The second flight of the space shuttle Columbia is an important step in America's effort to add a new technological revolution to another revolution hardly begun. The revolution hardly begun came with the use of the giant rockets of the 20th century to send men and equipment for the first time into outer space. It was a revolution that had its seeds in the Chinese fire-arrows of the 13th century and evolved through hundreds of years as small rockets were used for weaponry, signaling, and fireworks displays. The lineage from these small beginnings to the immensely larger rockets now used in space-launch vehicles is unmistakable.
With the ability to send men and instruments into space came the additional ability to do many things not hitherto possible. Scientific instruments on artificial satellites and space probes gave the researcher a new perspective on the earth and the solar system, and this new perspective was probably the single greatest contribution so far of space techniques to modern science. With this new view the scientist was able to solve previously intractable problems of the earth's upper atmosphere and ionosphere (the electrically charged regions of the high atmosphere); to study the sun, our nearest star, in detail; and to send television cameras and other instruments to the moon and to planets hundreds of millions, even billions, of miles away.
New satellites of Jupiter and Saturn have been discovered, and Saturn's rings , still as mysterious as ever, have been shown to be extremely complicated, probably somehow linked to those primordial processes that gave birth to the sun and planets. Closer to home, one of the first discoveries of this emerging new era of space science was that our own planet is surrounded by a huge belt of very energetic electrically charged particles, a region now called the Van Allen Radiation Belt after its discoverer, James A. Van Allen. A complete surprise was the hundreds of celestial X-ray sources revealed by what is now referred to as rocket and satellite astronomy.
Meteorological satellites came into being with the space are, giving the weather forecaster a powerful new tool with which to display and investigate our atmosphere and its weather. The annual contribution of weather satellites to the saving of lives and property is tremendous. Communications satellites not only expanded the transcontinental and transoceanic capabilities of telephone and television links, but at the same time brought down the costs to the consumer. More generally, the ability to view the earth in various wavelengths has made it possible to survey and monitor earth's resources: agricultural patterns; forest stands; and the way man is using and developing land for cities , highways, reservoirs, and recreational facilities. Moreover, all of these combined with specialized military applications are important to the nation's security in today's world. Some analysts estimate that the economic returns from such applications of space techniques repay us for our entire investment in space.
There have also been the contributions of the Apollo program to manned exploration of our universe, so dramatically demonstrated in the landings of astronauts on the moon.
If such were the returns from our first ventures into space -- in the time span of only two decades -- why should we fell the need for another revolution in space?What, indeed, would that additional revolution be? The answer is straightforward.
The first space launch vehicles were what are now referred to as expendable,m that is, each vehicle was used just once, a new one was required for each new mission. This is expensive, especially when a vehicle and its launching cost millions, tens of millions, or even (in the case of manned vehicles) hundreds of millions of dollars apiece.
There is also the question of reliability and safety. Having to use a new rocket each time doesn't give the engineers and astronauts a chance to become familiar with the idiosyncrasies of the vehicle and doesn't give the vehicle the opportunity to improve in reliability with continuing usage. The world will probably never know the intensity of concern Apollo managers and operators experienced each time they had to send astronauts to the moon on entirely new equipment, using what had to be regarded as still-experimental hardware. In contrast, the operators of commercial airlines can enjoy a growing sense of confidence as their airplanes make trip after trip safely and their mechanics become more and more familiar with the planes.
This, then, is at the heart of the second revolution in space operations: to make those operations routine and, therefore, safer and less expensive.
The vehicle intended to accomplish this revolution is the space shuttle, of which Columbia is the first. When its development was first approved, plans called for the space shuttle to:
* Launch payloads into near-earth orbit, including massive objects weighing 10 tons or more.
* Recover payloads in orbit and return them to earth, sometimes to be refurbished, updated, and launched again.
* Carry experimenters or observers with a minimum of spaceflight training into orbit and back, so that only the pilot and copilot of the shuttle would have to be fully qualified astronauts.
* Remain in orbit for several days or weeks, in effect operating as a temporary space station.
* Carry into orbit and later return to earth an outfitted laboratory in which investigators could carry out scientific and technological experiments in the environment of space.
Today the initial objectives remain unchanged, although the expected costs -- estimated at $5 billion for development and $10 million per flight in 1971 -- have risen somewhat.
To many, the space shuttle appears as the keystone to the future of America in space.What will tht future be? Undoubtedly it will include a continuation of those researchers and applications that proved to be so profitable even with the expensive, expendable rocketS. More economical launchings will make it possible for the scientist to realize greater returns per dollar from his research. Likewise, shuttle economies should further reduce long-distance telephone bills, bring down the costs of television coverage of overseas events, and spur the communications expert to devise new and important uses of space communications.
The multiton capabilities of the space shuttle will make it possible to place on orbit enormous astronomical facilities, composed of a variety of telescopes and astronomical instruments. One cannot, of course, predict what might be discovered with such an orbiting observatory, but it is in the field of rocket and satellite astronomy that some scientists feel that space science might make revolutionary contributions to science in general.
Much of the light that comes to us from the depths of space is in the visible and ultraviolet wavelengths -- often referred to as the optical wavelengths. So one would expect an observatory in the sky to include a large, very precise optical telescope. With the precision with which it is now possible to shape the mirrors that are an integral part of such telescopes, and the fact that such an observatory would not have to contend with the distorting effects of earth's atmosphere, it should be possible to extend the astronomer's reach into space by a factor of 10, perhaps allowing him to see to the very edge of the universe.
But an optical telescope will not be enough to completely outfit the orbiting facility. Working at the ground, astronomers have already shown that of the billions of galaxies known to exist in addition to our own, there are many that emit enormous quantities of energy in radio wavelengths, and many that radiate prodigiously in the infrared. Then there are also those hundreds of celestial X-ray sources discovered early in the space program. Indeed, in the investigation of these fascinating objects in the sky, the astronomer has today what may be called a new field of "high-energy" astronomy, high energy meaning not only the enormous quantities of energy being radiated over a given period of time, but also high energy in the sense of involving energetic wavelengths like X-rays and gamma rays.
Thus, the orbiting astronomical facility of the future will have to include -- in addition to the optical telescope -- a radio antenna, an infrared collector, and X-ray and gamma-ray telescopes. The radio antenna might well be so huge that it would have to be constructed in orbit, for which purpose the space shuttle would be especially useful.
Not so esoteric as space astronomy, but perhaps more directly connected with living on earth, will be the laboratory to be carried into space by the space shuttle. In this laboratory -- originally called a "sortie module" by American engineers, and now called Spacelab by the Europeans who are building it as part of a cooperation with the US in the space shuttle project -- various scientific and technological experiments will be carried out. Moreover, the experiments and observations will be done by the investigators themselves, not by astronaut surrogates. With a prudent amount of astronaut preparation and training, these investigators will ride the shuttle as passengers -- the only crew members requiring years-long specialized training and hardening as full-fledged astronauts will be the pilot and copilot.
Some spacelab-type experiments have already been devised, such as the purification of materials and the production of perfect castings in the weightless environment of the space station, but it is safe to say that the most productive ideas will emerge when the laboratory is actually put into use.
In recent years the potential of near-earth space for military applications has appeared to be very great, even though in the early days of the space program those involved were inclined to think that the benefits to the military might be limited to such things as weather, communications, geodetic, and reconnaissance satellites (it is expected that the Pentagon will be a major user of the space shuttle).
Finally, there are few who think that manned exploration of outer space ended with the Apollo expeditions to the moon.Many are convinced that outposts of earth will be established on the moon someday, possibly in the form of scientific bases initially. One obvious possibility is a radio astronomy facility on the far side of the moon, where the radio antenna will be shielded by the moon itself from the hodgepodge of radio noise that emanates continuously from the earth. Also, there are those who look to manned visits to other planets such as Mars.
The prospect of these future uses and explorations of space brings to the fore a necessary adjunct to the space shuttle to complete its usefulness; namely , upper staging. The shuttle alone will be capable of placing payloads and crews only in low-altitude, near-earth orbit. That will take care of only a fraction of the missions that the country might want to fly. The shuttle cost structure will probably not accommodate the small payloads of the kind that normally go into sounding rockets, which are relatively small instrumented rockets fired vertically or nearly vertically to make measurements and observations in the high atmosphere. The shuttle will likely not be appropriate for small satellites that the smaller expendable launch vehicles have taken care of in the past. Nor will the shuttle handle the requirements of those spacecraft that have to go into special orbits or trajectories, such as the earth-synchronous orbits into which communications satellites are usually placed , that is, those orbits at 23,000 miles above the equator in which the orbiting satellite remains always above the same spot on the earth below. Likewise, the shuttle alone cannot launch objects into those deep space trajectories along which spacecraft must move to reach the moon or the planets.
Thus, while the shuttle may replace most of the expendable launch vehicles of the past, it appears that sounding rockets and the smaller space launch vehicles for the smaller payloads will have to be ratained. Also, even though the shuttle might be used to carry most payloads into near-earth orbit, for those payloads that must go farther, suitable upper staging will still be required to carry those payloads beyond low-altitude parking orbits.
These additional stages will have to be fitted to the shuttle, they will have to be made extremely reliable so as not to endanger the shuttle itself, and means will have to be worked out for launching the upper stages from the earth orbits in which the stages are placed by the shuttle. Such staging is already being worked on, and it may be that some time in the 1980s the world will witness the departure for a planet of a space probe that was first placed on orbit by a space shuttle.