Cargo Needs going forward

[hutchel]

Given that Bigelow and the ISS are both going to need continued cargo supply/resupply capability and several of the original carriers are closing out their programs, does it make sense for SpaceX to look at upping what they can lift?  I was thinking in terms of a hybrid of the Progress/Apollo/Cygnus/Dragon collective approaches.

Basically use the Dragon V2 like the old Apollo CM and pull a Cygnus like can out of the top of the 2nd stage using the LIDS (or something like it).  The can would have a CBM on the other end which could be berthed to the station by the arm and a "tunnel" so astronauts could pass through the cargo section into the station.  Once full of trash, the Can is unberthed and Dragon V2 pulls it away and drops it for disposal on its re-entry path.  Alternatively the can could have some sort of expandable heat shield and parachutes if we really needed to reuse it.  Not sure what would be more economical.  I'm thinking mostly unpowered cargo, with just enough life support to allow it to be a pass through from the Dragon V2.  This would leave Dragon V1 for science payloads (power etc).  My sense is that Dragon V2 probably has sufficient control authority to do something like this.

This concept also allows the Dragon V2 to escape from the station if necessary in it's lifeboat role since it's connected with LIDS.

My thinking is that the CBM approach is useful for big pieces of equipment and that seems to be a capability that is dwindling as we go forward and Dragon is still volume limited, not mass, so why not create a no frills can that can go up with bulky items and then just be tossed.

If power is more of an issue put a set of solar arrays on it and make it self sufficient.

[Coastal Ron]

Last I remember hearing is that Dragon V1 will be used in parallel for a short time with the V2, but it looks like they plan on replacing the V1 with the V2.  Not sure I heard specifically if they plan to have different versions with the different hatch types (CBM and NDS/iLIDS), but that seems to make sense.

I'm not sure what current need your proposal addresses, unless you are proposing to eliminate the need for the Cygnus.  Of course to do that SpaceX (or someone) would need to spend some serious money to build and qualify the hardware, and they would have to feel there is a long-term need for such a system.

Where is the demand for such a system, and who would be paying for it?

[majormajor42]

Last I remember hearing is that Dragon V1 will be used in parallel for a short time with the V2, but it looks like they plan on replacing the V1 with the V2.  Not sure I heard specifically if they plan to have different versions with the different hatch types (CBM and NDS/iLIDS), but that seems to make sense.

so ISS cargo-only flights will ride on a V2 that has LAS capability even though they don't need it?

[JBF]

Last I remember hearing is that Dragon V1 will be used in parallel for a short time with the V2, but it looks like they plan on replacing the V1 with the V2.  Not sure I heard specifically if they plan to have different versions with the different hatch types (CBM and NDS/iLIDS), but that seems to make sense.

so ISS cargo-only flights will ride on a V2 that has LAS capability even though they don't need it?

Yes so they can propulsively land.

[OnWithTheShow]

Except V2 wont be able to transport ISS racks with the Nasa Docking System...I thought that was a capability they wanted to retain.

[guckyfan]

Except V2 wont be able to transport ISS racks with the Nasa Docking System...I thought that was a capability they wanted to retain.

They could fit the cargo version with NDS. I still prefer the option though to fit a second pressure vessel in the trunk so that pressure vessel can deliver bulky cargo with the Dragon only one version for cargo and crew. That alternative would also greatly increase cargo volume and weight capacity.

[newpylong]

Except V2 wont be able to transport ISS racks with the Nasa Docking System...I thought that was a capability they wanted to retain.

They could fit the cargo version with NDS. I still prefer the option though to fit a second pressure vessel in the trunk so that pressure vessel can deliver bulky cargo with the Dragon only one version for cargo and crew. That alternative would also greatly increase cargo volume and weight capacity.

Much easier to just have a V2 cargo version continue to use CBM. They will have to if they wish to retain the full cargo capability.

[baldusi]

That's what CRS-2 is for. Different companies will make proposals and (probably) two will get contracts. I guess that SpaceX is betting on reusability of Dragon v2 plus F9R to significantly reduce cost. Orbital appears to be proposing a slight increase in Cygnu's size and payload to reduce the total number of flights. Boeing and Sierra Nevada are probably making proposals. The only known thing is that the (yearly) mass and volume requirement will be a bit more than CRS-1, while there's a desire to cap the VV missions to five per year. Apparently, the are assuming that HTV will continue for a while. Which means that only ATV will have to be supplanted.

[Nomadd]

Last I remember hearing is that Dragon V1 will be used in parallel for a short time with the V2, but it looks like they plan on replacing the V1 with the V2.  Not sure I heard specifically if they plan to have different versions with the different hatch types (CBM and NDS/iLIDS), but that seems to make sense.

so ISS cargo-only flights will ride on a V2 that has LAS capability even though they don't need it?

Makes sense. Some of those payload might be extremely expensive and hard to replace. It would give SpaceX an edge over the competition, except maybe for a CST cargo capsule.

[baldusi]

Last I remember hearing is that Dragon V1 will be used in parallel for a short time with the V2, but it looks like they plan on replacing the V1 with the V2.  Not sure I heard specifically if they plan to have different versions with the different hatch types (CBM and NDS/iLIDS), but that seems to make sense.

so ISS cargo-only flights will ride on a V2 that has LAS capability even though they don't need it?

Makes sense. Some of those payload might be extremely expensive and hard to replace. It would give SpaceX an edge over the competition, except maybe for a CST cargo capsule.

SD for Cargo is not about LAS. Is about landing close to the scientists and/or doctors during an EVAC. Instead of waiting 6 or even 24 for getting the experiments back, they can get it within 30min.

[Nomadd]

Last I remember hearing is that Dragon V1 will be used in parallel for a short time with the V2, but it looks like they plan on replacing the V1 with the V2.  Not sure I heard specifically if they plan to have different versions with the different hatch types (CBM and NDS/iLIDS), but that seems to make sense.

so ISS cargo-only flights will ride on a V2 that has LAS capability even though they don't need it?

Makes sense. Some of those payload might be extremely expensive and hard to replace. It would give SpaceX an edge over the competition, except maybe for a CST cargo capsule.

SD for Cargo is not about LAS. Is about landing close to the scientists and/or doctors during an EVAC. Instead of waiting 6 or even 24 for getting the experiments back, they can get it within 30min.

Is there some you think LAS wouldn't be a factor? Why would they delete the capability when all the hardware is there and it would require them to develop another launch protocol with no advantages and a big disadvantage over the manned one? LOM not meaning LOC can be true for cargo as well as crew.

[Joffan]

Some of those payload might be extremely expensive and hard to replace. It would give SpaceX an edge over the competition, except maybe for a CST cargo capsule.

SD for Cargo is not about LAS. Is about landing close to the scientists and/or doctors during an EVAC. Instead of waiting 6 or even 24 for getting the experiments back, they can get it within 30min.

Is there some you think LAS wouldn't be a factor? Why would they delete the capability when all the hardware is there and it would require them to develop another launch protocol with no advantages and a big disadvantage over the manned one? LOM not meaning LOC can be true for cargo as well as crew.

Nobody is deleting LAS, although there would be a serious trade-off to be discussed whether it should be armed for a non-crew mission. Baldusi's main point, as I read it, is that the major advantage would be the direct-to-pad landing capability and thus the speed of experiment retrieval, allowing more time-sensitive returns. This is a direct operational benefit rather than a contingency benefit - that is, you'd get to use it on every mission, not just for (very rare) ascent failures.

Evac comes under "very rare" also, but again the direct-to-pad landing would be a selling point even for normal crew returns.

[Ronsmytheiii]

Except V2 wont be able to transport ISS racks with the Nasa Docking System...I thought that was a capability they wanted to retain.

Dragon doesnt carry full size racks right now anyhow, as that would be the only cargo in the current capsule volume.  The only VV that still has the ability to fly full racks is HTV, and HTV-4 only launched with resupply racks that dont leave the vehicle

http://www.nasaspaceflight.com/2013/08/japans-htv-4-launches-supplies-scienceiss/

The truth is, NASA probably just needs a craft to deliver Tang, Toilet paper and T-shirts, so a smaller hatch wont be a bid deal. If SpaceX decides to discontinue V1, ISS should be fine I as I am sure they will consult with NASA's needs first.

[Coastal Ron]

Except V2 wont be able to transport ISS racks with the Nasa Docking System...I thought that was a capability they wanted to retain.

Dragon doesnt carry full size racks right now anyhow, as that would be the only cargo in the current capsule volume.  The only VV that still has the ability to fly full racks is HTV, and HTV-4 only launched with resupply racks that dont leave the vehicle

Both Dragon and Cygnus have enough volume to carry ISPR's.  Cygnus has 27 m3 of internal volume, Dragon has 10 m3, and HTV has 14 m3.  Certainly HTV can carry more weight, but if they really need ISPR's on the ISS after the end of HTV flights I would think Cygnus and Dragon could do it.  An ISPR weighs 104 kg, or 804 kg fully loaded, so both Cygnus and Dragon could cary multiple ones depending on the volume restrictions.

And I thought NASA required that Commercial Cargo vehicles be capable of carrying ISPR's?

The truth is, NASA probably just needs a craft to deliver Tang, Toilet paper and T-shirts, so a smaller hatch wont be a bid deal. If SpaceX decides to discontinue V1, ISS should be fine I as I am sure they will consult with NASA's needs first.

I would imagine they will continue to use a CBM on the cargo version of the Dragon V2 since there will only be one docking port for vehicles using the NDS - and that will be used for visiting Commercial Crew vehicles.

[Robert Thompson]

I see advantage.

V2 cargo abort/recoverability is superior to:

Water in the experiment in the water several miles and hours from the PI.
Experiment in the water several miles and hours from the PI. (repeating)
Experiment several miles and hours from the PI. (repeating)
Marginal opportunity cost of not making maximum time sensitive use of IS$ before It ends up in the water.

An experiment with high probability of abort and precision landing recoverability (i.e., you're not losing it), can dial up appropriately in cost and complexity.

[Lars_J]

Except V2 wont be able to transport ISS racks with the Nasa Docking System...I thought that was a capability they wanted to retain.

Dragon doesnt carry full size racks right now anyhow, as that would be the only cargo in the current capsule volume.  The only VV that still has the ability to fly full racks is HTV, and HTV-4 only launched with resupply racks that dont leave the vehicle

Both Dragon and Cygnus have enough volume to carry ISPR's.  Cygnus has 27 m3 of internal volume, Dragon has 10 m3, and HTV has 14 m3.  Certainly HTV can carry more weight, but if they really need ISPR's on the ISS after the end of HTV flights I would think Cygnus and Dragon could do it. 

Cygnus has the volume for it, but the hatch is smaller than Dragon's. No ISPR could fit through it. (see image)

Dragon could fit one in theory, but would likely mean an interior redesign that would reduce other cargo storage.

[AnalogMan]

Just for info: International Standard Payload Racks (ISPRs) and system racks are not a required capability (or a suggested optional capability) in the draft RFP for the upcoming CRS 2.

[majormajor42]

why not have some V2's built with large berthing ports that will be for cargo and then have others with the docking ports for crew (and/or cargo)?

Are there also ISS logistical issues to consider when it comes to docking/berthing port availability?

Is there an anticipated need for berthing on commercial stations such as Bigelow? I haven't seen any Bigelow rendering that show berthing ports or the large robotic arm necessary to pull them in...so I would guess no at this point.

[woods170]

Just for info: International Standard Payload Racks (ISPRs) and system racks are not a required capability (or a suggested optional capability) in the draft RFP for the upcoming CRS 2.

Entirely understandable as the number of ISPR's planned to go up to ISS in the coming years is close to zero. You don't go around requiring a capability that is not actually needed beyond the final HTV vehicle.

[Lars_J]

why not have some V2's built with large berthing ports that will be for cargo and then have others with the docking ports for crew (and/or cargo)?

As far as I can tell, the parachute system redesign of Dragon v2 (in particular the new location of the drogues around the docking ring) leaves no room for a larger CBM hatch. But I could certainly be wrong.