Gemini 1

Gemini 1
Gemini 1.jpg
Launch of Gemini 1
Mission typeTest flight
Mission duration4 hours 50 minutes
Distance travelled2,789,864 kilometers (1,733,541 mi)
Orbits completed63
Spacecraft properties
SpacecraftGemini SC1
Launch mass3,187 kilograms (7,026 lb)
5,170 kilograms (11,400 lb) (with 2nd stage)
Start of mission
Launch dateApril 8, 1964, 16:01:01.69 (1964-04-08UTC16:01:01Z) UTC
RocketTitan II GLV, s/n 62-12556
Launch siteCape Kennedy LC-19
End of mission
DisposalUncontrolled reentry
Decay dateApril 12, 1964, 15:00:00 (1964-04-12UTC16Z) UTC
Landing siteMiddle of South Atlantic Ocean
Orbital parameters
Reference systemGeocentric
RegimeLow Earth orbit
Perigee155 kilometers (84 nmi)
Apogee271 kilometers (146 nmi)
Inclination32.5 degrees
Period88.76 minutes
EpochApril 10, 1964[2]

Gemini 1 was the first unmanned test flight of the Gemini spacecraft in NASA's Gemini program.[3] Its main objectives were to test the structural integrity of the new spacecraft and modified Titan II launch vehicle. It was also the first test of the new tracking and communication systems for the Gemini program and provided training for the ground support crews for the first manned missions.[4]

Gemini 1 was launched from Launch Complex 19 at Cape Canaveral, Florida on April 8, 1964. The spacecraft stayed attached to the second stage of the rocket. The mission lasted for three orbits while test data were taken, but the spacecraft stayed in orbit for almost 64 orbits until the orbit decayed due to atmospheric drag. The spacecraft was not intended to be recovered; in fact, holes were drilled through its heat shield to ensure it would not survive re-entry.


Gemini Spacecraft Number 1 was built specifically for an unmanned mission. Crew life support systems were replaced with ballast to approximate the weight of a crewed spacecraft. Four large holes were drilled in the capsule's ablative heat shield to ensure the spacecraft was destroyed during reentry. In place of the crew couches were measuring equipment that relayed telemetry measuring the pressure, vibration, acceleration, temperature, and structural loads during the short flight.

As with any new spacecraft, there were problems during system testing, and the Titan II launch vehicle faced delays as well. The Air Force did not have long experience developing it as an intercontinental ballistic missile, let alone as a manned launch vehicle.[5] A short circuit was discovered in the second stage, apparently caused by a defective clamp cutting into a wire's insulation. Several more were found with the same problem, meaning that 1,500 clamps had to be replaced. Organizational problems between NASA, the Air Force and their contractors caused more delays. The original launch date of December 1963 was pushed back to April 1964.[6]

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فارسی: جمینای ۱
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日本語: ジェミニ1号
norsk: Gemini 1
norsk nynorsk: Gemini 1
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русский: Джемини-1
svenska: Gemini 1