Author Topic: General Falcon and Dragon Discussion (Thread 10)  (Read 606699 times)

Offline manboy

  • Senior Member
  • *****
  • Posts: 2086
  • Texas, USA, Earth
  • Liked: 134
  • Likes Given: 544
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #40 on: 01/09/2014 01:17 am »
The existence of a cargo version of "Dragon 2" is just speculation
QuantumG is claiming otherwise.

We know from imagery of the recent parachute drop test that Dragon 2 has a captive nosecone which presumably opens (somehow) to expose the docking/berthing interface on-orbit and closes for reentry, with a parachute system (for aborts only?) that deploys through a small opening in the tip of the closed nosecone.
Dragon already has a nosecone, it's jettisoned during launch. The parachutes are on the side of Dragon not underneath the nosecone.

But the cargo craft really has no need for any type of LAS support or ECLSS or internal view ports (windows or portals), so there is a huge opportunity for cost savings vs the crewed version.
It does if they want to do terra firma landings.

Currently, NASA has stipulated that each Cargo Dragon be new so although they have not actually signed a contract with any potential provider for crew services yet, I suspect they will require a new Dragon for each crewed mission. But that certainly does not preclude SpaceX from re-using a crewed Dragon for another customer besides NASA.
http://forum.nasaspaceflight.com/index.php?topic=28486.msg909803#msg909803
« Last Edit: 01/09/2014 01:18 am by manboy »
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline AncientU

  • Senior Member
  • *****
  • Posts: 6257
  • Liked: 4164
  • Likes Given: 6078
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #41 on: 01/09/2014 01:24 am »
But then, I am pretty sure that SpaceX wants to land ALL of their Dragons on land to allow reuse. That would require the cargo Dragons to be Dragon 2s as well.

You can be pretty sure all you want, but I don't expect to see it during this CRS contract.

You can not expect all you want, but SpaceX will have to land a series of Dragon 2s on land before they land crew, so at some point, using cargo returns is the obvious way to demonstrate this capability.  If it needs to be done some time, why not now, or at least during the next three years of cargo deliveries.  Very similar approach to test-landing first stages as opportunity presents during commercial and CRS missions.
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline rcoppola

  • Senior Member
  • *****
  • Posts: 2355
  • USA
  • Liked: 1967
  • Likes Given: 970
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #42 on: 01/09/2014 01:29 am »
The existence of a cargo version of "Dragon 2" is just speculation
QuantumG is claiming otherwise.

We know from imagery of the recent parachute drop test that Dragon 2 has a captive nosecone which presumably opens (somehow) to expose the docking/berthing interface on-orbit and closes for reentry, with a parachute system (for aborts only?) that deploys through a small opening in the tip of the closed nosecone.
Dragon already has a nosecone, it's jettisoned during launch. The parachutes are on the side of Dragon not underneath the nosecone.

But the cargo craft really has no need for any type of LAS support or ECLSS or internal view ports (windows or portals), so there is a huge opportunity for cost savings vs the crewed version.
It does if they want to do terra firma landings.

Currently, NASA has stipulated that each Cargo Dragon be new so although they have not actually signed a contract with any potential provider for crew services yet, I suspect they will require a new Dragon for each crewed mission. But that certainly does not preclude SpaceX from re-using a crewed Dragon for another customer besides NASA.
http://forum.nasaspaceflight.com/index.php?topic=28486.msg909803#msg909803
Not sure what your point is linking to that thread?  As I already said, NASA wanted new Dragons for each cargo mission and will likely want the same for crew missions.  Is there something you think I may have missed?

However, considering that no actual contracts have been signed for crew services, we do not definitively know whether re-use will be acceptable at some point in the future. Although, as I said, I suspect not for crew.
Sail the oceans of space and set foot upon new lands!
http://www.stormsurgemedia.com

Offline manboy

  • Senior Member
  • *****
  • Posts: 2086
  • Texas, USA, Earth
  • Liked: 134
  • Likes Given: 544
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #43 on: 01/09/2014 01:39 am »
The existence of a cargo version of "Dragon 2" is just speculation
QuantumG is claiming otherwise.

We know from imagery of the recent parachute drop test that Dragon 2 has a captive nosecone which presumably opens (somehow) to expose the docking/berthing interface on-orbit and closes for reentry, with a parachute system (for aborts only?) that deploys through a small opening in the tip of the closed nosecone.
Dragon already has a nosecone, it's jettisoned during launch. The parachutes are on the side of Dragon not underneath the nosecone.

But the cargo craft really has no need for any type of LAS support or ECLSS or internal view ports (windows or portals), so there is a huge opportunity for cost savings vs the crewed version.
It does if they want to do terra firma landings.

Currently, NASA has stipulated that each Cargo Dragon be new so although they have not actually signed a contract with any potential provider for crew services yet, I suspect they will require a new Dragon for each crewed mission. But that certainly does not preclude SpaceX from re-using a crewed Dragon for another customer besides NASA.
http://forum.nasaspaceflight.com/index.php?topic=28486.msg909803#msg909803
As I already said, NASA wanted new Dragons for each cargo mission
That does not appear to be entirely true (i.e. there isn't a requirement for them to be new Dragons). Read the comments in the thread attached above.
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline QuantumG

  • Senior Member
  • *****
  • Posts: 9238
  • Australia
  • Liked: 4477
  • Likes Given: 1108
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #44 on: 01/09/2014 01:43 am »
The existence of a cargo version of "Dragon 2" is just speculation
QuantumG is claiming otherwise.

I am, but not very strongly. I can't be bothered tracking down Gwynne's comments.
Human spaceflight is basically just LARPing now.

Offline joek

  • Senior Member
  • *****
  • Posts: 4869
  • Liked: 2782
  • Likes Given: 1096
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #45 on: 01/09/2014 02:46 am »
http://forum.nasaspaceflight.com/index.php?topic=28486.msg909803#msg909803
As I already said, NASA wanted new Dragons for each cargo mission
That does not appear to be entirely true (i.e. there isn't a requirement for them to be new Dragons). Read the comments in the thread attached above.

What manboy said.  We've been through this discussion several times...

CRS solicitation did not require new.  CRS contract does not require new.  NASA's requirement for the CRS contract was (per FAR) firm fixed price (FFP) not to exceed (NTE).  Without knowing the economics of reuse, the CRS contract was necessarily bid on the assumption of no reuse, not due to any inherent NASA requirement.  As SpaceX stated in their COTS proposal:
Quote
Both Falcon 9 and Dragon are designed for reusability, but the costs as proposed assume no reusability economics.  Until a given launch system has flown several times and all costs are understood, it is very risky to make reusability cost assumptions.  However, SpaceX intends to work hard to make the reusability economics positive and has started that learning curve.  with the Falcon 1 first stage. If such economics work out, there is the potential for substantial savings in cost per flight.
While that precedes CRS, I think we can safely say the "learning curve" and making "reusability economics positive" is still a work in progress.

Moreover, SpaceX is already reusing Dragon components for CRS flights (IIRC that from a NAC presentation some time ago).  It's not a matter of whether reuse is allowed, but what and when.

Offline rcoppola

  • Senior Member
  • *****
  • Posts: 2355
  • USA
  • Liked: 1967
  • Likes Given: 970
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #46 on: 01/09/2014 02:59 am »
http://forum.nasaspaceflight.com/index.php?topic=28486.msg909803#msg909803
As I already said, NASA wanted new Dragons for each cargo mission
That does not appear to be entirely true (i.e. there isn't a requirement for them to be new Dragons). Read the comments in the thread attached above.

What manboy said.  We've been through this discussion several times...

CRS solicitation did not require new.  CRS contract does not require new.  NASA's requirement for the CRS contract was (per FAR) firm fixed price (FFP) not to exceed (NTE).  Without knowing the economics of reuse, the CRS contract was necessarily bid on the assumption of no reuse, not due to any inherent NASA requirement.  As SpaceX stated in their COTS proposal:
Quote
Both Falcon 9 and Dragon are designed for reusability, but the costs as proposed assume no reusability economics.  Until a given launch system has flown several times and all costs are understood, it is very risky to make reusability cost assumptions.  However, SpaceX intends to work hard to make the reusability economics positive and has started that learning curve.  with the Falcon 1 first stage. If such economics work out, there is the potential for substantial savings in cost per flight.
While that precedes CRS, I think we can safely say the "learning curve" and making "reusability economics positive" is still a work in progress.

Moreover, SpaceX is already reusing Dragon components for CRS flights (IIRC that from a NAC presentation some time ago).  It's not a matter of whether reuse is allowed, but what and when.
Most excellent. OK, I see what manboy and you are saying now. And now remember all those re-use conversations from what seems like a hundred years ago. So, Thanks. Always good to be reminded of the facts.
« Last Edit: 01/09/2014 03:01 am by rcoppola »
Sail the oceans of space and set foot upon new lands!
http://www.stormsurgemedia.com

Offline StuffOfInterest

  • Full Member
  • ****
  • Posts: 927
  • Just interested in space
  • McLean, Virginia, USA
  • Liked: 920
  • Likes Given: 231
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #47 on: 01/09/2014 07:53 pm »
Regarding differences between the eventual crew and cargo Dragon, I have to wonder if it would be possible to build a single base vehicle with plug in modules to make it crewed?  Docking adapter could be bolted into the CBM (just like how the station does it) as long as it is low profile enough to fit under the nose cone.  Seats, displays, and life support systems could bolt into attachments inside the Dragon.  This way you have a single production line for the spacecraft that only requires some post production installation to go from cargo to crew.  This would seem to fit with how SpaceX looks towards efficiency.

Offline AJW

  • Full Member
  • ****
  • Posts: 807
  • Liked: 1315
  • Likes Given: 136
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #48 on: 01/09/2014 07:59 pm »
If you look at the interior pictures of the crewed Dragon, parts of the seats already appear to be easily removable, so this may already be part of the design.  You won't always be sending a full crew compliment, so sending additional cargo would make sense.
We are all interested in the future, for that is where you and I are going to spend the rest of our lives.

Offline manboy

  • Senior Member
  • *****
  • Posts: 2086
  • Texas, USA, Earth
  • Liked: 134
  • Likes Given: 544
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #49 on: 01/10/2014 12:58 am »
Regarding differences between the eventual crew and cargo Dragon, I have to wonder if it would be possible to build a single base vehicle with plug in modules to make it crewed?  Docking adapter could be bolted into the CBM (just like how the station does it) as long as it is low profile enough to fit under the nose cone.  Seats, displays, and life support systems could bolt into attachments inside the Dragon.  This way you have a single production line for the spacecraft that only requires some post production installation to go from cargo to crew.  This would seem to fit with how SpaceX looks towards efficiency.
I know that was what they originally planned.

If you look at the interior pictures of the crewed Dragon, parts of the seats already appear to be easily removable, so this may already be part of the design.  You won't always be sending a full crew compliment, so sending additional cargo would make sense.
The unused space on crewed flights is planned to be used for additional up/down mass. But that doesn't mean the crew variant can be converted to the cargo variant or vice versa without having to reapply the outer mold line.
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline luinil

Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #50 on: 01/10/2014 01:10 am »
Wouldn't that be cheaper and more efficient to have only one version of Dragon, and only the embarked systems (batteries, panels, life support, etc...) would change between the cargo and human transport versions ?

Offline Falcon H

  • Full Member
  • **
  • Posts: 246
  • Liked: 108
  • Likes Given: 232
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #51 on: 01/10/2014 01:27 am »
This may be a stupid question, but ill ask anyway.
Will the CRS-3 Falcon have legs? They said that they would attempt recovery of the first stage, and I have herd that the legs will stop the spinning, so aren't they necessary?
Thank You 

Offline QuantumG

  • Senior Member
  • *****
  • Posts: 9238
  • Australia
  • Liked: 4477
  • Likes Given: 1108
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #52 on: 01/10/2014 01:32 am »
This may be a stupid question, but ill ask anyway.
Will the CRS-3 Falcon have legs? They said that they would attempt recovery of the first stage, and I have herd that the legs will stop the spinning, so aren't they necessary?
Thank You

As far as I'm aware, there's been no definitive information since the Sep 29 post-Cassiope press conference.

Quote from: Elon Musk
We have two geostationary flights: SES and Thaicom and then we have got the orbital resupply mission for NASA, the CRS flight and it's on that CRS flight that we are going to try to bring the first stage back. We are hoping to put the landing legs on that stage. It's still debatable whether at that stage, we will land with landing legs in the ocean or land with landing legs on land. Either way, we do want it to have the landing legs on.

but..

Quote from: Elon Musk
We are not going hold up that flight for landing legs. So if landing legs end up being delayed for any reason then we won't hold up the flight for that. But the full plan is to have landing legs on that mission. The schedule for that mission is mostly governed by upgrades to the Dragon spacecraft.

via http://shitelonsays.com/transcript/spacex-press-conference-september-29-2013-2013-09-29
Human spaceflight is basically just LARPing now.

Offline Falcon H

  • Full Member
  • **
  • Posts: 246
  • Liked: 108
  • Likes Given: 232
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #53 on: 01/10/2014 03:03 am »
Thanks for the info, I guess we'll all see in February. :D

Offline manboy

  • Senior Member
  • *****
  • Posts: 2086
  • Texas, USA, Earth
  • Liked: 134
  • Likes Given: 544
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #54 on: 01/10/2014 03:56 am »
Wouldn't that be cheaper and more efficient to have only one version of Dragon, and only the embarked systems (batteries, panels, life support, etc...) would change between the cargo and human transport versions ?
Yes but there may be some mass and volume issues; and there's a lot of stuff we don't know. Such as Falcon 9R's payload to LEO, Dragon's max payload mass (which would tell us how much margin they're working with) and what the mass of a CBM to NDS adapter would be. Also a CBM to NDS adapter may be too long to fit within the nose cap.

"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

Offline Wigles

  • Member
  • Posts: 52
  • Liked: 12
  • Likes Given: 5
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #55 on: 01/10/2014 01:39 pm »
Wouldn't that be cheaper and more efficient to have only one version of Dragon, and only the embarked systems (batteries, panels, life support, etc...) would change between the cargo and human transport versions ?
Yes but there may be some mass and volume issues; and there's a lot of stuff we don't know. Such as Falcon 9R's payload to LEO, Dragon's max payload mass (which would tell us how much margin they're working with) and what the mass of a CBM to NDS adapter would be. Also a CBM to NDS adapter may be too long to fit within the nose cap.

Also, sometimes being a jack of all trades / master of none is actually less cost efficient than having two similar but distinct designs. Even the provisions to add the human transport kit into the cargo version is going to take up mass & volume that could have been used for paying cargo.

Primary structure and major systems (computers, RCS etc) would probably be common, but I bet the fit out on the inside would be completely different and non-interchangeable.

You never see freighter versions of commercial aircraft used for passenger transport with palletised seating (unless you are military) because it is not efficient to use an aircraft optimised for cargo for passengers, I believe the same will be true of spacecraft.

Offline Elmar Moelzer

  • Senior Member
  • *****
  • Posts: 3661
  • Liked: 849
  • Likes Given: 1062
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #56 on: 01/10/2014 02:17 pm »
I think a good reason to use Dragon2 for cargo as well is to gain experience with landing on land and give the spacecraft more flight history prior to launching humans on it.

Offline guckyfan

  • Senior Member
  • *****
  • Posts: 7438
  • Germany
  • Liked: 2332
  • Likes Given: 2891
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #57 on: 01/10/2014 02:35 pm »
I think a good reason to use Dragon2 for cargo as well is to gain experience with landing on land and give the spacecraft more flight history prior to launching humans on it.

This plus land landing will facilitate reuse and has advantages in handling sensitive cargo. I also don't see NASA object to it in the present contract. They can find downmass they can risk losing for one flight once the present backlog of freezers is reduced.

Offline Elmar Moelzer

  • Senior Member
  • *****
  • Posts: 3661
  • Liked: 849
  • Likes Given: 1062
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #58 on: 01/10/2014 02:50 pm »
This plus land landing will facilitate reuse and has advantages in handling sensitive cargo. I also don't see NASA object to it in the present contract. They can find downmass they can risk losing for one flight once the present backlog of freezers is reduced.
Yeah, I fully agree about the reuse. Some people here seem to think that NASA wants a new Dragon for every mission. They do forget though that even if NASA wanted a new capsule every time, SpaceX could still reuse the capsule for other missions (Dragonlab) maybe at some discount.

Offline AJW

  • Full Member
  • ****
  • Posts: 807
  • Liked: 1315
  • Likes Given: 136
Re: General Falcon and Dragon Discussion (Thread 10)
« Reply #59 on: 01/10/2014 03:51 pm »
You never see freighter versions of commercial aircraft used for passenger transport with palletised seating (unless you are military) because it is not efficient to use an aircraft optimised for cargo for passengers, I believe the same will be true of spacecraft.

I believe that you will find that the majority of commercial passenger jet aircraft also have a freighter variant.  Same approach applies to automobiles with cargo vans and passenger vans.

http://www.ups.com/aircargo/using/services/services/domestic/svc-aircraft.html
We are all interested in the future, for that is where you and I are going to spend the rest of our lives.

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1