Moonport: A History of Apollo Launch Facilities and Operations|
Apollo 17 Launch Operations
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
The first launch vehicle stages for Apollo 17 arrived at KSC in late 1970 during preparations for the Apollo 14 flight. Spacecraft operations got under way in March 1972. During the next four months John Williams's directorate conducted the normal sequence of tests. Spacecraft engineers ran into some typical problems. In May Grumman engineers determined that the rendezvous radar assembly had received too much voltage during the tracking and pointing test at the boresight range. A new radar was installed on the 24th. A month later the landing radar began locking up intermittently and it was replaced. The lunar rover required several changes including replacement of forward and aft steering motors.32
The biggest change in command-service module operations concerned the scientific instrument module, which gained three new experiments: a lunar sounder, an infrared scanning radiometer, and a far ultraviolet spectrometer. The sounder was essentially a radar that could determine the physical properties of the lunar crust to a depth of 1.5 kilometers. This data, coupled with information gathered from cameras, the laser altimeter, and surface measurements, would allow the construction of a detailed topographical profile of the moon. The radiometer provided data from which scientists could prepare an accurate thermal map of the lunar surface. The new spectrometer measured compositional and density variations of the lunar atmosphere.33
The new experiments, particularly the lunar sounder, caused considerable headaches. For testing the sounder, the lunar surface had to be simulated. The sounder recorded the returning signals with an advanced optical recorder that required a special data reduction machine. After the launch team completed a lunar sounder test, the results were sent to the University of Kansas for interpretation. As the head of the Experiments Section recalled, "It would take weeks sometimes to get the results back and they might come back and say, 'You have nothing on the tapes."' North American had trouble integrating the new experiments with the service module hardware.34
The stacked vehicle emerged from the assembly building on 28 August. Although another Saturn V would make the slow journey for Skylab, area residents reacted as if this were the last one. Five thousand spectators watched Apollo 17 creep toward pad A. The astronauts (Eugene Cernan, Ronald Evans, and Harrison Schmitt) joined the Bendix crew aboard the crawler for part of the trip.35
Launch operations during the next three months followed the routine established in earlier missions. The few changes in hardware went smoothly. There was one scare in late-September, again involving the command module's reaction control system. While conducting a leak check, a technician overpressurized one of the oxidizer tanks. KSC officials feared the worst - the rupture of the bladder and the spacecraft's return to the operations and checkout building. At a press conference a few hours after the accident, NASA Administrator James Fletcher announced the possibility of a month's delay in the launch. Further tests, however, indicated that the teflon bladder was all right, and Apollo 17 stayed on schedule.36
In the outside world, there was an ill omen. A NASA request for 21 hours of Public Broadcasting Service network time to cover Apollo 17 stirred little excitement among the stations. Of some 70 replies, ten were favorable, ten opposed, and 50 expressed serious reservations. While this was blamed on a fear of governmental interference in programming, the commercial networks were no more enthusiastic. The prelaunch word was that they planned to cover only highlights of the flight.37
The morale at the spaceport remained generally high. For most companies, KSC contracts continued through Skylab and the Apollo-Soyuz flight. Apollo 17, however, marked the end of the road for the 600 members of the Grumman team. During its years at Merritt Island, Charles Kroupa's group had earned an excellent reputation with NASA counterparts and fellow contractors. The men working for test supervisor Ray Erickson wanted to assure the astronaut crew of their continued support. The result was a large poster at the lunar module working level of the mobile service structure. Signed by Grumman's employees, it read: THIS MAY BE OUR LAST BUT IT WILL BE OUR BEST. Fletcher said the slogan "should be the watchword for the entire Apollo team."38
The last Apollo mission was the first Saturn V launched after dark. As dusk approached, thousands of cars poured across the causeways leading onto Merritt Island. In front of the headquarters building, children threw footballs while the parents talked and listened for the progress of the countdown. The December weather did justice to Chamber of Commerce claims; in the mid-80s during the day, the temperature was 72 degrees at launch.
The countdown proceeded. At T-82 minutes launch control reported the cabin purge had been completed, and the booster protective cover closed. The spacecraft was pressurized and checked for leaks. Houston tested its command signals to the launch vehicle, and the first-motion signal was checked out with Houston and the Eastern Test Range; the next time, it would bring them word of liftoff. The last weather balloon was released to determine wind direction.
In the meantime the C-band and Q-ball tests were in hand. The first was used in tracking to report range velocity during the powered phase. The Q-ball, perched above the launch escape system, would warn the spacecraft commander of deviations in the first stages of flight. Cernan reported things looking good "up here." His next task was to check out the emergency hand control for the service module engine, normally operated by a computer. Far below him, little white wisps marked the topping off of the propellant loads.
At T-1 hour, the close-out crew had secured the white room and was clearing the pad area. The elevators were set at the 96-meter level, for the astronauts' use in an emergency. At T-50 minutes the launch control center initiated the power transfer test, switching the vehicle momentarily onto its own battery power and then restoring external power. Some five minutes later, swing arm 9 - the access arm to the spacecraft - retracted 12 degrees to a standby position. Range safety test signals were flashing to the still unarmed destruct receivers.39
At T-30 minutes, reports came from around the circuit. The water system was ready to flush the pad two seconds after liftoff. Final propulsion checks were completed, the C-band tests repeated, and the reaction control systems armed on the service module. The recovery helicopters were on station, and the weather looked good - a major front remaining well to the west. The launch control center began chilling the second- and third-stage propulsion systems to condition them for the final flow of cryogenic propellants. Swing arm 9 was coming back to a fully retracted position. With the swing arm back, the launch escape system, with twice the power of a Redstone, could loft the astronauts to parachute deployment height. At T-3 minutes and 7 seconds, the automatic sequencer took over.
This sequencer, the oldest and most reliable piece of automation on LC-39, chose this moment in the launching of the last Apollo to cause trouble. At T-30 seconds it went into an automatic cutoff indicating that one of the essential operations leading to the launch of the space vehicle had not been properly completed. Besides halting the countdown, the cutoff started a series of "safing" procedures which included the return of swing arm 9 to a standby position.40
As Launch Director Walter Kapryan explained in a postlaunch press conference:
At two minutes, 47 seconds, the countdown sequencer failed to output the proper command to pressurize the S-IVB LOX tank. The control room monitors noted it and immediately took steps to perform that pressurization manually. This was done, and at the time that we had the cutoff, we were up to pressure and everything was normal. The problem was that since the Terminal Count Sequencer did output the command, the logic circuitry said that we really didn't complete all of the launch preparation for the S-IVB stage. And we didn't have an interlock in our countdown circuitry that precludes the retracting of Swing Arm #1 which occurs at T-30 seconds, and this is the reason for the cutoff. Now, it didn't take us very long to determine that we should bypass this command failure and go through the pressurization manually and go through the rest of the countdown.41With the count returned to (and held at) T-22 minutes the launch team installed jumpers that took the countdown around the faulty relays. The fix was verified on Huntsville's Saturn breadboard, the two centers making good use of the launch information exchange facility. The work took about an hour, and Marshall's confirmation took somewhat longer. Finally the launch team was satisfied that there was no problem. In Kapryan's words: "We picked up the count and went on our merry way."42
Apollo 17 lifted off into space at 12: 33 a.m., 7 December. The flames, exploding into the darkness, made KSC momentarily as light as day. The launch was expected to be visible as far away as Montgomery. Miami observers saw a red streak crossing the northern sky, but Tampa was blacked out by a heavy ground fog and much of the Orlando area was under cloud cover.
During three days in the Taurus-Littrow valley on the moon, Cernan and Schmitt set up their multimillion-dollar array of scientific experiments, using the lunar rover to get them about the crater-pocked landscape. They took three excursions for a total of more than 32 kilometers in the rover, gathering rock samples and taking gravity measurements. Upon return to the command module, the team orbited the moon for nearly two more days of experimentation. They left the last of the Apollo lunar surface experiment packages. With four previously established nuclear-powered stations, the Apollo 17 equipment would allow scientists to monitor the moon's heat flow, volcanic activity, meteor impacts, and other phenomena. Also left behind were eight time bombs scheduled to go off after the astronauts started their return to earth. With the lunar module ascent stage, which was jettisoned into the moon, the bombs were expected to create artificial moonquakes that could be measured by seismometers and perhaps reveal more secrets of the moon's structure.43 The Apollo program was leaving the moon with nine bangs and no whimpers.