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Product Name: Gemini 9A

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Gemini 9A was the seventh crewed Earth-orbiting spacecraft of the Gemini series. It carried astronauts Tom Stafford and Gene Cernan. Primary mission objectives were to demonstrate (1) rendezvous techniques and docking with a target vehicle to simulate manuevers to be carried out on future Apollo missions, (2) an ExtraVehicular Activity (EVA) spacewalk to test the Astronaut Maneuvering Unit (AMU), and (3) precision landing capability. Scientific objectives included obtaining zodiacal light and airglow horizon photographs. Two micrometeorite studies were to be carried out, and there were also one medical and two technological experiments. Mission Profile The mission was originally scheduled for launch (as Gemini 9) on 17 May but was postponed when the Gemini Agena Target Vehicle failed to achieve orbit due to a booster failure earlier that day. The replacement Augmented Target Docking Adapter (ATDA) was launched successfully into Earth orbit on 1 June, but telemetry indicated that the shroud had failed to jettison properly. Gemini 9 was to launch shortly thereafter but ground equipment failure resulted in a postponement until 3 June. Gemini 9A was launched on 3 June from Complex 19 at 8:39:33 a.m. EST (13:39:33.335 UT) and inserted into a 158.8 x 266.9 km orbit. After three orbital maneuvers, rendezvous within 8 meters of the ATDA was achieved on the third revolution. It was confirmed that the launch shroud on the ATDA had failed to deploy and was blocking the docking port. The flight plan was then revised to include two equiperiod passive rerendezvous maneuvers in place of the docking. The first, using optical techniques without on-board radar, was completed at 3:15 p.m. EST, and the second, a rendezvous from above simulating rendezvous of an Apollo command module with a lunar module after abort from the Moon, was completed at 6:21 a.m. EST on 4 June and final departure from the ATDA took place at 7:38 a.m. The scheduled EVA was postponed due to crew fatigue and the second day was devoted to experiments. On 5 June at 10:02 a.m. EST the Gemini capsule was depressurized and the hatch above Cernan opened. Cernan was out of the spacecraft at 10:19, attached by an 8 meter long tether which was connected to Gemini's oxygen supply. He had no gas maneuvering unit as was used on Gemini 4. He retrieved the micrometeorite impact detector attached to the side of the capsule and then moved about the spacecraft. He had great difficulty manuevering and maintaining orientation on the long tether. He took photographs of Gemini from the full length of the tether and finally moved to the back of the capsule where the Astronaut Maneuvering Unit (AMU) was mounted. He was scheduled to don the AMU, disconnect from the Gemini oxygen supply (although he would still be attached to the spacecraft with a longer, thinner tether) and move to 45 meters from the capsule. The task of donning the AMU took "four to five times more work than anticipated", overwhelming Cernan's environmental control system and causing his faceplate to fog up, limiting his visibility. It was also discovered that the AMU radio transmissions were garbled. These problems caused Stafford to recall Cernan to the spacecraft. He reentered the spacecraft at 12:05 p.m. and the hatch was closed at 12:10. Cernan was the third person to walk in space and his total time of 2 hours, 8 minutes was the longest spacewalk yet. Retrofire occurred at the end of the 45th revolution on 6 June at 8:26:17 a.m. EST. Splashdown was at 9:00:23 in the western Atlantic at 27.87 N, 75.00 W, 550 km east of Cape Kennedy and 0.7 km from the target point. The astronauts stayed inside the spacecraft and were brought aboard the recovery ship U.S.S. Wasp at 9:53 a.m. Total mission elapsed time was 72:20:50. Of the primary objectives, three rendezvous techniques were demonstrated, although docking could not be achieved due to the failure of the augmented target-docking shroud to jettision. Testing of the AMU was not completed. The Agena micrometeorite experiment hardware was lost when the Agena target vehicle failed to achieve orbit. Other experiments functioned normally. The Astronaut Maneuvering Unit (AMU) The AMU was a 75 kg backpack, 81 cm high, 56 cm wide, and 48 cm deep, mounted on the rear of the Gemini capsule adapter section. It had a form-fitting seat, a 45 meter nylon tether, and self-contained life-support, communications, telemetry, propulsion, and manual and automatic stabilization systems. The propulsion system consisted of 12 small thrusters mounted on the corners of the pack using a hydrogen peroxide fuel supply and thruster controls on two sidearm supports. The backpack could be accessed by a spacewalking astronaut who would move to the back of the craft, put on the backpack, and disconnect the spaceship tether and oxygen supply before using the AMU.