Highways Into Space: A first-hand account of the beginnings of the human space program (27 page)

57:05 GET (1 hour and 10 minutes since problem start)

With full recognition of how demanding this situation was, The Black team and I came on duty. Positions were manned by Jack Lousma at Capcom, Larry Keyser at AFD, Gary Scott and Ed Fendell at INCO, Bill Boone and Maurice Kennedy at FIDO, Tom Weichel at Retro, Gary Renick and Will Presley at Guidance, Merlin Merritt at Telmu, Hal Loden at LM Control, Clint Burton at EECOM, Jack Kamman at GNC and Spencer Gardner and Elvin Pippert at FAO and all the other off-shift flight controllers and astronauts who gathered to help within less than an hour of the problem. (Consoles had four jacks for headsets to plug in and they were all occupied.) This flight control team was a solid set of operators, but hardly any had been in this kind of circumstance.

Chris and Sig were also there by this time. Besides the flight controllers, we also had the best brains available through our offline SPAN communications and data network with all of the engineering and program organizations, both in NASA and industry, and from all regions of the country.

The MCC was full. Even so, the comm loop discipline was good. No illusions by now – we all knew that this was a very big hill to climb. And it was ours to handle. It was time to get on with it. The situation was:

• A loud bang was reported at the start of this problem and eventually the crew reported.
  

• Particles were venting from the SM.
  

• O2 tank #2 was at 0 pressure. O2 tank #1 was predicted to last no more than two hours.
  

• Fuel cells 1 and 3 were not supplying power.
  

• Main bus B and AC bus 2 were zero, since both were fed by fuel cell 3.
  

• Considerable reconfiguration had been performed to get enough thrusters on main Bus A.
  

• The trajectory was not on a free return to the entry corridor and it needed correction.
  

To help in understanding our response, actions can be considered in two categories:

1. Managing the Configuration of the Spacecraft Systems – Sometimes the configuration choices were driven by troubleshooting of problems (e.g. leak isolation, switching redundant paths, preserving capability, etc.) – sometimes to support a mission need (e.g. a propulsion maneuver, a power down, the optimum control system capability, etc.). The mission need to operate within the reduced consumables also stressed the configuration choices well beyond the normal. The choices also required closer coordination among the flight controller positions in the MCC because the window for an integrated solution (balancing the demands of propulsion, electrical power, time, coolant water, guidance equipment, communications, etc.) was much narrower.
   

2. Return Home Steps – The necessary mission steps to return the vehicle and crew to a safe landing.
   

In the minute-by-minute voice traffic within MCC and with the crew, the return-home steps provided an overall mission framework towards the primary goal. But, the majority of time and interactions was spent evaluating, deciding and implementing the spacecraft configuration choices to stabilize and/or improve our posture to support the crew and accomplish the return steps. And burned into us from years of training and operations was the CARDINAL rule – “Don’t screw anything up and make the situation worse than it already is.” It also helps to understand the evolution of the return-home plan as an incremental process. We did not begin by having a comprehensive plan – but, rather, took steps as we judged them to be necessary, appropriate or keeping us with the best range of forward options. Think of the process as the fog clearing enough to commit to the next step. For example, the decision at 56:48 GET to go around the moon, rather than attempting a direct return, was the first of the RETURN-HOME steps. This STEP #1 was driven by a fact-based analysis of options illustrating that the go-around option was the only workable one. Some of the next steps were more based on the judgment (without a full factual analysis) of what was best. I will highlight each of the return-home steps as our shift and the flight progressed, with the first one being Gene’s earlier decision to swing around the moon.

With the vehicle rates under control with a new RCS configuration, the Black team first focused on the last-ditch steps to try to save some of the CSM cryo-fuel cell capability. The last step was to close the reactant valves to the non-performing two fuel cells in an attempt to isolate the possibility of an O2 leak inside the fuel cell itself. Once closed, the fuel cell was without the fuel to run, and could not be restarted. No joy on the first cell and then the second one ended up with the same negative result. The O2 leak continued.

57:35 GET (1 hour and 40 minutes since problem start)

The two LM crewmembers were making their entry into the LM at the same time we were calling up that recommendation. “We’re already on our way” was the reply. At this time, we had one good fuel cell #2, but the oxygen pressure to feed it was still dropping. The crew began the initial activation of the LM, designed to get the batteries, life support systems, and communication/instrumentation systems online. MCC received the initial LM telemetry signal at 57:57 GET. On a personal note, in managing and prioritizing the flow of comm traffic with the crew, Jack Lousma was a pillar of stability for this team over the course of a very long night.

During the power-up, I had a short time to consider options. My first strong inclination was to power down quickly, conserve LM consumables and work out a plan. But, I also had serious concern that the venting particles would preclude getting a good guidance platform alignment for the burns that would be required later. Tom Stafford was intense about getting and maintaining the alignment in the LM. There were confirming nods from Jack Lousma and other Apollo crewmen. This was now our only opportunity to get the CSM inertial guidance alignment transferred to the LM guidance system, even if we later decided that we did not want to use it and powered the LM platform down. And I decided to take the time and electrical power from both vehicles to accomplish that transfer and then decide what was next. If not done now, this opportunity would be lost and no longer available. It was much too early to foreclose this option going forward.

57:54 GET (1 hour and 59 minutes since problem start)

The CMP powered down as much in the CSM as he could while keeping the CSM guidance system up. Because of the decreasing O2, Clint Burton at EECOM was watching to see a degradation in fuel cell 2 in order to know when to put an entry battery on to support the electrical bus. We intended to stay “up” in the CSM until a LM guidance alignment was transferred. Once we were on entry battery A, we wanted to minimize the number of amp hours withdrawn from it since we did not know if we could charge it from the LM for later use. The alignment transfer itself was a tedious process of crew/MCC coordination and the reading and checking of a lot of numbers as they were entered into the LM guidance computer. During the period of transferring the alignment, there was a short period with neither of the attitude control systems on. This was quickly recognized and corrected. It was upsetting that we (and I in particular) missed that condition. Although no real harm attended, we could not afford mistakes.

Around the time of these final CSM closeout steps, I had a brief period when the severity of the problem really struck home. For the first and only time in ten years of console experiences in training and actual flights, I had the sense of the bottom falling out from under me and my stomach heading for that dark hole. I would like to believe that it was due to an acute awareness of the “Abandon Ship” situation. But the feeling was emotional, not intellectual. “Holy xxxx. I can’t believe this is really happening.” Scary – but the ten years of experience kicked in and it took about ten to twenty seconds to return from that place.

58:40 GET (2 hours and 45 minutes since problem start)

Jack Lousma helped get the LM team back on tailoring an existing checklist for LM power-up and it was now time to turn the CSM power off. We had used about twenty amp hours – or fifteen percent of total entry battery power – before power down. The CM was going to get cold and uncomfortable and we still needed Odyssey to get home.

I considered the decision to transfer the CSM platform alignment to the LM as key to maintaining our future options and it was RETURN-HOME STEP #2 in our still evolving plan. We still had the choice to power it all down and reconsider later. At this point, keeping the LM alignment was a good trade for accurate, reliable control of future propulsion burns against a modest amount of LM power being used for a near term mid-course maneuver in a few hours to get back on free return. The free return mid-course would also verify that the alignment and the propulsion systems were in good shape. Also significant, the fact of being on a free return should be a psychological lift for the entire team. With respect to using the LM consumables, my judgment was that this team would find a way to stretch a nominal two plus days of mostly powered up LM consumables to a four-day, powered down survival mission. (But it still made us all nervous, some more than others.) And after the mid-course in the next two hours, we would have more accurate consumable forecasts available to decide whether to power down or stay up after that. This was a good example of the incremental development of the return-home plan. Take the bird-in-hand, especially when the tradeoff – in this case, the consumable cost – was reasonably low.

58:54 GET (2 hours and 59 minutes since problem start)

Jim Lovell then reported, “I still see a lot of particles and I cannot identify any constellations, at least in this attitude.” This strengthened my resolve to save the alignment reference in the LM until the propulsion maneuver and consumable picture became more clear. At about this time, we had more time to confer with the flight controllers studying the return to earth options. The LM coolant water was the critical item and the initial cooling water usage was high, about double what was normal for the electrical load, because it was cooling down the entire loop. The usage rate would soon slow down. But, the first estimates would have depleted the coolant water by 94:00 GET at current usage rates. This was obviously not good enough but the estimates had also been made for a very high power level in the LM, about thirty-five amps, for the remainder of the flight – both of these assumptions were much too conservative Merlin Merritt at the Telmu position pressed for a quick power down. I told him, “Merlin, I appreciate your concern, but I am still waiting for an overall plan from Control on the control system options.”

It was time to focus the team’s attention on our primary goal of returning the crew safely. We had to develop a sound plan to accomplish that goal with LM power management as a supporting consideration. I selected what seemed to be the most promising option of those provided by the Trench. Then I asked for LM consumable forecasts, assuming a continued power up but at more nominal (lower) H2O usage rates. The power up would continue until a major propulsion burn at pericynthion (closest approach to the moon) plus two hours and then reduce the LM power to fifteen to eighteen amps for most of the trip home, allowing two mid-course opportunities. I asked for a range of variations in power levels around that timeline so we did not wait for “more perfect” answers. For now, the approach should be based on faster results including reasonable variations in order to enable the selection of the return home plan. We knew that the CO2 fix was needed, but definition of it was not urgent and the engineering team was on it.

While that was being done, there was time to refine our near term maneuver options. We could do a mid-course correction quickly to establish free return and then still choose to power down or not. I decided to take the option of getting on free return as soon as practical. We then began to select a time for the mid-course that was adequate for the team to assure proper checklist procedures. We offered sixty-one hours GET and the crew wanted a little more time, settling on 61:30 GET.

61:30 GET (5 hours and 35 minutes since problem start)

The mid-course was performed and delivered a forty feet per second correction with the descent engine. Burn parameters were nominal and the tracking confirmed the maneuver. The accuracy of the burn also verified that we had a good alignment in the LM. This decision to go ahead with the mid-course to re-establish free return was RETURN-HOME STEP #3 – and an emotional lift for the crew and team. We were back on free return, but still a long way to go. LM current was decreased from about thirty-two amps to twenty-five amps in the period before the PC+2 burn.

Through all this, Chris and Sig were present all the time and it was so easy to communicate with them. They followed all the traffic on the comm loops. Sometimes, we would sum up a situation and give them a how-I-am-thinking-about-this-subject before it came to decision time. Sometimes, the understanding was conveyed by a look or a thumbs up or down. I don’t really remember any questions that they had as we went along. I do remember a strong feeling of support. I always felt completely in sync with them, even with very little explanation communications.

Once the free return mid-course burn was performed, an attempt was made to setup passive thermal control (PTC) to control the thermal balance of the spacecraft with the usual difficulty made worse by the fact that we were doing this with the LM control system for the first time versus the CSM as on past missions. The PTC was designed to cycle cold (away from the sun) and hot environments (facing the sun) uniformly around the CSM/LM stack to avoid extreme temperatures anywhere. The technique is to stand the stack perpendicular to the earth/sun plane and spin it slowly, about one revolution every couple of hours, to spread the heating and cooling throughout the vehicle in a uniform way. It is a delicate maneuver in that the vehicle tends to wobble off like a top slowing down and not spin on the same axis for very long.