Space Suits Past and Future

Bill Elkins has been outfitting astronauts since before NASA was born.

Testing the AiResearch Advanced Extravehicular Suit’s range of motion in the 1960s. (Courtesy Bill Elkins)

Bill Elkins has been called “one of the true fathers of the space suit.” Within months of the Sputnik 1 launch in October 1957, he began working at Wright-Patterson Air Force Base in Ohio on “restraint couches” for astronauts. In the late 1960s, as a chief engineer at Garrett AiResearch, his team outcompeted four established space suit manufacturers to win the NASA contract to build long-endurance lunar suits that were to have flown on Apollos 18, 19, and 20. His suit never made it to the moon, however, because NASA cancelled all landings after Apollo 17 in December 1972.

Since then Elkins, who is in the U.S. Space Foundation’s Space Technology Hall of Fame, has founded several companies. Today, at age 80, he lives outside Sacramento, California, and continues working, having founded bioCOOL Technologies in 2004 and the consulting firm, WElkins in 2007. He spoke recently with Air & Space Associate Editor Mike Klesius.

Air & Space: How did the first astronaut restraint systems compare to jet pilot systems already in use?

Elkins: A jet pilot restraint system has a hard backpan and seat. It mainly is trying to contain the pilot in the seat, in a sitting position. In an astronaut couch you’re lying on your back. [In the late 1950s] they were planning a cast, form-fitting, backpan restraint couch for the astronauts. But in tests at high G it was causing substernal pain, where the sternum of the occupant would compress into the chest. I designed a sophisticated hammock supported by a tubular steel frame. It left your body in a more normal, natural form at high G. The Mercury project was then transferred to NASA and I lost track of that research. In the end, they went with the harder, backpan restraint couch.

A&S: You once sustained 16.5 Gs, an apparent record for pulling Gs and remaining conscious.

Elkins: We were examining a worst-case G scenario for a Mercury launch. So they put me in the 20-foot-arm centrifuge at Wright-Pat. The G profile was based on the maximum G that could be experienced during the launch. If the escape rocket was fired at maximum dynamic pressure—Mach 1 at roughly 40,000 feet—then 15.5 G would be experienced by the astronaut. So we [added] one G…and “flew” it on the centrifuge. The whole run duration was about three minutes. I began to gray out a bit at 13 G. Then I was above 15.5 G for about six seconds. I “flew” a tracking task with my right hand, and I had a button I could press with my left hand to respond to peripheral lights. I recently discussed this matter with Jim Brinkley, who was contemporary with me at Wright-Patterson. He became the head of the Biodynamics Lab and is an internationally recognized biodynamicist. He confirmed, to the best of his knowledge, that the 16.5 sustained G remains a benchmark achievement. They shut down that centrifuge for good not long after we did those runs in December 1958. We burned it out, I guess.

A&S: How did you get into designing space suits?

Elkins: Those runs are what got me into the spacesuit world, first at Litton where I developed the RX (rigid experimental) series of suits, and then at AiResearch, where, in about two years, I became chief engineer and developed the EX-1A and the AES [Advanced Extravehicular Suit] that won the competition for the extended Apollo mission suit.

Early on, a physicist at Litton was developing a vacuum chamber pressure suit, but Litton thought they were causing permanent heart damage. I had miles of EKGs from my centrifuge runs, so I had a certified healthy heart and was chosen as the test subject to verify or deny the problem. The lab they brought me to was in Beverly Hills, California, of all places. For lunch that day, at a local deli, I made the mistake of ordering a corned beef sandwich with the hottest mustard they had, and shortly before the test began, I started getting some serious heartburn. Well, they put me in a pressure chamber and took me up to 400,000 feet equivalent. The doctor asked me how I was feeling, and I said,  “Fine, but I’m feeling a little heartburn.” He said, “Lay back!” and made me swallow a nitroglycerin pill. A subsequent conference of heart specialists determined there was no problem with the vacuum chamber suit.

A&S: What’s the biggest challenge in designing an effective space suit?

Elkins: Well, a big one is mobility, specifically the joints. If you look at the Apollo [suit] joints, the farther you bent them, the more effort it took and the harder it was to hold that position. Those suits were spring loaded to come back to the neutral position. So it took a constant force to keep them out of neutral, and that was very fatiguing. But when you move a constant volume joint to a new position, no further force is needed. When I left Litton and went to AiResearch, I invented the toroidal joint. Toroids maintain constant volume so long as the centerline remains constant. At AiResearch I designed the EX-1A [suit], the first prototype suit to use toroidal joints, in 1967. It was an outstanding suit.

A&S: What were the advantages of the hard suit versus the soft suit? Why two totally different kinds?

Elkins: There are some advantages of the hard suit, although I did not remain a proponent of it. The hard suit had value for being able to go to much higher pressures. The higher you go, the less likely you are to have the bends when exiting a higher-pressure space vehicle. So if you were wearing one, you could scramble to do an emergency [spacewalk] because you didn’t have to pre-breathe for four hours. It’s a very mobile little spaceship, if you will. Vic Vykukal, a NASA Ames engineer, also did pioneering work on the hard suit. Although it demonstrated excellent mobility, it was heavier because of the hard structural components, and the joints did not exhibit the long-life capability of the toroidal joint.

The soft suit came from a line of pressure suits used by the Air Force and Navy. BF Goodrich’s soft suits for the Mercury project were evolved from a Navy pressure suit. David Clark made soft suits for Gemini. Then ILC came into the Apollo program. They all came from that same soft emergency pressure suit lineage. It was a question of cultures and politics within the R&D labs. There was the West Coast technology such as Litton, and NASA’s Ames Research lab; but then the older timers from the East who knew soft suits. Ultimately, soft suits won out.

A&S: It’s often pointed out that the moon suits were so heavy. What was the single heaviest element?

Elkins: I think it was the PLSS, portable life support system [backpack]. The suit by itself would weigh about 60 pounds.

A&S: What was driving the desire for design changes in lunar suits for the extended Apollo missions?

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