Draft and Final RFP for Gateway logistics/cargo services

[GWH]

The official RFP has been released today:
https://www.nasa.gov/feature/nasa-asks-american-companies-to-deliver-supplies-for-artemis-moon-missions

This solicitation is for a multi-award, firm-fixed price, indefinite delivery/indefinite quantity contract for 15 years, with a maximum $7 billion value. The guaranteed minimum value for any award is two missions.

NASA is also asking responders to address logistics spacecraft design, cargo mass capability, pressurized volume, power availability for payloads and, transit time to Gateway.

Following initial award, there may be future contract opportunities for new service providers to ensure capabilities remain competitive. If approved in advance by NASA, a commercial provider may also use a mission to deliver, remove and/or return non-NASA cargo as long as it does not interfere with the agency mission, furthering the development of a robust deep space economy.

Complete RFP can be found here: https://www.fbo.gov/index?s=opportunity&mode=form&id=fc4c9359483f1fa92e25e2425780e935&tab=core&_cview=1


A general update on Artemis in the press statement:

This solicitation is the latest in a line of work by the agency to accelerate its Moon to Mars exploration plans by working with American aerospace companies. NASA recently awarded a contract to Maxar Technologies to design, develop, launch and demonstrate the power and propulsion element by 2022. Negotiations are ongoing for development of the habitation and logistics outpost (HALO) module. The agency is also working on another draft solicitation for the integrated human landing system. A final solicitation will be released in the future.

[pochimax]

Hi,

now that SpaceX has confirmed Falcon Heavy as its launcher for Gateway cargo services....

I wonder if, for Dragon cargoes, it is needed (FH) to be fully expendable, partially reusable or fully reusable?

I have no clue.

Thanks for your answers (elaborated)

[Lar]

now that SpaceX has confirmed Falcon Heavy as its launcher for Gateway cargo services....

They did? Can you link to that?

[gongora]

The AIAA talk yesterday, Hans mentioned it.

[pochimax]

https://mobile.twitter.com/StephenClark1/status/1163476514530385920

[pochimax]

So, ... again... some doubts

Assuming a Dragon V2 with at least 3.4 pressurized tones of cargo and 1 Ton unpressurized...

Could Falcon Heavy launch a Dragon V2 directly to Gateway?

Need SpaceX to develop a transfer stage to do lunar injection, manouver corrections, approach, etc.?

The transfer stage, would use Super Dracos? (problem with reignition?)

Edit: That potential transfer stage, could be used also for launching lander parts? (as commercial launcher provider)

And the question about FH performance (fully reusable, fully expendable, a mix of both?

Many thanks for your inputs.

SpaceX (and the rest of tenders) have to make a proposal by October, 1. They must run, isn' it?

[speedevil]

So, ... again... some doubts

Assuming a Dragon V2 with at least 3.4 pressurized tones of cargo and 1 Ton unpressurized...

Could Falcon Heavy launch a Dragon V2 directly to Gateway?

Need SpaceX to develop a transfer stage to do lunar injection, manouver corrections, approach, etc.?

For slow transit, only a few tens of m/s over the required velocity for L1, and then a few tens of meters/s delta-v to stop in NHRO is required as I understand it.

Dragon 1 is 2 tons lighter than dragon 2, and the dracos would be just fine for this low delta-v.

5 tons cargo, plus 4 tons D1 is 9 tons.
FH nonreusable can throw 63 tons to LEO.

Assuming the second stage of F9 is 2 tons, that's 11 tons post-TLI required, or 27 tons pre.
25 tons cargo capacity to LEO can probably be done by falcon heavy in full reusable mode. (not S2).

Anything more than that is getting dodgy - adding 2 tons by going for D2, not D1 may make it mandatory to expend one core.
Expending a core on FH gets you ~22 tons through TLI, and a hair less than that once you stop in NHRO.

Developing a third stage of some form from storables has problems.
The ISP of Merlin vacuum is ~350, whereas the ISP of draco, and presumably superdraco expanded to vacuum, is 300.
The F9 stage is only 2 tons dry - once you get meaningfully close to 14 tons total mass of S2+Dragon+storables, the optimum size of a third stage with storables is zero - because the extra mass is completely compensated for by the better ISP.

A thought I've not seen asked yet.
FH has demonstrated a coast of 6h.
FH with one core expended has a payload of ~55 tons to TLI.
TLI is nominally ~3100m/s or so.

With a 9 ton (plus 2 ton S2 payload), the total delta-v available is 5.4km/s.

An energetic enough burn may be able to place a payload in NHRO with a coast not enormously longer than that already demonstrated.

[pochimax]

Thank you very much. I will think about it (I have little knowledge on this subjects  )

I assumed Dragon 2 because of docking requirement from NASA (Dragon 1 didn' t have, it berths)

[ThomasGadd]

As I understand it superdraco's will not be installed on cargo Dragon-2... How much does it weigh? 

[pochimax]

As I understand it superdraco's will not be installed on cargo Dragon-2... How much does it weigh?

I think so. But I don' t know how much mass involves Super Draco' s. According to wikipedia propellants are 1.080 kg.

On the othe hand, I think it is possible to make some changes to hardware. GLS contracts will have at least 3 missions, the first involves different price than the other 2. I suppose NASA do this to pay firms for necessary hardware changes. Even defer this costs and investments along 3 missions (so maybe through 2030)

For example, a direct SpaceX competitor (NGIS and its Cygnus) must achieve autonomous docking (vs. current berthing) and unpressurized payloads (current Cygnus doesn' t have). AFAIK.

It is the reason I think it is possible SpaceX could design a new third stage or service module or whatever... Changes paid in this contract (¿bigger fairing?) could even be beneficial when launching lander parts.

And they will offer Dragon-2 Cargo but, obviously, a modified one. Some kind of "Gateway Dragon" cargo version.

[Negan]

And they will offer Dragon-2 Cargo but, obviously, a modified one. Some kind of "Gateway Dragon" cargo version.

Musk has said before that removing the heat shield would give them a lot of mass savings so that's one mod I think would happen.

[pochimax]

Ok, but think also that "sample return" is determined to be a "unique cabability"

Obiusly, SpaceX will have to balance between different capabilities. Maybe offering "sample return" at cero cost (i. e. Dragon with heat shield) will be a valuable factor for NASA and one of SpaceX key point against Cygnus, to win a contract.

Remember NASA will probably select to different vendors (with two different rockets) as in ISS contracts. To protect the program from one provider failure.

[TripleSeven]

And they will offer Dragon-2 Cargo but, obviously, a modified one. Some kind of "Gateway Dragon" cargo version.

Musk has said before that removing the heat shield would give them a lot of mass savings so that's one mod I think would happen.

it will be hard to match OSC in price particularly if there is no down mass requirement.  OSC has developed a product (the adaption of the ninja turtles modules with a propulsion stage) that will do the job and is mass producable...if they keep the ISS contract then that will "slide" right into a Gateway project with almost trivial modification effort

launch on a NG rocket...well pretty cheap

[pochimax]

with almost trivial modification effort

Well, maybe optimistic. They must develop for the first mission (Cygnus):

- autonomous docking
- unpressurized payload.

At least.

On the other hand, if NASA wants to select 2 different cargo vehicles (and architectures) not being the chepeast offer its not as important as being credible and on schedule. For example, having an already capable fully functional existing rocket (falcon Heavy) its a plus over other rockets, that didn' t exist yet (Vulcan, New Glenn)

[TripleSeven]

with almost trivial modification effort

Well, maybe optimistic. They must develop for the first mission:

- autonomous docking
- unpressurized payload.

At least.

On the other hand, if NASA wants to select 2 different cargo vehicles (and architectures) not being the chepeast offer its not as important as being credible and on schedule.

none of those things will be a problem for OSC...the latter is trivial and well they could do the autodocking now if they didnt berth.  that technology is already in hand.

I doubt NASA will select two...why?

1. there is no money for two and 2...they dont need it.  theonly reason two exist on ISS is that it is constantly crewed...the gateway wont be...in fact one reason I oppose it...is that it will be hardly used

OSC so far has demonstrated that expendable rocks

[Negan]

Ok, but think also that "sample return" is determined to be a "unique cabability"

I thought Dragon 2 was only capable of a one-way trip to the gateway because it lacks the delta-v. That would be great if I'm mistaken.

[pochimax]

It is my opinion that NASA wants 2 vendors to protect schedule against failure of one firm.

It doesn' t matter Gateway is not permanently occupied. Most important thing here is schedule. You don' t want in any case to delay an SLS - Orion launch because of your cargo spacecraft.

Problem with this type of Commercial contracts is that NASA can cap costs but are not protected against program failures once the program has advanced.

Obviously, if you are much cheaper than the rest you will win the whole 7 billion contract. But it seems to me more likely to divide the contract

[pochimax]

Ok, but think also that "sample return" is determined to be a "unique cabability"

I thought Dragon 2 was only capable of a one-way trip to the gateway because it lacks the delta-v. That would be great if I'm mistaken.

And, ... what about Cygnus? I think they have the same problem. Or with an "Starliner Gateway Cargo"

It is the reason I wonder if SpaceX could fit a "transfer stage/service module" development cost withing first mission budget. I think it is expected the first mission to be more expensive than the other 2 (contract is for 3 missions, at least).

Getting paid your transfer stage in a GLS contract implies you can offer it without including development costs for launching the ascent or descent stages of the lunar lander(s). It could give some kind of advantage for SpaceX.

[ncb1397]

Anybody know the best way for Dragon to meet the pressurized cargo requirement?

Contractor shall provide a capability to deliver a minimum of 3,400 kg of
pressurized cargo to the Gateway within the overall constraints as defined in GLSRQMT-001.

For reference, the sizes, mass properties, resource interfaces, environmental requirements
and strapping/attachment interfaces for the MDL and CTB cargo and payloads are
provided in SSP-50833, International Space Station Program Cargo Transport
Interface Requirements Document, and may be used as a guideline. Note, typical
ISS cargo packing density for CTBs is approximately 290 kg/m3
. .

1.)Dragon has never came close to delivering 3400 kg of pressurized cargo.
2.)Dragon 2 with a pressurized volume of 9.3 cubic meters (wikipedia) and a payload density of 290 kg (per cubic meter) only nets you 2697 kg which is consistent with delivered cargo on past CRS missions.

You could: add an additional cargo carrier to the trunk, enlarge the pressure vessel or ..

This of course opens a can of worms. Once you start changing the pressure vessel, it starts looking like a different spacecraft. But ports on gateway are probably driving the minimum cargo per mission requirement and so the 3400 kg may only be able to use one port. In addition, the cargo services have to be delivered prior to arm arrival. That means you have two interfaces on the pressurized module in the trunk - one to interface with the dragon and one to interface with the gateway. This dance that is required prior to docking to remove the pressurized module from the trunk and attach it the end of dragon is similar to what was done for Apollo, but that was essentially two different complete fully capable spacecraft.

[pochimax]

Ooops, it is a problem. 

I have read Dragon capabilities on SpaceX web and thought... 6.000 kg cargo, ok no problem....

But it is true they don' t give separate numbers for pressurized and unpressurized mass.

https://www.spacex.com/dragon

Edit: maybe the solution is than not all the cargo is packed that way? (for example, liquid water, food, etc)...