COTS D Minus

[bad_astra]

In reference of notes in this article:
http://www.nasaspaceflight.com/content/?cid=5516

What would a COTS D minus entail? Would it be possible for a previous competitor to bypass the need for a commercial launch vehicle by using STS to put the lifeboat at the station? Just curious.

[antonioe]

Gee... can't you find a better name for the lifeboat-only option?... COTS D prime?  COTS D asterisk?...

[bad_astra]

True. Surely another letter of the alphabet will stand up and be counted for COTS.

The option of a D lifeboat is pretty exciting though (well to me, anyway.. I'm not the one that has to design one!)

[Jim]

What would a COTS D minus entail? Would it be possible for a previous competitor to bypass the need for a commercial launch vehicle by using STS to put the lifeboat at the station? Just curious.

Shuttle has nothing to do with it. 

[Jim]

What would a COTS D minus entail?

No crew capability for launch, just landing

[bad_astra]

What would a COTS D minus entail? Would it be possible for a previous competitor to bypass the need for a commercial launch vehicle by using STS to put the lifeboat at the station? Just curious.

Shuttle has nothing to do with it. 

It's a launch vehicle. It has a robotic arm. It goes to the station. It was supposed to originally bring the ACRV. That's why I mentioned it.

[Jim]

What would a COTS D minus entail? Would it be possible for a previous competitor to bypass the need for a commercial launch vehicle by using STS to put the lifeboat at the station? Just curious.

Shuttle has nothing to do with it. 

It's a launch vehicle. It has a robotic arm. It goes to the station. It was supposed to originally bring the ACRV. That's why I mentioned it.

It would negate the purpose of COTS with all the shuttle integration and safety requirements

COTS and shuttle are incompatible

[iamlucky13]

What would a COTS D minus entail? Would it be possible for a previous competitor to bypass the need for a commercial launch vehicle by using STS to put the lifeboat at the station? Just curious.

Aside from the proven ability of the shuttle to rendezvous, I'm not clear what such a scheme would provide over using an existing ELV, assuming ULA wants to make a proposal or Falcon or Taurus aren't ready in time.

Could EADS be a participant if they wanted to speed development of their Advanced Return Vehicle or would this be US-only? The ATV seems like the most mature new western spacecraft design.

[siatwork]

What would a COTS D minus entail? Would it be possible for a previous competitor to bypass the need for a commercial launch vehicle by using STS to put the lifeboat at the station? Just curious.

Aside from the proven ability of the shuttle to rendezvous, I'm not clear what such a scheme would provide over using an existing ELV, assuming ULA wants to make a proposal or Falcon or Taurus aren't ready in time.

Could EADS be a participant if they wanted to speed development of their Advanced Return Vehicle or would this be US-only? The ATV seems like the most mature new western spacecraft design.

ATV is great for what it was built for, but I'm not sure how it's mature for the COTS D CRV role.  There are a few sub-systems that could be reused (but repackaged), but otherwise a new project (even behind Orion in planning)

[Ronsmytheiii]

I could see an ACRV as a step towards what is described in COTS-D, however it at most should only be a mile-stone towards a crew launch vehicle.

[Jose]

I wonder if t/Space is one of the companies discussing this with NASA.  They wouldn't need the hammock seats anymore if they only have to carry crew on the way down.

Edit: No crew on the way up also means no LAS, which means no need to air launch anymore either.  You could just stick the CXV on top of an existing ELV and off you go. Interesting.

[siatwork]

I wonder if t/Space is one of the companies discussing this with NASA.  They wouldn't need the hammock seats anymore if they only have to carry crew on the way down.

Edit: No crew on the way up also means no LAS, which means no need to air launch anymore either.  You could just stick the CXV on top of an existing ELV and off you go. Interesting.

Might still want to have an abort system, just to recover the much more expensive spacecraft at a marginal LV cost increase.

[Jim]

I wonder if t/Space is one of the companies discussing this with NASA.  They wouldn't need the hammock seats anymore if they only have to carry crew on the way down.

Edit: No crew on the way up also means no LAS, which means no need to air launch anymore either.  You could just stick the CXV on top of an existing ELV and off you go. Interesting.

Might still want to have an abort system, just to recover the much more expensive spacecraft at a marginal LV cost increase.

Not really,
1,  LAS is a spacecraft cost and development cost would be probably more than a cost of a spacecraft
2.  refurb of the spacecraft may be just as expensive as a new one

[antonioe]

3. LAS weight 50% to 70% of the mass it "protects" (70% for Ares-type solid first stage vehicles, 50% for slower - but  not too slow - liquid boosters like Saturn V) which adds to the cost of the system.

[William Barton]

Gee... can't you find a better name for the lifeboat-only option?... COTS D prime?  COTS D asterisk?...

COTS D subprime?

[siatwork]

...
Not really,
1,  LAS is a spacecraft cost and development cost would be probably more than a cost of a spacecraft
2.  refurb of the spacecraft may be just as expensive as a new one

3. LAS weight 50% to 70% of the mass it "protects" (70% for Ares-type solid first stage vehicles, 50% for slower - but  not too slow - liquid boosters like Saturn V) which adds to the cost of the system.

Ah, these points make sense.  Thanks folks.

[William Barton]

The obvious developmental advantage of a Shuttle-delivered ACRV is, it doesn't have to be much more capable than a sort "big Mercury" capsule. It only needs enough OMS to back away from ISS and do a reentry burn (and keep six astros alive for a few hours while doing so). What are the non-Russian off-the-shelf alternatives to the Shuttle for delivering something like that to ISS?

[Jim]

The obvious developmental advantage of a Shuttle-delivered ACRV is, it doesn't have to be much more capable than a sort "big Mercury" capsule. It only needs enough OMS to back away from ISS and do a reentry burn (and keep six astros alive for a few hours while doing so). What are the non-Russian off-the-shelf alternatives to the Shuttle for delivering something like that to ISS?

Development disadvantages are more complex  propulsion systems to incorporate shuttle safety requirements.  Same goes for other systems like ECLSS tanks, ordnance chains, etc

Also the structure has to designed around unique load paths due to the shuttle ASE and also unique loads like abort landing nose wheel slapdown.

[beb]

Development disadvantages are more complex  propulsion systems to incorporate shuttle safety requirements.  Same goes for other systems like ECLSS tanks, ordnance chains, etc

Also the structure has to designed around unique load paths due to the shuttle ASE and also unique loads like abort landing nose wheel slapdown.

You're saying that meeting these shuttle safety requirements is harder and more expensive than developing an automated docking system with propulsion system?

[William Barton]

Development disadvantages are more complex  propulsion systems to incorporate shuttle safety requirements.  Same goes for other systems like ECLSS tanks, ordnance chains, etc

Also the structure has to designed around unique load paths due to the shuttle ASE and also unique loads like abort landing nose wheel slapdown.

You're saying that meeting these shuttle safety requirements is harder and more expensive than developing an automated docking system with propulsion system?

More like asking. All the ACRV would have to meet are the same safety requirements met by satellites that have been launched aboard Shuttle over the years. I have no idea how expensive that would be, but it seems likely it would take less time. The idea is, the ACRV has to be ready to go before the last Soyuz ride is over, and that development time fram has to be known accurately, since the procurement deadline for more Soyuz rides is more or less right now. How long would it take to develop an automated rendezvous and docking system for ACRV (and meet all the attendant ISS safety requirments), and how hard would that be? How long did it take to develop ATV? Can it be done in two years?