Interesting Paper on Shuttle Alternatives

Someone was digging around the ULA publications section, and stumbled on a very interesting paper I hadn’t heard about yet discussing a shuttle alternative for resupplying the space station. While I don’t agree with everything in it, it’s worth a good read.

One of the main ideas presented in the paper is a “Payload Bay Fairing” that would allow a heavy EELV to interface and launch payloads originally designed to launch on shuttle. The EELV would deliver the PBF with its encapsulated payload to just outside the ISS “visiting vehicle stay-out zone”, and then a tug of some sort would provide “last mile” services, hauling the PBF and its payload to the station, where it would be unloaded. They mentioned using Soyuz/Progress as the tug (like Constellation Services proposed), but decided to focus on ATV due to concerns about ITAR and INKSNA issues.

Payload Bay Fairing (courtesy ULA)

Payload Bay Fairing© (courtesy United Launch Alliance)

The PBF would be derived from the current 5m payload fairing used on the Atlas V. The PBF would have docking/berthing mechanisms on both ends, and would have structure to allow it to transfer loads into the payloads in a manner similar to the shuttle payload bay. I imagine it would also provide the necessary services for maintaining those payloads until they were ready to be installed at the ISS. By launching this on Delta-IV, you could pretty much deliver any payloads that the Shuttle was supposed to deliver, and probably at a far cheaper price. This includes the MPLMs, the AMS module that has received so much attention, and any other modules that isn’t going to get a shot at getting launched due to the 2010 shuttle retirement.

This is an interesting idea in several ways:

  1. For small payloads that the COTS providers can deliver, a Delta-IV/ATV derived solution isn’t going to be cost competitive so it doesn’t necessarily step on toes as much.  If the Shuttle is kept running after 2010, being a government jobs program it doesn’t have to be economically competitive with COTS, and therefore could easily squash the nascent efforts by SpaceX, OSC, and others in this area.  With a Delta-IV based system, procurements would have to be handled in a competitive manner if the payload is one that could be flown on other commercial options, and therefore it’s much less likely to interfere in that key initial market.
  2. This provides a commercial method for replacing the key functionality that we’ll be losing when the space shuttle retires.  This might allow us to drop the albatross sooner.  More importantly it might allow for some of the other modules that were deselected to be restarted and launched.  If Atlas V ever gets built there would even be some redundancy.  Building a station out of 20 tonne chunks isn’t a crazy idea so long as all those chunks aren’t stuck flying on the same system.
  3. Space Tugs for proximity ops are an idea whose time has come.  If you start with an ATV-based tug system, that might provide enough of a market for other more affordable competitors to start filling that niche.  Once you have space prox-ops tugs available, lots of things become much, much easier.  Most of the mass launched with Shuttle or Progress (or even ATV or HTV) ends up being used to handle things like prox-ops, rendezvous and docking, cargo handling, reentry, etc.  The more of those functions can be offloaded to something that can stay in orbit and not have to be relaunched every time, the higher a percentage of your delivered mass can actually go to paying cargo, propellants, or passengers.  Also, by removing offloading a lot of the Visiting Vehicles requirements to the tug, it makes it removes a big barrier to entry by new suppliers.Space tugs would also benefit people like Bigelow. If he didn’t have to design each of his modules as maneuvering, independently operable spacecraft, I bet his task would be a lot easier. Also, tugs would make it much easier for different groups that want to dock/berth with his stations to do so.

It’s also amusing to note that I tossed out such an idea on usenet back in 2003 right after Columbia.  Now, I’ll admit that at the time, I really had no clue of all the challenges involved.  And accusations that I sounded like an “engineering undergrad with lots of imagination but very little experience with real world considerations?” were probably more accurate than I’d like to admit now. But it’s always cool finding out that one of my ideas I had years ago actually was a good one after all.

This entry was posted in Commercial Space, COTS, International Space Collaboration, NASA, Space Transportation. Bookmark the permalink.

15 Responses to Interesting Paper on Shuttle Alternatives

  1. john hare says:

    Though they were careful not to say so, they made a fair case for canceling the Griffenshaft. It’s hard to believe they could go as far as they suggest and not be considering the manned option. I lost count of the number of times they stressed the existing vehicles argument.

  2. Rand Simberg says:

    …accusations that I sounded like an “engineering undergrad with lots of imagination but very little experience with real world considerations?” were probably more accurate than I’d like to admit now.

    Oh, who could possibly be so cruel as to say such a thing? Especially on Usenet? ;-)

  3. Jonathan Goff says:

    Rand,
    Oh, who could possibly be so cruel as to say such a thing? Especially on Usenet? ;-)

    I believe it was Herb Schaltegger. And then you had some sort of backhanded compliment along the lines of “You should’ve seen him when he really was just an engineering undergrad with lots of imagination but very little real world experience”. Or something like that.

    ~Jon

  4. Rand Simberg says:

    That sounds about right. Anyway, I linked this post–it’s good stuff, after my own heart.

  5. kert says:

    Hm, could it launch X-38 ?

  6. Jonathan Goff says:

    Hm, could it launch X-38 ?

    Probably. But how far did X-38 really get before it was cancelled?

    ~Jon

  7. ian says:

    Nice post by guest blogger Jon Goff :)

  8. Jonathan Goff says:

    Nice post by guest blogger Jon Goff :)

    All I can say is :-P

  9. Tom D says:

    A similar adapter was developed to allow very big satellites developed for the shuttle to be launched by the Titan 4. It didn’t have docking rings. It had the fittings necessary to mimic the shuttle’s payload bay. I wonder if this new adapter is related to the old one?

    http://adsabs.harvard.edu/abs/1990aeme.symp…89E
    http://www.planet4589.org/space/jsr/back/news.267

    The X-38 got pretty far along into prototype development, but not to a final design. It’s almost certainly not worth resurrecting.

  10. pat bahn says:

    pity

    i know of a tug

  11. Jonathan Goff says:

    Pat,
    Could you elaborate?

    ~Jon

  12. kert says:

    >>But how far did X-38 really get before it was cancelled?
    There were couple recent threads about this over at nasaspaceflight forums.
    http://forum.nasaspaceflight.com/index.php?topic=14362.0
    http://forum.nasaspaceflight.com/index.php?topic=12379.msg327782#msg327782

    Doesnt seem like out of realm of possibility to me.

  13. Eric Collins says:

    Wiki-pedia says that the X-38 V-201 (the orbital prototype), was 80% completed when the program was canceled. This prototype was to be carried into orbit by the space shuttle. Perhaps it could still fly in one of these modified PBF’s.

    I’ve been thinking recently about the life boat capability that the X-38 was supposed to provide for the ISS. Would it be possible for the SpaceX Dragon capsule to fulfill this role once they have successfully demonstrated its down mass capability (i.e. safe and controlled reentry) for the COTS program? Correct me if I’m wrong, but after the Dragon delivers its load of cargo to the station, it’s going to remain attached until the next one arrives, sort of like Progress does now. How hard would it be to install some bench seats inside of the Dragon while it’s sitting there empty and parked at the station anyway? In the event of an emergency, the entire crew can be evacuated in a single Dragon.

    Even if it takes a while to get the Falcon 9 / Dragon approved for crew launches, there’s no reason why it can’t start serving as a lifeboat once it’s reentry capabilities have been demonstrated. If NASA is persuaded to keep flying the Shuttle to the Station twice a year beyond 2010, then we can avoid “the Gap” altogether, and as Jon mentions, think of all of the complete (or nearly complete) ISS modules which would get the chance to fly.

    I’ve been getting the sense lately that NASA might have made some less than optimal design choices for the ESAS architecture based partly on the requirements that the Ares I / Orion would need to be developed as soon as possible to keep our astronauts flying on American vehicles. If the Dragon / Shuttle combination can be used to gracefully bridge “the Gap”, then perhaps some other options in the Constellation trade space will open up.

  14. Jonathan Goff says:

    Eric,
    Dragon could potentially provide crew return capabilities before it can provide crew launch capabilities. But I’d rather be able to get rid of the Shuttle. Spending 4-8 COTS programs worth every year just for 2-4 flights seems like a bloody waste. And if you’re flying the shuttle, the demand for COTS services will be substantially lower, thus making it that much harder for those companies to close their cases…While theoretically, if there was a law that required the shuttle to be retired as soon as there was an alternative, non-Russian way of getting people to the station, I might be ok with it being extended a little, temporary solutions have a way of becoming…not-so-temporary when push comes to shove.

    ~Jon

  15. Pingback: Selenian Boondocks » Blog Archive » Random Thoughts: CAM in a Can?

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