Space Shuttle Discovery Launched on the First Post-Columbia Mission on July 26, 2005, 905 Days After the Accident
Total Page:16
File Type:pdf, Size:1020Kb
AFTERWORD Space shuttle Discovery launched on the first post-Columbia mission on July 26, 2005, 905 days after the accident. Coincidentally, the launch took place at 10:39 A.M. EDT, the same time as Columbia’s launch on its final flight. STS-114 was the culmination of a $1.4 billion effort to improve the shuttle, most notably the External Tank. The bipod foam was replaced with an electrical heater to prevent ice from forming. Marshall Space- flight Center External Tank manager Sandy Coleman promised that no foam larger than a marshmallow would fall off of the improved tank. In the 147-page press kit’s description of all of the improvements to the shuttle, KSC’s acceptance of the industry standard definition for FOD (Foreign Object Debris) is presented as a positive. In a spin doctor- ing attempt it’s described how new FOD procedures improve safety, and ignores that FOD rules existed until two years before the Columbia acci- dent when the rules were reduced in a conscious move to make more bonus money for the contractor. Over 100 tracking cameras viewed Discovery’s launch. The E208 camera in Cocoa Beach, the one that had been “soft focused” on STS- 107, was replaced with a state-of-the-art setup. Cameras were also mounted on Discovery’s External Tank and Solid Rocket Boosters, and The bipod fitting on STS-114, on the right, shows the most significant external change— there is no longer any foam on the bipod fitting. 428 AFTERWORD 429 two aircraft with high-definition cameras offered the unique perspective of a shuttle flying toward the viewer. Everybody was shocked to see something fall off the ET shortly after the boosters separated. Fortunately, it didn’t hit Discovery. It was a piece of the Liquid Hydrogen PAL (Protuberance Air Load) ramp, an aerody- namic cover over the ET’s wiring. That 0.9-pound piece was the equiva- lent of 54 marshmallows. It was the third largest known ET debris, with only the STS-112 and STS-107 bipod foams larger. The entire PAL foam weighs 21.8 pounds. That’s an extremely large piece, and potential source of lethal debris. In two previous cases (STS-4 in 1982, and STS-7 in 1983) umbilical well cameras detected lost PAL foam. As with the bipod, there were many cases where adequate photog- raphy wasn’t available. NASA records say 62 flights had adequate PAL ramp photography. It’s likely PAL foam was lost on some of the 49 mis- sions without adequate photography and went unnoticed because it did- n’t damage the shuttle. Manager Wayne Hale acknowledged that if the PAL foam had fallen off earlier, while Discovery was still within the denser atmosphere, it could have hit the shuttle.” In September 2003, Coleman noted that PAL foam was lost in the past and would require improvements. Later the decision was made not to change the PAL foam on the STS-114 tank because engineers believed it wouldn’t be a problem. NASA thought the PAL ramps were okay, and improvements could be deferred. Shuttle flights were put on hold again until it could determined why the foam was continuing to fail. Certainly the PAL foam incident was a major embarrassment for NASA. After saying for two years that no large pieces of foam would fall off of any External Tanks, just that happened on the very next flight—in a dramatically visible fashion. Smaller amounts of foam were also lost from four other areas. But those losses need to be taken in context— they were far less than any other shuttle mission, and Discovery’s tiles and RCC came back in remarkably clean shape—with very little damage. The media and members of Congress who thought STS-107 wasn’t important followed the STS-114 mission in detail, but concentrated only on the changes since the Columbia accident and Discovery’s reentry health. Many media called it a “problem plagued mission” even though overall it went quite well. Discovery docked to the International Space Station and transferred 5,000 pounds of cargo. One key item was the Human Research Facility-2 (HRF-2), a more advanced version of the ARMS experiment the STS-107 payload crew dedicated so much of their time to. 6,000 pounds of cargo was returned to Earth—completed experiments, non-working hardware, Russian autopilot units for reuse on future missions, and even trash. The crew made three spacewalks to make repairs to the space station, 430 AFTERWORD installed new scientific experiments, added a storage platform for spare parts, tested tile and RCC repair techniques, and even made a simple repair to the shuttle’s belly. All of the major objectives were accom- plished, and many tasks were added while the mission was underway. Many STS-107 Mission Control team members also worked STS- 114. Entry flight director LeRoy Cain, MMACS officer Jeff Kling, and others sat in the same seats. Flight directors Paul Hill and Cathy Koerner, who handled photo analysis from the public, were two of STS-114’s flight directors. Flight director Kelly Beck led a team that analyzed Discovery’s thermal protection system. A couple of months before the mission, NASA announced a new class of flight directors, including STS-107 entry FDO Richard Jones, and entry GNC Michael Sarafin. Bad weather in Florida resulted in Discovery landing at the backup site at Edwards AFB in California. As Discovery passed over Oxnard, its sonic booms were heard by amateur astronomer Brian Webb. He was an eyewitness to Columbia’s reentry two and a half years earlier and an “ear- witness” to Discovery’s reentry. Webb said, “I heard a loud BOOM-BOOM that shook the house. The window was partially open and I saw the curtain move. Dogs in the neighborhood started barking, and one of my neighbors walked outside, apparently wondering what the explosion was.” After the landing commander Eileen Collins said, “Today is a very happy day for us—but it’s also a very bittersweet day for us too as we remem- ber the Columbia crew and we think about their families. The Columbia crew believed in their mission, and we are continuing their mission—that’s very important to us, that that mission of space exploration goes on.” While monitoring the STS-114 mission something totally ordinary which occurs multiple times on every mission creeped me out. Communi- cations was temporarily lost with Discovery while it was in orbit. Capcom Julie Payette in Mission Control called “Discovery, comm check” and did- n’t get an answer. She tried a second time. Intellectually I knew that noisy communications was no big deal and there almost certainly nothing wrong. But in my heart I remembered Charlie Hobaugh’s ordinary call “Columbia, Houston, UHF comm check.” After Payette’s second attempt Eileen Collins responded and I breathed a sigh of relief. The phrase “Comm check” may be a standard part of NASA’s communications proto- col, but there’s no way it’s ever going to sound as ordinary in the future. IRONIES Had the upper atmosphere winds been slightly different, or had Columbia’s solid rocket boosters burned just slightly differently, the bipod foam could have missed the wing entirely, or hit the wing at a different angle with a non- fatal blow. If the foam had come off earlier, it wouldn’t have slowed down so quickly, and even if it did strike the wing, it wouldn’t have hit it with as much AFTERWORD 431 force. If the foam came off a little later, at a higher altitude, then there would- n’t have been enough atmosphere to change its speed relative to the shuttle. Only under a very narrow range of circumstances would a piece of debris become deadly. It just happened that NASA’s luck ran out on January 16, 2003, and Columbia’s wing was in the way of a stray foam bullet. STS-107 didn’t need the shuttle’s 50-foot robot arm, so it wasn’t installed. But if the arm was onboard, it could have been used to inspect the left wing. If the damage occurred elsewhere, it could have been out of the robot arm’s reach, but Columbia’s damage was in a place where the robot arm could see it. If the damage was extensive enough to be visible on the video from the robot arm’s camera, it would have given engineers posi- tive evidence Columbia’s wing was badly damaged. In that hypothetical case, the rescue scenario in Chapter 48 might have actually happened. If STS-107 was a mission to ISS, then it would have been easy to use the space station’s robot arm to examine the place the engineers believed the foam had hit and determine the amount of damage. It would be extremely easy to ask the astronauts to inspect the wing for damage on an already planned ISS spacewalk before their other planned tasks. The ISS would have had the additional benefit of a shelter where the crew could wait for rescue, or even conceivably wait for an emergency repair kit to be designed on the ground and launched up to them. If the shuttle had been damaged on almost any other mission in the previous six years, the reentry path would have been from a completely dif- ferent direction. Most shuttles take a reentry path over the Gulf of Mexico on the way to Florida, or over Pacific Ocean if landing at the backup site in California.