Apollo 17 0.1 Prelaunch part 7

[edit] Launch Preparations

The terminal countdown was picked up at T-28 hours on at 12:53:00 GMT on 5 December 1972. Scheduled holds were initiated at T-9 hours for nine hours and at T-3 hours 30 minutes for one hour.

The launch countdown proceeded smoothly until 2 minutes 47 seconds before the scheduled launch, when the Terminal Countdown Sequencer failed to issue the S-IVB LOX tank pressurization command. As a result, an automatic hold command was issued at T-30 seconds which lasted 1 hour 5 minutes 11 seconds. The countdown was recycled to T-22 minutes, but was held again at T-8 minutes to resolve the sequencer corrective action. This hold lasted 1 hour 13 minutes 19 seconds The countdown was then picked up at T-8 minutes and proceeded smoothly to launch. The delays totaled 2 hours 40 minutes.

During the night launch of Apollo 17, the Cape Kennedy area was experiencing mild temperatures with gentle surface winds. These conditions resulted from a warm moist air mass covering most of Florida. This warm air was separated from an extremely cold air mass over the rest of the south by a cold front oriented northeast-southwest and passing through the Florida panhandle. Surface winds in the Cape Kennedy area were light and northwesterly. The maximum wind belt was located north of Florida, giving less intense wind flow aloft over the Cape Kennedy area. At launch time, stratocumulus clouds covered 20 percent of the sky (base 2,600 feet) and cirrus clouds covered 50 percent (base 26,000 feet); the temperature was 70.0° F; the relative humidity was 93 percent; and the barometric pressure was 14.795 lb/in2. The winds, as measured by the anemometer on the light pole 60.0 feet above ground at the launch site measured 8.0 knots at 5° from true north. The winds at 530 feet above the launch site measured 10.5 knots at 335° from true north.

[edit] Apollo 17 Launch Operations^[1]

The Kennedy Space Center team saved its most spectacular liftoff for the last Apollo mission. Apollo 17, launched on a dark December night, lit up the Florida sky for miles. Despite its early hour (12:33 a.m.), the launch attracted nearly 500,000 watchers in the immediate vicinity. Where clouds did not obstruct the view, thousands more saw the ascending Apollo-Saturn from as far away as 800 kilometers. Of course there was television coverage: the Florida launch site had become familiar to millions of viewers.

Other aspects of the Apollo 17 mission reawakened the interest of the American public. It represented man's last journey to the moon for an indefinite period. Apollo 17 would carry more scientific equipment than any previous mission and would number among its crew the first scientist-astronaut, Harrison Schmitt. The mission also marked the end of a dramatic and controversial program. Appropriately for Apollo, the last mission met acclaim and success.31

1. ↑ Charles D. Benson and William Barnaby Faherty, Apollo 17 Launch Operations chapter 23-7, Moonport: A History of Apollo Launch Facilities and Operations, NASA Special Publication-4204 in the NASA History Series SP-4204, 1978