Saturday, February 15, 2014

Tales of Immersion 2: Two Pictures, No Answers (But Many Inferences)

In October 2013, I purchased a pair of photographs on eBay which appear to illustrate an early episode in the history of neutral buoyancy by water immersion: Figure 1, labeled 69442B, and Figure 2, labeled 69471B. They were listed on eBay under the title, “2 ASTRONAUT [sic] UNDER WATER GENERAL DYNAMICS (181234004788#).” The eBay seller provided no provenance or additional information. All I know is what was stamped and written on the backs of the photographs: the photo numbers and the notations “unclassified,” “General Dynamics,” and “Convair Division.” Since then, I have been trying to uncover the story behind these pictures.

Figure 1. General Dynamics, Convair Division, photo 69442B.
Figure 2. General Dynamics, Convair Division, photo 69471B.

Nowadays everyone knows that astronauts train underwater for their spacewalks, or extravehicular activities (EVA). It was even featured prominently in the movie “Armageddon” (IMDb, 1998), probably the closest thing to “correct” in the whole movie.

The Convair Division of General Dynamics was in San Diego, California. A quick query to Francis French at the San Diego Air & Space Museum, repository for many of the company’s documents and records, did not yield any insights. It became clear that if I was to learn more about this particular activity, it would come from an analysis of the photos themselves.

Luckily, this pair of images seems as if it were composed specifically to tutor me on a step-wise analysis, starting with the human figure, working outward to the setting and ending (I hope) with a date and a context for the activity in the pictures. The steps of the analysis practically suggested themselves:
  • Person(s)
    • Central person(s), typically the test subject or trainee
    • Supporting person(s)
  • Body-worn equipment
    • Garments
    • Real or simulated life support equipment
  • Tools
  • Activities
  • Test fixture
  • Setting
    • Water tank
    • Location
  • Time factors
    • Approximate calendar date
    • Temporal relationship of images
I already knew that GD was an early developer of neutral buoyancy techniques using water immersion for astronaut training and procedures development (Mattingly and Charles, 2013). The company was certainly no stranger to neutral buoyancy, but at a different scale than a single astronaut: it has been building submarines for the U.S. Navy since 1900 (General Dynamics, 1998)

GD came close to becoming the first contractor to provide such training to NASA’s Gemini astronauts. In July 1966, NASA astronaut Scott Carpenter visited GD’s underwater facility in San Diego and was impressed with their capabilities. He was familiar with Convair from previous visits, starting in 1959 to monitor the development and construction of the Atlas rockets which boosted the Mercury capsules into low Earth orbit (Voas, 1960).

Carpenter was on his way back to Houston intending to recommend that the company train the Gemini astronauts. But he was diverted[1] to Baltimore, Maryland, apparently with no more information than to visit a group of contractors at the McDonogh School in nearby Owings Mills. He arrived unannounced at the school’s pool where he witnessed the neutral buoyancy capabilities developed by Environmental Research Associates (ERA). What he saw at McDonogh changed his mind, and soon thereafter Gemini astronauts arrived at the McDonogh School for EVA training (Mattingly and Charles, 2013).

I don’t know what he had seen in San Diego, but whatever it was is important for an understanding of NASA’s decision to go with ERA.

Persons. There was one central person in both images. Figure 2 also included a second person, probably a safety diver or in-water observer: note the second person’s right hand and forearm in a wetsuit visible behind the central person’s right elbow, and his right leg visible through the circular opening to the left of the central person’s right leg.

Body-worn equipment. The central person was wearing a full-pressure suit, apparently an Arrowhead version of the B.F. Goodrich Mark 4 garment (Young, 2009,  pp. 16-23), judging from its distinctive features including its unique zipper configuration (Figure 3). The suits shown in Figures 1 and 2 may have been different suits based on some visible structural details, although differences in lighting may explain the variation. The garments were apparently pressurized with water, not air, as indicated by the absence of external ballast on the torso and limbs and by the scuba mask visible inside the closed helmet. It appears that the transparent helmet visor has been removed to accommodate the scuba mask, but the visor frame assembly appears intact.  The helmet was prominently (and conveniently) labeled “General Dynamics” and “Convair Division.”

Figure 3. Arrowhead variant of B.F. Goodrich Mark 4 suit. Identification based on specific features in both Figures 1 and 2 and in image of Mark 4 from National Air and Space Museum: red, lower left leg fitting; green, upper left leg fitting; blue, right thorax fitting; yellow, right forearm corrugation unique to Arrowhead variants (see also corrugated sections visible above and below knees, and below elbows in all three images; corrugations around waist not visible in General Dynamics suit, and above elbow only in Figure 1). (Photo credits: General Dynamics, left and center; National Air and Space Museum, right.)
Life support for the central figure appears to have been provided by a large diameter pressurized hose extending horizontally underwater to the central person from out of frame at the left. It seems to have connected to the upper back of the test subject, between the helmet and the middle of his back. A thinner black cable, possibly a telephone line, was bundled with the pressure hose. In Figure 2, the pressurized hose was secured to the test fixture, possibly to provide stress relief and facilitate mobility by the test subject.

The central person was also wearing what appears to be a white mockup of a Garrett AiResearch EVA Life Support System (ELSS) (Figure 4) on his chest in Figure 2 only. This identification is based on the location and size of the unit, and its distinctive top panel (Thomas and McMann, 2006, pp. 66-7).

Figure 4. Astronaut Edwin Aldrin in 30-foot vacuum chamber of the McDonnell Aircraft Co., St. Louis, Mo., on Aug. 15, 1966, wearing Garrett AiResearch EVA Life Support System (ELSS) and Ling-Temco-Vought Co. (LTV) Astronaut Maneuvering Unit (AMU) for U.S. Air Force experiment D012. ELSS is on his chest, and AMU is his large backpack. (Photo NASA S66-51073, 1966.) 
Tools. In both pictures, the central person appeared to have his left leg inside a loose strap attached to what might have been a simplified wooden mockup of the Astronaut Maneuvering Unit (AMU) (Figure 4). The AMU was developed by the Ling-Temco-Vought Co. for the U.S. Air Force experiment D012 (Shayler, 2004, p. 57). Its tentative identification derives from features suggesting over-the-shoulder thruster assemblies and side-mounted hand controllers, and from the curved cut-out at its top to accommodate the wearer’s helmet, all present in the AMU (Figure 5). However, its front-to-back depth and the detail of the over-the-shoulder and side-mounted features merely suggest the structure of the corresponding features of the AMU; perhaps the GD mockup represented only the aspect of the AMU which would have interfaced with the astronaut’s suit and body. The visible straps around the subject’s left leg differ between the photographs: in Figure 1, there was a section of black fabric, presumably Velcro, while in Figure 2 the corresponding area appears white.

Figure 5. General Dynamics’ possible mockup (left image) of LTV AMU (right image). Detail from Figure 1 shows mockup elements corresponding to features on AMU: semi-circular cut-out for wearer’s helmet (bracketed at top of both images); over-shoulder protuberances in mockup corresponding to reverse thrusters (middle two-headed arrow); lower protuberances on mockup correspond to hand-controller mounts on AMU (bottom two-headed arrow). Scale model at right illustrates astronaut position during AMU operations. (Photo credits: General Dynamics, ca. 1964, left image; John Charles at National Museum of U.S. Air Force, 2011, right image).
A thin curved pipe or tube, apparently metallic and connected to the top of the AMU mockup (seen more clearly in Figure 1), was used by the central person as a hand-hold, but was not present on the LTV AMU.

The presumed AMU is seen in both photographs to be in proximity to the large test fixture, orthogonally aligned in Figure 1 but slightly askew in Figure 2, indicating that may have been loosely affixed to the test fixture.

Activities. In Figure 2, the central person’s umbilical appeared to originate out of frame to the left, and was routed through the open top side of the cylindrical structure, or tunnel, before exiting through the open end of the tunnel and then connecting to the figure. Apparently the central person had translated out of the tunnel through its open end before arriving at his work site, suggesting egress from an airlock for the EVA.

The central person interacted with the faux AMU in an unlikely manner. His left leg, but not his right leg, was behind a loose strap attached to the AMU. This is true in both photographs, suggesting it was a common practice and therefore intentional. However, it is not consistent with astronaut interaction with the AMU in other testing or spaceflight settings. There is no sign of any mobility aids or restraints as were provided for in-flight AMU activities (see Figure 6). In fact, there are no hand holds or mobility aids visible anywhere on structure.

Figure 6. Astronaut Eugene Cernan in weightlessness training aboard KC-135 wearing ELSS and AMU. Note handholds and foot restraints as flown on Gemini-9, which were notably absent in Figures 1 and 2. (Photo credit: NASA, 1966.)
Test fixture. The dominant feature of both photographs was a wooden framework about 10 feet (3.0 meters) tall, about 6 feet (1.8 meters) wide at its widest point, and about 12 feet (3.7 meters) in length. It was apparently painted, and what would have been contiguous surfaces were substituted by a metal mesh. The largest portion was laterally dissimilar: a large half-cylinder was mated to a rectangular structure. There was a triangular brace in the top half of main cylinder. The smaller portion was the tubular tunnel, about 3 feet (1 meter) diameter and 8 feet (2.4 meters) long, attached to the lower center of main section. A wire mesh disc at the unattached end of the tunnel may have simulated a hatch cover, shown swung open toward the right (Figure 2). Both the hatch end of the tunnel and the larger section appeared to be weighted down by ballast in fabric bags about 6 inches across.

Given the aerospace nature of work done by GD and the astronautical appearance of the central person, the test fixture may have been a representation of a then-current spacecraft design. The pairing of a tunnel and a large broad-faced bulkhead suggest either the Gemini-B/Manned Orbiting Laboratory (MOL) program of the Air Force or NASA’s Apollo Lunar Module (LM) docked to its Command Module.

The Gemini-B/MOL interpretation is unlikely for several geometrical reasons: the tunnel appears straight, whereas the tunnel from the MOL to the Gemini-B heat shield was angled and bent; the tunnel terminated too close to the periphery of the presumed heat shield, and at its bottom instead of at its top; and the diameter of the large element appears greater than the Gemini heat shield diameter (Figure 7).

Figure 7. Gemini-B/MOL tunnel configuration in artist’s concept from McDonnell Aircraft Company in 1967 compared with configuration of General-Dynamics mockup in Figures 2. Large bulkhead (bracketed in upper image) in mockup has different features and size than Gemini-B heat shield (bracketed in lower image). Tunnels in mockup and concept (indicated by two-headed arrows) have different diameter and shape. (Photo credit: McDonnell Aircraft Co., ca. 1967.)
Figure 8. Two-headed arrows indicate points of correspondence supporting the tentative identification of the General Dynamics test fixture as a version of the Lunar Module (LM) TM-1 mockup configuration, showing ascent stage (upper portion) with newly-added triangular windows for standing (not seated) astronauts but retaining round forward hatch originally intended for docking with Command Module. TM-1 was current between March 1964 and January 1965. (Photo credit: Grumman, 1964.)
Instead, the large element had some features which may correspond to the structure of the ascent stage and crew compartment of an early version of the LM (Figure 8). Of prime significance is a recessed triangular frame with a wire mesh interior, which appears to represent the forward facing window in the left half of the LM crew cabin. The triangular windows are unique to the LM, so their inclusion is strong evidence that this is a LM mockup. This is further supported by the combination of the rectangular central portion, from the bottom of which the tunnel exits, and the recessed rounded portion in the right half of the picture, which represented the left half of the cylindrical crew cabin. The round opening at the bottom of the rectangular section could have been the circular hatch once planned for the LM, which by 1964 was simply a vestige of its discarded role as a docking port (Aviation Week & Space Technology, 1964); by January 1965 it had been replaced by the familiar square hatch. Together they resemble most of the LM crew cabin structure, minus the corresponding rounded portion on the photo-left of the rectangular structure, which would have represented the right half of the cylindrical crew cabin. These features correspond to the stage of LM evolution represented by the TM-1 mockup, which was current between March 1964 and January 1965 (Godwin, 2007, pp. 72-3).

The tubular tunnel terminating in the circular LM hatch might have simulated the tunnel of another spacecraft which would have been docked to the front port of the LM. However, there is no external structure around the tunnel, and as described above such a docking is inconsistent with the inferred stage of LM development. Therefore, the tunnel attached to it does not reflect a contemporary aspect of the Apollo LM or its counterpart the Command Module.

Perhaps it represents an airlock attached to the front port of the LM (Figure 9). This might have been part of a proposal to use the LM in an Earth-orbiting research or operations role. Such an application is not shown among the options for LM-derived vehicles advertised by Grumman (Grumman Aircraft Engineering Corp., 1970), but it may have been considered briefly nonetheless.

Figure 9. Author’s concept of an airlock or other tubular structure attached to LM forward hatch. The right-hand panel in this image illustrates a hypothetical explanation of the mockup shown in the left-hand panel, but no such spacecraft concept is known from the available literature. Or it might just be a product of my pareidolia. (Photo credits: left, General Dynamics; right, John Charles, 2014.) 
There was a proposal to use the LM for long-duration lunar surface habitation (NASA, 1967, p. 29) which incorporated an airlock to minimize the loss of cabin atmosphere during repeated EVAs (Figure 10). However, that was a 1967 concept for use in a gravitational environment (albeit 1/6-g), not a ca. 1964 concept for weightlessness, and that airlock was noticeably different from the structure in Figures 1 and 2.

Figure 10. Lunar Module Shelter concept with airlock (circled in red). LM Shelter was proposed to support multi-week lunar surface missions in the Apollo Applications Program. This is the closest match to the concept illustrated in Fig. 9. (Photo credit: NASA, 1967.)
In light of this uncertainty, it is possible that the test fixture in Figures 1 and 2 may simply represent a generic LM-derived spacecraft concept for the neutral buoyancy activities being undertaken, and its specific features were not intended to correspond to actual or planned spacecraft.

The test fixture was apparently repositioned in the interval between Figures 1 and 2. In Figure 1, the rectangular component appeared nearly aligned with the three vertical lights between two windows. In Figure 2, the rectangular component was more aligned with the middle of the observation window to the left of the three lights. The ballast bags appear not to have been rearranged, indicating that the fixture was moved but not emersed and resubmerged.

Setting. Both photographs were made in the same facility, a water tank about 10 feet deep. If the large element of the test fixture represents the Lunar Module ascent stage (Grumman Aircraft Engineering Corp., 1964), then the depth of water required to submerge it completely (as demonstrated in Figure 2) was 9.4 feet (2.9 meters). The scenes in both images were well-lighted for photography purposes: from above water, perhaps using natural sunlight, suggested by the refraction patterns of surface ripples on the floor in Figure 1, and also apparently from a subsurface light source, out of frame left, judging from the shadows in Figure 2. The facility had at least three large distinctive observation windows and arrangements for subsurface lighting, suggesting a public facility for underwater shows or exhibitions. Thus, the setting was presumably an existing underwater exhibition facility in the San Diego area, in proximity to Convair.

A Google search of public aquariums near San Diego produced two possible venues. The Aquarium of the Pacific[2] in Long Beach, California, was established in 1998, according to the response to an email query, and was thus not a candidate. The Birch Aquarium at the Scripps Institute of Oceanography[3] was opened in 1992, and was likewise not a candidate. However, it was preceded by the T. Wayland Vaughn Scripps Aquarium-Museum in La Jolla, California, which existed from 1951 to 1992. A photograph (Figure 11) from the 1967 annual report (Scripps Institute of Oceanography, 1967, p. 35) shows what may be an interior view of one of its distinctive windows; it appears similar to the windows in Figures 1 and 2. Thus the Vaughn Aquarium may have been the setting for the neutral buoyancy activities in the photographs. However, some questions remain to be answered, such as how a tank which was presumably a habitat for its marine occupants came to be emptied, cleaned and made available for GD’s use.

Figure 11. Fred Spiess (right), Director of Scripps Institute of Oceanography, speaking with Donald Wilkie (left), Curator of the Vaughn Aquarium-Museum ca 1966. Note similarity of observation windows to windows in Figures 1 and 2. (Photo credit: Scripps Institute of Oceanography, 1967.)
Time. GD’s use of neutral buoyancy techniques was limited to the early to mid 1960s based on other evidence (Mattingly and Charles, 2013). The Vaughn Aquarium was in existence from 1951 to 1992. The Mark IV-type full pressure suits were introduced into service by the U.S. Navy in the 1950s (Young, 2009, pp. 19, 22) and decommissioned suits were available for widespread ground testing by 1964 (Mattingly and Charles, 2013). The presence of the mockup ELSS in Figure 2 indicates a date between January 1964 when the ELSS design was finalized (Thomas and McMann, 2006 p. 66) and November 1966 when the end of the Gemini program also ended use of the ELSS and presumably its usefulness in neutral buoyancy simulations (a different system was already in development for the upcoming Apollo flights). The faux AMU placed the date between May 1964, when LTV won the contract to build three flight units for U.S. Air Force experiment D012 (Shayler, 2004, p. 57) and September 1966 (Hacker and Grimwood, 1977), when the AMU was definitively deleted from the Gemini flight program (although the Air Force remained interested in using it for some period of time thereafter (Wade, undated)). The LM configuration TM-1, with its round forward hatch, was current between March 1964 and January 1965 (Godwin, 2007,  pp. 72-3). Thus I estimate the approximate calendar date for the two images as no earlier than May 1964, no later than September 1966, and probably not later than early 1965.

The scenarios in the two photographs are superficially similar but contain differences indicating they are from two different sessions. Presumably 69442B preceded 69471B, and the differences between them represent improvements or intentional modifications in the test scenario. These differences have been discussed above and are summarized in Table 1:

Table 1. Similar and different elements of Figures 1 and 2.

Common to both Figure 1 and 2
69442B (Figure 1) only
69471B (Figure 2) only
Test subject
Support diver
Body worn equipment
Water-pressurized Arrowhead Mk. 4 suit
Forearm bellows section visible
Forearm bellows section absent or covered
Faux AMU
Mounted orthogonal to test fixture
Black Velcro strip
Mounted rotated leftward re: test fixture
White Velcro strip
Left leg behind strap
Test fixture
LM mockup
Airlock mockup
Ballast bags apparently not re-stacked between photographs
Near 3 vertically-aligned lights
Aligned with window to left of 3 vertically-aligned lights
Vaughn Scripps Aquarium
Lighted from above, possibly natural light
Lighted from left of scene
Time factors
Ca. 1964
Not same session as 69471B
Not same session as 69442B


The available evidence indicates that the spacecraft and tool mockups in the photographs were likely used between mid-to-late 1964 and early 1965, although they might have continued to be used after those dates for general studies in neutral buoyancy.

The similarities in arrangement of the central person, the test fixture, the background and the perspective of the photographs suggest that they were made within a single session, perhaps showing a sequence of activities. On closer inspection, it becomes apparent that there were differences in lighting, body-worn equipment, features of the tools, possibly the space suit and even the location of the test fixture (see Table 1). These differences indicate that they were made during separate sessions, perhaps even on different days.

It is of interest that, despite their differences, the two images show the central person in nearly the same position and orientation with respect to the test fixture. He was above the top of the faux AMU, with his left leg inserted behind the same strap. This suggests that the action was intentional and significant. However, this does not represent an effective interface with the backpack-style AMU. Assuming a leg strap was part of the AMU restraint system, it should not have been necessary to enter it from the top of the unit. In addition, by early 1966, when Gemini astronauts were training to use the AMU in flight, there was a significant set of fixtures associated with donning it: handholds, footholds, straps and hoses (Figure 6). Despite those aids, Gemini 9 astronaut Eugene Cernan, the first person who attempted the task in spaceflight, abandoned the task it because the required physical effort overwhelmed his suit cooling system (Evans, 2013).

Perhaps the simplistic approach to AMU donning shown in these images was an early stage in the progressive development of the more robust (but still inadequate) donning aids used on Gemini 9, but any role of GD in preparations for AMU flights, including donning studies, has yet to be uncovered. If, however, the tool I have identified as a faux AMU was not, in fact, a mock AMU, then this analysis is moot, and the device being simulated remains to be identified.

Besides the faux AMU, there is the ambiguous test fixture and the mission it supported. Its resemblance to an early design for the Grumman’s Lunar Module suggests that GD was evaluating extravehicular activities associated with the Apollo program or perhaps the follow-on Apollo Applications Program (AAP) (Wikipedia, 2014; Shayler, 2002), which would have utilized surplus Apollo vehicles for scientific missions in Earth orbit as well as on the Moon. Judging from the course of the life support umbilical, the test subject had translated from the open end of the tubular tunnel, presumably representing an airlock, to the faux AMU which was affixed to the lower left front panel of the LM mockup, below its left forward window. While the AMU or similar maneuvering units were considered for AAP use (Figure 12), I have not seen any plans to use them in conjunction with a LM-derived vehicle.

Figure 12. Illustration of AMU application during an AAP mission outfitting a Saturn IVB upper stage for future in-orbit use. (Photo credit: Douglas Missile and Space Systems, 1965.)
What does all this mean? A great amount of detail can been inferred, but how close have my inferences come to the reality of GD’s role in spaceflight neutral buoyancy techniques? Were these photos really made in 1964? Where? What were the test fixtures intended to simulate? Does 69442B predate 69471B? Why was the scene duplicated so closely on a second occasion, and why were the obvious changes introduced? Why have no other photos surfaced?

If in fact these images date from 1964, it was two years before Carpenter almost recommended GD for the NASA contract. During those two years they must have made as much progress as ERA. My colleagues Francis French and Alan Renga at the San Diego Air & Space Museum, continued searching their General Dynamics records and found a document dated July 1968 (Braxell and Thomson, 1968) which reported on a different type of underwater work by subjects wearing the Mark 4 suit as well as in a Gemini-type suit; however, it is silent on the neutral buoyancy work illustrated in Figures 1 and 2.

I have taken my forensic analysis of these two photos as far as I can, without new information. Additional questions include: where are the photos and reports from 1965 and 1966 which document the capabilities that impressed Carpenter? Who funded that work? How much longer did they pursue neutral buoyancy work after it became obvious that NASA would not support it?

Maybe I can learn more when I am in San Diego in May 2014 for the 85th Annual Scientific Meeting of the Aerospace Medical Association. I will visit the San Diego Air & Space Museum, and possibly the Scripps Institute of Oceanography. Perhaps some of the answers are awaiting me there.

[Edited for clarity, 17 Feb. 2014]

My thanks to Addie Eure, Marketing Coordinator, Birch Aquarium at Scripps, the anonymous Guest Support Specialist, Aquarium of the Pacific, and especially to Francis French and Alan Renga, San Diego Air & Space Museum.


Aviation Week & Space Technology. 1964. Aviation Week & Space Technology. February 10, 1964.

Braxell, R. R. and Thomson, W. G. July 1968. Selected Experiments in the Assembly of Structures in Space. Life Sciences Department, Convair Division. San Diego : General Dynamics, July 1968. Sponsored by Aero Propulsion Laboratories, Wright-Patterson Air Force Base, Ohio. Contract F33-615-67-C-1302, "Assembly and Maintenance of Lightweight Metallic Structures in Space".

Cunningham, Walter. 1977. The All-American Boys. New York : Macmillan Publishing Co., Inc., 1977. ISBN 0-02-529240-4.

Evans, Ben. 2013. Date With An Alligator: The Trials of Gemini-IXA. Space Safety Magazine. [Online] June 7, 2013. [Cited: Dec. 27, 2013.]

General Dynamics. 1998. General Dynamics Electric Boat. [Online] 1998. [Cited: Jan. 1, 2014.]

Godwin, Robert. 2007. The Lunar Exploration Scrapbook / A Pictorial History of Lunar Vehicles. Burlington : Apogee Books, 2007. 978-1-894959-69-8.

Grumman Aircraft Engineering Corp. 1970. Apollo Program: Grumman's "Lunar Module Derivatives for Future Space Missions," Circa 1970... Heritage Auctions. [Online] 1970. [Cited: Jan. 19, 2014.]

Grumman Aircraft Engineering Corp. 1964. Inboard Profile of the Lunar Excursion Module, 1964. National Archives, Online Public Access (OPA). [Online] March 10, 1964. [Cited: December 4, 2013.] Entry 55, Box 3. 2657372.

Hacker, Barton C. and Grimwood, James M. 1977. On the Shoulders of Titans. Washington : National Aeronautics and Space Administration, 1977. p. 371.

IMDb. 1998. Armageddon (1998) Trivia. [Online] 1998. [Cited: Jan. 24, 2014.]

Mattingly, G. Sam and Charles, John B. 2013. A personal history of underwater neutral buoyancy simulation. The Space Review. [Online] February 4, 2013. [Cited: December 4, 2013.]

NASA. 1967. Lunar Mission Planning Data Book. Lunar Missions Office, NASA Manned Spacecraft Center. Houston : NASA Manned Spacecraft Center, 1967. p. 142. Library, Center for Advanced Space Studies, Houston TX 77058. TL 789.8 .U6 M282 1967.

NASA. 2008. NASA - T-38A Talon Performance and Specifications. Dryden Flight Research Center. [Online] Sep. 22, 2008. [Cited: Feb. 15, 2014.]

Scripps Institute of Oceanography. 1967. Annual Report for the Year Ending June 30, 1967. Scripps Institute of Oceanography. La Jolla, Calif. : s.n., 1967. p. 35.

Shayler, David J. 2002. Apollo: The Lost and Forgotten Missions. 1st. Chichester : Springer, 2002. p. 344. ISBN 978-1-85233-575-5.

Shayler, David J. 2004. Walking in Space. Chichester : Praxis Publishing Ltd., 2004. 1-85233-710-9.

Thomas, Kenneth S. and McMann, Harold J. 2006. US Spacesuits. Chichester, UK : Praxis Publishing, Ltd., 2006.

Voas, Robert B. 1960. Project Mercury Astronaut Training Program. NASA Space Task Group, Langley Field, Va. 1960.

Wade, Mark. undated. 1966.11.18 - NASA plans to include the DOD's astronaut maneuvering unit "back pack" aboard AAP flights. Encyclopedia Astronautica. [Online] undated. [Cited: Dec. 16, 2013.]

Wikipedia. 2014. Apollo Applications Program. Wikipedia. [Online] Jan. 10, 2014. [Cited: Jan. 24, 2014.]

Young, Amanda. 2009. Spacesuits / The Smithsonian National Air and Space Museum Collection. 1st. Brooklyn : powerHouse Books, 2009. 978-1-57687-498-1.

[1] If Carpenter was piloting a NASA T-38, this diversion was not trivial. Google Earth gives the straight-line distance from San Diego to Baltimore as about 2,300 miles. The T-38 is usually refueled every 700 miles (Cunningham, 1977 pp. 70-75), so a direct flight from San Diego to Baltimore would have needed three intermediate stops. A NASA website (NASA, 2008) gives the range of the T-38 as about 1,140 miles, although practical considerations such as weather and safety margins required more stops. Or, he might have flown commercial.

[2] Aquarium of the Pacific, 100 Aquarium Way, Long Beach, CA 90802,; email response received 25 Oct. 2013.

[3] Birch Aquarium at Scripps, 2300 Expedition Way, Scripps Institute, La Jolla, San Diego, CA 92037,; email response received 2 Dec. 2013. 

Monday, November 11, 2013

A Jones for MOL #10: Shadow MOL Men (Part 2)—the Bohannon Hypothesis

Gen. Richard Leland Bohannon,
in an Associated Press wire photo
released in Feb. 1964, after he became
Surgeon General of the U.S. Air Force. 
In 1964 the new Surgeon General of the U.S. Air Force, Lt. Gen. Richard Bohannon, arranged for two Air Force flight surgeons (ref. 1) per year to train as jet pilots in hopes that some of them would become astronauts aboard the planned military Manned Orbiting Laboratory (MOL). His further expectations are not available for analysis; a Freedom of Information request to the Air Force did not produce any relevant information. When the MOL program ended without any flights just five years later, 17 test pilots had been selected as military astronauts, but no physicians. Enthusiasm for the pilot physician program waned among Air Force leadership soon thereafter (ref. 2).

Dr. Bohannon’s efforts were consistent with the standards of the mid-1960s. When the “other” American space program, NASA, selected non-pilot specialists such as physicists, astronomers, geologists and physicians to increase the scientific productivity of planned space station and lunar exploration missions, their astronaut managers insisted that any who were not already qualified jet pilots be sent through Air Force pilot training before reporting for space duty (ref. 3). These managers were mostly either test pilots or aerospace engineers accustomed to working with test pilots, and they believed pilot training provided a minimum common background and necessary skills to all who would be astronauts.

Despite their impressive overall credentials, not all astronauts come to NASA with operational skills and experience. Since the mid-1960s, NASA astronauts have primarily used the T-38N jet (the “N” identifies NASA’s modified version of the Air Force T-38 trainer) to combine “rapid response training” with the skills, cognitive control and urgency of life and death decisions that is considered critical in the professional astronaut corps. Among all of the simulators and training systems used by astronauts, this was (and is) the only one providing an environment including acceleration and G-loads, confined stressful physical environments, and exposure to a realistic psychological stress environment in which participants cannot always walk away from their mistakes. Jet aircraft training has instilled and expanded candidates’ capability and competence in performing in a fast-paced spaceflight environment (ref. 4).

Four physicians selected by NASA as astronauts in 1965 and 1967 dutifully entered flight training, although one left NASA in short order for personal reasons. On graduation they joined a fifth physician-astronaut who was already a qualified jet pilot before coming to NASA (ref. 3). Together they embodied Dr. Bohannon’s vision of pilot-physicians eligible for space missions—but just not in the program he originally intended.

By 1978, when NASA next recruited physicians as professional astronauts, it no longer required pilot training for all astronauts. The Space Shuttle era promised flights of such mild conditions that non-pilots could successfully participate. In fact, the front seat in NASA’s two-seat T-38 jets was eventually limited to just highly-qualified test pilots, possibly for insurance purposes, so even the physicians NASA had earlier insisted become jet pilots were no longer eligible to be “first pilot.” However, even today, career astronauts who are not military pilots still maintain proficiency as back-seat crewmembers, doing everything except the actual piloting.

Twenty-eight physicians have been chosen as professional NASA astronauts from 1965 to 2013, including one who has only just been selected and is not yet eligible for spaceflight and another who left NASA before becoming eligible for spaceflight assignment (ref. 5). Of the remaining 26, 7 have been jet qualified, including 4 who were pilots before their selection by NASA. One physician astronaut was never assigned to a flight and is not currently on the active roster. Another one has been assigned and is now training for his first flight. Two others flew in space and received additional flight assignments but were unable to complete them.

Interestingly, all four of the physicians who arrived at NASA as qualified jet pilots were from the Navy or its sister service the Marine Corps, not the Air Force. Three of them were products of the Navy’s physician-pilot “dual-designator” program (ref. 6), similar to the Air Force pilot-physician program; the fourth was a Vietnam-era Marine Corps aviator who attended medical school after leaving the service. In fact, two of them had even been through test pilot school (ref. 7), which qualified them to continue piloting NASA’s training jets even when their colleagues lost that privilege. The Air Force had apparently considered sending their pilot-physicians to test pilot school, probably to increase their attractiveness as military astronauts, but it was rejected as an unnecessary complexity and delay (ref. 8). Individual pilot-physicians may have applied on their own initiative, as did these two Navy pilot-physicians, but apparently none were successful.

When he arranged for two pilot training slots per year for Air Force flight surgeons, Dr. Bohannon essentially posed a hypothesis: assuming that pilot-trained physicians will be important in developing means to protect military astronauts from the deleterious effects of long-duration spaceflight, are they likely to be more acceptable to spaceflight managers who select pilots to be astronauts, and thus more likely to fly on space missions? As I described previously, renowned test pilot General Chuck Yeager oversaw the selection of the military astronauts, who were all graduates of the test pilot school under his command.

Quantitative analysis in this case is not straight-forward. The independent variable is whether or not the astronaut was a military-trained pilot. Admittedly, many non-pilot astronauts earn ratings as private or commercial pilots, and those who had been military flight surgeons acquired considerable experience in the back seat of jets (ref. 9). Thus the distinction between pilot and non-pilot physicians is not always distinct. But for the purposes of this discussion, I am considering only those who graduated from military flight training, either before or during their NASA careers. This was the criterion invoked by Dr. Bohannon, since his candidates were already Air Force flight surgeons and still he pushed for them to become trained as pilots.

Two dependent variables can be evaluated. The most obvious is actual spaceflight. Perhaps a more informative variable is flight assignment. The state of being a physician-astronaut is not an intrinsic characteristic that independently results in a spaceflight. Such assignments are made by the astronaut’s superiors. Even if an assignment does not result in a flight, it reflects the value of the pilot qualification in improving the attractiveness of a physician-astronaut for that flight.


# physician-astronauts
# flights (total)
average # flights
# flight assignments (total)
average # assignments
To date, 26 of the 28 professional NASA physician-astronauts have been eligible for assignment to spaceflight during their active careers. Those meeting the pilot criterion received an average of 2.4 (range 1 to 6) assignments and made an average of 2.1 (range 1 to 6) flights, slightly exceeding the average of 1.7 (range 0 to 5) flights and assignments for their non-pilot counterparts. Rigorous statistical analysis is not appropriate in this case; it is sufficient for our purposes that all ratios round to the same whole integer: two spaceflight assignments per physician astronaut, regardless of pilot-training.

NASA’s experience vis-à-vis the contribution of piloting qualifications to the success of physician astronauts is informative. It is not obvious that qualification as a first pilot in jet aircraft has led to more success in spaceflight, as judged by flight assignments. However, from personal observation, all physician-astronauts performed as well in spaceflight as Dr. Bohannon had expected of his candidates in the 1960s. This speaks of the character of people who succeed as astronauts: many of them are able to undertake more than one complex career path and succeed, including such diverse skills as medicine and the engineering-intense test pilot training.

Earlier, I noted that NASA was the “other” American space program in regards to physician-astronauts. In fact, NASA has flown additional physicians on the Space Shuttle, from Canada, Europe, Japan and Russia as well as America. Except for the Americans, they were almost always professional astronauts in their national astronaut corps. Many were private and commercial pilots or had considerable experience as non-pilot crewmembers aboard aircraft (ref. 9). However, none of them met the Bohannon criterion of pilot-physicians.

Finally, there are still “other” space programs actively flying astronauts, namely the Russian and Chinese. So far, there have not been any Chinese physician astronauts flown or even selected for training.


# physician-cosmonauts
# spaceflights
average # flights
The Russian and former Soviet space program has launched seven physician-cosmonauts a total of 11 times (two flew twice and another one flew three times) (ref. 3, 10, 11, 12). Two of them met the Bohannon criterion, and one became a military test pilot after his medical training. A similar analysis can be performed as for NASA, except the dependent variable must be only actual flight and not assignment, given the vagaries of flight assignments during the Soviet era. In this case, there appears to be a disadvantage to being a non-pilot physician cosmonaut, because they have not been part of the same dominant cosmonaut cadre formed in 2011 as the pilots and engineers. Therefore, they were unlikely to have had the same eligibility and access to flight assignments. One of the non-pilots is currently making his first flight so the number of spaceflights by non-pilot physician cosmonauts would increase if he flies again, but their ratio will not soon approach that of the pilot-physician cosmonauts. The test pilot-physician left medicine completely before becoming a cosmonaut and devoted himself to aviation, so he was a pilot-physician in name only, and is now retired.

American (NASA)
Pilot physicians
 Thus, in the two populations of astronauts for which data are available, the trend is for pilot-physicians to be selected at a higher rate than non-pilot physicians. The distinction is slightly stronger in the Soviet-Russian case, but no statistical analysis seems appropriate given the small and uneven sample populations.

Professional astronauts throughout the histories of NASA and other space agencies have necessarily been generalists in the fields of spaceflight engineering and science. Physicians have skills that are beneficial during research and clinical care episodes, but those are not the majority of in-flight activities on space missions to date. Additional qualification as jet pilots seems not to have had a major bearing on the success of physicians as astronauts, probably due to the general preparation and specific training they have all received for their missions, and the highly integrated nature of space missions to date.

In conclusion, the hypothesis I have attributed to Dr. Bohannon has been tested in two separate space programs over the four decades since he conceived it. The answer so far seems to be: maybe. In the U.S. space program, there is no meaningful difference in the flight-assignment rate, and thus programmatic acceptability, of pilot-physicians over non-pilot physicians. In the Soviet-then-Russian program, there does appear to be a slight numeric advantage to being a pilot-physician, but the numbers are so small and confounded as to be unreliable. My assessment is that the null hypothesis cannot be rejected: there is no meaningful difference in the crew-assignment frequency of one group over the other. This indicates that both groups are viewed as equally important in constituting space crews.

Dr. Bohannon identified a need for clinical and biomedical expertise in early astronaut crew composition, which was already biased in the direction of operations and away from utilization. He acted to remedy that weakness within the constraints of his time and situation. His foresight and initiative helped make possible the diversity of disciplines now considered necessary for successful space missions and the capacity of modern astronauts to embody those disciplines.

  1. For a brief but helpful overview of this military medical specialty, see “Flight surgeon” at (retrieved Nov. 3, 2013).
  2. Mapes, P.B. “The history of the United States Air Force Pilot-Physician Program,” Aviation Space and Environmental Medicine 62:75-80, 1991; (confirmed Nov. 2, 2013).
  3. Shayler, David J., and Colin Burgess, NASA’s Scientist-Astronauts, Springer-Praxis Publishing, Chichester, UK, 2007.
  4. National Research Council, Committee on Human Spaceflight Crew Operations, Preparing for the High Frontier: The Role and Training of NASA Astronauts in the Post- Space Shuttle Era, The National Academies Press, Washington, D.C., 2011, pp. 70-78, (retrieved Nov. 1, 2013).
  5. “Astronaut Biographies,” (retrieved Nov. 2, 2013).
  6. Kelly, G.F. “The history of the United States Navy flight surgeon/naval aviator program,” Aviation Space and Environmental Medicine 69:311-6, 1998.
  7. One of them, Manley L. Carter, Jr., is documented in United States Navy Test Pilot School, Historical narrative and class information, Supplement for years 1984 to 1992, Fishergate Publishing Co., Annapolis, MD, 1992.
  8. Koritz, T.F., “USAF Pilot/Physician Program: History, Current Program, and Proposals for the Future,” USAFSAM-TP-89-9, July 1989, specifically comments of Dr. Burt Rowen, p. 24, (retrieved Jan. 7, 2013).
  9. National Research Council, 2011, pp. 70-78.
  10. Vlassov, Vasiliy, and Igor Ushakov, “Soviet Pilot-Physician Program,” Aviation, Space and Environmental Medicine 70:713-6, 1999.
  11. Hooper, Gordon R., The Soviet Cosmonaut Team, Volume 2: Cosmonaut Biographies, 2nd ed., GRH Publications, Gunton, England, 1990. 
  12. McHale, Suzy, “RuSpace, Cosmonaut Group,” (retrieved Nov. 2, 2013).