• Visual observation of rocket launch plumes using the Svinets device
• Film and photography of the spacecraft 15-16 docking from spacecraft 14
• Demonstration of welding in weightless vacuum conditions using the Vulkan device
• Demonstration of autonomous navigation by the cosmonauts using a sextant
• Medium wave radio communications
• Test of new television sensors for the Soyuz orientation system

Spacecraft 17 through 20 will fly 15 to 16 day missions to demonstrate the new SZhO life support system for the L3, and conduct rendezvous and docking operations using the L3's Kontakt system. Additional Details: Soyuz program review. References: 376.

1. contingency sample;
2. ALSEP deployment; and
3. field geology investigations.

On May 19 the crew elected not to make the first of a series of midcourse maneuvers. A second preplanned midcourse correction that adjusted the trajectory to coincide with a July lunar landing trajectory was executed at 3:19 p.m. The maneuver was so accurate that preplanned third and fourth midcourse corrections were canceled. During the translunar coast, five color TV transmissions totaling 72 minutes were made of the spacecraft and the earth.

At 4:49 p.m. EDT on May 21 the spacecraft was inserted into a lunar orbit of 110.4 by 315.5 kilometers. After two revolutions of tracking and ground updates, a maneuver circularized the orbit at 109.1 by 113.9 kilometers. Astronaut Cernan then entered the LM, checked all systems, and returned to the CM for the scheduled sleep period.

On May 22 activation of the lunar module systems began at 11:49 a.m. EDT. At 2:04 p.m. the spacecraft were undocked and at 4:34 p.m. the LM was inserted into a descent orbit. One hour later the LM made a low-level pass at an altitude of 15.4 kilometers over the planned site for the first lunar landing. The test included a test of the landing radar, visual observation of lunar lighting, stereo photography of the moon, and execution of a phasing maneuver using the descent engine. The lunar module returned to dock successfully with the CSM following the eight-hour separation, and the LM crew returned to the CSM.

The LM ascent stage was jettisoned, its batteries were burned to depletion, and it was placed in a solar orbit on May 23. The crew then prepared for the return trip to earth and after 61.5 hours in lunar orbit a service propulsion system TEI burn injected the CSM into a trajectory toward the earth. During the return trip the astronauts made star-lunar landmark sightings, star-earth horizon navigation sightings, and live television transmissions. References: 2, 6, 16, 26, 27, 33,60.