Thursday, February 24, 2011
So, today’s journey to witness the final liftoff of shuttle Discovery was an adventure, full of thrills, epic crowds and perhaps the worst case of roadway gridlock in Florida’s history.
It all started with a trip to Orlando in early November for a first launch attempt that scrubbed when microscopic bits of glass and epoxy caused a fuse to send erratic voltages to one of the shuttles six, redundant main engine controllers during preparation for fueling. A launch attempt two days later would shed light on a serious problem with the main cryogenic fuel tanks: the tank was constructed with deficient stringers (metal alloy vertical support brackets that connect the lower liquid hydrogen tank section to the upper liquid oxygen tank section). During fueling of the tanks with super-cold propellants, 3 stringers cracked. Cracked stringers had never before, in 132 previous launches, been found on a flight ready tank. The tank is safety rated to fly with 3 broken stringers, with a margin of error allowing for as many as 8 cracked stringers if spaced sufficiently apart. If not spaced sufficiently apart, the likely scenario would be collapse of the fuel tank in flight, with loss of crew and craft. Fortunately, the 3 cracked stringers caused main tank insulating foam to crack as well, creating an unacceptable flight condition: remember, it was cracked foam that “liberated” from the main tank during the ascent of shuttle Columbia on mission STS-107. That chunk of foam would strike Columbia’s port wing leading edge, creating an undetected whole in the wing. During Columbia’s reentry into Earth’s atmosphere in February 2003, hot plasma entered the damaged wing, causing its disintegration.
Ultimately, it was found that nearly all of Discovery’s 118 stringers were cast using a mottled, substandard alloy. An unprecedented campaign was put in place to reinforce the mottled stringer. In all of this, some lasting truths about the shuttle program were laid bare.
First, the shuttle system was remarkably complex and flexible and capable but extraordinarily fragile. From a systems perspective, right up to the very end, to this last flight of Discovery, NASA and its contractors were never able to fully model and comprehend the myriad risk factors. A superb analysis of the organizational, cultural and resource factors that made this so can be found in The Challenger Launch Decision by sociologist Diane Vaughan of Columbia University. Vaughan’s basic thesis is that NASA after Apollo was forced to meld a capitalistic/bureaucratic operating culture, one dependent on demonstrating profitability, with what once was a pure engineering and experimental culture and mission. In the latter culture, practically all significant technical challenges and risk factors were assigned high priority, with near limitless resources available to develop solutions. Engineers had a strong voice and could readily bring forward to senior managers critical issues. In the former culture, resources were limited, highly determined by political processes, and line engineers were subordinated to a bureaucratic, hierarchical authority structure. In the new organizational culture, the concepts of “acceptable risk” and “experience bases” were abused and misused, to at once prioritize and rationalize critical elements of risk. Vaughn’s work tries to answer the question “How, after 132 prior missions, could a lead contractor and dedicated NASA engineers let the deficient stringers make it all the way to the fueling and launch stage. Where was the quality control? “
Second, the shuttle system after 30 years of service and 133 missions (as of today), was never the “operational” system NASA claimed it was after the first 4 flights of Shuttle Columbia. The loss of Challenger and Columbia, and the screw up with Discovery’s fuel tank, all speak to this. The shuttle was a phenomenal platform for testing and extending technologies for travel to and from low earth orbit, conducting science in microgravity, assembling a complex, semi-permanent space station in orbit, and hauling, deploying and fixing on orbit huge commercial and pure science payloads. But its operation and maintenance were anything but routine. Operating costs never approached breakeven.
Back to the present. Up at 5:30am, got to the rally point for buses to Kennedy Space Center by 6:30am, with arrival at the KSC visitor center at 8:15am. My daughter, Melissa, and I toured the rocket garden, sitting for a time on a bench adjacent to an ancient, rusting Saturn IB, displayed horizontally. We spent some time looking at various exhibits, and then queued up at 11:00am for the buses to the NASA causeway along the Banana River. The skies were blue, with some puffy cumulus and wispy cirrus clouds speeding along, a nice breeze of 10-15 knots blowing at sea level. The lines to the causeway buses were epic. The number of buses deployed was epic. It took 2 hours to travel about 10 miles. Our bus was one of the very last to roll out of the visitor center, depositing us ultimately at the extreme eastern end of the causeway around 1:45pm.
No matter our position on the causeway. We laid out a blanket. Melissa kicked off her sneakers. I set up a tripod with video camera and began snapping photos of the launch pads arrayed in front of us. About 7 miles away stood Discovery against a hazy blue sky, fully fueled, the astronauts onboard, no cracks in the main tank foam — indicating that the reinforced stringers were working as intended. Very few problems were “in work.” Somehow, as support staff closed the crew hatch, a small section of a thermal protective tile broke off, this tile being one of the many thousands of tiles protecting shuttles from searing temperatures when returning to Earth. In the end, this was not a show stopper.
Pink flamingos, pelicans, buzzards and egrets scooted past from time to time. Long silvery fish jumped out of the water and into the air. (Merritt Island, where the space center resides, is a national wildlife refuge.). The atmosphere of the crowd in attendance was tense but euphoric. These were committed people, real enthusiasts, some traveling from Australia, Britain, Canada, France, and all parts of the US, who had accomplished the pilgrimage to witness a shuttle flight from about as close as one can get — and they were among the very lucky few who won tickets in the lottery to see Discovery go on its final flight. (I actually purchased my ticket from a resident of Isle of Man who couldn’t adjust his travel schedule after the initial scrub of Discovery’s flight in November.) Lots of attendees talked about bucket list. Surprisingly, there was very little wistfulness and no institutionally-engineered schmaltz in evidence as we gathered to see the ship fire its engines one last time.
With my video and still cameras set up and shots framed, I headed off in search of the US Postal Service tent to buy and have postmarked first day covers of the launch. Some were addressed to Graham Weinschenk, some to Melissa Blum and some to home. On a day with 80 degree temperatures, bright sun and some humidity, it was my luck that the postal tent was situated as far west along the causeway as one could travel by foot from where Melissa and I had set down our things. No matter. It was a good 2 mile walk. Along the way the NASA launch support helicopter passed overhead doing its traditional, slow security sweep of the causeway and launch site before the T-minus 20 minute hold commenced. The crowds waved at the crew who appeared to be waving back. On the way back to our place on the causeway, I walked between the columns of parked buses, where it was shaded and eerily quiet.
Back with Melissa, with the T-minus 20 hold underway, people-watching was the primary activity. Melissa worked her phone, texting her BFF’s. All seemed well. Great weather, great vehicle with no technical issues, time to fly. Every 30 minutes or so, the countdown audio feed of flight and mission controllers verifying equipment readiness and crew prelaunch steps, broadcast all along the causeway, would pause for an official announcement warning spectators of possible mild skin irritation from the hydrochloric mist created by the solid rocket booster exhaust at launch. Another announcement reminded the causeway crowd that its presence so close to the launch represented a de facto waiver of NASA’s liability in the event of an unanticipated mishap within 30 seconds of launch: including liability due to personal injury from blast effects, debris and toxics. Spaceflight is inherently dangerous the announcer would remind us.
As the countdown clock approached the end of T-minus 9 minute hold, the loud speakers broadcast the go/no-go status reports in launch control and mission control. All sounded well until the launch director polled for go/no-go from the Range Safety Officer (RSO), the Air Force officer responsible for destroying the shuttle system remotely during ascent should it veer off-course or suffer a major malfunction. The RSO replied that “Range Safety cannot support launch at this time due to issues with the range safety master computer console.” Most folks on the causeway did not immediately grasp the implications. The RSO continued, “we will not be able to confirm our status before the end of the T-9 hold, troubleshooting efforts are underway but we do not know if we’ll be ready in time.” Basically, an unexpected electrical surge had hit the range safety ground support systems and it was uncertain whether the range safety systems would perform as needed should a contingency arise. Range Safety has an actual physical go/no-go switch. Unless the switch is in the “go” position, a shuttle launch is impossible. For the moment, the switch would remain at no-go.
Children and groups of teens horsing around didn’t seem to mind, but the grownups hushed up and conversational tones became muted and serious. In launch control, the news apparently created a stir, prompting the launch director to state on the open loop: “okay people, let’s calm down and work the problem.” A few controllers started positing possible solutions to no avail. It was decided that the countdown would continue as planned at the end of the T-minus 9 minute hold. Should it be necessary, Launch Control would initiate an extraordinary hold at T-minus 5 minutes as the single pane launch window opened at 4:45:27PM. This meant, effectively, that NASA was willing to run the countdown all the way to the very last second of the launch window, past the ideal launch time of 4:50:27PM, right up to the point at 4:53:27PM when the mechanics of orbital dynamics, spacecraft weight and thrust, and the boiling off of cryogenic fuel would make it impossible for the shuttle to reach the International Space Station if launched this particular day.
How this was processed by the crowd is difficult to explain. The pessimists among us thought the day was done. Melissa kept telling me I was wrong, it would take off. A level of tension and confusion began to develop. The countdown had moved from an exciting normality, to a contingency mode where the quality of the excitement was less than positive. Those of us who had thought through the timing of video and still shots, who were depending on the typical countdown cues signaling an impending launch, were confused. I lost track of time — it seemed to speed up — overwhelmed by the new countdown timeline and the need to rethink my photographic plans.
T-5 arrived and passed with silence from the RSO. The hold took effect. The launch director polled certain stations again and declared that some would not be polled again in order to provide as much margin as possible to make a last minute launch decision. The voice of shuttle launch control kept announcing the whittling away of the hold which now correlated second-for-second with the closing of the launch window. When the hold ended, if the indication from the RSO remained red, the launch would be scrubbed. As the countdown to the end of the hold approached single digits seconds, there was another poll of stations. A controller came on line and reported hurriedly to the launch director that he had just received verbal confirmation from the range safety manager that the board was green. The launch controller, in turn, announced immediately “we are GO for launch!” This all happened with 3 seconds remaining before the hold would have violated the launch window, leaving Discovery earthbound for at least another day.
The crowd went nuts with elation. I screamed with joy and did a 360 spin, ending with father-daughter fist bumps. Time seemed to accelerate further and tunnel-vision set in. I was too excited to concentrate fully on the public address countdown. After the fact, I swore that the regular countdown marks were not announced. Melissa agreed. In fact, when reviewing the tape, it was clear that almost all of the usual countdown milestones were announced. What did go missing was the traditional count from T-16, when the waterflow sound suppression system started. As I kept trying to line up shots of the pad, suddenly the announcement came, “go for main engine start…,” followed three seconds later by “…we have main engine start!”
In the end, I did not see the main engines or the solid rocket boosters ignite. While trying to center my video camera’s display, I did get sideways glimpses the growing launch plume and the orange blast forces emerging from the right side of the cloud viewed face on. Through climb out and roll program, I was wrestling with my camera but finally found the good sense to put my still camera aside at approximately T+15 seconds.
The ocular experience was breath-taking and glorious though not as much so as with the night launches of STS-97 and STS-130 that I’d also witnessed from the causeway. On those two prior occasions, Endeavour brought about a sunrise in miniature and the white-blue flame of its three main engines remained visible all the way to main engine cutoff at the threshold of low earth orbit: it was a rising star. (At the launch of STS-97, the climb out was made all the more spectacular by two shooting stars moving east to west across the apparent flight path of Endeavour.)
My primary visual memories of the Discovery launch are these:
• The cloud-white pillar of smoke generated by the solid rocket boosters. It was massive, expanding rapidly in circumference long after the shuttle had sped away. At night, the coumn of smoke simply is not visible.
• The beautiful contrast of the white contrail against a blue sky.
• The intense, pin-point hot yellow of the booster flames at altitude.
• The sudden burst of avian activity around Banana River in the minutes following liftoff.
• Melissa looking skyward, tracking the outbound shuttle.
• As always, the visual and auditory disjuncture in the first 20 seconds of flight between the sight of the shuttle racing upward and the near complete absence of sound — other than the rising, self-synchronized vocalizations of the spectators reacting to the scene.
The latter observation leads to the one auditory memory I took from Discovery’s final liftoff. When the sound/shockwave generated by ignition reaches the causeway, it’s not one wave but two. First, for 5 seconds, is the roar of the main engine’s coming to life. Then, there immediately follows the sound of the air being fried continuously by the crackling, explosive forces of the boosters. These sounds arrive at a point in time when the shuttle is already miles away from the pad and thousands of feet in altitude. Whether night or day, the effect is the same always: the shockwave drives the spectators to release a primal yell that has something to do with joy and the basic intensity of the moment.
It was wonderful to witness one last time. The sadness I fully expected to feel at the closing of this era, representing the lost promise of “regular” spaceflight, just didn’t happen.
If there was any immediate regret, it was that I became part of one of the worst traffic jams in the history of Central Florida following the launch. How many people came to Kennedy Space Center, and Titusville and Cocoa Beach to witness the launch I do not know. Some reports suggested it might be the third or fourth largest turnout for a NASA launch. Whatever the facts, it took 5 hours, 30 minutes to return to Orlando, a distance of about 50 miles. In the time it took to get back to our hotel, Discovery had completed more than 3 orbits of Earth.
One closing note is in order. In 1980, inspired by a fantastic Physics teacher, Rusty Davis, and the national investment NASA made in engaging youth in space science, I fell headlong in love with science and space exploration. At the time, NASA organized a competition inviting high-school students to submit proposed experiments to be launched aboard early shuttle missions. Students were given a basic set of parameters for designing an experimental platform: one that would interface with Space Shuttle power systems and storage compartments, and would allow for relatively straightforward human manipulation and data collection. I conceived of an experiment to measure observed differences in Brownian motion in micro-gravity versus an earthbound control. The proposed experiment was typed up and mailed by the deadline to NASA. It was not accepted among the 10 finalists – was not even close. I really never addressed the design of the experimental platform, which was too bad. NASA sent me an acknowledgement with a letter of thanks for my interest and support. No matter, I was hooked. And I am happy (and a bit proud) to report the following: in February 1984, an experiment designed by scientists affiliated with the European Space Agency (ESA) flew on mission 41-B (Challenger), the eleventh flight of the space shuttle program, its purpose being to measure the differences in Brownian motion in orbit and on Earth.
I wonder today what our nation, as a matter of policy, is doing to capture and fascinate youthful minds and imaginations, to make young people fans of science, to encourage the same level of investment in scientific understanding that we promoted three decades ago.