Essay: No mere rock: Issues in cost of orbital spaceflight
Blue Origin, the private spaceflight company founded by amazon dot com's founder, aims to make orbital spaceflight economical. I'm not confident he, or anyone, is ever going to achieve that aim. But, I do have some thoughts on how it might be achieved:
Leonardo Da Vinci envisioned human flight.
But, Da Vinci didn’t know about space. Nevertheless, he knew about Alexander the Great.
Alexander the Great was the man who understood the cost-effective means of conquering worlds: ‘travelling light’. That is, he sought to understand the ‘mundane’, down-to-Earth things of domain-specific systems, to adapt himself to them, to master them, and to fully own each of them. This is how he penetrated far beyond the place of his origin. This is how he became the first mere man to truly ‘fly above his world’.
Do you recall the scene in the original Star Wars movie showing the Millenium Falcon escaping Mos Eisley space port? Or, the scenes showing Luke Skywalker’s magically floating Landspeeder? Such fantasies of technology are not faithful to what we know, only to what we desire. They’re just magic carpets we’ve repackage to give ourselves ‘airs’ about the ultimate technology: spaceflight.
(re: AIRS: Aerometric Information Retrieval System).
The unfortunate real-world version of the Millenium Falcon, namely the ground-to-orbit rocketry system, is an attempt to keep it as simple as Newton envisioned it. But, Newton was very pre-aviation.
Nevertheless, Newton was by no means pre-balloon. Nor was Da Vinci. Nor, really, was Alexander. Nor, for that matter, were the Nazca ‘Indians’ who made those geoglyphs out in the American deserts.
But, with the advent of the airplane, the balloon took a backseat: the airplane fulfilled Da Vinci’s vision. Then, with the advent of the rocket, the airplane took a backseat: the rocket promised to fulfill Newton’s vision: Space, the final frontier to Other Worlds.
But, there is a catch to that Final Frontier.
The title of the TV sitcom, 3rd Rock from the Sun, is telling of the failure to fully distinguish between the desire for mastery of space and the need for ‘mundane’ knowledge of transport systems. We don’t live on a zero-atmosphere chunk of rock. In fact, the atmosphere is much more an advantage in terms of costs of travel on and above the globe than it is an obstacle to such travel.
Of course, a lack of atmosphere would, in some ways, ‘assist’ space flight: you’re already in space, so the only obstacle is the challenge of achieving escape velocity and orbital flight; There is no atmosphere to drag you down, so no need to master aerodynamics. But, if you’re actually going to be living on that world...
A lack of atmosphere is massively prohibitive. It not only increases the cost of non-orbital above-ground travel-steering-breaking to that of rocketry, it makes on-ground travel massively costly in terms of in-vehicle life support systems. And, to further complicate matters, not only could you not hear the sirens of emergency vehicles, but, without a spacesuit, you couldn’t get out of your car just anywhere, much less when your tire goes flat. Gravity still works, but you’re caught outside in a vacuum: you can’t live there.
And, do you know how much a spacesuit costs just to operate, much less to rent or buy? Your very life would depend on not getting too cheap a one just to ride a bike. The Wright Brothers would understand: without an outdoors atmosphere, the cost of living would make renting a New York Luxury Apartment on the real world much-more-than-suspiciously cheap on a no-atmosphere world.
High atmosphere is Earth’s front door to space. The question is whether we can build much of anything just inside that threshold. The back kitchen may be hot, but at least it’s livable. Not so with standing at the threshold to space with the door wide open.
Think about how we’ve made the Terra-bound transportation system so cost-effective: it’s comprised of the various land and ocean transport subsystems. Now imagine how inefficient it would be if we relied on only one or, at most, two such systems. The reason we’ve made the various sub-systems is because each is a Cost-Effect Specialist System. There is no way around this, short of an obscenely cheap form of locomotive force allowing the extreme inefficiencies of a mono-system to be ignored.
So, what's the most cost-effective means of putting mass into high atmosphere? I'm ignorant, but I think it's the balloon.
Again, the current huge costs in sending mass to orbit is due to a failure to fully distinguish between the intensity of our desire to achieve a science-fictional mastery of orbital/space flight and the ‘mundane’ need to understand technologies best suited for each stage of the trip to orbit.
So, think about a balloon-based high atmosphere station (High Atmosphere Balloon-based Station/HABBS).
Add Rutan's idea of a Ferry plane (for the orbital rocket-propelled craft), or, in my ignorant ideal, a Ferry Zeppelin.
Add, also, a Ground-to-HABBS Primary Supply System.
That makes four primary Cost-Effect Specialist Systems: 1) orbital craft, 2) ground-to-high-atmosphere ferry craft, 3) high-atmosphere refueling-and-maintenance station (HABBS), and 4) primary ground-to-HABBS supply system.
The Ferry craft, (2), does double-duty: One, it gets the orbital craft to high-atmosphere. Two, given its airplane design, it prevents the rocket launch of the orbital craft from effecting the High Atmosphere Balloon-based Station (HABBS). The Ferry craft has enough fuel to get from ground-to-HABBS and back while loaded with the orbital craft. But, the HABBS is basically a high-atmosphere version of the ground stations. This allows, first, a docking station for the ferry.
But, secondly, and more importantly, it allows the orbital craft to be made big enough to have on-board fuel sufficient both for achieving orbital velocity and for the above-atmosphere back-burn necessary to rejoin with the ferry. This second advantage allows the orbital craft to entirely avoid the otherwise-indispensable heat shielding needed for passive re-entry. Any heat shielding used would then be a mere compliment to the back-burn.
Moreover, given the HABBS as a high-altitude base for fuel, the orbital craft can be built so big that it can take on enough fuel to allow a much slower acceleration to orbital velocity, thus retaining its structure integrity much longer---perhaps much longer, even, than that of atmospheric craft.
Today, given the common man's near-zero-employment in above-Terra transportation technology, we have a near-exclusion of that employment to highly trained specialists. Such exclusion was never the case for on-Terra transportation. So, the most the common man today has ready access to working with above-Terra transport technology is little beyond the leaf-on-a-string we call a kite: hobby aircraft and balloons. Even the advent of the automobile had more ready potential of advancement. But, the reason for this exclusion is fairly simple: there is nothing naturally habitable about either space or our planetary neighbors. Otherwise, we would have mastered economical space flight by now.
Nevertheless, if you want economical spaceflight, you need more than ambition, money, and a love of perfectly fantastical versions of science fiction.
…You need a fourth element: a ‘down-to-Earth’ knowledge of specialist transport systems.
Specifically, you need to master, and to fully own, the threshold to space. The foyer cannot be left to the weather alone, even if you do leave the front door wide open.