USS HASSAYAMPA (AO-145)

United States Navy

Home Port Pearl Harbor, Hawaii

Gemini VIII
Mission Objective

Primary objective was to rendezvous and dock with Gemini Agena target vehicle (GATV-5003) launched on 3/16/1966 from Complex 14 (TLV-5302) and conduct EVA operations. 

Secondary objectives included: 

• Rendezvous and dock in 4th revolution. 
• Perform docked-vehicle maneuvers, 
• Evaluate systems and conduct 10 experiments. 

Orbit: Altitude: 298.7km (161.3 nm)
Inclination: 28.91 degrees
Orbits: 7
Duration: 0 Days, 10 hours, 41 min, 26 seconds

Landing:

March 17, 1966. Landing was at 25 deg 13.8 min North and 136 deg 0 min East. Pacific Ocean. Recovered by the USS Mason (crew onboard in 3 hours).

Mission Highlights:

Gemini-VIII successfully docked with Gemini Agena target vehicle GATV 6 hours 34 min after liftoff. Because of problems with the spacecraft control system, the crew was forced to undock after approximately 30 min. The spacecraft-target vehicle combination had begun to encounter increasing yaw and roll rates. The crew regained control of their spacecraft by using the reentry control system, which prompted an early landing in a secondary landing area in the Pacific. No EVA was performed.

The failure was caused by an electrical short in control system. Docking and re-rendezvous secondary objectives were not achieved due to the shortened mission.

Within hours of the launch and after completing the docking, Gemini 8 began to spin uncontrollably. Armstrong took control and released Agena. However, Gemini continued to whirl at better than 1 revolution per second. A half an hour later, Armstrong finally got Gemini under control and made an emergency reentry and splashdown. It was later discovered that one of the maneuvering thrusters on the vehicle was stuck open, thus creating a spin. The total mission only lasted just under 11 hours.

If Neil Armstrong encountered any serious problems during the first moon landing, he would be well prepared. Armstrong and copilot Dave Scott were launched into space to conduct NASA's first orbital rendezvous and docking. The target was an Agena rocket. The linkup was flawless but short-lived: a jammed thruster sent the spaceship and Agena rocket tumbling.

The Gemini VIII spacecraft lifted from Launch Complex 19 at 11:41 a.m., with command pilot Neil A. Armstrong and pilot David R. Scott aboard. The spacecraft and target vehicle rendezvoused and docked, with docking confirmed 6 hours 33 minutes after the spacecraft was launched. This first successful docking with an Agena target vehicle suffered a set back by a major space emergency. About 27 minutes later the spacecraft-Agena combination started unexpected roll and yaw motions. A stuck thruster on Gemini put the docked assembly into a wild high-speed gyration. Near structural limits and blackout, Armstrong undocked, thinking the problem was in the Agena, which only made it worse. The problem arose again and when the yaw and roll rates became too high the crew shut the main Gemini reaction control system down and activated and used both rings of the reentry control system to stabilize the spacecraft. This used 75% of that system's fuel. Although the crew wanted to press on with the mission and Scott's planned space walk, ground control ordered an emergency splashdown in the western Pacific during the seventh revolution.

Although the flight was cut short by the incident, one of the primary objectives -- rendezvous and docking (the first rendezvous of two spacecraft in orbital flight) -- was accomplished.