to ISS:
http://www.nasaspaceflight.com/2015/07/saving-spaceship-dragon-contingency-chute/
In fact, there may be a second unmanned Dragon2 which would also carry cargo.
« Last Edit: 07/28/2015 05:40 am by TomH »

Offline TomH

  • Senior Member
  • *****
  • Posts: 2938
  • Vancouver, WA
  • Liked: 1868
  • Likes Given: 909
Re: SpaceX DragonFly Discussion Thread
« Reply #452 on: 07/28/2015 05:48 am »
So Chris' latest article http://www.nasaspaceflight.com/2015/07/saving-spaceship-dragon-contingency-chute/  indicates that the first uncrewed Dragon2 will carry cargo, and that there may also be a second uncrewed Dragon2 which would also carry cargo. My question is this, being that the vehicle is uncrewed, how likely is it that the SuperDracos could be tested in a DragonFly landing scenario? Or would the first docking attempt of the spacecraft with ISS be too risky to carry the hypergolics aboard? What if the first flight is done successfully with no hypergolics, if there is a second uncrewed Dragon2, might they try a DragonFly landing on that flight? Or is DragonFly too far down the line to attempt it so early? After enough manned Dragon2 vehicles fly, I assume the first DragonFly landing will have to be an unmanned test. It just seems that the initial unmanned flight of Dragon2 to ISS would also be a good opportunity to test the powered landing ability of DragonFly.
« Last Edit: 07/28/2015 05:49 am by TomH »

Offline TrevorMonty

Re: SpaceX DragonFly Discussion Thread
« Reply #453 on: 07/28/2015 05:48 am »
Can SpaceX use Dragon2 on a CRS mission?
 Would have smaller hatch, limiting cargo options but that is a small price to pay for extra flight testing of a crew capsule.

Offline TomH

  • Senior Member
  • *****
  • Posts: 2938
  • Vancouver, WA
  • Liked: 1868
  • Likes Given: 909
Re: SpaceX DragonFly Discussion Thread
« Reply #454 on: 07/28/2015 05:55 am »
They have to fly it unmanned to test it. It will go to ISS. Why send it empty when smaller cargo items that are able to fit through the hatch can be carried to the station? This would not be a regular resupply mission, but at the cost/Kg of cargo, sending it empty rather than with cramming it full of smaller cargo just doesn't make sense.

Offline guckyfan

  • Senior Member
  • *****
  • Posts: 7438
  • Germany
  • Liked: 2332
  • Likes Given: 2891
Re: SpaceX DragonFly Discussion Thread
« Reply #455 on: 07/28/2015 06:11 am »
They have to fly it unmanned to test it. It will go to ISS. Why send it empty when smaller cargo items that are able to fit through the hatch can be carried to the station? This would not be a regular resupply mission, but at the cost/Kg of cargo, sending it empty rather than with cramming it full of smaller cargo just doesn't make sense.

It is clear that the big size of the berthing port is needed for ISS supply. But on which percentage of  flights do they really transport big items? I would guess it is not that many. Am I wrong?

Online docmordrid

  • Senior Member
  • *****
  • Posts: 6334
  • Michigan
  • Liked: 4207
  • Likes Given: 2
Re: SpaceX DragonFly Discussion Thread
« Reply #456 on: 07/28/2015 06:32 am »
Dragon 1 has a 127x127 cm CBM hatch.  AIUI Cygnus uses a 94x94 cm CBM hatch, but IDA's tunnel is only 80 cm.  A tad tight.
« Last Edit: 07/28/2015 06:33 am by docmordrid »
DM

Offline Req

  • Full Member
  • ****
  • Posts: 405
  • Liked: 434
  • Likes Given: 2580
Re: SpaceX DragonFly Discussion Thread
« Reply #457 on: 07/28/2015 10:37 am »
So Chris' latest article http://www.nasaspaceflight.com/2015/07/saving-spaceship-dragon-contingency-chute/  indicates that the first uncrewed Dragon2 will carry cargo, and that there may also be a second uncrewed Dragon2 which would also carry cargo. My question is this, being that the vehicle is uncrewed, how likely is it that the SuperDracos could be tested in a DragonFly landing scenario? Or would the first docking attempt of the spacecraft with ISS be too risky to carry the hypergolics aboard? What if the first flight is done successfully with no hypergolics, if there is a second uncrewed Dragon2, might they try a DragonFly landing on that flight? Or is DragonFly too far down the line to attempt it so early? After enough manned Dragon2 vehicles fly, I assume the first DragonFly landing will have to be an unmanned test. It just seems that the initial unmanned flight of Dragon2 to ISS would also be a good opportunity to test the powered landing ability of DragonFly.

The first, and probably the first several V2 flights will be chute/ocean landing because they need to prove that system works as a primary objective of the program.  They will not bypass that notch on their belt to try to leap ahead to propulsive landing, they will mimic the entire mission that humans will be going on exactly.

The first Dragon V2 to visit the ISS will have a full load of hypergolics, because even when they are eventually doing propulsive landing, it's actual primary purpose is for abort.  And much like the chute landings, they will fly with a full load because they will be proving that the spacecraft works how humans will be using it, so that humans can begin using it.
« Last Edit: 07/28/2015 10:44 am by Req »

Offline Chris Bergin

Re: SpaceX DragonFly Discussion Thread
« Reply #458 on: 10/16/2015 04:53 pm »
By the way, per L2's McGregor Photos and Update Section, Dragonfly has been photographed at McGregor, as has a big, big crane. I've asked SpaceX if they want to talk to us about the upcoming test objectives, but we'll be writing an article next week regardless.
Support NSF via L2 -- Help improve NSF -- Site Rules/Feedback/Updates
**Not a L2 member? Whitelist this forum in your adblocker to support the site and ensure full functionality.**

Offline Okie_Steve

  • Full Member
  • ****
  • Posts: 1886
  • Oklahoma, USA
  • Liked: 1141
  • Likes Given: 725
Re: SpaceX DragonFly Discussion Thread
« Reply #459 on: 10/16/2015 05:55 pm »
When SpaceX first started work on landing stages there was a lot if nay saying in some quarters, but for "DragonFly" you can hear the crickets chirping. They are being take *much* more seriously now, and for good reason.

I've got to admit, that pending a successful 'chute landing on the first (un)crew test it would be exciting to see a  propulsive landing test on the second, probably filled with trash bags or very low value down mass.

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0