Question: The Rendezvous Docking Simulator at NASA's oldest field center was constructed for what program?

Context paragraphs:
ETS-VII: The ETS-VII, or Engineering Test Satellite No. 7, was a satellite developed and launched by the National Space Development Agency of Japan (NASDA).  It is also known as KIKU-7.  It was launched aboard an H-II rocket from Tanegashima Space Center, on 28 November 1997.  The ETS-VII was equipped with a 2 metre long robotic arm, which was used to carry out several experiments related to rendezvous docking and space robotics.  It was the world’s first satellite to be equipped with a robotic arm, and also the first unmanned spacecraft to conduct autonomous rendezvous docking operations successfully.  Although it was originally intended to be used for 1.5 years, the satellite was functional for a period of almost five years.

DRAGONSat: DRAGONSat (Dual RF Astrodynamic GPS Orbital Navigator Satellite) is a pair of nanosatellites that will be demonstrating autonomous rendezvous and docking (ARD) in low Earth orbit (LEO) for NASA.  It will be gathering flight data with a global positioning system (GPS) receiver strictly designed for space applications to gather flight data in the space environment.  ARD is the capability of two independent spacecraft to rendezvous in orbit and dock without crew intervention.  One DRAGONSat was built by the University of Texas and the other one was built by Texas A and M University, the Space Shuttle Payload Launcher (SSPL), These satellite projects will rendezvous and dock with each other in space without the benefit of human intervention.

Rendezvous Docking Simulator: The Rendezvous Docking Simulator, also known as the Real-Time Dynamic Simulator, is a simulator at the Langley Research Center.  It was constructed for the Gemini program in Building 1244 and it became operational in June 1963 at a cost of $320,000 and later reconfigured for the Apollo program.  The simulator consists of a gantry frame, with an overhead carriage from which test craft were suspended by cables.  A gimbal was powered hydraulically and was capable of changing pitch and yaw at a rate of 1 radian per second or roll at 2 radians per second.  The gantry also moved like an overhead crane using electric motors and was capable of travelling 210 ft longitudinally at up to 20 ft/s , 16 ft laterally at up to 4 ft/s and vertically 45 ft at up to 10 ft/s .

Neptec Design Group: Neptec Design Group is an Ottawa based, Canadian vision systems company, providing machine vision solutions for space, industrial, and military applications.  Privately owned and founded in 1990, Neptec is a NASA prime contractor, supplying operational systems to both the Space Shuttle and International Space Station programs.  Starting in 2000, Neptec began expanding its technology to include active 3D imaging systems and 3D processing software.  This work led directly to the development of Neptec's Laser Camera System, which is an operational system used by NASA to inspect the shuttle's external surfaces during flight.  Building on Laser Camera System technology, Neptec has also developed a 3D imaging and tracking system designed for automated on-orbit rendezvous, inspection and docking.  The TriDAR combines a high precision, short range triangulation sensor with a long range LIDAR sensor into the same optical path.

Flight Research Laboratory: The Flight Research Laboratory (building 1244) at NASA's Langley Research Center houses fixed and rotary wing aircraft used in atmospheric and flight research.  It also housed simulation equipment used during the Gemini and Apollo programs such as the Rendezvous Docking Simulator (which remains stowed in the ceiling of the hangar) and Projector Planetarium.

TriDAR: TriDAR, or Triangulation and LIDAR Automated Rendezvous and Docking, is a relative navigation vision system developed by Neptec Design Group and funded by the Canadian Space Agency and NASA.  It provides guidance information that can be used to guide an unmanned vehicle during rendezvous and docking operations in space.  TriDAR does not rely on any reference markers positioned on the target spacecraft.  Instead, TriDAR relies on a laser based 3D sensor and a thermal imager.  TriDAR's proprietary software uses the geometric information contained in successive 3D images to match against the known shape of the target object and calculate its position and orientation.

Langley Research Center: Langley Research Center (LaRC) is the oldest of NASA's field centers, located in Hampton, Virginia, United States.  It directly borders Langley Field and the city of Poquoson.  LaRC has focused primarily on aeronautical research, but the Apollo lunar lander was flight-tested at the facility.  In addition, a number of the earliest high-profile space missions were planned and designed on-site.

Agena target vehicle: The Agena Target Vehicle (ATV), also known as Gemini-Agena Target Vehicle (GATV) was an unmanned spacecraft used by NASA during its Gemini program to develop and practice orbital space rendezvous and docking techniques, and to perform large orbital changes, in preparation for the Apollo program lunar missions.

Neutral Buoyancy Simulator: The Neutral Buoyancy Simulator was a neutral buoyancy pool located at NASA's George C. Marshall Space Flight Center (MSFC).  Engineers and astronauts developed hardware and practiced procedures in this tank from its completion in 1968 through its decommissioning in 1997.  Marshall recognized the need for underwater simulations of extra-vehicular activities (EVAs) and developed three successively larger tanks for the purpose.  The Neutral Buoyancy Simulator contributed significantly to the American manned space program.  Skylab, the Space Shuttle, Hubble Space Telescope, and the International Space Station have all benefited from the Neutral Buoyancy Simulator.  Until Johnson Space Center constructed the Weightless Environment Test Facility in the mid-1970s, MSFC had the only NASA-owned test facility that allowed engineers and astronauts to become familiar with the dynamics of body motion under weightless conditions.

Shenzhou 10: Shenzhou 10 () was a manned spaceflight of China's Shenzhou program that was launched on 11 June 2013.  It was China's fifth manned space mission.  The mission had a crew of three astronauts: Nie Haisheng, who was mission commander and previously flew on Shenzhou 6; Zhang Xiaoguang, a former PLAAF squadron commander who conducted the rendezvous and docking; and Wang Yaping, the second Chinese female astronaut.  The Shenzhou spacecraft docked with the Tiangong-1 trial space laboratory module on 13 June, and the astronauts performed physical, technological, and scientific experiments while on board.  Shenzhou 10 was the final mission to Tiangong 1 in this portion of the Tiangong program.  On 26 June 2013, after a series of successful docking tests, Shenzhou 10 returned to Earth.

Supporting paragraphs: Rendezvous Docking Simulator Langley Research Center
Answer: Gemini program