Beyond the Atmosphere: Early Years of Space Science

[37] But not all of the results had been obtained from the V-2. To be sure, the immediate availability of the V-2 as a sounding rocket was a boon to the program, for it meant that the scientists could start experimenting without delay. Its altitude performance of 160 kilometers with a metric ton of payload far exceeded that of any other rocket that the experimenters might have been able to use, making investigations well into the ionosphere possible from the outset. More significantly, the large weight-carrying capacity of the rocket meant that experimenters did not have to miniaturize and trim their equipment to shoehorn them into a very restricted payload, but could use relatively gross designs and construction. This capacity was a great help at the start, when everyone was learning, for it permitted the researcher to concentrate on the physics of his experiment without being distracted by added engineering requirements imposed by the rocket tool. Later, with some years of experience behind him, the experimenter would be able to take the outfitting of much smaller rockets in stride. And it was of advantage to go to smaller rockets as soon as possible.
Smaller rockets would be much cheaper, far simpler than the V-2 to assemble, test, and launch. Moreover, with the smaller, simpler rockets the logistics of conducting rocket soundings at places other than White Sands would be manageable. With such thoughts in mind, as panel members pressed the exploration of the upper atmosphere with the V-2 they also set out to develop a variety of single and multistage rockets specifically for atmospheric sounding.9 James Van Allen and his colleagues at the Applied Physics Laboratory undertook, with support from the U.S. Navy's Bureau of Ordnance, to develop the Aerobee sounding rocket.10 At the same time NRL took on the job of developing a large rocket-first called Neptune, [38] but later Viking when it was learned a Neptune aircraft already existed-to replace the V-2s when they were gone.11 At the 28 January, 1948 meeting of the panel, Van Allen reported on a series of test firings of the Aerobee-three dummy rounds and one live round.12 As soon as it was ready the Aerobee was put to work exploring the upper atmosphere and space, with firings not only from the original Aerobee launching tower at White Sands, but also from a second tower that the Air Force erected some 57 kilometers northeast of the Army blockhouse at the White Sands Proving Ground. The Air Force tower was located at Holloman Air Force Base near Alamogordo. Not content with the payload and altitude capabilities of the first Aerobees, both the Air Force and the Navy continued the development, producing something like a dozen different versions, one of which could carry 23 kilograms of payload to an altitude of 480 kilometers.13 In its various versions Aerobee was used continuously in the high-altitude rocket research program through the 1950s and 1960s and was still in use in the mid-1970s.
In contrast, the Viking, although of a marvelous design-Milton Rosen, who directed the Viking development program, used to point out that in its time Viking was the most efficiently designed rocket in existence-found very little use. The dozen rockets bought for the development program were, of course, instrumented for high-altitude research. But Viking was too expensive. The groups engaged in rocket sounding each had perhaps a few hundred thousand dollars a year to expend on the research, and a single Viking would have eaten up the whole budget. When the supply of German V-2s began to run low, consideration was given to building new ones; but estimates placed the price per copy at around half a million dollars, which was prohibitive. It had been hoped that Viking would be much less expensive, but before the end of the development these rockets became almost as expensive as new V-2s. So Viking found no takers among the atmospheric sounding groups and would probably have been shelved had it not been chosen as the starting point for the Vanguard IGY satellite launching vehicle.14
The contrast between Viking and Aerobee typified a situation that has recurred in the space science program. One group of scientists would favor developing large new rockets, spacecraft, or other equipment that would greatly extend the research capability. Another group would prefer to keep things as small and simple as possible, devoting its funds to scientific experiments that could be done with available rockets and equipment. The former group could always point to research not possible with existing tools, thus justifying the proposed development. In rebuttal the latter could always point to an ample collection of important problems that could be attacked with existing means. There was right on both sides of the argument, and it was usually a standoff. As far as upper atmospheric research was concerned, however, Viking was too far ahead of its time. [39] While in the next decade researchers would be able to buy $1-million Scouts (chap. 10), in the early years of rocket sounding Viking cost too much.
Once the ball had started rolling with Aerobee and Viking, other rocket combinations began to appear. The experimenters sought less cost, greater simplicity, higher altitudes, more payload, and especially a capability to conduct firings at different geographic locations. Great ingenuity was displayed in putting together new combinations. Sounding rockets were taken to the California coast, to Florida, to the Virginia coast, out to sea, and to the shores of Hudson's Bay in Canada.15 They were even launched in the stratosphere from balloons, a combination that the inventor, Van Allen, called a Rockoon.16 In the panel meeting of 9 September 1954, Van Allen reported that Rockoon flights in the Arctic had established the existence of a soft radiation in the aurora zone above 50 kilometers height, which proved to be one of the milestones along the investigative track that ultimately led to the discovery of the earth's radiation belt.