ISS Commercial Resupply Services 2 (CRS2) 2017-2030

[jongoff]

"With no crew, the capsule will be able to carry more than 1,100 kilograms of cargo"

Not sure I've seen that figure before, and it's interesting.  Dragon can carry about 3,310 kg of pressurized cargo to the ISS and return the same, and the Cygnus can carry 1,800 kg to the ISS.

Maybe Boeing and Cygnus are using a sensible means of calculating up mass. SpaceX hasn't flown a single Dragon flight with up mass even close to their claims.

Part of the challenge is that pressurized upmass tends to be very low density. They've typically filled Dragon flights up as much as they could volume-wise and had tons (literally) of excess mass performance left over. I believe the term of art is "voluming-out".

~Jon

[abaddon]

For those keeping score at home, comparing Cygnus and Dragon deliveries:

Orbital D1: 700
Orbital CRS1: 1,261
Orbital CRS2: 1,494

SpaceX C2+: 525
SpaceX CRS1: 905
SpaceX CRS2: 881
SpaceX CRS3: 2,268

Upcoming:
SpaceX CRS4: 2,272
Cygnus CRS3: ?

Assuming SpX-4 goes off without a hitch, that leaves 13,149kg left over eight flights, which means an average of 1644kg flight, which seems pretty conservative given the manifest for CRS3 and CRS4.

Note: sourcing this data has been painful, and I've already found some mistakes myself, so please correct me with sources if some of these are in error.

[baldusi]

For those keeping score at home, comparing Cygnus and Dragon deliveries:

Orbital D1: 700
Orbital CRS1: 1,261
Orbital CRS2: 1,494

SpaceX C2+: 525
SpaceX CRS1: 905
SpaceX CRS2: 881
SpaceX CRS3: 2,268

Upcoming:
SpaceX CRS4: 2,272
Cygnus CRS3: ?

Assuming SpX-4 goes off without a hitch, that leaves 13,149kg left over eight flights, which means an average of 1644kg flight, which seems pretty conservative given the manifest for CRS3 and CRS4.

Note: sourcing this data has been painful, and I've already found some mistakes myself, so please correct me with sources if some of these are in error.

Are you counting Dragon's unpressurized mass? Btw, Spx contract is 20tonnes upmass and 3 tonnes downmass. But tonnes can be exchanged one for the other. Which means that it's quite possible that Spx will end up with some extra money.

[abaddon]

Are you counting Dragon's unpressurized mass? Btw, Spx contract is 20tonnes upmass and 3 tonnes downmass. But tonnes can be exchanged one for the other. Which means that it's quite possible that Spx will end up with some extra money.

Yes, these figures include unpressurized mass and packaging (as best I can tell).  I don't believe anything in the NASA contract stipulates how much mass should be pressurized vs unpressurized, or any indication that NASA has a valuation for one over the other, or that they don't consider their packaging to be part of delivery mass, so it didn't seem correct to exclude them.

I wanted to limit the comparison to upmass only, to make this as apples-to-apples as possible.  But for downmass figures:

SpaceX C2+: 665kg
SpaceX CRS1: 905kg
SpaceX CRS2: 1,370kg
SpaceX CRS3: 1,600kg

If it is only 3,000kg they are contracted to bring down then they've already passed that mark and are going to blow that out of the water over the life of the contract.

[AnalogMan]

For those keeping score at home, comparing Cygnus and Dragon deliveries:

Orbital D1: 700
Orbital CRS1: 1,261
Orbital CRS2: 1,494

SpaceX C2+: 525
SpaceX CRS1: 905
SpaceX CRS2: 881
SpaceX CRS3: 2,268

Upcoming:
SpaceX CRS4: 2,272
Cygnus CRS3: ?

Assuming SpX-4 goes off without a hitch, that leaves 13,149kg left over eight flights, which means an average of 1644kg flight, which seems pretty conservative given the manifest for CRS3 and CRS4.

Note: sourcing this data has been painful, and I've already found some mistakes myself, so please correct me with sources if some of these are in error.

As of July 28, 2014

Orbital-3 Mission:

• 2290 kg upmass
• 1714 kg disposal

SpaceX-5 Mission:

• 2073 kg upmass
• 1580 kg return mass

[Garrett]

For those keeping score at home, comparing Cygnus and Dragon deliveries:

Orbital D1: 700
Orbital CRS1: 1,261
Orbital CRS2: 1,494

SpaceX C2+: 525
SpaceX CRS1: 905
SpaceX CRS2: 881
SpaceX CRS3: 2,268

Upcoming:
SpaceX CRS4: 2,272
Cygnus CRS3: ?

Assuming SpX-4 goes off without a hitch, that leaves 13,149kg left over eight flights, which means an average of 1644kg flight, which seems pretty conservative given the manifest for CRS3 and CRS4.

Note: sourcing this data has been painful, and I've already found some mistakes myself, so please correct me with sources if some of these are in error.

Thank you for that work! I was thinking about doing the same thing but quickly realised that it would take quite a lot of time. Any chance you kept notes of where your sourced those figures?

I started a table for SpaceX figures on the Wikipedia talk page for CRS back in January, but unfortunately it didn't get updated. Maybe you can add your figures (with sources?) there:
http://en.wikipedia.org/wiki/Talk:Commercial_Resupply_Services

I didn't add the the SpaceX C2+ figures because I'm not sure if that counts as part of the CRS contract?

[sdsds]

Part of the challenge is that pressurized upmass tends to be very low density.

The CRS2 Draft RFP provides a hint at the expected density:

2.1.1 A minimum usable pressurized cargo volume of 74 Cargo Transfer Bag Equivalents
(CTBE) per 1000 kg of pressurized cargo shall be used.

[baldusi]

Are you counting Dragon's unpressurized mass? Btw, Spx contract is 20tonnes upmass and 3 tonnes downmass. But tonnes can be exchanged one for the other. Which means that it's quite possible that Spx will end up with some extra money.

Yes, these figures include unpressurized mass and packaging (as best I can tell).  I don't believe anything in the NASA contract stipulates how much mass should be pressurized vs unpressurized, or any indication that NASA has a valuation for one over the other, or that they don't consider their packaging to be part of delivery mass, so it didn't seem correct to exclude them.

I wanted to limit the comparison to upmass only, to make this as apples-to-apples as possible.  But for downmass figures:

SpaceX C2+: 665kg
SpaceX CRS1: 905kg
SpaceX CRS2: 1,370kg
SpaceX CRS3: 1,600kg

If it is only 3,000kg they are contracted to bring down then they've already passed that mark and are going to blow that out of the water over the life of the contract.

From what I remember they said that it was basically a 23 tonne contract and all mass had the same basic price. So everything should, AIUI, got to the same pool. Mrs Shotwell stated that they were quite confident on covering the quota.
Orbital, unless disposal mass is considered, will have a harder time. But I believe that there is a clause about volume limited flights counting as one flight.

[abaddon]

Thank you for that work! I was thinking about doing the same thing but quickly realised that it would take quite a lot of time. Any chance you kept notes of where your sourced those figures?

I started a table for SpaceX figures on the Wikipedia talk page for CRS back in January, but unfortunately it didn't get updated. Maybe you can add your figures (with sources?) there:
http://en.wikipedia.org/wiki/Talk:Commercial_Resupply_Services

I didn't add the the SpaceX C2+ figures because I'm not sure if that counts as part of the CRS contract?

No problem, it did take longer than I expected .  I ended up sourcing my data from Wikipedia because it seemed to have the most consistent figures.  Each flight has a link with a section detailing upmass and downmass.  Maybe disposal mass (Cygnus) too but I had to actually stop and do my job .  A table would be nice but I am not sure I have time or energy to do something like that right now.  That said since it is all Wikipedia cited that might make it easier.

[abaddon]

As of July 28, 2014

Orbital-3 Mission:

• 2290 kg upmass
• 1714 kg disposal

SpaceX-5 Mission:

• 2073 kg upmass
• 1580 kg return mass

Interesting, thanks for the data.  One thing that surprises me, is the quoted 2290kg upmass listed for Cygnus.  According to their fact sheet the regular Cygnus is limited to 2000kg upmass, and Orb-3 is supposed to use the regular (not enhanced Cygnus).  Any idea what gives there?  Is it because of the Antares 130 being used on this flight?

[MTom]

Is it meaningless that ESA finished with their ATV-launches with 7 tonnes / year?
Somehow this amount of cargo on top has to be transported to ISS.

[arachnitect]

As of July 28, 2014

Orbital-3 Mission:

• 2290 kg upmass
• 1714 kg disposal

SpaceX-5 Mission:

• 2073 kg upmass
• 1580 kg return mass

Interesting, thanks for the data.  One thing that surprises me, is the quoted 2290kg upmass listed for Cygnus.  According to their fact sheet the regular Cygnus is limited to 2000kg upmass, and Orb-3 is supposed to use the regular (not enhanced Cygnus).  Any idea what gives there?  Is it because of the Antares 130 being used on this flight?

Correct.

[baldusi]

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.

[arachnitect]

It seems to me that a licensed HTV variant with enough domestic content to satisfy Congress, launched on an EELV, would have a pretty good chance of capturing half of the launches and most of the payload.

The problem with that is storage; unless you are willing to let the large cargo module stay berthed to the ISS for 4-6 months there is not enough room aboard to store everything. Heh 53t of supplies in one heavy launch.  Plus you want to rotate science experiments faster to get more through the pipeline.

Boeing proposed something like this back in the COTS era, buying ATV/HTV and launching on DIV-H.

ATV is out of production, and might need pretty serious mods to work in this case anyway. I'm guessing they would switch over to dock/berth at US segment for example. Would have to fly on DIV-H

HTV can almost fly on AV551. Maybe with bulky cargo they could fill the PLC and be light enough. They already have a foreign content problem, and flying on Atlas doesn't help.

HTV variant with a big US made PLC on DIV-H could be interesting. I estimate they would need to be delivering 8000+ kg. to keep the costs in the neighborhood of current CRS prices. If they could max the launch vehicle it would look cheap.

The idea is NASA basically stays with the current providers, but also adds a ULA launched HTV every 12-18 months to help keep the station topped up. Might help convince JAXA to extend their HTV commitment as well.

NASA wants more cargo, low/no development costs, "made in USA (mostly)", and fewer flights. Something needs to give.

[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.

This was sugested earlier in this thread with the refernce of the liberty spacecraft

[yg1968]

Contract award date for CRS2 has been added:

Release Final Request for Proposal 09/30/14   
Proposals Due 11/14/14   
Contract Award 04/28/15

http://procurement.jsc.nasa.gov/crs2/schedule.asp

Next big award is CRS2 on April 28th 2015.

[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.

[guckyfan]

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.

I think it will need to be a separate unit transported inside the trunk. That way it can be taken out by a robot arm and attached to a separate berthing port. It would solve another problem too. A mostly unmodified Dragon 2 can be used for cargo with the docking adapter. Bulky goods can go into the mini MPLM.

[baldusi]

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.

[Pollagee]

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?