Space Progress Dyna-Soar Project—Maimed Space Glider

Press, Volume C, Issue 29616, 12 September 1961, Page 19

Space Progress Dyna-Soar Project —Maimed Space Glider

(Specially written Jot “The Press" by COLIN S. L. KEAY, Physics Department. University of Canterbury}

In less than two years a sleek, delta-winged aircraft, destined for space operations, will begin its first flight tests, according to LieutenantGeneral R. C. Wilson. United States Air Force DeputyChief of Staff for Development. The Dyna-Soar Project, as it is called, will bridge the present gap between manned satellite capsules and conventional piloted aircraft. The Dyna-Soar vehicle will be capable of orbiting the earth before descending through the atmosphere and landing like any ordinary jet aircraft on whatever airstrip the pilot may choose. Dyna-Soar derives it pre-historic-sounding name from two words: “dynamic” and “soaring,” both referring to its peculiar mode of flight. While in orbit, it will stay up for the same reason as any other satellite—the necessary “lift” being a dynamic result of its orbital velocity of more than 17.0C0 miles an hour. At low speeds it will fly purely and simply as a glider, obtaining its lift by soaring aerodynamically. At intermediate speeds. DynaSoar will use a combination of both methods, being the first vehicle to exploit fully this new flight regime. Like A Paper Dart Superficially, Dyna-Soar will look very much like a schoolboy’s paper dart, but appearances can be deceptive, since Dyna-Soar will be more complex than any aircraft yet designed. This is not surprising when its performance is considered. Dyna-Soar will be launched as the third stage of a giant booster rocket and will need to withstand the usual severe vibrations, high accelerations, and buffetting air loads as it climbs up out of the atmosphere. Later, in order to return safely to earth it has to face the scorching temperatures of re-entry into the atmosphere. As it glides through the tenuous reaches of the upper atmosphere its leading edges will glow brightly from the heat generated by air friction. An interesting result of these extreme conditions is the decision to use wire, brush skids instead of con-

ventional landing gear. The searing re-entry temperatures rule out the use of wheels, lubricated bearings and braking mechanisms: the wire brushs will provide all the support and braking required. Crew Protection During the flight the crew will be protected from the heat by a liquid hydrogen cooling system. After acting as a refrigerant the hydrogen, combined with oxygen, will provide power for the host of equipment carried on board. Dyna-Soar. incidentally, has required the most exhaustive wind-tunnel testing programme in the history of flight. Every conceivable configuration of the glider and its booster must be tested at various speeds. Even gentle breezes to simulate off-shore winds at Cape Canaveral are directed at models of the glider-booster combination to determine how it will react while standing on the launching pad. The first flight tests of Dyna-Soar will be made from under the wing of a B-52 jet bomber, exactly as the present X-15 rocket plane is launched. Afterwards will be unmanned and. later, manned suborbital flights. These will be conducted down-range from Cape Canaveral, using a modified Titan II 1.C.8.M. as booster rocket. The Titan IT, now in the final stages of development by the Martin Company, will use storable, non-cryogenic propellants—that is, fuels and oxidisers which do not require to be maintained at extremely low temperatures to prevent their boiling and consequent rapid evaporation. The storable propellants used in the two stages of Titan II are aerosene fuel (a hydrasine mixture) and nitrogen tetroxide oxidiser. The fuel and oxidiser are hypergolic. which means that they burn spontaneously when they come in contact with each other. When Dyna-Soar has shown its paces at near orbital speeds it will be sent on space flights to become a true earth satellite. Larger booster rockets will be needed for these missions and it seems likely that the giant Saturn will be chosen to hurl Dyna-Soar into orbit. Dyna-Soar’s Potentialities The inherent usefulness of Dyna-Soar ensures. that before very long it will be one of America's key space vehicles. It will answer many of the problems involved in maintaining manned space stations in orbit by functioning as a space ferry between the stations and earth. Small scientific payloads could be retrieved by Dyna-Soar if. as often happens, their own rockets fail to return them to earth when commanded to do so.

Scientists studying the properties of the upper atmosphere are eagerly devising experiments to be performed by Dyna-Soar during its long glides at very high altitudes. Dyna-Soar will be the- first vehicle to operate for long periods at altitudes too high for aircraft and balloons yet too low for ordinary earth satellites. It is not too much to hope that Dyna-Soar will help to reveal some of the final secrets of the ionosphere which have defied earth-bound investigators for decades. No wonder, then, that the United States Air Force, according to LieutenantGeneral Wilson, considers Dyna-Soar the most important research and development project it has. Readers’ Questions Questions should be sent to the address at the top of this column or to the Space Progress Column, C/o “The Press.” Would It Be Unusual For An Artificial Satellite To Cross The Sky In An East To West Direction? S.H., Shirley. Unusual, yes. but by no means impossible. The answer lies in the distinction between direct orbits, in which a satellite revolves around the earth in the same direction as the earth’s spin, and retrograde orbits in which a satellite moves in the opposite direction. Polar orbits, in which satellites pass over the polar regions of the earth, lie between these extremes. Because close satellites speed along in their orbits much faster than the rotation of the earth beneath they appear to rise in the west if they are in direct orbits and in the east if they are in retrograde orbits. Until now no satellites have been launched into retrograde orbits with the exception of Samos II whose polar orbit is only just retrograde. Direct orbits are easier to achieve than retrograde orbits (for the same reason that it is easier to board a merry-go-round by running in the same direction!) and for almost all purposes they are just as good. Do You Believe In The Possibility Of Life, At A Higher Level Of Intelligence Than Ours, Existing Elsewhere In Our Galaxy? G.R.N., Sydenham. I do. I feel that all of the available evidence, slender though it may be, leads to the conclusion that our existence is not unique. There doesn't seem to be any valid reason why we should be the only rational beings in the universe and indeed one of the great benefits of modern science has been to show the fallacy of our old anthropocentric concepts of the universe. Whether we ever establish contact with higher orders of life or not is anybody’s guess. The consequences of such a contact are almost unimaginable.