History of Research in Space Biology and Biodynamics
- PART V -
Other Research Related to G-Forces
Anticipated in Space Flight
[70] Track-testing could not, of course, provide all the data needed to study the g-patterns of future space flight. It could produce extremely high g-forces but was limited to short durations. For more prolonged exposures, it is necessary to turn to centrifuge testing, and especially to the human centrifuges located at the Aero Medical Laboratory of Wright Air Development Center and at the Aviation Medical Acceleration Laboratory of the Naval Air Development Center, Johnsville, Pennsylvania. The Johnsville centrifuge, in particular, was used for one series of tests oriented toward the re-entry problem in which Holloman's Aeromedical Field Laboratory also participated.
During the winter and spring of 1956-1957, the Human Factors Division (later Directorate of Life Sciences) of Headquarters, Air Research and Development Command arranged this test series as an inter-service research effort in which the Aero-medical Field Laboratory supplied chimpanzees, the Navy's Johnsville centrifuge spun them at high g, and the Armed Forces Institute of Pathology performed autopsy services. Colonel Stapp helped coordinate all these efforts, and Captain John D. Mosely, who headed the Aeromedical Field Laboratory's Biodynamics Branch, assisted the Navy at Johnsville in the actual centrifuge runs.
Several different tests were made, subjecting chimpanzees to as much as forty g's applied transversely for sixty seconds. The test configurations were dictated primarily by re-entry planners, who allowed a wide margin for possible difference between chimpanzee and human tolerances. All five chimpanzees used survive the centrifugation, but electrocardiograp abnormalities were recorded during the tests, and internal injuries were found when the animals were sacrificed afterward. The one animal that took forty g's for sixty seconds, in a completely supine position was a apparently little harmed by the experiment; the same could not be said of the other four which were tested in partially prone or partially supine position and suffered more severe damage. Just what this prove for re-entry was not wholly clear, in view of the uncertain correlation between chimpanzee and human tolerances. However, the test results did confirm the dangers involved in exposure to prolonged high g.13
The Aeromedical Field Laboratory proposes to conduct further experimenta of its own on the g-forces anticipate in manned space travel as a part of Task 78506 (of Project 7850), Patterns of Deceleration in Space Flight. As a1ready mentioned, this task was established in place of the former Task 7850, Tolerance to Aircraft Crash Forces, at the same time that Project 7850 was rewritten as Biodynamics of Space Flight. Task Scientist since the beginning has been Lieutenant Albert Zaborowski, although he has never been able to devote all his time to this one activity.
Despite the formal title Pattern of Deceleration in Space Flight, the task gram is concerned with acceleration as well as deceleration problems. Principally, it [71] aims to simulate the following conditions of space flight with both animal and human subjects:14
1. The "notched" decelerations encountered during multi-stage rocket takeoff, with varying periods of coasting between the three thrust stages.
2. The forces encountered during maneuvering of the space vehicle at extremely high velocities using reverse or unbalanced rocket thrust.
3. The forces encountered on impact during landings on other planets.
4. The forces encountered during re-entry into the atmosphere.
The Holloman complex of test facilities offers many possibilities for experimentation along these lines. The recent extension of the high-speed track to 35,000 feet naturally increases the range of possible test performance with that instrument. Task 78506 may also use the short Daisy Track for some purposes, and has already used the Bopper or crash-restraint demonstrator for deceleration experiments 'in which the "test subjects"' were blocks of wood immersed in sugar solution.15
As indicated by this last type of experimentation, the Aeromedical Field Laboratory is one of the various research agencies currently interested in the use of fluids for g-protection. Journalists and information officers have taken delight in tracing the theoretical principles involved in this all the way back to ancient Greece, and In giving credit to Archimedes as the spiritual father of underwater g-protection.16 The starting point for modern research in this field appears to be a German effort in the 1930's to develop water-lined anti-g suits. Even better known are Canadian tests during World War II in which the subject was spun on a centrifuge with most of the body under water. The Canadians were looking for ways to improve their aircraft anti-g suits, and they decided at the time (as the Germans had earlier) that water protection was not wholly practical for this purpose.17
Since 1957, the United States Navy's Aviation Medical Acceleration Laboratory and the Aero Medical Laboratory at Wright Field have been conducting human centrifuge tests on the water-immersion principle. So far, the Navy holds the record as to maximum g-forces sustained with the aid of water immersion: four seconds above fifteen g's, with a peak of sixteen. This is part of one simulated re-entry pattern, and indications are that "considerably" higher tolerance levels can be attained in future experiments. But the Wright Field scientists, whose present equipment sets a limit of about twelve g's for this type of testing, hold the record as to durations. Tolerance has been established at twelve g's for almost four minutes.18
From human experiments it is a far cry to Lieutenant Zaborowski's wooden blocks. Obviously, his Bopper tests were only to explore test procedures, including the effects of using different solutions. Later tests will be made with fish, frogs, and small mammals; in fact, another activity in which Lieutenant Zaborowski has been engaged is the design and fabrication of a special mouse diving suit. The culmination of this one type of research will be tests on the 35,000-foot track with chimpanzee or human subjects submerged in a special water tank that is already on order. It should not be thought, however, that Task 78506 is exclusively concerned with the possible uses of fluids in manned space flight. It merely happens that the first actual experimentation was directly related to this procedure. In the end, a wide range of g-patterns will be tested both with and without this and other protective devices. 19
Although research on acceleration and deceleration patterns of space flight was primarily a responsibility of the Biodynamics Branch, at least until the recent reorganization of the Aeromedical Field Laboratory, staff members of the Space Biology Branch--which has been abolished outright--made some contribution to these studies. The Space Biology Branch, headed by Lieutenant Colonel (Doctor) David G. Simons, had charge of Project 7851, Human Factors of Space Flight, which took in both subgravity research and the various cosmic radiation and cabin environment studies that gave rise to the Man-High balloon flights. However, Project 7851 also contained a separate Task 78502, entitled Descent and Recovery (Re-entry).
When first established in 1954, this task was regarded as a natural outgrowth and continuation of work done earlier in devising techniques for the recovery of animal capsules carried to the upper limits of the atmosphere in research rockets. Simons personally had been concerned with "descent and recovery" of the first two [72] biological V-2 experiments in 1948-1949, when, as an officer of the Aero Medical Laboratory at Wright Field, he helped launch these flights from White Sands Proving Ground, New Mexico. Some of his experience in recovery of balloon-borne animal experiments for cosmic ray research was likewise valuable for the task program. As it developed, however, the task also looked ahead from recovery of animal experiments toward an examination of deceleration, thermal effects, and related problems posed by re-entry of manned vehicles into the earth's atmosphere.20
For lack of sufficient people and resources, Descent and Recovery (Re-entry) as a separate task was never fully activated. One of several part-time task scientists who worked on the program at different periods was Mr. Reinhard Krause, an aeronautical engineer whose primary assignment was to another unit of the Air Force Missile Development Center's Directorate of Research and Development (now Directorate of Advanced Technology). Krause did not attempt to conduct a test program but contributed some theoretical calculations concerning velocities and decelerative force in possible re-entry trajectories. (Subsequently he published a technical report, co-authored with W. F. Haldeman, entitled Vertical Descent Trajectories Including Re-entry into the Atmosphere.) The most recent task scientist was Captain Druey P. Parks, who also served as administrative officer of the Space Biology Branch, but he inherited this role at a time when he was chiefly engrossed in preparations for the Man-High program of high-altitude balloon flights and thus unable to devote much attention to Task 78502.21
Part of the effort spent on Man-High was at least related to Task 78502. Various scientific experiments were planned in connection with the Man-High flights in order to accumulate data on physical-conditions of the upper atmosphere. These naturally had some bearing, directly or indirectly, on such problems as re-entry, one example being the attempt (which proved unsuccessful) to measure gravity at high altitude with a balloon-borne gravity meter.22 Then, in the lull that followed Simons' record ascent of 19-20 August 1957, Captain Parks was able to devote his main efforts at least briefly to the work of Task 78502. He began modestly, proposing to drop anthropomorphic dummies from high-altitude balloons in an open escape device, either the experimental Convair "B" ejection seat with rounded bottom and stabilizing booms or the intermediate Weber F-106 seat. After a number of balloon bursts and weather difficulties, the first wholly successful test took place on 29 January 1958, when the Convair seat was dropped from 85,000 feet and accelerated by free fall in 37.12 seconds to a maximum speed of .98 mach, at which point it began to slow down from air resistance. G-forces, oscillations, and other free-fall characteristics were studied in this carefully-instrumented introductory experiment. According to project plans, test were to be staged later on with high-velocity rocket test vehicles, in order to simulate and study different re-entry curves.23
These later tests have not and will not be conducted, since shortly after the 29 January experiment the task itself was formally eliminated from the Aeromedical Field Laboratory program. This move was taken chiefly on grounds of duplication of research at Wright Air Development Center, which had primary responsibility for re-entry work in the United States Air Force.24 The Holloman laboratory will nevertheless continue to contribute pertinent data on re-entry decelerations through its over-all program in biodynamics.
Another scientist who was assigned until recently to the Space Biology Branch, Dr. Harald J. von Beckh, has been working intermittently on a device of his own for protection against g-forces. Von Beckh came to Holloman as task scientist for subgravity studies, and within the general field of subgravity research he was especially interested in the effect of weightlessness immediately preceded or followed by relatively high g-forces, as in rocket take-off and re-entry. His experimentation along these lines has been discussed in another monograph of this series.25 At the same time, however, he has conceived an "anti-g capsul" which could give protection not by water immersion but by automatically positioning the body at all times to receive g-forces transversely, in which case human tolerance levels are invariably highest. Dr. von Beckh has proposed that this system be used in developing a capsule for escape from aircraft, but it is also applicable I for use in space vehicles.26
Von Beckh has already tested the basic features of his idea in animal experiments at Holloman. In the early part of 1958, he exposed mice to high g-forces on two small materiel centrifuges and established that their tolerance was substantially increased by attaching them to a swinging anti-g platform of his own making. Accelerative stress in a direction longitudinal [73] to the body was negligible, since the platform automatically positioned the mice to receive their g's transversely. Though dizzy from spinning at the end of the run, the mice survived exposure to 400 g's for almost fifteen seconds.27
A slightly different form of Dr. von Beckh's device has produced similar results (though at much lower g-levels) with rats on the short Daisy Track,28 which is discussed in the following section of this monograph. Still another variation has even been used operationally, in rocket experiments with animal subjects. This was a purpose for which Von Beckh predicted that his device would prove extremely helpful, since 29
... during the re-entry phase, during ejection from the nose cone and especially during uncontrolled parts of the trajectory, which might be caused by imperfections of the automatic guidance system, the subject would be exposed to severe accelerations with continuously varying direction, intensity, and rate of onset.

Accordingly, Dr. von Beckh's principle was frankly copied in the experiment that sent three ill-fated mice aloft in three Thor-Able missiles from the Air Force Missile Test Center, Florida, in the course of 1958. Two of Von Beckh's Holloman colleagues, Captain (Doctor) Grover J. D. Schock and Technical Sergeant Edward C. Dittmer, were even present at the Ramo-Wooldridge Corporation in Los Angeles, helping project scientists to incorporate the anti-g device as well as giving advice on environmental control problems for the Thor-Able mouse compartment.30 Alas, all the mice were lost at sea, so that there is no way of knowing how well the anti-g device functioned in this case.