Gemini and the Ejection Seat
In Memory of William L. Meyer, Jr. (5/23/1933 to 12/22/2012)
Fifty years ago this week, an aeronautical engineer celebrated his 30th birthday while working with other McDonnell Aircraft engineers on a problem – how to safely jettison two astronauts out of their Gemini capsule in the event of a low atmosphere catastrophe.These were amazing and inspiring technological times. We were in the “Race to Space” – a competition with the USSR that touched upon both countries need for supremacy. Challenges often lead to inspiration and to achievement; this quest for manned space flight and a trip to the moon did much more. It not only provided exciting opportunities for those lucky few charged with the goal to take us into space, but it also inspired a generation of new scientists and engineers to dream big.
The Mercury and Gemini projects were the beginnings of our space program in the US. Project Mercury set the goal to send one man safely into orbit around the Earth at the earliest possible date and to recover the space vehicle at the end of the trip. The US desire to also send the first man into space was not achieved – a Russian cosmonaut Yuri Gagarin made the first manned orbit of Earth in the Vostok capsule on April 12, 1961. One month later, on May 5, American Alan Shepard became the second man to orbit the Earth. The race was underway. Following Shepard’s first ride, Mercury capsules took 5 more astronauts into space for one, then three, then six orbits. When the final Mercury mission was completed, astronaut and aeronautical engineer Leroy Gordon Cooper, Jr. spent over 34 solo hours in space completing 22 orbits.
McDonnell Aircraft Corporation was a fundamental part of the early space program – the Mercury space capsules were built at their St. Louis facility. McDonnell proposed Gemini to NASA as experiments that would answer questions the Mercury project could not. Astronauts sent to the moon would be in space longer than the Mercury mission and they would be sending more than one person. Repairs on equipment, inside and out, might be necessary during the mission. Improvements in the design of the capsule were needed to improve repair work and Extravehicular Activities, or Spacewalks, were part of the Gemini program to determine whether it was possible to conduct difficult manual work at length in space. While the Mercury vehicles were automated – essentially controlled from the ground – the Gemini modules would be flown by an astronaut pilot. Not just flown in orbit around the Earth, but maneuvered in space and docked with an unmanned vehicle that would supply the fuel and propulsion needed for extended time in space or a return trip from the moon. Finally, the Gemini team sought to improve re-entry methods, which included the goal of landing not in the ocean but on land. This last goal, to touch down on land, was the only one that was not achieved.
The Gemini capsule, as proposed by the McDonnell team, was different from Mercury. The controls and electronics were now modular and allowed individual parts to be repaired without disturbing other equipment. Where the Mercury capsule had an escape tower attached at the nose, the Gemini capsule would contain ejection seats and blow-out panels on the spacecraft in the event of a low atmosphere catastrophe. The capsule would be taken into space by the Titan II missile, which had more power than the Atlas rocket used with Mercury. It also used a new fuel mix that could be stored on Titan II until used – earlier rockets required super-cooling of the propellants. The initial design for Gemini included a new design for touchdown on land. Part hang-glider wing, part balloon, part parachute, the Rogallo flexible wing was eventually removed from the project scope in favor of the tested parachute ocean landing. In 1962, McDonnell engineers in St. Louis worked with Rocket Power Inc. (Mesa, AZ) and Weber Aircraft (Burbank, CA) on an interesting but controversial problem – how to eject two men from the Gemini capsule 45 meters high and with enough force to outrun the fireball of an exploding Titan II rocket. The safety of the astronauts was paramount to a successful space program and so plans were needed should a low atmosphere catastrophe like the explosion of the rocket booster occur. The Mercury capsule had an escape tower attached at the nose – in an emergency, a sequence of events would cause the escape tower’s rocket to fire and pull the capsule away from danger. This tower added significant weight to the capsule, so the Gemini designers tried something new.Ejection seats were used in military aircraft, but to use them in a spacecraft was novel. The seats would be propelled to travel a distance of about 800 feet at a trajectory high enough to allow the parachutes to open. To achieve this, Rocket Power designed a rocket catapult (ROCAT) that attached to the Weber Aircraft seat. Tests of the ejection seat were conducted at China Lake in the California Mojave Desert and as innovations go, each experiment would highlight a problem, each problem would be solved by a fix, the fix would be tested and work, but a new problem would arise. In the fall of 1962, the system trials would be considered a success from what was learned but actual success of the seat was in doubt. A second series of tests were started in February of 1963. Again, the complete system did not work as planned, but with a key problem identified, technical progress was more assured. The final design package was completed on April 22, 1963 and testing of this system initiated on May 15 and continued through the summer with positive results. The ejection seats would be ready in time for launch.
The engineers and scientists on the Gemini Project faced and overcame many other challenges. In the end, the program successfully paved the way for the Apollo moon trip by answering a number of questions. The first unmanned test flight of Gemini occurred on April 8, 1964, and less than one year later, on March 3, 1965 the first manned flight of Gemini III with astronauts Virgil “Gus” Grissom and John W. Young blast off. Aboard Gemini IV, Edward H. White made the first US space walk on June 3, 1965 – again, following the Russians who were first to achieve the landmark. By the final flight on Gemini XII, Edwin “Buzz” Aldrin successfully accomplished a 5 ½ hour spacewalk with exercises.Several missions were conducted to work out the challenges of docking with the unmanned Agena vehicle. Initial attempts were cancelled due to equipment malfunction but early rendezvous experiments were completed when Gemini VI and VII flew together in space separated by a few feet for several hours. The first actual docking of Gemini VIII with Neil Armstrong at the helm caused a serious and potentially fatal spin and ended the flight in an emergency landing. Gemini X accomplished the first successful docking mission and use of the Agena propulsion system to power both vehicles. This mission was followed by further success on Gemini XI, which made 44 orbits of Earth, and Gemini XII, the last Gemini flight November 11, 1966.
It is an amazing thing to see a project from design to manufacture to operation. The Gemini Project team could celebrate 12 missions, each one bringing back knowledge to pass along to Apollo. All systems tested save one – the ejection seats were never used. Sometimes, our best challenges and successes go unnoticed. But the effort and the achievement are there just the same and while the glory might just be in the memories of a few people working on a great project 50 years ago, the accomplishment is not diminished. Great job Dad!
For a detailed look a the Gemini Project, read “On the Shoulders of Titans: A History of Project Gemini” by Barton C. Hacker and James M. Grimwood, 1977 at: http://history.nasa.gov/SP-4203/toc.htm. Photo images obtained from NASA.
Courtesy of Jeff Quitney on YouTube.
Video from STAR FLIX on YouTube.