Part 1: Late Night With The Saturn V
By Wes Oleszewski
For months we had been told that Apollo 17 would be the end of the Apollo program. Some in the media, such as the ever-pompous David Brinkley, reported the story almost gleefully. Of course Brinkley gracefully avoided the fact that the end of Apollo had already cost nearly 20,000 jobs over the past few years just at the Kennedy Space Center (KSC) alone. After all, what are 20,000 families without a pay check and just as many lives and careers shattered when viewed from his position high atop the media elite. Others in the media, such as John Chancellor were almost embarrassed to speak of the ending of humanity’s greatest effort; the exploration of the moon. For me, a ninth grader and rabid space-buff, the excitement of the coming mission seemed tempered with the first doubt about the future of America’s manned spaceflight program. For all 15 years of my entire life we Americans had always had a manned space program that was always moving forward, outward into the unknown of space and doing
more in giant leaps. Now we were being told that it was all going to stop and pull back.
As far back as Apollo 16 I knew that Apollo 17 would be a night launch of the Saturn V. In fact it would be NASA’s first manned night launch and its last until STS-8 on August 30, 1983 just over a decade later. During the Apollo 16 mission Walter Cronkite interviewed Gene Cernan, who would be the commander of the upcoming Apollo 17 mission. They agreed that the night launching of his Saturn V would really be something to see; that was an understatement. Of course for me, the down-side of a night launch was that I would not get to take my normal day-off from school to watch a late evening launch. It was a good lesson in life for a kid- there is always a down-side.
At 8:30 on Thursday morning, November 30th, 1972 the countdown for the launch of Apollo 17 began at KSC for a scheduled liftoff at 9:53 pm the following Wednesday. The evening news reports garnished that fact with the prospect of a labor action spoiling NASA’s plans. Technical writers and illustrators were threatening a strike at KSC. Although their duties alone had nothing to do with the launch itself, there was the possibility that other KSC employees, who did have a direct responsibility in the launch process, may refuse to cross the picket lines. As it turned out, the labor issues were settled long before the matter turned into a picket line and could threaten any part of the launch process.
Taurus-Littrow was the name of the landing site for Apollo 17 (shown in LRO image). Located near the south east rim of the Moon’s Sea of Serenity, the site is a meandering valley between three mountains called “massifs” in a range dubbed Taurus. Littrow is the name attached to a nearby crater. Overall the lunar EVAs would be the longest ever and I could hardly wait for them to take place. In order to tape record the mission as I had recorded Apollos 14, 15 and 16, I had been saving up what money I could in order to buy what I believed to be “the best” quality cassettes. In my arsenal I had two Memorex 120 minute cassettes and two off-brand 60 minute cassettes. The Memorex tapes were for the actual mission audio and the off-brands were to capture the “extras” that the news media may just toss out there. Yep- I had it all covered from flight broadcasting to contingency broadcasting. This time I’d be using the best of everything… right?
Well, 300 years later when I went to take my carefully stored “Apollo Tapes” and transfer them to digital CD, the only ones that gave me trouble were those expensive Memorex cassettes! They were so bad that I had to take apart freshly bought modern cassettes and physically cut the 120 minute tapes in half and the place the historic tapes into modern, off-brand, cases in order to get them to play. Meanwhile, my off-brand cassettes from the Apollo and Skylab era still play just fine. Yet, in December of 1972, I thought that I had it all covered.
It was clear from the beginning that the TV coverage of Apollo 17 mission would be at a bare minimum. NBC, for example, came on the air at 9:45 pm, just 13 minutes before the scheduled launch time. For Apollo 16, NBC’s launch coverage had started nearly a full hour before launch time. But Apollo 16 had launched on a Sunday at mid-day when most network affiliates were showing old movies on some sort of “Award Theater.” Apollo 17, however, was supposed to launch in “prime-time” and most network executives would have blood shooting out of their eyes at the thought of losing even a minute of prime-time to cover a spaceflight. ABC and CBS were both on at 9:30 with launch coverage; meaning either that their executives had a greater sense of history and the news coverage thereof, or that their eyes did not bleed as easily as the suits at NBC. The plan of all of the networks, however, was to catch Apollo 17 getting off the ground and into orbit, which was scheduled to take
a total of 11 minutes and 46 seconds, and then switching at the top of the hour to,“…our regularly scheduled program, already in progress,” thus keeping those prime-time advertising dollars and ratings points firmly in their pockets as well as keeping the shooting of blood from their eyes to a minimum. They would also rob us space-buffs of scads of spaceflight TV watchin’ in the process. After all, no moon flight had ever suffered any sort of a technical delay, so their bet seemed to be a sure thing. The network suits would win and the space-buffs would get skunked. It was well planned by the three big networks- who were all we had to watch in this era before wide-spread cable TV. Of course, events of that Wednesday evening would cast immense suffering upon those network suits- especially at NBC.
The final minutes of the countdown, to those of us not in the firing room at KSC, appeared to be moving along smoothly for Apollo 17; that included the crew of Commander Gene Cernan, Command Module Pilot Ron Evans and Lunar Module Pilot Jack Schmitt. What only a few people in the firing room knew was that there had been a glitch at the 2 minute and 47 second mark in the count. At that point the automatic sequencer failed to send the signal to pressurize the third stage’s (S-IVB) Liquid Oxygen (LOX) tank. Controllers in the firing room quickly moved to manually pressurize the tank and it did come up to pressure, but their action was not enough to satisfy the sequencer and at T-30 seconds the count was “cut-off” by the sequencer itself. There was a great deal of confusion in the media as the NASA Public Affairs Officer, Chuck Hollingshead, went into low-flow mode. The public was left guessing as to what the problem was and whether or not there would be a launch tonight. It soon
became clear that that those “regularly scheduled programs” were not going to be seen tonight and the well planned broadcast schedule of those network executives turned to toilet paper.
AS-512, the Saturn Booster that was supposed to send Apollo 17 to the moon just sat there, venting LOX in that familiar white trail of vapor; commonly called “goxing.” Of course as the countdown clock stood frozen at the 30 second mark the controllers in the firing room were already working the problem and actually had in place a “work around” solution. First, however, the countdown and the sequencer needed to be recycled to the T-22 minute mark. This recycle was a long involved procedure-rich activity that would take nearly a full 40 minutes just to complete. Of course I was glued to our family TV as everyone else in the family went to bed- with the exception of my dad who worked midnights on the railroad. He just wished me luck by saying to me, “I hope you get that one off the pad tonight,” as he left of work. Dad always had a keen sense of how involved I was in spaceflight- even if it was through a TV set located 1,042.93 miles away from Launch Complex 39A.
Before going to bed for the night, my mom left me alone in the living room with a clear warning, “No matter how late you stay up for that tonight,” she half snarled in a firm parental tone, “yer’ still getting’ up and goin’ to school tomorrow.” Indeed our deal had been that I could only stay home from school to watch the critical parts of the mission that took place during school hours. Now she had me on a technicality.
I kept CBS tuned in during this phase of the mission. The other networks had good people working the flight, but a good space-buff always kept Cronkite and Schirra tuned in during an anomaly; provided they could actually get a CBS station, of course. The broadcasters did their best to make something out of the nothing that PAO was spooning out. Unknown to us all was the fact that the engineers in the firing room were all set to implement their work-around and by-pass the sequencer. This was not a work-around in the sense that we would see in the Space Shuttle era. This was a “bread-board” work-around. A bread-board is a term for a type of tool used in electronics to study and test circuits. Components are connected together with “jumpers” which consist of a single wire with either clips or plugs on each end. Those jumpers can be used to either connect or by-pass a given component or circuit. In the case of the Saturn V sequencer, (and you electrical engineers reading this
please forgive me for over simplifying here, but I’m writing for “normal” people), there was no big master computer teaming with scads of hard-drives. Much of what the sequencer did came down to open relays and closed relays which executed each action that needed to be done by triggering additional relays down the chain. Each of these banks of circuits had a one-hole jack on one side and a similar jack on the other. If the circuit, or its associated relay should fail to trigger its task by closing, a technician could by-pass it with a switch or a by-pass could be done by inserting a jumper with a banana plug on each end into the two holes and thus “jump” across the circuit. The system hardware had actually been built with this option in mind. Basically what had happened was that when the sequencer looked, at the speed of light, for the S-IVB pressurization trigger it saw that K577, the “S-IVB LOX Tank Pressurized” interlock relay was open. Although the tank
had been pressurized manually the sequencer instantly cut-off the count, it never got as far as the switch that the technician had closed. In the work-around, the jumper would show the sequencer a closed circuit and so would the manual switch. The sequencer would then simply move along and launch the Saturn V.
There was, however, one last hang-up that delayed the launch even farther. The folks at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama- who had designed and constructed the Saturn V- needed to convince themselves that the bread-board work-around would actually work safely. It was an expected delay by the ever cautious MSFC engineers, however, and while the team in the firing room at KSC waited, they successfully rolled the countdown clock back to T-22 minutes and began counting down again. They could go as far down as T-8 minutes where the chill-down of the J-2 engines in the second and third stages had to be started. If they had no decision from Huntsville by then, they would have to wait until the launch window was violated by the remainder of the countdown. The count did indeed tick down to T-8 minutes and then was held again awaiting word from MSFC. Meanwhile excess hydrogen from the S-IVB and S-II stages was being drained off and sent to a “burn pond” adjacent to the
launch pad where it set aflame. Cronkite went to great lengths to assure the viewing public that this was an intentional, necessary and totally harmless fire. For more than an hour, everyone, from the news broadcasters, to the firing room engineers, to a little kid in Saginaw, Michigan all waited tensely for the count to resume.
Swing Arm Number 9, which was the access arm to the command module, had been swung back to the 12 degree “park position.” I wondered what it was like inside the Apollo 17 command module as the crew waited out the protracted delays. In his later book, “The Last Man on the Moon” Gene Cernan summed it up by reporting that CMP Ron Evans, "… didn't think the delay was any big deal and he went to sleep, his relaxed snore a deep undertone to the chatter on the radio net."
Somewhere near 20 minutes after midnight Eastern Time, MSFC finally transmitted their blessing upon the KSC work-around that the folks at Huntsville had actually, themselves, designed into the system. The count began again at 25 minutes after midnight and progressed to the point where the S-IVB LOX tank was to be pressurized. Again the console operator manually pressurized the tank. Then when the sequencer looked toward the K577 relay and electronically saw the jumper and thus concluded that the relay was closed. The count continued to ignition and liftoff- which took place at 33 minutes past midnight.
It was impossible to grasp the full glory of a Saturn V night launch through our family television set, but the voice of Chuck Hollingshead as he called the liftoff gave a good indication of what was taking place. “It’s just like daylight here at Kennedy Space Center…!” he shouted with the greatest of excitement as the TV cameras that had focused on the vehicle were video smeared by the brightness. Reporter John Chancellor afterward stated, “ …the whole sky became pinkish-green, like nothing I have ever seen. It looked like a hazy day… it was as bright as the sun with a flaming tail, maybe half a mile long… every car in the parking lot here, in the middle of the night at the press site was clearly identifiable, the license numbers could be read…” The boost of the S-IC first stage on Apollo 17 was completely nominal and at staging the firing of the eight retro-rockets shot out a brilliant halo of yellow flame that seemed to be a few
thousand feet across as it expanded in the near-vacuum of the upper atmosphere. From that point on, Apollo 17 was little more than a white dot on our TV set.
I listened intently to all of the onboard reports and calls. “Mark, 1 Bravo,” an abort mode, “Skirt Sep.” the point where the interstage skirt that had held the first stage to the second stage separates. If it had not dropped away the crew would have to abort using their escape tower. “Tower Jet,” since the skirt departed cleanly, the launch escape tower was no longer needed, and was jettisoned to save weight. Now all three astronauts could look outside. Prior to this the Command Module had a Boost Protective Cover (BPC) over it, but when the tower jettisoned it took the BPC with it. Later in the second stage burn as its fuel and oxidizer drained away, the stage’s level sensor was armed and prior to that the crew was given an expected time for “Lever Sense Arm.” Level sense referred to a set of five probes in the LOX tank’s bottom that while wetted remained neutral, but when any two of these were uncovered they signaled the Saturn V’s
Instrument Unit (IU) to begin the sequence of engine shutdown and staging. The system was not armed until late in the stage’s burn to prevent a false shutdown. Level Sense, shutdown and staging for Apollo 17 took place as planned.
As separation of the second and third stage took place a series of four retro-rockets buried in the S-IVB’s adapter ignited while at the same time two posi-grade ullage motors on the stage fired. These were all solid propellant rocket motors that burned briefly; the retros to separate the two stages and the ullages to seat the S-IVB’s propellant and oxidizer . Once expended the ullage motors were jettisoned to scrub weight. In the end the S-IVB’s lone J-2 engine shut down some three seconds early, but Apollo 17’s parking orbit was fine. Unlike previous lunar missions, Apollo 17 would make its Trans-Lunar Injection burn at the beginning of its third orbit some three hours after launch.
One loss caused by the delayed launch was that there would be no TV coverage of the Transposition and Docking event- where the CSM separates, moves out, turns and then goes back to dock with and remove the Lunar Module from the S-IVB. The tardy launch left the earth-bound antennas that would normally receive the onboard TV out of position, so there would be nothing to watch. I packed it up and went to bed with two thoughts heavy on my mind; 1) this was the last time that humans would launch aboard a Saturn V and fly to the moon, and 2) my mom was going to wake me up in about five hours so that I could trudge off to waste yet another day in the mayhem of Webber Jr. High School.
For the record, 40 years later I remember every detail about the launch of Apollo 17 that night- but I don’t recall a damned thing that went on at that “school” the following day.
(Images courtesy NASA)