by Paul Dye
There were nowhere near as many vehicle changes after the loss of Columbia as there were after Challenger, but there was a lot of work done on trying to once again figure out tile repair. More importantly, a great deal of effort was spent on how to inspect the Orbiter after launch. A great deal of effort was put into developing an inspection boom that could be grappled by the RMS, and then use it to put cameras underneath the Orbiter to take pictures of the entire tile surface—very much like a selfie stick. The RMS wasn’t long enough, or flexible enough, to do it by itself, but the boom made the work possible. Because we generally rendezvoused with the ISS on Flight Day 3, the natural place to add an inspection day was Flight Day 2. The crew launched on Flight Day 1, then got a good night’s sleep. They spent Day 2 checking out equipment for the upcoming docking and EVAs. A couple of crewmembers did the on-orbit inspection to make sure there had been no damage from the ascent.
The data was sent down to the ground via video links and was thrown to the engineering group to analyze. They spent thousands of hours each mission looking over every image they could find, comparing what they saw to prelaunch photos to make sure there were no damaged tiles, RCC panels, or loose gap fillers—pieces of felt-like material inserted between tiles that kept them from vibrating against each other. In addition to the data gathered on Flight Day 2, the crew of the ISS was trained to take a series of pictures with very long lenses as the Shuttle approached the ISS during the rendezvous of Flight Day 3. The Orbiter would approach from below the station and stop about 600 feet out. At that point, it would do a complete 360-degree backflip—the Rotational Pitch Maneuver (RPM)—and the ISS crew would take their pictures in a predetermined scan pattern using both 400mm and 800mm lenses. These images would then be downlinked and added to the pile of data already being looked at by the engineering teams. There were places that the boom couldn’t reach, and the RPM filled in those blanks. As a result, we got a very good idea of what we had, and where problems might lie.
The good news is that we never had to declare an Orbiter derelict because of an inspection—but we did do at least one EVA to pluck out some loose gap fillers that might have disrupted the critical hypersonic flow pattern of the plasma during entry, causing uneven and localized heating. That really was good news, because the bad news was we never really trusted the repair techniques that were created to deal with lost tiles or missing RCC. A lot of work had been done in this area, but very few folks at the highest level got comfortable with them—at least so long as we had a rescue capability. And we always made sure that we had that capability, just in case.
It was clear that most Shuttle missions after the Return to Flight were going to be to the ISS. The only thing left on the manifest other than station assembly was a final return to HST. So for all but that final Hubble mission, our philosophy became what I called the “desert island scenario.” If we got the vehicle to orbit, then we could get it to the ISS. If we discovered that we had damage that would preclude bringing it home, we’d strand the crew onboard the ISS, jettison the damaged vehicle before it ran out of cryo and prop, and then send another Orbiter to pick up the crew and bring them home.
Because we always had another mission planned to the ISS, all we really had to do was make sure that the consumables onboard the ISS would support the extra crewmembers for the time it would take to get a rescue Orbiter ready to go and up to the station. For the first few missions, we actually planned to steal the next mission’s Orbiter and get it ready in an expedited fashion. After some time, and some pencil sharpening, we realized that we really could generally wait for the next mission, and fly it fairly normally, if we had to bring the previous crew home with that crew. It made for efficient mission planning and made the rescue scenario pretty routine. One of my assignments for the remainder of the program was to keep the plans for the rescue mission up to date and ready to go—something that sort of fit in with my lifelong interest and participation in rescue work. (I spent twenty-five years of my NASA career as a volunteer firefighter and officer in our local fire department—as if I didn’t already have enough to do.) That made me the Rescue Flight. But since we never really got close to launching such a rescue mission, it was really just another office assignment. It was fun though, because it required a few creative touches to the planning process, and some of the usual constraints were loosened to make it happen.
The rescue mission for the final HST mission would have been much more challenging because the Hubble was in nowhere near the same orbit as the ISS. Both the inclinations and altitudes were so far off that it was physically impossible to go from one orbit to the other. I think it would have taken something on the order of all the propellant ever carried in all the Shuttle missions (combined) to get that much maneuvering capability. So in order to launch to the HST with the required rescue capability, we needed to have a complete and ready-to-go plan. Once again, as Rescue Flight, I got to build that plan. Since we didn’t have the luxury of a space station in which the crew could take refuge, we had to come up with a more interesting idea.
The rescue flight for the final HST mission (STS-125) was a fully planned and paid for mission. We had a complete crew training plan for it and, in fact, the crew had to be headed to the Cape only a few days after the HST mission launched in order for such a rescue to work. STS-125 had only so many days of on-orbit life; we couldn’t let the crew sit and wait for rescue on the ISS for months, because the ISS was out of their reach from the Hubble. So, as I told the program, we had to assume that the rescue crew was launching until we called them off. The mission was designated STS-400 and had its own planning process and flight preparation products. A lot of the planning could piggyback on the STS-125 planning, since it was going to the same orbit, but it still required a lot of unique mission analysis because the weights were different.
The basic plan for the rescue was that the STS-400 crew—a reduced crew of just four astronauts—would launch and rendezvous with the damaged STS-125 vehicle. That crew would have already gotten rid of the HST (hopefully fully serviced and ready to do science for as long as it lasted), and been made ready to receive the rescue vehicle. Because the docking systems of both Orbiters were not designed to extend beyond the payload bay door moldline, it was not really possible to dock them. It was a situation like how human noses tend to get in the way of a kiss. The rescue vehicle was going to have to grab the damaged vehicle with its RMS (a special grapple fixture was installed on the STS-125 vehicle to facilitate this). Once the two vehicles were grappled, the fun could really begin. The transfer of crewmembers was going to have to be done not via a docking tunnel, but using space suits and a series of EVAs.
There were seven crewmembers on the STS-125 Orbiter. Four of them were EVA specialists. They weren’t a problem. The fifth Mission Specialist was the RMS operator, Megan McArthur. She had sufficient experience in EVA training that she was also not a difficult transfer, although she didn’t have an EVA suit sized and ready for her. The two final crewmembers, Commander Scott Altman and Pilot Greg Johnson, had minimal EVA training because they were pilots; they were not intended to be space walkers. They would essentially be cargo in suits, carried across by other space walkers more experienced with the process. Suits would have to be shuttled back and forth, and used several times by different astronauts, sort of like the old “chicken and fox in a row boat” logic problem. It was going to take a number of EVAs, and two days, to get everyone off the damaged ship, but it could be done.
After everyone had been shuttled across (along with their launch and entry suits and escape gear), the damaged Orbiter would be cast off and sent on a reentry trajectory by ground command. The rescue Orbiter then just needed to get home. Of course, the crew size now numbered eleven souls—far more than there were seats. So we developed a special assembly of recumbent chairs and harnesses. Four would ride home on the Flight Deck, and seven would have to squeeze onto the floor of the Mid-deck. In order to be sure this would work, we tried it out on the gro
und with suit-qualified volunteers. It was tight but it worked. Someone looked into the side hatch while this test was going on and reported seeing “a sea of orange, all the way across the Orbiter!” It was so tight that some crewmembers couldn’t reach the emergency oxygen knob on their suit, so we had to train for their neighbor to pull it for them in case it was needed.
The Orbiter used for STS-400 wasn’t wasted, of course. The vehicle was already prepared to accept the next payload in line, so when it was no longer needed for potential rescue, the Orbiter was simply loaded with that payload and launched to the ISS. But STS-400 was real, and had real training; it even had a patch. We were glad we didn’t need the mission, but everyone involved was a little sad to see all the work that went into it go unused. Not that we wished ST-125 ill, of course—but we would have loved to see the plan work.
When we started flying again after the loss of Columbia, the missions always felt different. While management was always on top of Shuttle flights before, it now seemed that the center of gravity of almost all decisions was shifted more toward the MMT. Less took place in the Control Center. That’s not a complaint. The MCC personnel didn’t “own” the Orbiters and the missions, we merely executed them for the program. As such, the program had the right to make decisions on the direction of a flight. But the feeling was that there was always a bit more of a “Mother May I” in the flights in the later years. Unless you had a true emergency, something not covered in the flight rules wasn’t decided by the flight control team, it was put on hold until the MMT could meet. There was a sense that much of the responsibility had been taken off the flight control team’s shoulders, and that the authority had gone with it.
You can delegate responsibility, provided you also delegate authority to act. You can’t delegate responsibility without delegating authority. That is, you can’t hold someone responsible for the outcome without giving them the means to effect change. If you give folks authority without responsibility, then you can create havoc because enabled people will be running around doing things without the burden of taking responsibility for their actions. If you delegate neither, then people are merely acting on orders without any freedom of action—an unrewarding place for the workers to be.
One of the things that changed the culture and gave more oversight to MMT was, of course, the findings that came out of the Columbia investigation. While the MMT was designed to be a way for all involved organizations to make their inputs into each mission after Challenger, it had, in fact, become a small executive committee of sorts, with a few top leaders of the program making decisions without always bringing the entire MMT into the picture. This happened slowly and without any evil intent. It simply happens when an operation becomes “routine”—you assume that since a group has made the same decision on a particular case before, it will always do so again, and so having a meeting is really just a formality. So the meetings were assumed and not held, and the folks at the top became more insulated from differing points of view to the point where some of the outlying viewpoints were never heard.
The MMT after Columbia was deliberately set up to avoid this concentration of problem solving and decision-making in isolation. In fact, physical signs of this effort were apparent in the development of a much larger MMT room. It was carefully thought out in terms of the shape of the table, and there was plenty of room for spectators and backup personnel from each organization who were expected to speak up and participate. Microphones were even added on the periphery of the room to facilitate this. MMT meetings were held every day, not just when needed, and the whole process became quite formalized. Formal processes are good. It is why airliners, for instance, have such a tremendous safety record these days—everyone follows the process, and the process is well thought out to prevent gaps. In experimental aviation (or spaceflight) there is always the problem that what you are doing has never been done before, so the process has to allow for improvisation and new information, and that was the challenge faced by the MMT in the last decade of the Shuttle program.
Coming up with a process that was rigid but that allowed variation was something everyone struggled with, but overall it worked out reasonably well. There were still hallway meetings and decision-making done by small groups, but everything had to see the light of day in the MMT meeting. This ensured there were opportunities for challenge from all points around the room. It worked, but it was a struggle. And the struggle was worth it as NASA’s human spaceflight program moved from the fast-paced “Decide now!” culture of the Shuttle era into the “Hey, we’ve got plenty of time…” culture of the ISS era. The two types of program are fundamentally different because of the time frames involved—the longest Shuttle mission was two weeks, while an ISS crew was just beginning to get its bearings after a month. The process developed in the high-stress Shuttle era had to be adapted to one of a more relaxed posture that still retained the capability to react quickly when the situation required.
The flight control teams in the later Shuttle years never relinquished their responsibility to take whatever action was necessary for the safe and successful completion of the mission, and no Flight Director ever shirked their duty to execute based on their best judgment. But there was much more deference to the decisions of the MMT as the program drew to a close, and frankly there was less need to “make it up as you went along” anyway. More emphasis was put on outside team involvement when time allowed, and on waiting for things like inspection team reports to decide if things were going nominally, or if a redesign of the mission was going to be required.
It has to be observed that the ISS assembly went amazingly well, almost impossibly so for those of us who were involved in the Shuttle for its entire flight program. If you had told anyone in 2001 that thirty-plus assembly flights would all go more or less according to plan, with all the pieces fitting together as expected, and with all the EVA assembly tasks working out, we would have told you that you were nuts. But it turned out that way. Sure, there were problems, but nothing that required dumping an entire payload into space or the ocean, and there were no emergencies that turned out to be more than could be handled in flight. It was an amazing testament to the men and women of the program who grew up and learned how to handle adversity. For over thirty years they turned problems into success.
It was clear to all that after the loss of Columbia, the Shuttle program’s days were numbered. We were directed to finish the ISS, and then move on to other goals. It was sad. In my opinion, as someone raised on exploration and pushing boundaries, it was a bad decision for the future. The Shuttle was not, and never would have been, “safe” as determined by the kind of numbers the general public expects in anything they are exposed to—auto transportation, airlines, even recreational activities. But exploration has always been about risk, and explorers are used to it.
You calculate the risk, you examine it, you minimize it where you can, mitigate it where you can’t, and accept what is left. But you still go. Giving up the Shuttle was something we all worried about after Challenger. In fact, many of us believed that if we ever lost another Shuttle, the program would be terminated—we saw the writing on the wall that early on. America was losing its determination to do great things. When we lost Columbia and were told that we could still fly to finish the station, many thought that we had dodged a bullet—but we hadn’t. The program was going to end and, unfortunately, the programs to come after were never well defined or properly funded. So when the Shuttle ended, the ISS was all that the agency really had left on its plate.
Commercialization of space transportation bothered many, but in the end that has been the goal all along. You use a national effort to explore, to develop, and to invent—then you take the results of those explorations and inventions and give it to the public to run with. That is how aviation worked. Here in the US, we don’t fly on a national airline—we fly on for-profit, commercial airliners owned by private corporations. Space travel should become that, and I hope that it does. But it will b
e painful. There will be losses. And just like the Shuttle program and our two tragic accidents, the future depends not on how an organization handles success but on how it handles its failures. NASA handled its failures by applying huge resources to understand the causes, and then applying fixes to make the program better.
What we learned, however, was that it is hard to remain vigilant, to keep the processes rigid (yet flexible) enough to always force good decision-making. Success leads to relaxation, and relaxation leads to failure—and it is important to remember that you are never as good as you think you are, and that you are always susceptible to those things you haven’t thought about that are waiting to bite you. If we had kept flying the Shuttle, there is little doubt in my mind that we would have lost another one, and it would have been for a technical reason we simply hadn’t thought about. But if we examined ourselves, we would have noted signs that we could have seen coming. It is hard to remain focused year after year, decade after decade. It is hard—but it is required. And our only hope is that future generations of flight controllers, Flight Directors, engineers, and managers keep looking back as they leap forward—looking backward for the reminders that no matter how good you think you are, you can still stumble. The legacy of Challenger and Columbia will be that warning—and we have to hope that people will continue to heed it for generations to come.