Gemini 9A

Gemini 9A
Mission insignia
Mission statistics
Mission name	Gemini 9A
Spacecraft name	Gemini 9
Spacecraft mass	8,300 pounds (3,800 kg)
Crew size	2
Call sign	Gemini 9
Launch vehicle	Titan II #62-12564
Launch pad	LC-19 (Cape Kennedy AFS)
Launch date	June 3, 1966, 13:39:33 UTC
Landing	June 6, 1966, 14:00:23 UTC 27°52′N 75°0.4′W
Mission duration	3d/00:20:50
Number of orbits	47
Apogee	168.2 nautical miles (311.5 km) (highest)
Perigee	85.7 nautical miles (158.7 km) (lowest)
Orbital period	88.78 min (1st orbit)
Orbital inclination	28.91°
Crew photo
(L-R) Stafford, Cernan
Related missions
Previous Subsequent Gemini 8 Gemini 10

Gemini 9A (officially Gemini IX-A) was a 1966 manned spaceflight in NASA's Gemini program. It was the 7th manned Gemini flight, the 13th manned American flight and the 23rd spaceflight of all time (includes X-15 flights over 100 kilometres (62 mi)).

Crew

Original Prime Crew

The original prime crew of Gemini 9 - Elliot See and Charles Bassett

Position	Astronaut
Command Pilot	Elliot M. See, Jr.
Pilot	Charles M. Bassett II
Crew died in plane crash four months before launch

On the 28th February 1966, See and Bassett were flying from Texas to inspect the Gemini 9 spacecraft at the McDonnell Aircraft plant in St. Louis, Missouri. The conditions at Lambert Field were poor and, as a consequence, in attempting a visual approach and landing, See hit one of the assembly buildings of the factory and caused the aircraft to crash, killing himself and Bassett instantly. As a consequence, the backup crew was promoted to prime crew, the first time this had occurred since the flight of Mercury-Atlas 7 in 1962.

For more details on this topic, see 1966 NASA T-38 crash.

Original Backup Crew/New Prime Crew

Position	Astronaut
Command Pilot	Thomas P. Stafford Second spaceflight
Pilot	Eugene A. Cernan First spaceflight
Originally backup crew Assigned to fly after deaths of original prime crew

Backup crew

Position	Astronaut
Command Pilot	James A. Lovell, Jr
Pilot	Edwin E. Aldrin, Jr.

The promotion of Stafford and Cernan from backup to prime crew meant that a new backup crew was required. Jim Lovell and Buzz Aldrin were originally the backup crew for Gemini 10.This is significant as the standard crew rotation meant that a spot on the backup crew of Gemini 10 would have placed Buzz Aldrin on the prime crew of the non-existent mission after Gemini 12 (The crew rotation usually meant that after serving on a backup crew, an astronaut could expect to skip two missions and then be on a prime crew). Being moved up to the backup crew of Gemini 9 meant that Aldrin flew prime crew on Gemini 12, which played a major part in his selection for the Apollo 8 backup and Apollo 11 prime crews, ultimately making him the second man on the Moon.

Mission parameters

Gemini 9 original prime crew (front row, L-R) Elliott See, Charles Bassett;
and backup crew (back row, L-R) Tom Stafford, Gene Cernan

• Mass: 3,750 kilograms (8,300 lb)
• Perigee: 158.8 kilometres (98.7 mi)
• Apogee: 266.9 kilometres (165.8 mi)
• Inclination: 28.91°
• Period: 88.78 min

1st rendezvous

• June 3, 1966 - 17:45 - 18:00 UTC

Spacewalk

• Cernan
  • Start: June 5, 1966, 15:02:00 UTC
  • End: June 5, 1966, 17:09:00 UTC
  • Duration: 2 hours and 7 minutes

Objectives

Gemini 9A launch from LC-19

One of the mission objectives was to dock with an Agena Target Vehicle in the same manner as the Gemini 8 mission. However, during the launch of the Gemini 9 Agena on May 17, 1966, its Atlas booster malfunctioned (rather than the Agena itself, as had previously caused Gemini 6 to be recast as Gemini 6A), and it failed to make it to orbit. As a result, the Gemini 9 launch scheduled for later that morning was scrubbed.

On June 1, 1966 a substitute for the Agena was launched in the form of the ATDA (Augmented Target Docking Adapter), designed and built by McDonnell (the manufacturers of the Gemini spacecraft). The ATDA was made from the forward docking section of an Agena with the reentry control section of a Gemini. It was built using already tested equipment and launched using the Atlas-SLV3 rocket. The docking was canceled, though, after Stafford and Cernan rendezvoused with the target to find its protective shroud still attached over the docking port, which made it look, in Stafford's words, like an "angry alligator."

The ATDA is launched from Cape Kennedy's Pad 14 atop an Atlas launch vehicle at 10 a.m., June 1, 1966.

As well as the docking there was also a planned EVA by Cernan. The plan was for him to move to the rear of the spacecraft and strap himself into the Air Force's Astronaut Maneuvering Unit (AMU). This was the first 'rocket pack' and a predecessor of the Manned Maneuvering Unit used by Shuttle astronauts in the 1980s. It had its own propulsion, stabilization system, oxygen and telemetry for the biomedical data and systems. It used hydrogen peroxide for propellant, and because it produced extremely hot gases, Cernan's spacesuit was modified with "pants" made of woven steel known as "Chromel-R," which was later used on the gloves and Moon walking boots on Apollo spacesuits. This material was developed by the Air Force Systems Command for use in high-temperature deceleration devices for aerospace systems. (The current MMU uses nitrogen gas, which remains cold when vented.)

However, Cernan's spacewalk was troubled from the start. After pumping up his pressure suit to three and one half pounds of pressure per square inch, "the suit took on a life of its own and became so stiff that it didn't want to bend at all." He struggled to move inside his stiff suit." As soon as he left the spacecraft, he began tumbling uncontrollably. He eventually made it back to the hatch area and began the slow climb to the rear of the spacecraft where his AMU was stored. While he was disconnecting himself from his capsule and hooking up to the backpack, his heart rate rose to about 155 beats per minute. His spacesuit had "all the flexibility of a rusty suit of armor".", which made everything take much longer than expected. While making the connections, Cernan became very tired. As he sweated, his visor began to fog. He rubbed his nose against the visor the clear a hole so he could see." After making all the necessary connections, Cernan rested for a few minutes while Mission Control decided whether or not to proceed with the planned test of the AMU. Cernan, while physically exhausted wanted to proceed, but Stafford called an end to the proceedings and ordered Cernan back inside before getting a chance to fly the AMU". The device was not finally tested in space until a modified version called the Manned Maneuvering Unit (MMU) was flown by astronaut Bruce McCandless on Shuttle Mission STS-41-B in 1984, 18 years later. As a result of Cernan's experience, the AMU never again flew on Gemini, as it was not essential to developing technology for the Apollo Moon landing mission.

The Gemini spacesuit was cooled by air. When an astronaut had an increased work load he began to sweat and in the confined space of a suit the cooling system would become overwhelmed and the visor would fog. The astronaut would then be effectively blind because he had no way of wiping off the faceplate. In future Gemini EVAs, the work loads of the astronauts were reduced, but it was clear that during lunar exploration workloads could be significant and changes were made to ensure that the Apollo EVA suit would be water cooled. This was accomplished by having the astronaut wear a garment that contained many thin tubes that circulated water near the skin. It was very effective and there were very few cases where astronauts used the "High" Cooling selection even though they were working hard and on the Moon in a 100 °C sun.

Flight

Launch attempts

	Gemini 9 Target Vehicles
Agena	GATV-5004
Mass	3,252 kilograms (7,170 lb)
Launch site	LC-14
Launch date	May 17, 1966
Launch time	15:12 UTC
Destroyed	15:19 UTC
ATDA	#02186
NSSDC ID:	1966-046A
Mass	794 kilograms (1,750 lb)
Launch site	LC-14
Launch date	June 1, 1966
Launch time	15:00:02 UTC
1st perigee	298.4 kilometres (185.4 mi)
1st apogee	309.7 kilometres (192.4 mi)
Period	90.5 min
Inclination	28.87
Reentered	June 11, 1966

The first launch attempt of Gemini 9A was on June 1, 1966. The ATDA had launched perfectly into a 298 kilometre orbit, though telemetry from it indicated that the launch shroud had failed to open properly. But the Gemini spacecraft was not able to launch the same day as planned. At T-3 minutes, the ground computers could not contact the Gemini computers for some reason and the 40 second launch window opened and closed without the launch. This earned Tom Stafford the title of "Mayor of Pad 19."

The second launch attempt went perfectly with the spacecraft entering into orbit. With this launch, Stafford could say that he had been strapped into a spacecraft six times ready for launch.

Rendezvous

Tom Stafford inside Gemini spacecraft

Stafford made the first thruster burn 49 minutes after launch, to add 22.7 meter per second (74 ft/s) to their speed, raising their perigee from 160 to 232 kilometers (86 to 125 nmi). An hour and 35 minutes later, Stafford corrected phase, height, and out-of-plane errors by pointing the spacecraft 40° down, and 3° to the left. Fifty-one seconds later, he fired the thrusters again to add 16.2 meter per second (53 ft/s) to their speed and put them into a 274-by-276-kilometer (148 by 149 nmi) orbit, closing at 38 meter per second (120 ft/s) on the ATDA.

The first radar contact with the target registered a distance of 240 kilometers (150 mi) away and they had a solid lock at 222 kilometers (138 mi). Their first visual sighting came 3 hours and 20 minutes into the mission, when they were 93 kilometers (58 mi) away. They noted that they could see the flashing strobe lights on the ATDA, designed to aid identification from a distance. This made them hope that the launch shroud had in fact been jettisoned and that the telemetry was wrong.

As they got closer, they found the ATDA to be in a slow rotation, with the conical nose shroud still attached, the two pieces hanging agape at the front like a giant, open jaw. Stafford described "It looks like an angry alligator out here rotating around". He asked if maybe he could use the spacecraft to open the 'jaws' but the ground decided against it, fearing this might cause damage to the spacecraft.

ATDA, with its payload fairing still attached, as seen from Gemini 9

The crew described how the shroud's explosive bolts had fired, but two neatly taped lanyards were holding the shroud together. In Mission Control, backup pilot Buzz Aldrin suggested that Cernan cut the spring-loaded lanyards with surgical scissors from the equipment pack. An experiment on the ground demonstrated this could indeed slice the lanyards, but also showed the ATDA bristled with dangerous, sharp edges. Ground controllers were, in Deke Slayton's words, "just aghast" at the idea, which did not take into consideration the substantial risks of the explosive bolts holding the lanyards together, the constant spinning of the ATDA, or the fact that the lanyards, under pressure from the springs, might snap apart, whip back, and puncture Cernan's spacesuit. The reason for the lanyards' condition was soon discovered: Douglas built the shroud to be attached to the Agena second stage but the Air Force decided at the last minute that Atlas could achieve the desired orbit without NASA's second stage. This dropped NASA out of the launch and meant that the ATDA and fairing would be installed directly on Atlas—not Agena—and by a McDonnell crew instead of the normal Lockheed crew.

ATDA in orbit, the "angry alligator"

NASA had contracted the Douglas engineer to witness, inspect and sign off on the fairing installation, but before the mission he had gone home to be with his pregnant wife. On launch day, the McDonnell crew followed procedures published by Lockheed, which had been copied from Douglas documents. The instructions said, "See blueprint," but the Lockheed drawing was not used. The Douglas technician who normally hooked up the lanyards knew what to do with the loose ends, even without the blueprint. But he was not there, and the strangers fixing the ATDA's shroud looked at the dangling straps, wondered what to do with them, and taped them under the small fairings that protected the explosive bolts. After the launch, the Douglas engineer, with the help of Lockheed, set up a backup fairing and demonstrated the problem to McDonnell personnel and to George Mueller, NASA assistant administrator.

The crew then did some planned rendezvous practice that involved them moving away from the ATDA by firing their thrusters and then practising approaching from below the target. They then got some much needed food and rest.

On the second day of the mission, they again approached the ATDA, this time from above. Once they were stationkeeping alongside, they were given permission for their EVA. But they were tired and Stafford didn't want to waste fuel keeping himself near the ATDA during the EVA when there was little they could do with it. So it was decided to postpone the EVA until the third day.

EVA

Astronaut Eugene Cernan during EVA

On the third day Cernan finally reached the rear of the spacecraft and began to check and prepare the AMU. This took longer than planned due to lack of hand and foot holds. He was unable to gain any leverage which made it hard to turn valves or basically any movement. All this was made worse when after sunset, his faceplate fogged up. His pulse soared to about 195 beats per minute. The flight surgeon on the ground feared he would lose consciousness.

At this point Cernan decided that there was considerable risk in continuing the EVA. He had poor visibility from within his spacesuit and had found that he could not move very well. He would have to disconnect himself from the umbilical that attached him to the Gemini (though would still be attached by a longer thinner lead), after he had connected himself to the AMU. But when he had finished with the AMU he would somehow have to take the thing off with one hand, while the other held onto the spacecraft. He decided to cancel the rest of the EVA, with Tom Stafford and the Mission Controllers concurring.

He managed to move himself back to the cockpit and Stafford held onto his legs to give him a rest. After trying to remove a mirror mounted to the side of the spacecraft, his suit cooling system overheated and his faceplate fogged up completely, denying him any vision. He and Stafford managed to get the hatch closed and repressurised. Cernan had spent 128 minutes outside the spacecraft. Cernan's difficult EVA experience, which continued the EVA problems of the previous Gemini missions, contributed to a complete NASA reappraisal of EVA training and procedures for future Gemini and Apollo flights.

Stafford has said in a 2001 interview that there was a real concern that Cernan would not be able to get back into the capsule. As it would not have been acceptable for Stafford to cut Cernan loose in orbit he stated that the plan was to make re-entry with the astronaut still attached by his umbilical. However, such an action would have resulted in the deaths of both men.

As well as the rendezvous and EVA, the other major objective of the mission was to carry out seven experiments. The only medical experiment was M-5, which measured the astronauts reactions to stress by measuring the intake and output of fluids before, during and after the flight.

Experiments

There were two photography experiments. S-1 hoped to image the Zodiacal light during an EVA, but this was changed to inside the spacecraft after the problems encountered by Cernan. And S-11 involved the astronauts trying to image the Earth's airglow in the atomic oxygen and sodium light spectra. They took 44 pictures as part of this experiment with three being of actual airglow.

S-10 had hoped to retrieve a Micrometeorite Collector from the ATDA, though this failed after they were unable to dock with it. They were able to image it though during their close approaches. Instead they were able to recover the collector from the Gemini spacecraft (S-12). D-12 also failed as it was an investigation of controlling the AMU.

The last experiment was D-14 which was UHF/VHF Polarization. This was an extendable antenna mounted on the adapter section at the rear of the spacecraft. It was hoped to obtain information about communication through the ionosphere. Six trials of this were performed but the antenna was broken by Cernan during his EVA.

Reentry

Gemini 9 splashes down at 9:00 A.M., June 6, 1966.

The day of the EVA was also their last in space. On their 45th revolution of the Earth, the crewmen fired the retrofire rockets that slowed them down so that they would reenter. This time the computer worked perfectly, meaning they landed only 700 meters from the planned landing site and were close enough to see the prime recovery ship, USS Wasp. The splashdown happened closer to the recovery ship than any other manned spacecraft.^{[citation needed]}

After the mission it was decided to set up a Mission Review committee to make sure that the objectives planned for each mission were realistic and that they had a direct benefit for Apollo.

The Gemini 9A mission was supported by the following U.S. Department of Defense resources: 11,301 personnel, 92 aircraft and 15 ships.

Insignia

The Gemini 9 patch is in the shape of a shield and shows the Gemini spacecraft docked to the Agena. There is a spacewalking astronaut, with his tether forming the shape of a number 9. Although the Gemini 9 mission was changed so that it docked with the ATDA, the patch was not changed. It is also not known whether Bassett and See had designed a patch for the mission as the original crew.

Spacecraft location

The spacecraft is on display at the Kennedy Space Center Visitor Center, Florida.

• 

  Gemini 9 spacecraft

• 

  Heatshield

See also

• Agena Target Vehicle
• Extra-vehicular activity
• List of spacewalks
• Splashdown
• Space exploration
• U.S. space exploration history on U.S. stamps
• Space suit
• Space capsule

References

 This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration.

External links

• NASA Gemini 9-A press kit - May 28, 1966
• On The Shoulders of Titans: A History of Project Gemini: http://www.hq.nasa.gov/office/pao/History/SP-4203/cover.htm
• Spaceflight Mission Patches: http://www.genedorr.com/patches/Intro.html
• Buy the AMU trainer: http://www.collectspace.com/buyspace/artifacts-gemini.html
• http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1966-047A
• U.S. Space Objects Registry http://usspaceobjectsregistry.state.gov/search/index.cfm