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.