SSI Presentation and Panel Discussion

As mentioned previously, I was on a panel discussing a roadmap for near-term cislunar transportation development at the SSI conference this last weekend in Silicon Valley.  For the panel, Dallas Bienhoff and I put together a presentation about some important in-space transportation technologies, with a focus on a depot-centric architecture (Here’s a link for those of you who weren’t able to make it). We’re in the process of co-authoring a paper that goes into more detail about what we covered in the presentation.

The short version is that there are a credible set of near-term transportation technologies that could enable a reusable cislunar transportation system. Specifically, the technologies revolve around handling/storing/transferring cryogens on orbit, aerobraking/capture, robust reusable and flexible MR cryo-propellant rocket engines, improved autonomous rendezvous and docking, and ISRU related technologies like low-g electrolysis and cryogenic liquification. Dallas illustrated an example of how those technologies could enable a reusable cislunar transportation system, using propellant tankers, tugs, depots, reusable in-space habitats, and reusable landers. He also showed how these technologies allow us to take advantage of lunar ISRU propellants, that are now looking more and more feasible.

The cool thing is that an approach like this can be made fairly open, allowing for an actual transportation system and not a point-design architecture. For the presentation and paper, we’re trying to keep things kind of general. For instance, there are several approaches to handling cryo propellants on-orbit, including both work that Dallas’ group at Boeing has been looking into, as well as the settled cryo-handling work done by Bernard Kutter and Frank Zegler’s team at ULA. For aerobraking/capture you have both traditional heat-shield approaches, ballutes, as well as exotic ideas such as MHD aerobraking. Anyhow, the possibilities are exciting, and even if you only reuse the hardware a handful of times, such an architecture starts moving space transportation in a direction that is capable of continuous improvement in affordability.

So, what does all of this have to do with Altius? I don’t think any of us are delusional enough to think that a 2-person company is somehow going to beat ULA or Boeing to building a depot. However, several of the technology focus areas that we at Altius are looking into can be enablers. Our boom-rendezvous concept has a lot of potential for lowering the difficulty of some parts of autonomous rendezvous and docking as well as depot operations, and even pre-depot cryo-fluid management experiments. The reusable TPS concepts we’re investigating could play a role in aerobraking/capture development. And our interest in providing aerospace rapid-prototyping services could also allow us to work with larger companies to lower the cost of critical flight demonstrations.

Now that’s all still pretty ambitious, but I hope it gives another glimpse into how we see our place in the larger aerospace community.

12 Responses
  1. Someone asked me the other week what I thought of Mars Direct.. after giving my standard answer – that it’s a promising concept that was revolutionary at the time for incorporating ISRU but it hasn’t been developed in nearly 2 decades – they said that they thought it was good because there was no rendezvous involved. I’ve heard other people, even Shuttle flight controllers say avoiding rendezvous and docking is a paramount concern.. as I know you have too Jon – which I’m sure motivates your interest in the boom rendezvous concept. This irrational fear of actually doing things in open space is rife. In a way, it explains why tethers have not reached their potential.. when it comes to space travel, we loathe to actually go outside. Spacewalks are the necessary evil of long term habitation, never to be included in a mission architecture, so we build complicated all-in-one docking mechanisms.

  2. Tom D

    As far as spacewalks go, I personally think that it’s not so much “irrational fear” that deters planners as it is the big hassles involved with doing it with current technology and methodology (I have worked in this field). Eventually better, more robust spacesuits will change this, but better docking methods shouldn’t be sneered at. Rendezvous and docking in microgravity really is a bit tricky.

    I liked the presentation, but it was somewhat depressing to notice that it could almost have been lifted out of the 1986 report of the National Commission On Space (NCOS):

    To be sure NCOS proposed a lot more. The Boeing presentation was rather more to the point.

    1. admin

      Yeah, a lot of the technologies are ones people have known for 20-30 years were ones we needed to master. The fact that nobody has done them yet doesn’t mean they’re the wrong technologies, just that people either weren’t trying very hard, or were taking the wrong approach, or the general state of other technologies needed to mature a bit more before you could try them.

      Also, I agree with you about EVAs with existing technology. I think we can probably improve on things quite a bit in the future, but I think that tools that enable better robotics, better tugs, easier rendezvous/docking, easier propellant transfer etc should also be high on the list. Basically, if I achieve nothing else with Altius than finding a way to reduce the hassle of rendezvous and docking to the point where nobody could with a straight face use that as an argument against affordable, depot-centric space transportation, I’d be a happy man.


  3. Gary Snyder

    A Mars Surface Rendezvous mission like the poorly named Mars Direct has a very difficult rendezvous. Two Gemini spacecraft could meet in orbit, but never land within walking distance of each other.
    -Just a thought.

  4. Blackjax

    Speaking of improving EVA technology, I’ve been wondering if we aren’t going in the wrong direction with suits and attempts to solve the ‘glove’ problem. Perhaps we should have suits that are

    – spherical or oval (but still as compact and close to man sized as possible)
    – have a small ‘airlock’ of some kind on them for faster entry and exit
    – pressurized at the same level as the station

    I seem to recall (although I am not an expert so I could be wrong) is that one of the reasons that suits aren’t pressurized like this is that it would make the gloves even more difficult & tiring to use. Why not simply ditch the gloves altogether?

    Something like the following might provide a COTS solution for a durable, user friendly, and relatively (vs. traditional aerospace) inexpensive way to do fairly fine grained manipulation of objects:

    With the ability to mount various cameras on the suit and arm(s) you might even gain visibility and dexterity vs direct manipulation via traditional gloves.

  5. Blackjax, many people assume that the way NASA does it is the only way, and judge everything based on that experience. But just take a gander over at Russian spacesuits sometime. They don’t need help to get in or out of their suits and they don’t have to camp out for hours in the airlock before they can go on a spacewalk. Their suit tech is clearly superior, but NASA continues to use their own.

  6. Gary, everything in space is difficult.. especially if you limit yourself to what has been done already.. doubly so if you limit yourself to what has been done ~40 years ago.

    I really don’t think it’s unreasonable to suggest crew vehicles carry enough fuel to get to a fuel station.. even with significant margins for that the advantages of having propellant waiting on the other end is great.

  7. Paul

    Blackjax, if you are gripping with robo-arms, seeing with cameras, why have the human in the “suit” at all? Tele-op from inside the ship/station. Smaller, safer, lower power requirements, no life-support. (Although I like the visual of your sphere suit 2001 pod-ship.)

  8. Blackjax

    Paul, you make a good point, perhaps we do need to ask the question of what has historically driven the need for people in suits doing work, and whether there is a practical COTS approach now which might get comparable results without the people outside.

  9. Paul

    Of course, you could have just as easily said, “Build an EVA-capable space suit… discover how incredibly hard it is.” Coz I’d be floundering just as much. But the issue is which is harder (or costlier, or riskier). At the moment, history favours the gloved hand. But I think technology has reached the cross-over point where tele-op is a better option for the bulk of EVA work.

    (That said, I thought new “smart” materials would revolutionise spacesuits. I even sent in a lame NASA Challenge suggestion to that effect, back when they were doing that…)