I’ve been wanting to get this specific number — 1.5 g-forces
This number is the acceleration that would be felt by crew of the Dreamchaser spacecraft on reentry, and I have it from a primary source in this video. It’s still not 100% clear that this is a maximum acceleration, or some other metric.
This is important, for reasons that I think are numerous and not entirely clear to us from our current vantage point in history. Above all, I believe that the Dreamchaser is the perfect example of a “reasonable” design. It’s not too crazy in any direction. It’s a fairly logical extrapolation from Shuttle-era technologies, but in a way that eliminates a lot of the cruft and confusion of purpose that plagued that era of spaceflight.
Short End of the Hype Stick
Yet, I feel like there’s a certain failure to generate excitement by space fanboys. It’s just missing a hook to captivate our imaginations in the sense of the public conversation. However, I feel like that’s a mistake… a certain kind of failure of imagination.
Bigelow inflatable habitats have a very solid hook — they do something new. Now their design is in use in actual space. SpaceX has been doing something so obviously new and groundbreaking that they’re dominating the news cycle, which is further fueled by rock star status of their CEO.
By comparison, the Dreamchaser is conservative and modest. It feels like their thing has been done before. But… not really. In my book, it hasn’t been done. This is new, and it should feel new. Part of it might just be that the design has lacked advocates to tell its story.
The Difference is a Baby Elephant
For hand-picked fighter pilot kind of astronauts, maybe an extra baby elephant on their chest isn’t so much of a big deal. But that was the old, and New Space demands rethinking everything. we need to talk seriously about normal people making trips into orbit.
Launch has some severe g-forces, but it’s not that bad in comparison to re-entry. Plus, it’s a straightforward cost/comfort tradeoff with launch. You can cap the max acceleration at a lower value and simply bring up less payload in the trip. So, if launch costs went down dramatically, and if we’re going to be sending people into space for pleasure, the re-entry is the real experience buster, and possibly bone-breaker.
The Space Shuttle wasn’t the same, as it would reach 4g, or around that territory in reentry. There are a couple of big picture reasons for this. But right now we have 2 other companies competing with their own capsule designs, all of which would result in dramatically higher g-forces. The Dreamchaser is insanely gentle by comparision.
Safety is Make or Break
Of course, comfort only matters if you don’t die. The Shuttle had a really bad answer to launch abort scenarios. Capsule designs have really good answers to launch abort scenarios (even if they are straight out of the era of Apollo). I think Dreamchaser could have a good answer to this, although I see how there’s a much steeper R&D hill for them to climb.
All Kinds of Synergy with Other Tech
The era of first-stage reusability is upon us. This is amazing, and it will fundamentally affect all space activities. But beyond the first stage, there needs to be a technology separation for cargo and crew. Mixing the two together is simply a stupid decision.
What we need is a launch system that couples a reusable (and reconfigurable) first stage with a Dreamchaser vehicle. We also need winged planes like this to be dedicated ferries for moving humans from ground to orbit and back again, and no where else. This is the niche that the Shuttle should have been going for, but the political tides caused it to float away from that sensible configuration.
If you want space hotels, you need something like the Dreamchaser. I would go so far as to say that “ordinary” people may just not be cut out for capsule travel. Every component of the equation for reasonable g-force space travel can be worked out on their own, but reentry can’t without the technology of winged spacecraft.