Latex and Laughing Gas
The biggest block to commercial spaceflight – to all spaceflight, really, commercial and government-sponsored – is the fact that we live at the bottom of a deep gravity well. A tremendous amount of power has to be released and harnessed to push a rocket payload up that steep, steep hill, and that power, traditionally provided in the form of liquid oxygen (an oxidizer) and a hydrogen compound of some kind (the fuel), is expensive. But it is also relatively safe. The rocket won’t explode – usually – unless the oxidizer and the fuel mix very quickly. You can also shut off the thrust of the rocket by stopping these gasses from mixing within the combustion chamber, something you cannot do with a solid fuel booster, such as the ones that flank the big tank on the Space Shuttle.
Various other propulsion methods have been tried, using a variety of fuels, oxidizers, and elegant technologies. Most have been rejected out of hand by NASA and ESA as too dangerous and untested. Let’s face it: government agencies are by their nature conservative, and unless there is a tremendous amount of pressure from above, most won’t take the time to develop new technologies unless they absolutely have to – say, when a shuttle blows up.
Enter the Ansari X Prize, the innovative private venture that locked dozens of teams from around the world in competition to get a three seat spaceplane launched into the upper reaches of our atmosphere, return safely, and repeat the feat with the same plane within two weeks. Space Ship One did this successfully, just under deadline, and walked away with the $10 million prize (of course they had spent $20 million to do it, but that’s life in the aerospace industry!) While this seems a bit pointless – NASA has been doing this kind of thing as a matter of course since the 1950s – the fallout from the contest may extend well beyond the glory for the winning team. The reason is the innovative hybrid engine that Space Ship One uses.
Quite simply, it is made up of two parts: the fuel is a solid form of latex rubber, the same stuff used to make tires. The oxydizer is a gas – laughing gas, to be precise, known in high-school chemistry labs as nitrous oxide. The gas is pumped from a spherical tank into the combustion chamber, which is lined with latex. When a fire of sufficient heat is applied, the hydrocarbons in the rubber react explosively with the oxygen in the nitrous oxide and generates thrust – a lot of thrust. Thrust comparable to that generated by NASA’s best rockets. It even produces less atmospheric pollution.
Rubber is cheap, as is nitrous oxide. And that is the amazing thing about the hybrid engine: using this simple but brilliant technique could bring rocketry – and therefore spaceflight – to dozens of countries and hundreds of companies around the world.
Imagine a spaceship designed to take off on an airplane runway, orbit the globe, and land to refuel anywhere on the planet. The ships themselves would not have to be too much different than a modern pressurized airliner – that aspect of the technology is well proven. The holdup to commercial spaceflight boils down to two simple issues: thrust and political will.
For forty years now the US has had a virtual monopoly on the space industry in the West. While ESA (Europe’s version of NASA) and the Russians have been able to put a commercial payload in orbit, the lion’s share of the lucrative launch market has belonged to the US Government. For obvious reasons of security (a rocket that can deliver an orbital payload can also deliver a nuclear weapon) the space business was tightly controlled, and, therefore, stifled. Since September 11, 2001, however, there has been a subtle shift in the idea of ballistic missile technology. Since our greatest threats seem to come not from continent-wide, nuclear-armed evil empires, but from airplane-flying fanatical terrorists who prefer C4 explosives to Saturn 4 rockets, there has been a relaxation of the regulations regarding commercial space flight.
This has been coming for some time, of course. NASA is a horribly inefficient agency for launching rockets, bloated with bureaucracy and weighed down by politics. But the actual producers of the launch technology, the aerospace industry who contracts the work, has been quietly lobbying for an expansion of their market. On the other side of the Invisible Hand of the Marketplace, hundreds of businesses are seeing opportunities in Low Earth Orbit that can be had only if they can get their satellites up quickly. Such economic pressure forced a number of quiet changes in regulation and a law that has considerably widened the playing field. The current Administration has embraced this new openness, and in the wake of the publicity of the Ansari X Prize they have directed NASA to stage similar contests in order to drive technology.
It’s a wise use of taxpayer money, though some see it as frivolous. The prizes tend to be relatively small, in government funding terms, but enough to whet the appetite of both garage inventor and high tech start up alike. Instead of paying directly for research and development by handing out University grants or studying issues in-house, the idea of prizes for technological gains in space hardware allow the spur of competition to fuel development. The same problem may be solved by several different groups in several different ways, producing unimagined, serendipitous results.
Besides, contests are more fun than government-issued white papers. They draw more attention to the industry, and they engender interest in complex subjects by those who traditionally would never have thought about experimenting with rocketry science. They fuel the economy and give jobs to aerospace engineers who are looking for something to do now that Defense Department work has dried up, keeping them from finding jobs working for terrorists – or, worse yet, Boeing’s commercial competitor Airbus.
On the horizon are dozens of wildcat companies poised to jump at the chance to gain entry into this market, the growth of which would be called explosive if that term didn’t have such negative connotations. The next big step will be the development of privately owned, commercially viable means of reaching Low Earth Orbit, not just space. LEO is where all the good satellite spots are. It is also where the first wave of commercial, privately owned space stations will be. There are several companies that are seriously looking at the possibility of investing in a LEO Hotel, a kind of ultra-exclusive playground for the rich and bored. Estimated costs for such a project may be large – a couple of billion, easily – but that kind of capital isn’t as scarce as it used to be. The Information Technology boom of the 1980s and 1990s created so many millionaires, billionaires, and billion-dollar investment funds that finding a few hundred million for start-up cost should not be difficult.
And after that? The moon. Our closest neighbor is a huge pile of potential resources, not to mention its handy location at the bottom of a gravity well one sixth of ours. In order to reach the other planets with more than robots, we will need someplace cheap to get the resources from. The moon is perfect for that. From there, Mars and the Asteroids, and then the outer planets.
But what, you may ask, is the point of all this, besides space hotels and cell phone satellites? It’s not a stupid question. Potential investors ask that on a regular basis, and while some of the more high-profile players, like Richard Branson, will see benefits merely from their involvement with the industry, there is a lot at stake – and a lot of potential reward. Richard Branson apparently believes it is more than a publicity gimmick: he has paid a significant sum to license the SpaceShipOne propulsion technology, and has plans to start the first privately owned commercial Spaceline, Virgin Galactic. His vision extends beyond the three-minutes of weightlessness the Ansari Prize winner achieved, however. He believes that there will be upsurge of interest that will lead to the mass commercialization of Space. Space may just be bigger than computers and microchips when it is all said and done.
In the next fifty years it will be possible to build orbital factories, orbital greenhouses, and orbital power stations. The Space Tether experiment, a joint Italian-American venture, showed us back in 1996 that tremendous electrical current could be generated simply by dragging a 12 mile long copper tether through the Earths magnetosphere. The current generated was so strong, in fact, that it exceeded design parameters and melted the tether before the experiment was completed. Imagine a large satellite or space station, rotating rapidly in orbit with hundreds of copper tethers whipping through the magnetosphere. Assuming that engineering and design issues can be worked out, these “space windmills” have the potential for producing almost limitless electrical power.
The recent discoveries on Mars and the moons of Saturn have given us some tantalizing clues about just how interesting – and potentially exploitable – our solar system really is. These first baby steps by commercial enterprises are vital if the technology to reach those resources is going to be developed. The honest answer to the question is we don’t know exactly how there will be a profit, but the exploitation and colonization of space is inevitable, and the people who have “picks and shovels” to sell to those eventual prospectors will be making money for centuries to come.
Which brings us back to those twittering geeks for whom this is such a big deal. They are pumped because a vital piece to that puzzle has been found with the use of the hybrid engine that powered SpaceShipOne. Mojave Aerospace just made it possible to build big rockets with little capital. With the advances in materials technology that make ultralight, ultrastrong structural materials a certainty, and the improvements on operations that can be achieved by taking advantage of computerization (reducing the size of the launch crew from 150, NASA style, to 15), it is quite likely that in the next decade we will see commercial reusable orbital rockets fill our skies. By the year 2030 it is highly likely that the first commercial trips to the moon will be on the table. There is a convergence of politics, technology, and market forces that are driving this, and when such forces come together, magical things can happen.
