33 replies on “NASA Issues RFP for Next Round of Commercial ISS Resupply Missions”

  1. I wonder if SNC will enter the dream chaser for cargo. It would give NASA more down cargo capability and it is a backdoor for SNC to get dreamchaser certified for cargo.. a bit easier then human ratings and would keep dream chaser in the hunt for human rating it later.

    2. I don’t see how they could compete with SpaceX and Orbital, which already have their vehicles in service, and they’d be priced out of the market having to launch on Atlas V (at least until ULA fields Atlas V-R or Atlas VI, whatever it is). Orbital might run into trouble by having to develop a new first stage for Antares once NK-33s run out, so that’s an outside chance SNC can slip in, I suppose. But it is still a long-shot.

          1. It was my understanding that solids were more expensive then liquid fueled launch vehicles. Would they still be competitive?

          2. Maybe not. I checked and a Shuttle SRB was 23 million $. They may be cheaper than SpaceX. The shake does not matter since Shuttle did launch HST and a lot of other satellites. All solids are simpler, safer and I think the way to go. The SRB had 3 million lbs. of thrust. They could launch a ATV. Only go once a year. Change number of segments to adjust performance. Umbilicals for power and data only.

          3. Solids safer? Seriously? You must be ignoring past experience with large segmented solids. They occasionally “leak” at the joints (i.e. Challenger disaster) and occasionally go “boom” without warning (Titan 34D loss in 1986 due to SRM case rupture). Other failure modes also exist for solids beyond the more spectacular ones (Titan IV loss in 1993 due to another SRM malfunction).

            One of the distinct advantage of liquids is that thrust termination is usually a lot less violent than with solids. When things go bad, they tend to go bad faster and more violently with solids. Google “Solid Rocket Motor Failure Prediction” and you will find an interesting page at ti.arc.nasa.gov that goes into detail about the many possible failure modes for solids.

          4. Sounds bad. USAF said in an abort the crew would be killed because the high temp gas would melt the nylon parachutes. NASA said they would clear. I guess there is more bad than good.

          5. More like flaming chunks of solid propellant would turn the parachute into Swiss cheese. Google “titan solid rocket motor explosion” and then click on the “Videos” tab. Yes, I know these are technically “case ruptures”, but to find it on Google, “explosion” provides more hits. You should find videos of a Titan 34D SRM failure, a Titan IV SRM failure, and a Dleta II strap-on solid failure (to name a few).

            Even at the low resolution of the videos, in every one there are lots of flaming bits of solid rocket motor propellant flying in all directions. That is what you call a “bad day” for a solid rocket motor. Sure it doesn’t happen often, but when it does, you don’t want to be riding on top of it.

          6. the Shuttle’s SRBs did have an extremely good success rate of 270/271 = 99.63% (135 Shuttle launches and one Ares I-X launch), which is better than many liquid fueled rocket engines. so they can clearly be reliable when they are well designed, but the same is true of liquid fueled engines. there are pros and cons for each.

          7. But “reliable” isn’t the whole story. The extremely violent failure modes of solids when they *do* fail typically means loss of vehicle, payload, and crew. Solids may be acceptable for “bulk” deliveries of cargo to LEO, but for carrying people, not so much. It was well known within NASA and ATK that a shuttle SRB failure like a case
            rupture would cause loss of vehicle and crew. Designing an escape system for Ares I that would allow for crew survival following a case rupture was decidedly non-trivial.

          9. Given the ATK-Orbital merger, they may be able to fly cheaper on an all-solid Antares by not having to pay retail.

          10. solid rockets are far less complex and simpler to manufacture than liquid rocket engines, so they are usually cheaper. the Shuttle’s SRBs cost considerably more due to the amount of labor that was required to clean and inspect their casings for reuse. that said, there are a lot of other negatives that go along with using solid rockets.

  2. I expect to SpaceX to be able to lowball everyone. If the contract is written so it won’t require a new Dragon each time and if they can show reuse of F9 cores…well, there is no one even on the radar that compete with that.

    1. I expect NASA will want a new dragon on this one yet. It will back door some development money to SpaceX for reusablity. I would imagine that SpaceX will use the Dragon V2.0 for cargo in the future to eliminate the water landings.

      1. Good points.

        Docking for v1 and v2 are different, though, and I don’t think there is room for two v2’s to be docked at any one time. (PMA3 will have BEAM attached to it leaving only PMA-2, formerly only used by shuttle for Dragon v2).
        I think they might need to stick with v1 for cargo. Perhaps some modifications…especially to the trunk, might be in order.
        Further along this line, they could cast off the PLM and perhaps build “PMA-4” (hauled up in a Dragon trunk) and installed at nadir of Node 3 and use the nadir of Node 2 for cargo docking.
        With regular visits of Antares and Progress to dispose of trash and Dragon for stuff to keep, the PLM might be on the cusp of having served it’s use.

        1. The soyuz use two ports for the emergency escape. If a Dragon is used in that role they would only need one on station… could that free a port of it that the older docking infrastructure?

        2. Boeing is installing two crew docking ports. SpaceX has designed there own port for Dragon. They will not take the free one from NASA. They did not like some things about it.

          2. Yes, primarily they were going to have to buy them after the first freebie, they were more complex and IIRC they weren’t available for commercial habitats so SpaceX did their usual thing and designed and produced in-house.
            Cheers

    2. while reuse for cargo is a great idea and they maight be ato to reuse the F9 cores, why did Elon up production rates to 200 engines a year?
      I dont expect spacex to lowball, its never a real competition on price.

      1. He has to build out a fleet of Falcon Heavies, each with 28 engines, and a fleet of Falcon 9s each with 10 engines. Each flight (until reuse of upper stage) loses an engine, say 30-60 per year. Each government flight requires 10 – 28 new engines. Plus replacement engines for the occasional failure and replacements after 10 or so uses.
        That’s just the beginning. SpaceX expects to launch daily very soon, and almost hourly in the not too distant future.
        They are planning with the reusable falcons to drop prices by first a factor of 10 per kilogram, then at least a hundred.

        1. He wants to do 10 falcon 9 and 10 falcon heavies. That’s 360 engines a year for the atmospheric optimized engines and 20 of the second stage. That is without any reuse. I believe he has stated before he wants to have a 400 engine capability. I would imagine just incase the reuse doesn’t pan out right away.

          1. with all due respect, the original EELV contract was based on 40 flights a year, which never panned out. satellites are lasting longer than ever and multiples of the small ones are easily launched from one vehicle. While there is a commercial market, you have to factor in how fast satellites are built and the cost of the fixed sites. I dont see him displacing much of the ariane market, nor china and india. I imagine once he hits 400 engines he can shut down production and fly for the next ten years making pure profit.

          2. Bigelow Aerospace said they will need 20 flights a year for the first station. He has already committed 250 million and stated he will contribute another 250 million. I do not believe he is the kind of guy that will toss a half billion away on a lark. He is confident that there are plenty of sovereign clients willing to sign up with him.

        2. “SpaceX expects to launch daily very soon”

          if by “very soon” you mean “20 years or more from now”

          as much as I love SpaceX, there’s not a chance in hell they will be launching daily any time in the next 20 years, even with 4 fully operational launch pads, we might realistically see one launch per week, and that’s spread out over the 4 launch sites.

          “almost hourly”

          that would be 8,766 launches PER YEAR. that’s about half as many launches (to Earth orbit or beyond) as there has EVER BEEN.

          i will say this now – this will NEVER happen in our lifetimes. SpaceX would need about 50 launch sites, each cranking out a launch every 2 days to achieve that…

  4. Well I guess the fix is off. NASA sent out an RFI to see if anyone objected to to just extending the current contracts. I guess someone did. Others know how much the contracts are for, so they know how they must bid.

    1. Dragon’s trunk is its ace in the hole. The 14 m3 version now flying is one thing, but SpaceX also had a longer 34 m3 unit in their DragonLab PDF. Wonder if it could be made large enough to haul up replacement folded ISS solar blankets for when the time comes? They aren’t terribly large.

      1. I have always thought they could make a trunk long enough for the solar panels. HTV cut a notch to carry external. Cygnus could do that. Probably don’t have enough room inside the fairing for solar though. The last I heard NASA will have HTV, instead of Dragon, to carry the new main batteries.

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