For those who would defame the development of spaceplanes, especially suborbital ones, it behooves me to insert a few words here in their defense. It may seem that such vehicles are nothing more than the space toys of rich entrepreneurs, a contrivance of those with too much time and too much money on their hands. In truth, suborbital spaceplanes represent the first toddling steps in the development of real spaceships. We are talking about vessels that, marshalling immense energies, will one day ply the interplanetary spaceways and sail the cosmic sea. We are not talking about modified ballistic missiles used to start spacecraft coasting toward their eventual targets. Suborbital spaceplanes really are baby spaceships, and as babies their abilities are understandably limited. It is entirely fitting that they would be helped into flight by the strong wing of a mothership.
And yet, the potential of the infant spaceplane is far greater than even the most powerful aircraft ever conceived. For airplanes, no matter how large, no matter how fast, no matter how far they may fly, can never leave Earth. It may well be that when the history of our era is written in the centuries to come, the ballistic method of entering space will be seen as a temporary aberration on the true path to the development of a sustainable space-based civilization. Only spaceplanes, with their potential to leave Earth as often as airplanes today leave the ground, can make a real difference in expanding our civilization into the far reaches of space.
You already know what makes a spaceplane - a plane that can fly in space. But what defines a suborbit? Just as a submarine is a boat that floats under water, a suborbit is a trajectory below an orbit, specifically one with a speed below that of orbital velocity. Suborbital space vehicles are either too low, too slow, or both. If they are too low, then they are still inside the sensible atmosphere, and aerodynamic drag will soon bring them down. If they are too slow, then gravity will play its part in dragging the spacecraft back to Earth, even in the absence of an atmosphere. Typical suborbits reach an apex, or apogee, outside the atmosphere, but with insufficient speed the orbit quickly succumbs to the will of gravity and arcs back toward the ground. Nevertheless, passengers and pilots of suborbital craft can still experience a few minutes of real spaceflight conditions. These include the weightlessness of suborbital free fall, the inkiness of a daytime sky, the curvature of Earth, and the silence of space. In the very near future, thousands of space tourists will experience the joys of suborbital spaceflight.
M.A. Bentley, Spaceplanes: From Airport to Spaceport, 69
doi:10.1007/978-0-387-76510-5_5, © Springer Science + Business Media, LLC 2009
Was this article helpful?
Discover What It Really Takes To Succeed And Profit From Your Online Business And Find Out The Little Discussed Facts That People Ignore - Or Choose To Ignore - That Makes You Either An Internet Entrepreneur Or Simply, Plain Broke! The Ultimate Factors That Decide Your Internet Business Journey And Success Has LITTLER To Do With The Techniques You Use Or The Programs You Join Than You Expected!