Apollo 16

This is Apollo Control; 96 hours, 15 minutes. About 50 seconds now away from Acquisition Of Signal with Orion and Casper coming around from the backside of the Moon. Separately this time. Standing by for confirmation from the network controller that the tracking station does have data and downlink from the two spacecraft. There'll be some trouble shooting around this rev on the steerable antenna on Orion, and a further checkout of the discrepancy in regulator pressures on the Lunar Module Reaction Control System thrusters. We have AOS confirmation from [the] Network controller. Let's come up on the air-ground circuit to monitor the first words.

This is Apollo Control. And both spacecraft have passed behind the Moon during the end of the 12th lunar orbit. During this past rather interesting frontside pass, several nagging problems have cropped up or have been carried over from the preceding revolution. One concern is the Landing Radar which, in its self-test mode, gave some spurious readouts, the readouts never agreeing with what the test should be. Later on in a repetition of the Landing Radar self-test, the numbers on the onboard display came out as they should. John Young speculated that perhaps because of the low altitude at the time of the first attempt at the Landing Radar self-test, they were getting some ground reflections from the lunar surface which caused the self-test to be invalid. The self-test of the Rendezvous Radar has been postponed until the upcoming backside pass prior to acquisition on Rev 13. The steerable antenna situation is still coming in and out as the steerable antenna appears to be locked in a stowed position. However, with the spacecraft attitude, oriented such that the antenna faces the Earth, we've had fairly good communications during the better part of this front side pass. The 210-foot [64-metre] dish at Goldstone will acquire the spacecraft at the start of Rev 13, and even if the steerable antenna is completely inoperative, all high-bit-rate data, communications, voice; everything normally carried by the steerable antenna through the 85-foot [26-metre] dishes will be available on the ground. [On] the Lunar Module Reaction Control System regulator situation, the crew is still running through some procedures to manage the two systems, A and B, of the Reaction Control System aboard the Lunar Module to balance the regulator pressures for the propellants. System A appears to creep upward slightly, periodically, and by opening the crossfeed valve and venting some of the propellant into the ascent tanks, it appears that the situation will stabilize. The Descent Propulsion System throttle check and the Descent Propulsion System pressurization routines were carried out completely normally earlier in Revolution 12. Ken Mattingly, meanwhile, was given a Go to circularize with the Command Module, Casper. Ignition time for this burn is 97 hours, 40 minutes, 17 seconds. It will be a Service Propulsion System burn, [of] 99.6 feet per second, which will circularize at about 51.8 by 68.2 [nautical miles, 95.9 by 126.3 km]. This is slightly elliptical but because of the perturbations of lunar orbit, the orbit of the Command Module should be almost circular at the time of rendezvous. Acquisition: 43 minutes, 23 seconds from now, as both spacecraft come around the front side. None of the problems mentioned with the RC - Reaction Control System regulators or the steerable antenna preclude the lunar landing. Even if the S-band - steerable S-band antenna is completely inoperative, we're still Go for landing using the Omni antennas through the Goldstone 210-foot dish. 42 minutes, 36 seconds away from acquisition on the PDI - or landing orbit. At 97:28 Ground Elapsed Time, this is Apollo Control.