Commercial Crew Spacecraft Competition

[Prober]

Thought it was time for a Commercial Crew Spacecraft Competition thread.

This might be premature since we don’t have all the details; we can add those in the future.  The Idea is to see all the spacecraft side by side for a comparison.

I’ll start this out with one of my favorites, the CCM.

These two pics of Orion and the Composite Crew Module (CCM) really impressed me.   

From the fine article:  http://www.nasaspaceflight.com/2012/07/nasa-esd-key-orion-requirement-lunar-missions/
http://www.nasaspaceflight.com/wp-content/uploads/2012/07/Z38.jpg

Having seen the Apollo, the space inside is impressive.   I realize they are standing in the crew supply area in the 2nd photo; but even with equipment installed, the CCM/Orion space is impressive.

I’m not going to post pics of the others; I leave it to the supporters of each in the competition to post their own.   Enjoy all ..

[Lars_J]

Did you mean competition or comparison?

Anyway, I took the liberty (heh) of adding in Dragon and CST-100 into the image you attached.
 - The Dragon illustration is not from SpaceX, it was created by the started of this thread: http://forum.nasaspaceflight.com/index.php?topic=29182.0
 - The CST-100 image was 'shopped to remove the SM, but I was too lazy to remove the "claw'. 

These four capsules should be to scale.

EDIT: I'm also attaching a speculative crew Dragon cross-section I created based on SpaceX images, to give an idea of the interior space.

[Prober]

thats a good layout and glad Apollo got in there for reference.

Blue Origin and DC fans how about some input?

[BrightLight]

DC scaled to rest of the vehicles.

[Ronsmytheiii]

DC scaled to rest of the vehicles.

I do believe that is the HL-20.... I know splitting hairs.

[BrightLight]

DC scaled to rest of the vehicles.

I do believe that is the HL-20.... I know splitting hairs.

nit, nit,nit - of course you are correct, however I scaled it to the Dream Chaser spec of 29.5 feet/ 9 m.

[newspacer]

It's always nice to see things side by side

[rmencos]

Not as nice as above, but here's another side by side from the Liberty presentation with Almaz.  I added Dragon (eye-balled the scale).

[Prober]

DC scaled to rest of the vehicles.

I do believe that is the HL-20.... I know splitting hairs.

Ronsmytheiii:  believe I have made a monster thread here.  I posted last night and this morning "dreamchaser comparison.jpg (1846.82 KB, 2200x2925 - viewed 415 times.)" 

that's alot of interest in a few hours.

[Lobo]

DC scaled to rest of the vehicles.

CAn someone add a scaled approximateion of Liberty capsule to that for comparison?  Or will it have approximately Orion's dimensions?  I think it'll have systmes commonality with Orion, but I don't know about it's external dimensions, and how they scale with the others.

Also, imagine how much habitable volume Orion would have if it had Dragon's sidewall angle instead of Apollo's?  I believe I read somewhere that Orion actually doesn't need the steep wall angle that Apollo had.  The angle of Dragon's would be fine, even at BLEO velocities.

[Prober]

DC scaled to rest of the vehicles.

CAn someone add a scaled approximateion of Liberty capsule to that for comparison?  Or will it have approximately Orion's dimensions?  I think it'll have systmes commonality with Orion, but I don't know about it's external dimensions, and how they scale with the others.

The Orion dimensions and CCM shown above are about the same.  The missions LEO and BEO are different so supplies will change.   

Did you read the thread on the CCM?
http://forum.nasaspaceflight.com/index.php?topic=27265.0

[BrightLight]

The differences in the outer mold lines of the SNC Dream Chaser and the NASA HL-20 are not large. Cockpit windows, I think the RCS and maybe the entry/egress hatch might be different.  Thanks to Dr. Mordrid for the cutaway.

[rmencos]

Thanks.  I hadn't noticed the squeegee man on the HL-20 windows before.

[BrightLight]

Thanks.  I hadn't noticed the squeegee man on the HL-20 windows before.

Its still not clear to me where he is on the elevator, or does he get strapped on for the ride?

[Prober]

The differences in the outer mold lines of the SNC Dream Chaser and the NASA HL-20 are not large. Cockpit windows, I think the RCS and maybe the entry/egress hatch might be different.  Thanks to Dr. Mordrid for the cutaway.

oh thats a nice cutaway......

[docmordrid]

The differences in the outer mold lines of the SNC Dream Chaser and the NASA HL-20 are not large. Cockpit windows, I think the RCS and maybe the entry/egress hatch might be different.  Thanks to Dr. Mordrid for the cutaway.

oh thats a nice cutaway......

Actually, it started with simonbp posting a photo of a cutaway from a presentation over a year ago. It was off-angle, blurry etc., so I did my graphics kung-fu to correct the perspective, rotate,  sharpen, re-draw and otherwise make it more presentable.

Consulted with BrightLight about a smooge to his images levels for the cutaway. Re-post attached.

[BrightLight]

Now all we need to do is put Korelev in the cockpit 

[Rocket Science]

Ya done good Doc...

[manboy]

DC scaled to rest of the vehicles.

CAn someone add a scaled approximateion of Liberty capsule to that for comparison?  Or will it have approximately Orion's dimensions?  I think it'll have systmes commonality with Orion, but I don't know about it's external dimensions, and how they scale with the others.

The Orion dimensions and CCM shown above are about the same.  The missions LEO and BEO are different so supplies will change.   

Did you read the thread on the CCM?
http://forum.nasaspaceflight.com/index.php?topic=27265.0

I thought the Liberty capsule was going to be smaller then the CCM, and that they were just using the CCM for tests as a cost savings decision.

The differences in the outer mold lines of the SNC Dream Chaser and the NASA HL-20 are not large. Cockpit windows, I think the RCS and maybe the entry/egress hatch might be different.  Thanks to Dr. Mordrid for the cutaway.

Are you sure that's an image of the Dream Chaser test article and not the HL-20 mock-up that was shipped to Sierra Nevada?

[BrightLight]

DC scaled to rest of the vehicles.

CAn someone add a scaled approximateion of Liberty capsule to that for comparison?  Or will it have approximately Orion's dimensions?  I think it'll have systmes commonality with Orion, but I don't know about it's external dimensions, and how they scale with the others.

The Orion dimensions and CCM shown above are about the same.  The missions LEO and BEO are different so supplies will change.   

Did you read the thread on the CCM?
http://forum.nasaspaceflight.com/index.php?topic=27265.0

I thought the Liberty capsule was going to be smaller then the CCM, and that they were just using the CCM for tests as a cost savings decision.

The differences in the outer mold lines of the SNC Dream Chaser and the NASA HL-20 are not large. Cockpit windows, I think the RCS and maybe the entry/egress hatch might be different.  Thanks to Dr. Mordrid for the cutaway.

Are you sure that's an image of the Dream Chaser test article and not the HL-20 mock-up that was shipped to Sierra Nevada?

The bottom image is the HL-20 mockup, the middle image is of unknown provinance and is most likely an intermediate design, and the cutaway is several year old vintage DC. Getting up to date DC images in the right orientation is problematic, it would great to have a solid works file to run the images. That being said, the size and general mold lines hold true.

[Prober]

found this inside view of the Boeing was 2010 so it might be old?

[Lars_J]

A partial mock-up of the CST-100 interior:

[Orbital Debris]

A partial mock-up of the CST-100 interior:

http://www.boeing.com/defense-space/space/ccts/docs/CCDev2%20Boeing%20CST-100%20Overview.pdf

This is a pretty good public domain presentation with some of my favorite views of the interior of the mockup (the folks in the mockup are the engineers that worked on it.  For those interested, slides 9&10 the background is the interior of the Bigelow plant.

[Rocket Science]

I did a rough calculation of the interior volume of the CST-100 vs Dragon due the intrusion of the docking tunnel at about 1 cubic meter less.  Nate said a bit more…  Anyone else?

http://forum.nasaspaceflight.com/index.php?topic=9921.1215

[mr. mark]

You have to wonder if Boeing will have a spacecraft after next week if they are not selected.

[Rocket Science]

You have to wonder if Boeing will have a spacecraft after next week if they are not selected.

I say yes...

[Lars_J]

I did a rough calculation of the interior volume of the CST-100 vs Dragon due the intrusion of the docking tunnel at about 1 cubic meter less.  Nate said a bit more…  Anyone else?

http://forum.nasaspaceflight.com/index.php?topic=9921.1215

The only metric that matters in the end is the 'habitable'/usable volume. It's hard to know for either exactly, without knowing exactly how the cabin will be configured. (although the CST-100 internal mockups give us a decent idea, and they appear to be further along in that aspect compared to Dragon)

[Rocket Science]

I did a rough calculation of the interior volume of the CST-100 vs Dragon due the intrusion of the docking tunnel at about 1 cubic meter less.  Nate said a bit more…  Anyone else?

http://forum.nasaspaceflight.com/index.php?topic=9921.1215

The only metric that matters in the end is the 'habitable'/usable volume. It's hard to know for either exactly, without knowing exactly how the cabin will be configured. (although the CST-100 internal mockups give us a decent idea, and they appear to be further along in that compared to Dragon)

Like I said... "Totally full of error"!

[vt_hokie]

No word on a selection announcement date?

[A_M_Swallow]

Has the 'simple life support system' been tested?
Would it work in other vehicles, habitats and spacestations?

[docmordrid]

I thought Paragon had developed one in CCDev-1 that was approved by NASA for commercial crew partners. At the least they are partnered with SpaceX.

[QuantumG]

I thought Paragon had developed one in CCDev-1 that was approved by NASA for commercial crew partners. At the least they are partnered with SpaceX.

You'd figure integrating life support would be a priority.. it's not like they can fly without it.

[pathfinder_01]

Has the 'simple life support system' been tested?
Would it work in other vehicles, habitats and spacestations?

For CST100 yes. Paragon also developed a lifesupport system that can be used in any vechile. Paragon is working with Space X on it's life support.

Life support is a tricky thing. ISS life support systems are rather differnt than that of the Shuttle. Orion's would be more different still.  The needs of a spacecraft that must be launched but only work in space for a short period of time and return are differnt than ISS or Bigeleow or to a degree Orion's life support system(which Paragon was also working on).

[Orbital Debris]

I thought Paragon had developed one in CCDev-1 that was approved by NASA for commercial crew partners. At the least they are partnered with SpaceX.

You'd figure integrating life support would be a priority.. it's not like they can fly without it.

Well, they can't fly crew without it.  Life support tends to be one of those systems that gets taken for granted, or pushed down in priority until it doesn't work.  I am surprised that we have not heard much about testing results, in favor of landing systems, prop, outer mold lines, etc.  However that may be due to the fact that it doesn't pitch to the public well.

As noted above Life Support is tricky, and I would be interested in the competitors pitches in that respect.  I think it gives insight to a maturity of design.  Even if you decided to subcontract that out, Life Support has large impacts on other systems (particularly power, thermal, volume) that make integration difficult.

[Prober]

Orbital Debris did you have a chance to get close up (must be nice) to the mock up of the CST100?

[Orbital Debris]

Orbital Debris did you have a chance to get close up (must be nice) to the mock up of the CST100?

Yes, I spent quite a bit of time in it.

[kirghizstan]

ok this is getting ridiculous, can't they just announce the "winners" already so we can move on hearing the endless discussions about how nasa both blew it and made the smartest choices every. 

[edkyle99]

ok this is getting ridiculous, can't they just announce the "winners" already so we can move on hearing the endless discussions about how nasa both blew it and made the smartest choices every. 

No matter how it turns out, someone will claim conspiracy, etc., rather than just accept on face value that NASA chose the winners based on who best met the bid criteria.  This delayed announcement is already fueling those theories, because, "clearly", some politician or NASA HQ type with connections is trying to change the results as we speak. 

 - Ed Kyle

[MikeAtkinson]

ok this is getting ridiculous, can't they just announce the "winners" already so we can move on hearing the endless discussions about how nasa both blew it and made the smartest choices every. 

No matter how it turns out, someone will claim conspiracy, etc., rather than just accept on face value that NASA chose the winners based on who best met the bid criteria.  This delayed announcement is already fueling those theories, because, "clearly", some politician or NASA HQ type with connections is trying to change the results as we speak. 

 - Ed Kyle

I hope and expect that these "political" delays are just various people satisfying themselves that the process has been carried out correctly. We don't want the decision challenged in the courts by someone claiming process has not been followed and that criteria other than those set out are being used to choose the winners.

[Prober]

ok this is getting ridiculous, can't they just announce the "winners" already so we can move on hearing the endless discussions about how nasa both blew it and made the smartest choices every. 

No matter how it turns out, someone will claim conspiracy, etc., rather than just accept on face value that NASA chose the winners based on who best met the bid criteria.  This delayed announcement is already fueling those theories, because, "clearly", some politician or NASA HQ type with connections is trying to change the results as we speak. 

 - Ed Kyle

I hope and expect that these "political" delays are just various people satisfying themselves that the process has been carried out correctly. We don't want the decision challenged in the courts by someone claiming process has not been followed and that criteria other than those set out are being used to choose the winners.

Everyone misses the point and the process should be kept in perspective, it’s a “Competition”.   The best that met the specs should get into the next round period.

Those firms who have bragged about continuing “no matter what” will have to put up, or shut up.   All the firms have a chance to be in final “Competition” for the contract in aprox two years.  That being said only stupid firms would bring this into a court.

Anything that needs correcting?

[erioladastra]

ok this is getting ridiculous, can't they just announce the "winners" already so we can move on hearing the endless discussions about how nasa both blew it and made the smartest choices every. 

No matter how it turns out, someone will claim conspiracy, etc., rather than just accept on face value that NASA chose the winners based on who best met the bid criteria.  This delayed announcement is already fueling those theories, because, "clearly", some politician or NASA HQ type with connections is trying to change the results as we speak. 

 - Ed Kyle

I hope and expect that these "political" delays are just various people satisfying themselves that the process has been carried out correctly. We don't want the decision challenged in the courts by someone claiming process has not been followed and that criteria other than those set out are being used to choose the winners.

What delayed announcement?  The Commercial Crew Program has always said July/August.  Bolden fueled speculation that it would be mid July but that was a target date.   Things like the selecting official being on travel for a bit can cause minor "delays".  Other minor things can add time too.  Small wickets to check through for a good roll out. Keep the powder dry, its coming...

[spectre9]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

[Downix]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

The Dream Chaser does it's own final burn, as a quasi third-stage. Boeing's design does not.

[spectre9]

Now it has the prop for a 3rd stage burn too?? 

On hybrid engines?

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

Are composites (in any old irregular shape) really that light?

[pathfinder_01]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

Are composites (in any old irregular shape) really that light?

In a sense dreamchaser isn't carring around wings. The body is the wing(i.e. lifting body). There will be stuff in thoose areas. And CST 100 is carring around airbags and parachute so wheels vs. no wheels is not a good comparision.

[joek]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

[Prober]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

Was thinking the same.....we don't have the fine details on the CST-100.  Boeing does have alot of experience with composites, so we just don't know.

[manboy]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

Was thinking the same.....we don't have the fine details on the CST-100.  Boeing does have alot of experience with composites, so we just don't know.

What does composites have to do with CST-100?

[anonymous1138]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

Are composites (in any old irregular shape) really that light?

In a sense dreamchaser isn't carring around wings. The body is the wing(i.e. lifting body). There will be stuff in thoose areas. And CST 100 is carring around airbags and parachute so wheels vs. no wheels is not a good comparision.

This is a good point. As seen in the previously posted cutaway, there is little space that is not used inside DC structure. It would be interesting to get a feel for how much the wings, rudder, wheels/skid, actuators, etc. weigh in comparison to parachute systems, mortar/pyros. 

[edkyle99]

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

What's the basis for asserting that "the inected mass of the CST-100 is so much higher"?

It requires an Atlas with a solid booster versus the Atlas 5-402 needed by Dream Chaser.

 - Ed Kyle

[erioladastra]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

Boeing is much farther along on real analysis on their systems on things like power, mass... and they are planning for margin on the early flights and plan to go down smaller if possible.

[Jim]

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

No, Atlas is easier to manrate

[adrianwyard]

Do we know that the CST-100 actually suffered from bloat? With the addition of the SM it is more capable than the Dream Chaser in some respects, having more power on hand for abort, and can use that capability to do station reboost. DC cannot do that.

With the weaker abort capability I suspect that SNC are painted into a corner in terms of staying lightweight: if they gain enough weight to require the addition of a solid motor on the Atlas, their abort capability will look really suspect unless they upgrade that too, which will be very hard to do, and presumably add mass... Plus staying lightweight puts less stress on the TPS. If people are suspicious of the all carbon composite structure on DC (versus traditional manufacturing on CST-100), that same skepticism should be applied to the Liberty capsule too.

So it might be just a design decision. SNC chose the lightweight path. Which decision was best is hard to say right now.

[Robotbeat]

I'm not sure the difference between CST-100 and DC is due entirely to DC using more advanced materials. I suspect it has a lot to do with CST-100 being arguably a more mature and conservative design (that doesn't automatically mean /better/, though it does usually mean less risky schedule-wise).

[anonymous1138]

I'm not sure the difference between CST-100 and DC is due entirely to DC using more advanced materials. I suspect it has a lot to do with CST-100 being arguably a more mature and conservative design ...

Personally, I don't believe that this is an accurate statement.

[Go4TLI]

I'm not sure the difference between CST-100 and DC is due entirely to DC using more advanced materials. I suspect it has a lot to do with CST-100 being arguably a more mature and conservative design ...

Personally, I don't believe that this is an accurate statement.

Me either.  They are completely different designs and as a consequence to that have different concepts of operations which strongly influence the requirements and engineering. 

Neither is more mature and neither is more conservative over the other.  Don't let simple shape of a vehicle try to imply that one can make all the necessary, and correct, deductions. 

[hkultala]

Now it has the prop for a 3rd stage burn too?? 

On hybrid engines?

The same propellant can be used for either. Carrying around fuel which is ONLY used for abort is waste of mass. (CST-100)

But on DC and draron:

If there is an emergency, the propellant is used for abort.

If there is no emergency, in DC the propellant is used as third stage propellant.

If there is no emergency, on dragon the propellant is used for landing.

Why is the injected mass of CST-100 so much higher when it doesn't carry around things like wheels and wings?

It's not higher. But it has "worse staging", it's carrying the second stage all the way up to orbit, while DC discards the second stage before orbit.

and DC does not have wings. It just has flatter shape.

[Prober]

Do we know that the CST-100 actually suffered from bloat?

answers to your questions lie in the videos I listed.  No one has picked up on it yet.

 http://forum.nasaspaceflight.com/index.php?topic=22125.960

[pathfinder_01]

The same propellant can be used for either. Carrying around fuel which is ONLY used for abort is waste of mass. (CST-100)

Small correction. CST100 has a pusher system and will use it's propellant for abort or boost the ISS.  Only Orion has a puller system that is only used for escape.

DC plans to use it for abort, to get into orbit and/or if needed during atmospheric flight.

Dragon just for abort or landing.

[Lars_J]

The same propellant can be used for either. Carrying around fuel which is ONLY used for abort is waste of mass. (CST-100)

Small correction. CST100 has a pusher system and will use it's propellant for abort or boost the ISS.  Only Orion has a puller system that is only used for escape.

DC plans to use it for abort, to get into orbit and/or if needed during atmospheric flight.

Dragon just for abort or landing.

Incorrect (regarding Dragon). It will only have one set of propellant tanks, so whatever margin is not set aside for landing can be used for orbital maneuvers and/or ISS reboost.

[DaveH62]

NASA to Announce New Agreements for Next Phase of Commercial Crew Development.
Is this THE announcement of the 2.5 Comm Crew Providers?

http://spaceref.com/news/viewpr.html?pid=38013

[Go4TLI]

I don't know where all this reboost stuff is coming from. The LAS engines are likely not throttleable.  And something that is intended to get one off an exploding rocket as quick as possible would also destroy ISS if fired while docked.

Shuttle reboosted ISS with 25 lbf thrusters

[cleonard]

The amount of boost that a Dragon can give to the ISS will be limited.  The Dragon is so much smaller.  To be useful for abort the deltav will need to be in the 500 m/s or more range.  The deorbit burn for the Dragon will be around 100 m/s to 120 m/s depending on the exact situation.  There is some other maneuvering and reserves so lets say a Dragon has 300 m/s extra. 

When you are pushing a 420mT ISS that 300 m/s will only do so much.  If you go most optimistic and say that 300 m/s is for a max weight Dragon at 10mT, when you combine masses you get a deltav on the order of 7 m/s.  It's better than zero, but it's not going to boost the ISS all that much.

I see mentions of using the Super Draco to boost the ISS.  It would not be done that way.  That's too much force.  A longer lower thrust burn of an attitude control Draco is how it would be done.   

EDIT:
If I'm doing this right that 7m/s should boost a 320km low ISS orbit to a little under 330km.  I think that the ISS operates between 320km and 350km or so.  That makes it a useful boost, but not a real big boost.

[pathfinder_01]

I don't know where all this reboost stuff is coming from. The LAS engines are likely not throttleable.  And something that is intended to get one off an exploding rocket as quick as possible would also destroy ISS if fired while docked.

Shuttle reboosted ISS with 25 lbf thrusters

The propellant for reboost could be used by either LAS thrusters or other thrusters. CST-100 plans two differnt types of thrusters that could use the same propellant.

[Orbital Debris]

How come the CST-100 suffered from bloat that didn't effect Dream Chaser? 7 crew, life support, abort system, docking hatch, power for 60 hours of free flight. Then add the weight of wings and wheels for landings.

How do they fit all that on Atlas 402? I'm sceptical.

Dragon & CST look to be built the right way looking towards being on time/budget even if they might be a little heavier. Aluminium pressure vessel and small round simple heat shield.

I wonder if Boeing would want to change to Delta IV if it becomes the sole customer on Atlas V.

Isn't that upper stage being man rated anyway for SLS?

DEC might not be needed in that case. 

I also like the money that Bigelow/Musk invested in those 2 spacecraft and that is one of the things CCDev was trying to do.

Bigelow did not invest money in either Dragon or CST-100. 

[spectre9]

I don't know where all this reboost stuff is coming from. The LAS engines are likely not throttleable.  And something that is intended to get one off an exploding rocket as quick as possible would also destroy ISS if fired while docked.

Shuttle reboosted ISS with 25 lbf thrusters

The propellant for reboost could be used by either LAS thrusters or other thrusters. CST-100 plans two differnt types of thrusters that could use the same propellant.

The SM supplies prop to both abort engines and the OMAC thrusters. There are 24 of them. I'm sure there is a way to give ISS a little push.

[erioladastra]

I don't know where all this reboost stuff is coming from. The LAS engines are likely not throttleable.  And something that is intended to get one off an exploding rocket as quick as possible would also destroy ISS if fired while docked.

Shuttle reboosted ISS with 25 lbf thrusters

The propellant for reboost could be used by either LAS thrusters or other thrusters. CST-100 plans two differnt types of thrusters that could use the same propellant.

The SM supplies prop to both abort engines and the OMAC thrusters. There are 24 of them. I'm sure there is a way to give ISS a little push.

CST-100 will use the RCS for reboost.  The OMAC and LAE are too powerful.  Not it still remains to be seen how much total delta V will be available to see if worth it.

[Orbital Debris]

CST-100 Reboost will be important for Bigelow.  They need every spare m/s that they can get.

[Robotbeat]

Really, ANY of the commercial crew vehicles could be used for reboost, since all have maneuvering thrusters. Some are better than others. (And some surely have thrusters in better spots for the burn.) And no, in no case would the high-thrust abort motors be used for reboost for any of the vehicles. The only vehicle that has talked about it is the CST-100. But the others could do it, too (though DC would be less efficient, since it is using a lower Isp monopropellant for RCS/ACS). Though of course, the exact arrangement of thrusters and which docking port is used will matter. I think CST-100 has more options in this regard.

[Prober]

CST-100 Reboost will be important for Bigelow.  They need every spare m/s that they can get.

News on Bigelow, also some links to SpaceX, SNC

http://www.lvrj.com/business/nasa-contracts-benefit-north-las-vegas-outfit-164988796.html

[docmordrid]

So they're hiring again. Good.

[Nomadd]

If I'm doing this right that 7m/s should boost a 320km low ISS orbit to a little under 330km.  I think that the ISS operates between 320km and 350km or so.  That makes it a useful boost, but not a real big boost.

ISS has been around 390-400 km since ATV-2 last year.

 Is that where they'd like to be, or will it go higher in the future?

[erioladastra]

If I'm doing this right that 7m/s should boost a 320km low ISS orbit to a little under 330km.  I think that the ISS operates between 320km and 350km or so.  That makes it a useful boost, but not a real big boost.

ISS has been around 390-400 km since ATV-2 last year.

 Is that where they'd like to be, or will it go higher in the future?

They may go as high as 410 km during the upcoming solar maximum. They will not go much higher than that because Soyuz and Progress have a "ceiling" of 425 km and ISS needs some "wiggle room" for debris avoidance.

Actually, Progress can reach 460 km, hence why 1130 requires that the CCVV be able to reach that.  It is a contingency case, likely only to be used if ISS had to be unmanned and put in a parking orbit for safe keeping.

[Robotbeat]

If I'm doing this right that 7m/s should boost a 320km low ISS orbit to a little under 330km.  I think that the ISS operates between 320km and 350km or so.  That makes it a useful boost, but not a real big boost.

ISS has been around 390-400 km since ATV-2 last year.

 Is that where they'd like to be, or will it go higher in the future?

They may go as high as 410 km during the upcoming solar maximum. They will not go much higher than that because Soyuz and Progress have a "ceiling" of 425 km and ISS needs some "wiggle room" for debris avoidance.

Actually, Progress can reach 460 km, hence why 1130 requires that the CCVV be able to reach that.  It is a contingency case, likely only to be used if ISS had to be unmanned and put in a parking orbit for safe keeping.

+1, Informative.

[Zed_Noir]

Just out of curiosity, what's the operational ceilings of the 3 commercial crew vehicles in their current configurations?

[erioladastra]

Just out of curiosity, what's the operational ceilings of the 3 commercial crew vehicles in their current configurations?

Not really the right question.  Given a big enough booster these companies can all readch very high altittudes and get back.  I think what you are getting at is how high could they reboost.  Depends on how much delta V they can produce.  Also a factor, is even a small reboost won't be useful for ISS (different story for Bigelow) if they also don't have enough prop to swing the large ISS around so you can do the burn in the right direction, burn and swing back.  If you have to use a lot of RS prop and only getting a really small burn that doesn't help.  of course we now have the Optimized Prop Manuever that helps.

[Zed_Noir]

Just out of curiosity, what's the operational ceilings of the 3 commercial crew vehicles in their current configurations?

Not really the right question.  Given a big enough booster these companies can all readch very high altittudes and get back.  I think what you are getting at is how high could they reboost.

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

[Lars_J]

Just out of curiosity, what's the operational ceilings of the 3 commercial crew vehicles in their current configurations?

Not really the right question.  Given a big enough booster these companies can all readch very high altittudes and get back.  I think what you are getting at is how high could they reboost.

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

It also depends on how heavily loaded the spacecraft will be. A lightly loaded spacecraft with 2 crew would be able to higher than a fully loaded spacecraft.

For example, the SpaceX C2+ mission got themselves extra delta-V by flying a lighter load of cargo than they could have flown.

[Prober]

thats a good layout and glad Apollo got in there for reference.

Blue Origin and DC fans how about some input?

back in the game....

[docmordrid]

http://www.flightglobal.com/news/articles/spacex-completes-system-requirements-review-for-crewed-launches-378446/

SpaceX completes system requirements review for crewed launches 
>

[mr. mark]

http://www.flightglobal.com/news/articles/spacex-completes-system-requirements-review-for-crewed-launches-378446/

SpaceX completes system requirements review for crewed launches 
>

"The SRR, which was completed at a meeting at SpaceX's Hawthorne, California headquarters on 29 October, signify that NASA is satisfied that the Dragon capsule, Falcon 9 launch vehicle and other components of SpaceX's proposal can meet the CCiCap requirements, and that questions raised at the project kickoff meeting in August have been answered or mooted".

[Jim]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

Boeing and SNC can add more solids to the Atlas to increase altitude as desired

[pathfinder_01]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

The issuse might be less rocket performance and more TPS and other system issuses. I know the shuttle was limited in how high it could go and safely return by it's TPS system.

[Go4TLI]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

The issuse might be less rocket performance and more TPS and other system issuses. I know the shuttle was limited in how high it could go and safely return by it's TPS system.

No.  The orbiter was limited based on prop quantity since it took a substantial amount to get the vehicle and payload to altitude and then still having enough to de-orbit the large vehicle in a standard amount of time

[Oberon_Command]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

The issuse might be less rocket performance and more TPS and other system issuses. I know the shuttle was limited in how high it could go and safely return by it's TPS system.

No.  The orbiter was limited based on prop quantity since it took a substantial amount to get the vehicle and payload to altitude and then still having enough to de-orbit the large vehicle in a standard amount of time

Was there an known entry velocity that the orbiters were rated to? How high could an orbiter go assuming it had the propellant?

[joek]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

Good question, especially since we don't really have anything definitive as to a "current stack configuration".  IIRC commercial CTS requires nominal ~400km(?) reach.  Presumably anything above that would be a lower payload?  Unless the CTS contenders have more margin than required?

[Garrett]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

The issuse might be less rocket performance and more TPS and other system issuses. I know the shuttle was limited in how high it could go and safely return by it's TPS system.

No.  The orbiter was limited based on prop quantity since it took a substantial amount to get the vehicle and payload to altitude and then still having enough to de-orbit the large vehicle in a standard amount of time

Was there an known entry velocity that the orbiters were rated to? How high could an orbiter go assuming it had the propellant?

FWIW, orbital velocities decrease with increasing altitude.
I don't know how that works for reentry velocities however. My first intuition would be that reentry velocities also decrease, but then I also presume that the craft picks up extra vertical velocity from "falling" to Earth during reentry?

[Jason1701]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

The issuse might be less rocket performance and more TPS and other system issuses. I know the shuttle was limited in how high it could go and safely return by it's TPS system.

No.  The orbiter was limited based on prop quantity since it took a substantial amount to get the vehicle and payload to altitude and then still having enough to de-orbit the large vehicle in a standard amount of time

Was there an known entry velocity that the orbiters were rated to? How high could an orbiter go assuming it had the propellant?

FWIW, orbital velocities decrease with increasing altitude.
I don't know how that works for reentry velocities however. My first intuition would be that reentry velocities also decrease, but then I also presume that the craft picks up extra vertical velocity from "falling" to Earth during reentry?

All vehicles have the same gravitational potential when they hit the atmosphere, so their speed at entry interface goes up with the square root of their previous orbital radius.

[JohnFornaro]

Everyone misses the point and the process should be kept in perspective, it’s a "Competition".   The best that met the specs should get into the next round period.

Those firms who have bragged about continuing "no matter what" will have to put up, or shut up.   All the firms have a chance to be in final "Competition" for the contract in aprox two years.  That being said only stupid firms would bring this into a court.

Anything that needs correcting?

Only the word "stupid".  Any firms bringing that hypothetical case would pat themselves on the back as being "smart".  Those of us who like the idea of "competition", would call them "obstructionists", on the other hand.  "Wasters of time and effort", maybe, but not really "stupid".

The scaled comparison fotos up there are particularly good.  Note how four of the five designs start looking very much alike.  This demonstrates one of my sketchy principles:  A pound of spacecraft is a pound of spacecraft, when functionality and operation remains constant.  When you add wings the pound per spacecraft ratio changes, which is not surprising since there is a fundamental change of functionality and operation.

Great thread, very informative.

[Lobo]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

Boeing and SNC can add more solids to the Atlas to increase altitude as desired

Will the Atlas SRB's be man rated too?  I thought the plan was to use an SRB-less Atlas so they wouldn't have to deal with man-rating them?

[Lars_J]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

Boeing and SNC can add more solids to the Atlas to increase altitude as desired

Will the Atlas SRB's be man rated too?  I thought the plan was to use an SRB-less Atlas so they wouldn't have to deal with man-rating them?

AFAIK, CST-100 is already going to be launched with the 412 variant of Atlas V - 1 solid.

[Lobo]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

Boeing and SNC can add more solids to the Atlas to increase altitude as desired

Will the Atlas SRB's be man rated too?  I thought the plan was to use an SRB-less Atlas so they wouldn't have to deal with man-rating them?

AFAIK, CST-100 is already going to be launched with the 412 variant of Atlas V - 1 solid.

Ok, thanks, so apparently that's a "yes".  I thought both SNC and Boeing were using AV402's. 
Any idea of what's involved in modifying the standard Atlas SRB to make it man-rated?  if anything?

[hkultala]

Not about ISS reboost. Just what is the maximum altitude can the commercial crew vehicles can get to in their current stack configuration. Someone might want to operate some sort of facility/platform higher up than the ISS requiring visits in the future.

Boeing and SNC can add more solids to the Atlas to increase altitude as desired

Will the Atlas SRB's be man rated too?  I thought the plan was to use an SRB-less Atlas so they wouldn't have to deal with man-rating them?

AFAIK, CST-100 is already going to be launched with the 412 variant of Atlas V - 1 solid.

I think you remember incorrectly. It's 402, not 412.

Osc Prometheus was planning to use 412, but it has been canned a long time ago.

So no man-rated solids for atlas.

[Lars_J]

AFAIK, CST-100 is already going to be launched with the 412 variant of Atlas V - 1 solid.

I think you remember incorrectly. It's 402, not 412.

Osc Prometheus was planning to use 412, but it has been canned a long time ago.

So no man-rated solids for atlas.

My source, an article on this site: http://www.nasaspaceflight.com/2011/08/atlas-v-wins-boeing-selects-launcher-cst-100-capsule/

...According to Dr Sowers, the Atlas V will fly in the 412 configuration, involving one solid strap-on booster and a dual-engine Centaur Upper Stage...

Another source: http://spaceflightnow.com/news/n1108/04boeingatlas/

That might have changed since then, but at the time of the announcement, the 412 configuration was the chosen one.

[yg1968]

You are right, the CST-100 will use the Atlas V 412. It has not changed and it has been mentionned a number of times. In Boeing's CCiCap SAA, there is a picture of an Atlas V 412.

[Lobo]

There’s some interesting news on the DC, as it seems to be proceeding well. 

It’s a fan favorite for sure.  I’m just wondering how things will shake out in the long run.  Sounds like they want Commercial crew to be downselected to just one.  Not sure what they’ll do for commercial cargo once the SpaceX and OSC contracts are filled.  Will they keep both or down select to one?

Seems like ultimately, probably the best fiscal sense would be to get down to two suppliers who can both do cargo and crew.  Cygnus can’t do crew obviously, and DC can’t do unpressurized cargo, and not a lot of pressurized cargo.  So maybe DC gets cut before the final downselect for crew and Cygnus is cancelled once it’s current cargo contract is done?  Leaving CST-100 and Dragon.  Both could do crew and cargo.  Dragon already has a trunk, so they could do unpressurized cargo during a crew mission.  And, since commercial crew vehicles can handle 7 people, but likely won’t be taking up any more than 3 or 4 at a time (Russians will continue doing their own crew rotations I’m pretty sure), that means Dragon wouldn’t need both rows of seats.  They could have Dragon set up for four crew, and use the area behind for a fair amount of pressurized cargo, as well as unpressurized cargo in the trunk.
(I’m assuming the robot arm could unload the trunk if Dragon is at the docking port instead of the berthing port?)

I would assume CST-100 will be similar.  That would mean that crew and pressurized cargo can be combined.  Perhaps augmented by dedicated cargo for large pressurized components and/or if unpressurized cargo cannot be accessed while a capsule is at the docking port.  See below, and imagine the back row of 3 seats taken out, and that volume filled with storage racks for pressurized cargo like the current cargo dragon is.

This seems like the most efficient way to go.  However, DC seems to have a lot of support by fans, and it would seem by some in NASA.  NASA seems pretty interested in it, and are apparently planning on leasing them a OPF for processing them?  Probably not something they’d be worrying about right now if they didn’t think DC had a pretty good shot.  They are doing the same for CST-100 too.  So I just can’t see how this all shakes out in the end.  Anyone have some educated guesses on that?

[Zed_Noir]

Seems like ultimately, probably the best fiscal sense would be to get down to two suppliers who can both do cargo and crew.  Cygnus can’t do crew obviously, and DC can’t do unpressurized cargo, and not a lot of pressurized cargo.  So maybe DC gets cut before the final downselect for crew and Cygnus is cancelled once it’s current cargo contract is done?  Leaving CST-100 and Dragon.  Both could do crew and cargo. 

There is the possibility that Orbital could send the Cygnus up on the Falcon 9. After all, what matters is tonnage delivered, not the delivery vehicle. So SpaceX becomes one service provider with 2 delivery vehicles (Dragon & Cygnus).

The CST-100 might not come online if Boeing doesn't put up some money itself.

[yg1968]

I am not sure why SpaceX would compete against itself. I also doubt that Orbital would want to use the Falcon 9 for its spacecraft given that it already has Antares.

[thydusk666]

There is the possibility that Orbital could send the Cygnus up on the Falcon 9.

Where did you get that from?

[Comga]

(I’m assuming the robot arm could unload the trunk if Dragon is at the docking port instead of the berthing port?)

Simple questions get lost in long posts, but this one is interesting and should have a simple answer. 
Could the SSRMS reach into the trunk of a crew version of Dragon if that capsule was docked to the forward port on Node 2?

[baldusi]

Lobo, do you really think that in this reduced budget environment NASA will use two suppliers for crew and cargo if it's more expensive than two for cargo and one for crew? In particular, SpaceX will have a very strong business case. I don't think they will be able to afford a second crew carrying supplier. In fact, I don't think any country in the world had two simultaneous crew rated vehicles at the same time.
And don't forget that most payload is volume limited in CRS, and Cygnus has lots of volume. DC would be permanently volume limited, and CST-100 might need a an extended SM. In particular, if they want a good USD/kg, and since Atlas V is so powerful, and the incremental cost of adding solids is so little, they would need a lot of volume to carry it. This would also mean that CST Cargo would fly very little. Probably once per year. That's not good for scales.
Antares is quite a bit less powerful than Atlas V, but it's also a lot cheaper, and Cygnus doesn't have to carry the extra weight of a returnable vehicle. It does overlaps a bit with HTV (current Cygnus can't bring up full rack). But it's very cost effective. In fact, my WAG is that a second CRS contract would allow OSC to develop a more powerful US+fairing and use a wider PCM for less than what it would take to Boeing to convert CST to robotic cargo and adapt it to Atlas V. That would probably allow them to get even better pricing. Or spend nothing on R&D and make a really low bid.
My point, is that the crew capable vehicles have to carry a lot of dead weight for return. And Atlas V is a very expensive/powerful LV. The only way to compete, is to increase volume to get the best USD/kg. Both DC and CST are very difficult to extend their pressurized volume. And they carry the "deadweight" of their returnable parts. CST could be made lighter and disposable, but it's the wrong form for a disposable vehicle, and it would be so different that it would be a new development.

[MikeAtkinson]

Starting from the expected end date of CRS and working backward allowing time for long lead items, leads to the date that any follow-on contract will have to be negotiated. My guess is that this will be some time in 2014.

If I'm right about that date then the CRS contract will have to be in place a before commercial crew contract could be made. This is one reason I think that crew and cargo will be kept separate.

The other reason is that frequency of access and return is just as important as cargo mass or volume. Relatively cheap frequent cargo flights are the best way to achieve this, both cargo Dragon and Cygnus will be cheaper per flight than any likely prospective cargo version of CST-100 or DC on Atlas.

[baldusi]

I think they could push it in 2015. The current CRS is well behind schedule. What I'm wondering is if they would need to do a full and oppen competition or just extend the contracts.
If the ISS is extended beyond 2020, when would that decision be made? If the do CRS in 2014 and the extension decision goes to 2015 or 2016, NASA would have to do the extension assuming just 3 or 4 years of service, nos 8 to 10. Few years of extra service is a good argument for extension. How long took CRS from the call of proposals to CRS-1? Six years? Its already late for 2018!
What they could do, would be to extend it by a year or so, just enough to know if the ISS is going to las to 2020/25/28 and then do a second round of CSR-2

[joek]

Starting from the expected end date of CRS and working backward allowing time for long lead items, leads to the date that any follow-on contract will have to be negotiated. My guess is that this will be some time in 2014.

If I'm right about that date then the CRS contract will have to be in place a before commercial crew contract could be made. This is one reason I think that crew and cargo will be kept separate.

The other reason is that frequency of access and return is just as important as cargo mass or volume. Relatively cheap frequent cargo flights are the best way to achieve this, both cargo Dragon and Cygnus will be cheaper per flight than any likely prospective cargo version of CST-100 or DC on Atlas.

Maybe.  CRS is an IDIQ contract (Indefinite Delivery Indefinite Quantity). Within certain constraints, NASA may order as much or as little as they want from whoever they want.  That is the same model used for NLS (NASA Launch Services).  The CRS contract period is through Dec 31 2015.  The "Contractor shall not be required to make any deliveries under this contract after December 31, 2016" (NB: "not required", which does not preclude).  Note also that CRS has an on-ramp provision for new providers as does NLS.

Prior to Dec 31 2015 NASA will likely issue an RFP for "CRS II", at which time any and all will be welcome.  If it follows the NLS contract model, that will grant only the right to bid on specific NASA CRS task orders.  And even if a provider misses that 2015 (or whenever) window, on-ramp provisions allow for them to subsequently compete for CRS services.  In short, I wouldn't put a lot of weight on those dates as to who may or may not be in the running in then (or after) or the relevance to CCiCap/CTS.

[baldusi]

Joek,
  CRS-I also included COTS. For a CRS-II, would NASA be obligated to offer a similar program to prospective competitors? Because else, it would be sort of a win by default.
  I can only think of CST-100 to compete with Dragon. But they would have to develop the whole robotic approach, the CBM and have the extra cost of Atlas V. I simply don't see how could they compete on price. In other words, I don't see anybody who wouldn't have to spend a few hundred millions just to be able to compete on CRS-II.

[Jim]

Joek,
  CRS-I also included COTS. For a CRS-II, would NASA be obligated to offer a similar program to prospective competitors? Because else, it would be sort of a win by default.

No, COTS was a one time unique project.  There is no requirement for it.

[baldusi]

Joek,
  CRS-I also included COTS. For a CRS-II, would NASA be obligated to offer a similar program to prospective competitors? Because else, it would be sort of a win by default.

No, COTS was a one time unique project.  There is no requirement for it.

So, if there is a single existing commercial supplier NASA can't offer money to develop an alternative? Or is just that it's not required?

[happyflower]

I am a Dream Chaser fan simply because its one beautiful spaceship. But beyond that doesn't DC have other advantages to the other capsules? For example isn't the DC the "easiest" on the human body? If so, wouldn't it be best suited for space tourism? What about bringing back an injured astronaut? How about being able to land in a much wider range of locations than the capsules?

[Jim]

Joek,
  CRS-I also included COTS. For a CRS-II, would NASA be obligated to offer a similar program to prospective competitors? Because else, it would be sort of a win by default.

COTS shouldn't have included launch vehicles in the first place

No, COTS was a one time unique project.  There is no requirement for it.

So, if there is a single existing commercial supplier NASA can't offer money to develop an alternative? Or is just that it's not required?

[yg1968]

Joek,
  CRS-I also included COTS.

CRS-1 does not include COTS. COTS and CRS were completely independant of each other. For example, Planet Space submited a bid for CRS despite not being a COTS winner. CRS-2 (if there is one) would be open to new entrants.

[joek]

For a CRS-II, would NASA be obligated to offer a similar program to prospective competitors? Because else, it would be sort of a win by default.

As Jim & yg1968 said, COTS & CRS (as CCP & CRS) were separate programs, at least from a funding-contract-bid-award perspective.  Whether NASA would (or would be permitted to) institute another COTS-like program likely depends on a number of factors...

Simply to increase the number of suppliers?  IMHO unlikely. Although there may be future conditions that msy justify another such effort.  Highly speculative but possible reasons might include:
1. Demand increases to the point existing providers cannot meet NASA's needs.
2. Existing suppliers have problems, drop out and we end up with zero or one.
3. New capabilities are required which cannot be met by existing providers.
4. ...?

[Lobo]

I am not sure why SpaceX would compete against itself. I also doubt that Orbital would want to use the Falcon 9 for its spacecraft given that it already has Antares.

Yea, that would seem odd.  Orbital makes Antares and Cygnus, so I doubt they'd switch to F9 after all of that development they've invested.

[Lobo]

Lobo, do you really think that in this reduced budget environment NASA will use two suppliers for crew and cargo if it's more expensive than two for cargo and one for crew? In particular, SpaceX will have a very strong business case. I don't think they will be able to afford a second crew carrying supplier. In fact, I don't think any country in the world had two simultaneous crew rated vehicles at the same time.

Baldusi,

First, I mean that NASA would keep just two suppliers period, that could do  both commercial crew and cargo contracts.  Not two for crew and two for cargo (4 total).  Then both systems are backed up by the other one.  If there’s a problem with one, the other one could do both cargo and crew in the interim until that problem is resolved.

Secondly, would I think that NASA would take the –more- expensive option of two choices, regardless of the budget environment?  Yea, it wouldn’t surprise me at all.  At least for the visible, capitol programs that are easy to see, I’ve really never seen NASA take the more sustainable and affordable routes.  (Maybe in small scale things that don’t get much visibility they have a better track record) From Apollo to STS to CxP to Altair to SLS, they seem to take the most expensive possible way forward each time.  They had the budget to take the most expensive way forward with Apollo, but have always been budget limited since then.   Wouldn’t surprise me all that much if they tried to support all 3 commercial crew providers as well as 2 commercial cargo providers, and periodically flew just Orion on SLS up to the ISS to boot.  ;-)
Yes, I am being facetious here.  But in general, they do seem to miss opportunities to cost share and save money and stream line quite consistently.

And don't forget that most payload is volume limited in CRS, and Cygnus has lots of volume. DC would be permanently volume limited, and CST-100 might need a an extended SM. In particular, if they want a good USD/kg, and since Atlas V is so powerful, and the incremental cost of adding solids is so little, they would need a lot of volume to carry it. This would also mean that CST Cargo would fly very little. Probably once per year. That's not good for scales.
Antares is quite a bit less powerful than Atlas V, but it's also a lot cheaper, and Cygnus doesn't have to carry the extra weight of a returnable vehicle. It does overlaps a bit with HTV (current Cygnus can't bring up full rack). But it's very cost effective. In fact, my WAG is that a second CRS contract would allow OSC to develop a more powerful US+fairing and use a wider PCM for less than what it would take to Boeing to convert CST to robotic cargo and adapt it to Atlas V. That would probably allow them to get even better pricing. Or spend nothing on R&D and make a really low bid.
My point, is that the crew capable vehicles have to carry a lot of dead weight for return. And Atlas V is a very expensive/powerful LV. The only way to compete, is to increase volume to get the best USD/kg. Both DC and CST are very difficult to extend their pressurized volume. And they carry the "deadweight" of their returnable parts. CST could be made lighter and disposable, but it's the wrong form for a disposable vehicle, and it would be so different that it would be a new development.

Now here you bring up some good points.  Yes, if NASA downselected the entire commercial program to just two providers that could do either crew or cargo, like CST-100 and Dragon, they would be pressurized volute limited.  I suppose what I don’t know, is how large of pressurized volumes are there in need of for ISS cargo?  What sort of regular pressurize cargo is needed that Dragon or CST-100 couldn’t fit?  I was assuming the larger cargo would be unpressurized, and thus could fit in the trunk of Dragon. 
But if there is a need for pressurized cargo larger that what CST-100 or Dragon could do without a redesign of the capsule, then it seems like it would make sense to cancel Dragon and just keep Cygnus.  Small pressurized downmass can still go down via the commercial crew provider, and non-returnables would be placed in Cygnus for disposal upon reentry.  Then just have the one cargo provider and the one crew provider.

[baldusi]

What I meant was that if Cargo Dragon + Cygnus + 1 Crew Provider is significantly cheaper than two suppliers that can do either, it's quite probable that they'll do the former. In the end, Soyuz is a crew back up.
ATV is retiring and neither Progress nor HTV can bring up significantly more cargo. If you look at projections, the 3 Dragons + 2 Cygnus per year might not be enough to fully utilize the ISS. Both OSC and SpaceX could send at least one more mission per year, but USD/kg will rule the day. Don't forget that Enhanced Cygnus will have 27m³ of pressurized volume.
NASA can afford to have the crewed spacecraft grounded for an investigation, and still rely on the Soyuz not to have to decrew the station. But they do need the full cargo capacity.
What's more, to have cheap and redundant cargo capability is almost "free" with Dragon/Cygnus (i.e. no development or certification money). While adding a second Crew supplier means more many, and adapting it again to Cargo, means more money yet.
Again, disposable cargo carriers have great USD/kg. And also tend not to be volume limited.

[guckyfan]

The Dragon spacecraft could be made to carry much more pressurized cargo, too. They are alredy working on a bigger trunk. Make that trunk pressurized and give it its own berthing mechanism. When the Dragon is unloded, disconnect, have it flipped over by the robotic arm and berth the dumb pressurized trunk for much more cargo. The temperature control could be much more basic than for the Dragon if that makes things easier. Sensitive cargo would be in the Dragon, less sensitive stuff in the trunk.

Weight would be of little concern with Falcon 9 1.1 and the trunk should be quite cheap.

Then fly whatever is needed. Unpressurized if needed, otherwise pressurized. When Dragon flies manned unpressurized cargo would go with the manned flight.

[douglas100]

Certainly it could be done. A pressure vessel could be mounted inside the current trunk. But it wouldn't be just a "dumb tank." It would need its own berthing mechanism and environmental controls. So I'm not sure about "quite cheap."

Other vehicles already cover this kind of service. It's not clear that a pressurised trunk is needed for current ISS requirements.

[Dappa]

The Dragon spacecraft could be made to carry much more pressurized cargo, too. They are already working on a bigger trunk. Make that trunk pressurized and give it its own berthing mechanism. When the Dragon is unloaded, disconnect, have it flipped over by the robotic arm and berth the dumb pressurized trunk for much more cargo. The temperature control could be much more basic than for the Dragon if that makes things easier. Sensitive cargo would be in the Dragon, less sensitive stuff in the trunk.

Who said that SpaceX is already working on a bigger trunk? Last I heard they could make a bigger trunk, if there is a requirement for it.

[guckyfan]

Who said that SpaceX is already working on a bigger trunk? Last I heard they could make a bigger trunk, if there is a requirement for it.

I think I read it on this forum. It makes sense too. I would think that some vacuum experiments may require larger structures than could fit into the present trunk. How much space is required for VASIMR?

However if they are not working on it yet the statement that they can is enough to support my proposed additional pressurized cargo module.

[baldusi]

Present trunk is little more than an aluminum structure. What you propose is more complex than a MLPM. We don't know if Dragon has enough control authority to fly with such a thing attached, the process is more than cumbersome, too. If you want a lot of pressurized volume, the disposable crafts rule. If you still want it to return, you should go with a blunt object, not a cone. Look at t/space proposal.

[guckyfan]

Present trunk is little more than an aluminum structure. What you propose is more complex than a MLPM. We don't know if Dragon has enough control authority to fly with such a thing attached, the process is more than cumbersome, too. If you want a lot of pressurized volume, the disposable crafts rule. If you still want it to return, you should go with a blunt object, not a cone. Look at t/space proposal.

I cannot agree with any of your points. There is a mass known that Dragon can handle in total, as pressurized load as well as load in the trunk. That's a lot of load and I don't propose to exceed that so there is no issue in handling. It is up to SpaceX to see if that load can be increased, dependent on a lot of factors.

Why would the added ability be more complex than MPLM? OK, the present function of the trunk, solar array and cooling panels need to be kept. But what would be added is just a pressure container and a berthing mechanism.

And why would it be cumbersome to add just one additional action by the robot arm?

Yes it would be in total more complex than Cygnus, because it can do more than Cygnus, returning freight to earth.

Other vehicles already cover this kind of service. It's not clear that a pressurised trunk is needed for current ISS requirements.

I agree, it might not be needed, when Cygnus is flying. But it would be able to replace it if required.

[Jim]

Why would the added ability be more complex than MPLM? OK, the present function of the trunk, solar array and cooling panels need to be kept. But what would be added is just a pressure container and a berthing mechanism.

You should agree because he is right.  It is more complex than MPLM because unlike a MPLM, it has to hold solar arrays, radiators and separation system.  And unlike a trunk, it has to hold pressure, have internal lighting and air recirculation ducts, and a berthing system.

[guckyfan]

Why would the added ability be more complex than MPLM? OK, the present function of the trunk, solar array and cooling panels need to be kept. But what would be added is just a pressure container and a berthing mechanism.

You should agree because he is right.  It is more complex than MPLM because unlike a MPLM, it has to hold solar arrays, radiators and separation system.  And unlike a trunk, it has to hold pressure, have internal lighting and air recirculation ducts, and a berthing system.

All of which I have mentioned and said the added complexity is not more than a MPLM.

Which is in a way a confirmation of what he said, yes. But it is still a very simple and therefore relatively cheap device compared to a Cygnus for example.

[Silmfeanor]

Why would the added ability be more complex than MPLM? OK, the present function of the trunk, solar array and cooling panels need to be kept. But what would be added is just a pressure container and a berthing mechanism.

You should agree because he is right.  It is more complex than MPLM because unlike a MPLM, it has to hold solar arrays, radiators and separation system.  And unlike a trunk, it has to hold pressure, have internal lighting and air recirculation ducts, and a berthing system.

All of which I have mentioned and said the added complexity is not more than a MPLM.

Which is in a way a confirmation of what he said, yes. But it is still a very simple and therefore relatively cheap device compared to a Cygnus for example.

But IT is more than a MPLM. That's the whole point; you saying that it isnt doesnt make it so.
How is it simple / cheap compared to Cygnus?

[guckyfan]

But IT is more than a MPLM. That's the whole point; you saying that it isnt doesnt make it so.

Which I confirmed by saying the added function is no more complex than the simplest possible system, that MPLM was as it does nothing at all by itself. It was placed at the ISS by the shuttle like this is by Dragon.

How is it simple/cheap compared to Cygnus?

Because it has no active components for maneuvering. Cygnus must perform orbit maneuvers and approach ISS, as Dragon does. The trunk by itself does not do these functions.

[Jim]

Which is in a way a confirmation of what he said, yes. But it is still a very simple and therefore relatively cheap device compared to a Cygnus for example.

NO, it is not cheap because a Dragon is connected to it.

[guckyfan]

Which is in a way a confirmation of what he said, yes. But it is still a very simple and therefore relatively cheap device compared to a Cygnus for example.

NO, it is not cheap because a Dragon is connected to it.

I am quite clearly talking about increments. Of course Dragon is there and it performs a task that is worthwile because it can do and does so many different things. The pressurized trunk is a cheap addon that stretches those abilities a lot for little extra money. Little money in spaceflight terms of course.

[Jim]

The pressurized trunk is a cheap addon that stretches those abilities a lot for little extra money. Little money in spaceflight terms of course.

It isn't cheap or a little extra money

[spectre9]

Jim is correct.

All pressure vessels cost big money. It's extremely customised hardware.

Not a big enough market for the stuff for the USA to even bother with such things.

Thales Alenia is the biggest supplier in the world as far as I know. That's if you don't count Progress I guess 

[guckyfan]

Jim is correct.

If you say so.

[spectre9]

Jim is correct.

If you say so.

My opinion might not mean much compared to the wealth of experience Jim has in the aerospace industry but that doesn't mean it's not worth anything and you can just hand wave it with a snide comment.

[guckyfan]

Jim is correct.

If you say so.

My opinion might not mean much compared to the wealth of experience Jim has in the aerospace industry but that doesn't mean it's not worth anything and you can just hand wave it with a snide comment.

Oh please! This is bordering on the absurd.

How much did SpaceX spend to develop Dragon? How much does a Dragon cost to build? Are you or Jim really trying to tell me developing and building an additional pressure vessel is anywhere near those costs? The additional berthing mechanism will be the biggest item in building.

[spectre9]

DDT&E

You can't skip any of it and expect working space hardware.

[guckyfan]

DDT&E

You can't skip any of it and expect working space hardware.

This has now definitely passed the border to the absurd. I never even remotely suggested anything like that.

The arguments are exchanged and every reader can form his opinion.

[spectre9]

It is my opinion you have unrealistic expectations of how cheaply SpaceX can produce space hardware.

Thanks for the discussion 

[guckyfan]

It is my opinion you have unrealistic expectations of how cheaply SpaceX can produce space hardware.

Thanks for the discussion 

I don't base my opinion on some assumption how cheap SpaceX can do something. I have no basis how to calculate that.

I base it on the opinion, that what I propose is by at least an order of magnitude simpler to develop than the development of Dragon was. So I assume the cost will be also be roughly an order of magnitude lower, independent on how cheap or expensive that develoment was.

That assumption may be wrong, but I don't think so.

Thanks for the discussion from me too.

[Jim]

Are you or Jim really trying to tell me developing and building an additional pressure vessel is anywhere near those costs?

It will be manrated and therefore much different requirements than the existing trunk.  It will be close to the costs of the Cygnus payload module.

[mmeijeri]

In an optimistic scenario where we have lots of commercial LEO traffic ten years from now, would a reusable capsule still be the preferred way to resupply pressurised cargo? Or would a disposable module similar to ATV's Pressurised Equipped Module be cheaper, perhaps using a capsule as its carrier for the "last mile"? Or perhaps even an unpressurised carrier that carried its own liquid air to resupply any air that was lost by having to use an airlock?

[guckyfan]

In an optimistic scenario where we have lots of commercial LEO traffic ten years from now, would a reusable capsule still be the preferred way to resupply pressurised cargo? Or would a disposable module similar to ATV's Pressurised Equipped Module be cheaper, perhaps using a capsule as its carrier for the "last mile"? Or perhaps even an unpressurised carrier that carried its own liquid air to resupply any air that was lost by having to use an airlock?

The majority of supplies may be on disposable modules. But the need for downmass dictates there are capsules capable of landing needed as well. From return capability to reusability is not that huge a step.

[baldusi]

Again, if you are having a reusable system and project a huge demand, you'd go with a big blunt object or lifting body. Think of either an enlarged Dream Chaser (at least 2X in each dimension, probably 3X) or look at the t/space proposal.