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Post-Landing Orion Crew Survival in Warm Ocean Areas: A Case Study in Iterative Environmental Design George E. Rains1, Grant C. Bue2, Jerry Pantermuehl1 1ESCG-Jacobs-Svedrup, Houston TX 2NASA Johnson Space Center, Houston TX Copyright © SAE International ABSTRACT varied across different vehicles, programs, and nations, but a common component has always been some capability for crew survival following The Orion crew module (CM) is being an unplanned or off-nominal water landing. designed to perform survivable land and water landings. There are many issues Given the geography of the U.S. manned space associated with post-landing crew survival. program, where all manned launches have taken place eastward over the Atlantic Ocean, it In general, the most challenging of the was inevitable that all of NASA’s early manned realistic Orion landing scenarios from an spacecraft would be capable of performing water environmental control standpoint is the off- landings. Since a water landing capability had nominal water landing. Available power to be provided, in any case, for the first and other consumables will be very limited astronauts to survive possible contingencies following a launch failure, it was expeditious for after landing, and it may not be possible to NASA to make water landing the normal mode provide full environmental control within of operation following a successful mission. the crew cabin for very long after This programmatic logic held true for Mercury, splashdown. Given the bulk and thermal Gemini, and Apollo, and was revised only with insulation characteristics of the crew-worn the advent of the Space Shuttle. The new Orion spacecraft may return to water landing as the pressure suits, landing in a warm tropical normal mode of operation, but with additional ocean area would pose a risk to crew capability for post-landing crew support. survival from elevated core body temperatures, if for some reason the Previous NASA Experience crewmembers were not able to remove their Mercury [1] suits and/or exit the vehicle. This paper summarizes the analyses performed and Due to the constraints imposed by technology, conclusions reached regarding post-landing vehicle weight, and very aggressive program crew survival following a water landing, schedules, the capability of Mercury capsules to from the standpoint of the crew’s core body sustain their sole occupants following landing temperatures. was very limited. The capsules were always intended to land in the ocean; investigations into the possible consequences of an unplanned INTRODUCTION landing on dry land were also apparently very limited. Nevertheless, the capsules did not float Following long-established standard practice in very well, and there were no on-board provisions the aircraft industry, safety provisions for for additional vehicle flotation beyond the limited manned spacecraft have always included some inherent buoyancy of the capsule. One Mercury arrangements for survival of the crew in capsule, that of Virgil “Gus” Grissom, was lost contingency situations. These provisions have when it quickly filled with water following a 1 premature hatch opening. Another, containing a a pre-designated secondary landing site. The chimpanzee test subject named “Ham,” was vehicle landed outside of helicopter range from almost lost when it sustained damage on landing the nearest aircraft carrier, and the sea was that allowed the water to leak in more slowly. quite rough, with sea swells of 4 to 5 meters in height. However, larger land-based search and Mercury astronauts were provided with a small rescue aircraft were in the air and on the way to inflatable dinghy as part of their personal the projected landing site as soon as the emergency equipment, but the only astronaut emergency was declared. Three rescue divers who needed to make use of it following his flight jumping from the first aircraft to arrive were able was Scott Carpenter. He came down some 250 to attach a flotation collar to the outside of the miles past his intended landing zone, and had to spacecraft 45 minutes after splashdown. exit his capsule and then wait 3 hours in the Despite some nausea caused by the high seas, water before being picked up. The other Mercury the crew were still able to climb a rescue ladder astronauts were all recovered less than an hour onto the first ship to arrive, a U.S. Navy after landing. Alan Shepard and Gus Grissom destroyer, approximately 3 hours after both exited their capsules and were in the water splashdown. This feat may have been possible briefly before being hoisted aboard a helicopter. only because of the short duration of the flight, “Ham,” John Glenn, Walter Schirra, and Gordon as the thruster failure occurred early in the Cooper all remained inside their capsules until mission, and Gemini 8 was in space for less after the capsule was brought aboard the than 11 hours. recovery ship. Apollo Gemini [2] Following on the obvious utility of the Gemini The two-man Gemini capsule was a significantly flotation collar, the three-man Apollo spacecraft enlarged and refined version of the original retained this feature, and also added some Mercury design. Gemini missions were still seemingly minor, but significant, provisions for intended to conclude with a landing in the crew support after landing. Should the ocean, and again the capability of capsules to spacecraft roll over after it was in the water, sustain their occupants following splashdown inflatable balloons called “uprighting bags,” was very limited. installed near the top of the conical capsule beneath the parachutes, provided enough In seven of the ten manned Gemini flights, at the buoyancy to prevent the vehicle from remaining end of the mission the crewmembers exited the upside down. A battery-powered fan and vehicle while it was still in the water, and were ventilation openings were also added near the then individually hoisted aboard a recovery top of the vehicle, to provide fresh air and some helicopter. Two crews (those of Gemini 6 and 9) cooling to the interior of the spacecraft after elected to remain within the capsule until after it landing (with appropriate safety devices to was lifted onto the recovery ship. In all nine of prevent water ingestion or opening to vacuum these missions, the spacecraft came down very while in space). However, support divers or close to its intended landing point, and divers para-jumpers were still needed in order to attach were present to quickly attach an additional the separate flotation collar to the outside of the flotation collar to the outside of the spacecraft. vehicle before the side hatch could be safely The flotation collar represented a significant opened, as the base of the side hatch was only improvement compared to Mercury, and about 1.6 feet above the water level in a lessened the danger that the spacecraft would perfectly calm sea. fill with water and sink, either due to damage or when the hatches were opened. It was originally intended that the Apollo capsules would be able to land on dry land as Only one mission, Gemini 8, had what could be well as water, but early drop testing revealed considered a contingency or off-nominal landing. that the descent rates and impact loads were too Following the on-orbit failure of a maneuvering high for safe landings on land. Correcting the thruster, the crew (Neil Armstrong and David problem would have delayed the program Scott) had to conduct an emergency de-orbit to significantly, and would also have added 2 considerably more mass to the spacecraft. a water landing, a single large life raft and Given the urgent and heated nature of the survival equipment were nevertheless provided, “space race” at the time, NASA decided that a in the hope that the crew would be able to land landing capability for Apollo was an egress the vehicle before it sank. unnecessary luxury, and all the Apollo capsules returning from space conducted water landings Following the loss of the space shuttle only. Challenger on STS-51L, more thorough studies were conducted of shuttle abort modes and Including the follow-on Skylab and Apollo-Soyuz contingency water landings. It was determined flights, there were a total of fifteen manned that, even when in controlled gliding flight, the missions of the Apollo spacecraft. All fifteen shuttle’s high landing velocity compared to came down inside their planned landing zones, normal aircraft would most likely lead to a within easy helicopter range of a waiting aircraft catastrophic breakup of the vehicle upon contact carrier. At the conclusion of each of the eleven with the water. The only way for the crew to Apollo missions, divers first attached the survive an impending water landing would be to external flotation collar, and then the three bail out first. crewmembers opened the side hatch, exited the vehicle while it was still in the water, and were This realization led to the addition of an in-flight lifted aboard a recovery helicopter. The Apollo 8 bailout system, carried on every subsequent mission recorded the longest time from shuttle flight, featuring pressure suits, individual splashdown to crew recovery (88 minutes), and parachutes, small enclosed personal life rafts, the Apollo 9 mission encountered the roughest and communications and survival gear. A sea conditions, experiencing wind waves seven telescoping guide pole was also necessary so feet (2 meters) in height. Despite the high sea, that crewmembers bailing out of the side hatch the Apollo 9 crew was still recovered in a near- would not hit the wing. average time of 49 minutes after splashdown. Once in the water, the greatest threat to For the three long-duration Skylab missions and surviving crewmembers was thought to be the single Apollo-Soyuz flight, the crewmembers hypothermia (cold).

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