NASA recently announced its “down-select” of the two space contractors who will receive additional federal money to further develop a space vehicle to transport human crew to and from the International Space Station (ISS). Perhaps not too surprisingly, they chose the two companies whose vehicle concepts most closely resemble NASA’s own Orion capsule: the Boeing CST-100 and SpaceX’s Dragon 2. A truly innovative design, the Dream Chaser lifting body of Sierra Nevada Corporation, was not selected. The ramifications of the selection illustrate some important facts about the current state of our national space program and the future of true commercial human spaceflight.
Conventional wisdom holds that we’re on the cusp of a new age of human spaceflight – a revolutionary transformation whereby space is opened to many users, rather than being available to only a few. It is proclaimed that with the development of commercial human transport to LEO and the accompanying advent of low cost launch services, the general public will soon be able to voyage into space. We are told that this follows an expected, natural progression, as private sector facilities and services always follow on the exploratory trail blazed by government or large, government-chartered efforts. NASA says that New Space companies are prepared to rush in where government has already trod. With this handoff, Mars is now the official exploratory horizon of our civil space efforts and all work shall be directed to that end, including the missions within the critical strategic arena of cislunar space, now deemed useful merely as a testing ground for “deep space vehicles” being designed to take us to Mars.
So, where are we in this “transformational” scenario? Let’s begin with a reality check on our current situation, as well as the likely prospects for the coming decades or so, a.k.a. “the near future.” Looking around, we see that the advent of commercial human spaceflight has yet to occur and, despite the hype, is not likely to occur for some time. Commercial operations have markets driven by needs and (to a much lesser extent) desires. At the moment, there is very little commercial demand for human flights to LEO. The belief of many New Space advocates – that there is an unrealized demand in space tourism or simply joy-riding into orbit – is not tenable. It’s been ten years since Space Ship One captured the Ansari X-Prize and we’ve yet to see a single, regularly scheduled commercial spaceflight company carrying paying passengers. True enough, seven people paid Russia for trips to space on the Soyuz, but these occurred on an ad hoc, non-scheduled basis and were more a procession of stunts than the purchases of a commercial service from a provider.
A notable effort to establish human spaceflight commerce in LEO is being undertaken by Bigelow Aerospace, with the aim of providing orbital facilities than can be leased out for whatever purpose a customer has in mind. Many hold the mistaken impression that Bigelow wants to build orbital hotels (probably because that’s how he made his fortune on Earth). However, his intention is to provide pressurized, human-qualified facilities in orbit without specifying how such facilities should be used. In technical terms, Bigelow’s company has made significant progress – they have successfully fabricated, launched into orbit and operated two prototype inflatable space structures. Yet no commercial flight to a Bigelow space station has occurred. The current focus of the company is to provide and operate an inflatable module to be attached to the ISS.
People should ask what’s holding up commercial human space efforts – that flood of commercial enterprises they’re being told are just itching to follow and fill the void left by NASA. One answer is that despite their best efforts to encourage its development, Bigelow Aerospace has been frustrated by the fact that no simple, inexpensive transportation system to and from LEO has emerged. In 2004, Bigelow offered a $50 million prize to find a provider who would develop such a system; that prize offer expired five years after its announcement without a single attempt to win it. So a commercial orbital facility remains a dream. To survive organizationally, Bigelow Aerospace has fallen back on the traditional venue of “Old Space” – being a contractor for NASA.
What do these facts say about possible markets for commercial human orbital flight? To me it says that despite slick New Space marketing, no robust demand for commercial human spaceflight yet exists. Both the Boeing CST-100 and the SpaceX Dragon 2 are prototype contractor space vehicles; they are specifically designed to service the International Space Station – and are funded by NASA. In the broadest sense, they simply represent space business as usual, albeit with a slightly modified contracting instrument.
And what of our national space program? Do these new developments (or more precisely, the lack of new development) in “commercial” spaceflight pick up where NASA left off? It’s hard to believe that commercial entities are back-filling capability in old areas (like cislunar space) for NASA when no capability is yet evident. However, this remains the agency’s attitude as they proclaim – “We’re on the critical path for Mars!” So, let’s examine that proposition.
The Orion spacecraft and SLS launch vehicle are designed for “deep space” exploration, i.e., human flight beyond LEO. When discussing these vehicles, NASA implies they are the pieces needed for future human Mars exploration. However, while they may be necessary pieces (that is debatable), they are not sufficient for a human mission to Mars. The SLS core stage can put about 70 metric tons into low earth orbit; a yet-to-be developed advanced version could ultimately put 120 tons into orbit. Yet, a human Mars mission powered with chemical-propellant requires at least 500-700 metric tons in LEO (perhaps more, depending upon the mission architecture and the opportunity provided by planetary alignment). Thus, at least 5 to 10 SLS vehicles are needed simply to get the required total mass into orbit (logistical problems of subdividing and packaging, preserving cryogenic propellant from boil-off, and assembly in space are left as an exercise for the student).
Next, envision the Orion spacecraft’s habitable volume, a space similar to a large walk-in closet – about 9 cubic meters (300 cubic feet, or a closet 5 by 10 by 6 feet in dimension). This volume must accommodate the 4-5 astronauts living in the spacecraft for almost three years. Clearly, Orion is not a suitable habitat for long-term living in space; it is simply an Earth-return vehicle designed to re-enter Earth’s atmosphere at escape velocity (about 11 km/sec). Its limitations recall its origin – the Orion vehicle is a spacecraft designed for missions to and within cislunar space, i.e., trans-LEO missions of short duration (up to a month), with a high-velocity, aerothermal entry at the end. Thus, some type of habitation module (probably of ISS derivation) will be needed. I have not addressed the (currently unresolved) problem of entry, descent and landing on the martian surface (these problems are also left as an exercise for the student).
In short, we are still a considerable distance from a human Mars mission, an event so far in the future that I contend it literally makes no sense to discuss at this point how these pieces will be used. The current penchant of NASA to discuss hypothetical missions, like asteroid retrieval, is a de facto recognition of this situation. NASA – now “on its way to the stars” – has created a void in cislunar space. This condition must not be confused with a vacuum about to be filled with commerce. It is instead a playing field of unfulfilled promise, now abandoned, for which no commercial market of any potency or necessity yet exists.
The down-select of the two commercial vehicles for crew transport to ISS continues the lacuna in which we currently find ourselves. It remains neither a program with a sustainable destination nor with the means to get anywhere, yet one that insistently and repeatedly proclaims a firm possession of both. Once NASA had a vision that would demonstrate the economic potential of cislunar space but they retreated before it could happen. Regrettably, we find ourselves stranded in this relentless fog of space “transition,” arguing over rockets with no place to go, while other nations clearly see the potential that awaits in cislunar space and are firmly fixed on obtaining it.