ISS Commercial Resupply Services 2 (CRS2) 2017-2030

[Zed_Noir]

I've just realized that with all that extra margin on F9 v1.1, what if Cargo Dragon replaces the thunk with a mini-MLPM? Something that's 3.6m wide would not change a thing, and could multiply the volume significantly. What's more, it would serve for disposal, too. Only problem is that it would need two CBM ports and detachment+berthing and unberthing+reattachment.
But if it is an optional (say, in 30% of the missions), they could cover it all: pressurized up/down, pressurized disposal, unpressurized up/disposal. If F9 v1.1 can do 14tonnes (NLS says 15 to 56.1 x 350km), then, assuming that the normal stack is 8 tonnes, plus say 2 tonnes for the mini-MLPM, they could carry an additional 4 tonnes, for a total of 7 tonnes of cargo (probably more, since I doubt insertion orbit is 350km circular). They could be taking 20 tonnes per year in just three launches! Seems a very interesting possibility.

I believe the original MPLM on the Orbital CRS1 & CRS2 will fitted inside an extended Dragon trunk from discussions on various Inspiration Mars threads. Think an extended trunk is faster & cheper to developed for the Dragon to carry additional pressurized cargo than a new mini-MPLM.

Dragon v1 and v2 are volume limited on F9v1.1. They need more volume to achieve the cargo requirement of CRS-2 within the requested number of missions. CRS-2 calls for 14 to 17tonnes and 55m³ to 70m³ per year with a desired cap of five missions. Stock Dragon has just 10m³, so they couldn't even fit the lower bound of volume. And they haven't shipped more than 1.5tonnes in a single trip. So they need the extra volume. The F9v1.1 can do 16 tonnes to the ISS insertion orbit, and current Dragons are weighting around 6 tonnes with cargo. Thus, they are "wasting" upto 10 tonnes of performance.
The amount of flights per year is a microgravity and crew availability requirement, so I don't see as easily solved. Let's remember that CRS-1 benefited from the stock up did during Shuttle final missions and ATV's huge payload, but all that margin will be long gone by CRS-2.
The original MPLM was a Shuttle design, and was 4.6m x 6.6m of pressurized volume. You might be confused by the OSC Cygnus pressurized module, which is manufactured by the same factory that MPLM (Thales Aliena of Turin, Italy), but are significantly smaller, at just 3m wide and 4.3m long (in the new extended version).
The Dragon's trunk is an unpressurized frame, with an OD of 3.7m, which also works as radiator and has the solar cells. But that's it. The need for pressurized cargo would require a new pressurized module, since the Dragon pressurized vessel can't be significantly increase without ending with a whole new vehicle. And NASA won't want a huge penetration on the heat shield to connect to a pressurized module.
I'm proposing that they develop a pressurized module of similar dimensions to an extended trunk, to replace it on certain missions. A 3.7m x 4m module would supply an ample 32m³ of volume. It would require an additional 1.2m upper stage adapter (the unpressurized trunk also works as the adapter).
But then you could use a stock Dragon v2, that could dock at the NDS. And then the arm would take the pressurized module and berth it to the CBM. Since they could still use the stock trunk for unpressurized cargo, I'm assuming two unpressurized and two pressurized missions per year.
That would get them 100m³ of pressurized volume, 15tonnes of pressurized cargo (at current 150km/m³ density, MPLM was more like 250kg/m³) and almost 70m³ of unpressurized cargo (if using the extended trunk) in just four missions per year.
They could cover the whole CRS-2 needs with a single craft design, with very little incremental development, and just a little bit of extra risk (detaching and re attaching the pressurized module). All in all, a very strong proposal with minimum impact on logistics.

I am referring to the pressurized module on the first 2 Cygnus CRS missions which are shorter than the current ones on the Cygnus.

[abaddon]

And they [SpaceX] haven't shipped more than 1.5tonnes in a single trip.

Yes they have, see the previous page.

I'm proposing that they develop a pressurized module of similar dimensions to an extended trunk, to replace it on certain missions.

I like this idea a lot!

[abaddon]

I hear alot about our paying the Russians $71M per seat to fly to the ISS, but I can't find information on what the estimated cost will be per seat on the CST 100 and manned Dragon. Is this information published any where?

It's apparently up to over $80 million now, by the way http://www.cbsnews.com/news/boeing-spacex-to-team-with-nasa-on-space-taxi/.  Although I have to say I am a little dubious about that claim, I had a hard time trying to find it amid lots of reports that it is over $70.

We don't have an estimated price per seat if you are excluding development costs.  I don't know that anyone has done an estimated price per seat including CCiCAP and CCtCAP but it would obviously be far  higher than anything the Russians have charged us.

[baldusi]

And they [SpaceX] haven't shipped more than 1.5tonnes in a single trip.

Yes they have, see the previous page.

That includes the unpressurized. I was talking about pressurized cargo. They have still to ship the 3,000kg that they were supposed to. And looking at MPLM numbers, I seriously doubt that they'll be able to improve much more. They would have to achieve 300kg/m³, when they haven't done better than 150. And I still don't see the MPLM actual volume, as 31m³. I calculated that they had an actual volume of 80m³, which would have implied a maximum density of 150kg/m³.
In other words, average ISS density seems to be 100kg/m³ to 150kg/m³. Planning for higher density is pie in the sky. BTW, look at Cygnus and its payload capabilities are around 100kg/m³. So SpaceX would have to realistically achieve that to offer a complete solution.

[dror]

I've just realized that with all that extra margin on F9 v1.1, what if Cargo Dragon replaces the thunk with a mini-MLPM? Something that's 3.6m wide would not change a thing, and could multiply the volume significantly. What's more, it would serve for disposal, too. Only problem is that it would need two CBM ports and detachment+berthing and unberthing+reattachment.
But if it is an optional (say, in 30% of the missions), they could cover it all: pressurized up/down, pressurized disposal, unpressurized up/disposal. If F9 v1.1 can do 14tonnes (NLS says 15 to 56.1 x 350km), then, assuming that the normal stack is 8 tonnes, plus say 2 tonnes for the mini-MLPM, they could carry an additional 4 tonnes, for a total of 7 tonnes of cargo (probably more, since I doubt insertion orbit is 350km circular). They could be taking 20 tonnes per year in just three launches! Seems a very interesting possibility.

I believe the original MPLM(PCM) on the Orbital CRS1 & CRS2 will fitted inside an extended Dragon trunk from discussions on various Inspiration Mars threads. Think an extended trunk is faster & cheper to developed for the Dragon to carry additional pressurized cargo than a new mini-MPLM.

[guckyfan]

Elon Musk has said that a flight of Dragon V2 will cost about 140 Million $. That translates to 20 Million/seat with seven passengers or 35 Million with 4 passengers. However with 4 passengers there will be capacity for cargo so the seat price is lower than 35 Million $.

@baldusi

I don't understand your argument about payload. It is not the shipper that achieves the packing density. It is NASA that decides on the cargo and the packing and so determins the density.

[dror]

I hear alot about our paying the Russians $71M per seat to fly to the ISS, but I can't find information on what the estimated cost will be per seat on the CST 100 and manned Dragon. Is this information published any where?

It's apparently up to over $80 million now, by the way http://www.cbsnews.com/news/boeing-spacex-to-team-with-nasa-on-space-taxi/.  Although I have to say I am a little dubious about that claim, I had a hard time trying to find it amid lots of reports that it is over $70.

We don't have an estimated price per seat if you are excluding development costs.  I don't know that anyone has done an estimated price per seat including CCiCAP and CCtCAP but it would obviously be far  higher than anything the Russians have charged us.

Let's try.
For SpaceX Total $2.6B
(1)Excluding development (as 60%) including 6 flight of 7 seats: ~$25M
(2)Excluding development (as 60%) including 6 flight of 4 seats: ~$43M
(3)including development and 6 flights of 7 seats: ~$61M per seat
(4)Including development and 6 flights of 4 seats: ~$108M per seat

For Boeing its about 60% up.

I favor (3) for this contract and (1) for subsequent flights. NASA is paying for 7 seats and will use as many as needed.

[guckyfan]

NASA is paying for 7 seats and will use as many as needed.

No, NASA is not paying for 7 seats. NASA is paying for a flight and they utilize up to 4 seats and use the space where 3 more seats could go for cargo. The contractual requirement is for 4 seats.

[yg1968]

The price per seat discussion doesn't belong in this thread. This thread is about cargo only (CRS2).

To discuss the price per seat, please use this thread:
http://forum.nasaspaceflight.com/index.php?topic=28699.msg1257651#msg1257651

[baldusi]

@baldusi

I don't understand your argument about payload. It is not the shipper that achieves the packing density. It is NASA that decides on the cargo and the packing and so determins the density.

That was how CRS-1 works. But for CRS-2 they have made some very specific request wrt volume, payload and total missions. With CRS-1 they could under deliver since they had Shuttle margin plus ATV. For CRS-2, the whole ISS will depend on them (luckily the Japanese appear to have commited to HTV-8/9).

[arachnitect]

Inspector General report on ISS extension. Has a fair amount to say about ORUs and resupply.

http://www.spaceref.com/news/viewpr.html?pid=43979

In our judgment, it is unlikely NASA will obtain the increased capacity sought in the CRS2 request for a price similar to what it paid under the original CRS contract. Orbital’s cargo vessel does not meet the payload weight requirement and therefore would require additional development work. Moreover, given the tendency to exhaust available space on past cargo missions before reaching the maximum weight capacity of the vehicles, even SpaceX would likely have to redesign its vehicle to meet these requirements. Unless a new commercial cargo transportation company emerges to satisfy the requirements of the CRS2 request or SpaceX and Orbital redesign their capsules, NASA will need to procure more than the four to five missions contemplated in the request, which would increase costs to the Agency.

[oiorionsbelt]

Does extended trunk and F9H alter that?

[docmordrid]

ISTM, not for pressurized cargo.  That said, aren't the major drivers in Cygnus expansion how many segments are in the pressure vessel and perhaps an increased prop margin? Doesn't sound that difficult.

[baldusi]

ISTM, not for pressurized cargo.  That said, aren't the major drivers in Cygnus expansion how many segments are in the pressure vessel and perhaps an increased prop margin? Doesn't sound that difficult.

There's a presentation of a super Cygnus with an extra pressurized ring (four total) that has a mass capability of 3,400kg and 33m³. But it would require something like 5,500kg to 300km x 51.6deg from the Antares. The 131 can do 5,260kg and it would also require an extra fairing extension. If the new re-engined Antares can get the extra performance, the total cost to OSC of this development will be quite low.
I believe that the SpaceX solution that I propose is also relatively cheap. But in general it's quite clear that SNC, Boeing, SpaceX and OrbitalATK will need some investments for CRS-2 and thus I expect a pretty leveled field.

[Patchouli]

I wonder if SNC will try to compete for CRS2 since their vehicle can be flown uncrewed?

It does have more pressurized cargo capacity then both Dragon and the CST-100 plus it's interior volume is cylindrical which is more easily utilized.

For uncrewed cargo missions they could fly with an interim propulsion system using off the shelf parts if the hybrid motors are not ready.

[robertross]

Inspector General report on ISS extension. Has a fair amount to say about ORUs and resupply.

http://www.spaceref.com/news/viewpr.html?pid=43979

In our judgment, it is unlikely NASA will obtain the increased capacity sought in the CRS2 request for a price similar to what it paid under the original CRS contract. Orbital’s cargo vessel does not meet the payload weight requirement and therefore would require additional development work. Moreover, given the tendency to exhaust available space on past cargo missions before reaching the maximum weight capacity of the vehicles, even SpaceX would likely have to redesign its vehicle to meet these requirements. Unless a new commercial cargo transportation company emerges to satisfy the requirements of the CRS2 request or SpaceX and Orbital redesign their capsules, NASA will need to procure more than the four to five missions contemplated in the request, which would increase costs to the Agency.

Thanks
IG report linked on the article

[dror]

ISTM, not for pressurized cargo.  That said, aren't the major drivers in Cygnus expansion how many segments are in the pressure vessel and perhaps an increased prop margin? Doesn't sound that difficult.

There's a presentation of a super Cygnus with an extra pressurized ring (four total) that has a mass capability of 3,400kg and 33m³. But it would require something like 5,500kg to 300km x 51.6deg from the Antares. The 131 can do 5,260kg and it would also require an extra fairing extension. If the new re-engined Antares can get the extra performance, the total cost to OSC of this development will be quite low.
I believe that the SpaceX solution that I propose is also relatively cheap. But in general it's quite clear that SNC, Boeing, SpaceX and OrbitalATK will need some investments for CRS-2 and thus I expect a pretty leveled field.

What are the chances for us to see an "extra large cygnus" on Falcon9 ?

[baldusi]

ISTM, not for pressurized cargo.  That said, aren't the major drivers in Cygnus expansion how many segments are in the pressure vessel and perhaps an increased prop margin? Doesn't sound that difficult.

There's a presentation of a super Cygnus with an extra pressurized ring (four total) that has a mass capability of 3,400kg and 33m³. But it would require something like 5,500kg to 300km x 51.6deg from the Antares. The 131 can do 5,260kg and it would also require an extra fairing extension. If the new re-engined Antares can get the extra performance, the total cost to OSC of this development will be quite low.
I believe that the SpaceX solution that I propose is also relatively cheap. But in general it's quite clear that SNC, Boeing, SpaceX and OrbitalATK will need some investments for CRS-2 and thus I expect a pretty leveled field.

What are the chances for us to see an "extra large cygnus" on Falcon9 ?

I don't see it. Specially after OSC and ATK merge. They need just an extra 5% performance out of the Antares, and adding a single extra ring to the pressure vessel. They could do a Castor30XLB, increase the propellant load of the Cygnus or something. Overall, they might even fly like that and do five missions instead of four. But they have barely enough AJ-26 to transition to a new engine by 2017/18. A dual RD-193 Anatares would have just enough performance and might cover the quota with just four launches (which, if NASA keeps dual suppliers might mean two missions per year).

[yg1968]

Inspector General report on ISS extension. Has a fair amount to say about ORUs and resupply.

http://www.spaceref.com/news/viewpr.html?pid=43979

In our judgment, it is unlikely NASA will obtain the increased capacity sought in the CRS2 request for a price similar to what it paid under the original CRS contract. Orbital’s cargo vessel does not meet the payload weight requirement and therefore would require additional development work. Moreover, given the tendency to exhaust available space on past cargo missions before reaching the maximum weight capacity of the vehicles, even SpaceX would likely have to redesign its vehicle to meet these requirements. Unless a new commercial cargo transportation company emerges to satisfy the requirements of the CRS2 request or SpaceX and Orbital redesign their capsules, NASA will need to procure more than the four to five missions contemplated in the request, which would increase costs to the Agency.

Thanks
IG report linked on the article

The observations on CRS2 are on page 26 of the report.

[yg1968]

ISTM, not for pressurized cargo.  That said, aren't the major drivers in Cygnus expansion how many segments are in the pressure vessel and perhaps an increased prop margin? Doesn't sound that difficult.

There's a presentation of a super Cygnus with an extra pressurized ring (four total) that has a mass capability of 3,400kg and 33m³. But it would require something like 5,500kg to 300km x 51.6deg from the Antares. The 131 can do 5,260kg and it would also require an extra fairing extension. If the new re-engined Antares can get the extra performance, the total cost to OSC of this development will be quite low.
I believe that the SpaceX solution that I propose is also relatively cheap. But in general it's quite clear that SNC, Boeing, SpaceX and OrbitalATK will need some investments for CRS-2 and thus I expect a pretty leveled field.

Why would SpaceX need to make investments for CRS2? Can't they just offer Dragon V1 and V2? There was talk of an extended trunk. But I don't think SpaceX has other plans for improving Dragon.