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| The tenth flight of Challenger lifts off on Jan. 28, 1986. (NASA) |
The frigid cold weather created a launch pad coated in thick ice which wrapped itself around the fully fueled space shuttle on the morning of January 28, 1986. Challenger's tenth crew, led by commander Francis Dick Scobee, included NASA's Teacher in Space representative, Sharon Christa McAuliffe, on a very publicized mission flying the first average citizen into space.
America's first "teachernaut" planned to conduct two live classroom sessions, including "The Ultimate Field Trip", a tour through the orbiter; and a lesson on why people explore and work in space from 176 miles above. The broadcasts were to be shown in classrooms around the planet on NASA-Select TV. Christa's excitement and enthusiasm made her a popular role model both in the public school systems and with the media.
This shuttle stack was the heaviest to launch weighing 4.53 million pounds, and carrying the second massive Tracking and Data Relay Satellite (TDRS). The SPARTAN satellite, designed to be placed over the side of the shuttle for a free flight close study of the popular visit by Haley's Comet, was to be deployed on day three of the mission and retrieved twenty orbits later.
The freezing temperatures associated with a cold front which moved over the Kennedy Space Center the evening before provided for much discussion inside the space agency. Many engineers were convinced that the below freezing temperatures could harm the spacecraft in unproven ways.
"The temperature at Cape Canaveral overnight was predicted to be in the 20s, far colder than any other shuttle launch," said Dr. Rhea Seddon, a member of NASA's first selection of women astronauts and a three time shuttle veteran. "Would that cause problems? The solid rocket booster engineers were uncertain what the cold temperatures would and voted to delay. The NASA managers overruled them and gave the crew the go for launch."
The flight had been delayed nearly one week, first due to the delays getting sister ship Columbia launched from nearby pad 39A. The day before the fatal launch, a stuck handle due to a bolt on Challenger's crew hatch could not be removed in time. The delay allowed for higher than allowed crosswinds over the shuttle's return to launch site runway which forced NASA to scrub for the day.
As the crew walked out on launch morning to a waiting silver van for the ride to launch pad 39-B, smiles crossed the excited crew of seven's faces as they hurried to get out of the cold. Scobee, pilot Michael Smith, Flight Engineer Judy Resnik, mission specialists Ron McNair, El Onizuka, McAuliffe and payload specialist Greg Jarvis departed their living quarters for their trip out to Challenger.
As schools opened for business across America, classrooms with TV sets provided students with the excitement to watch a school teacher travel into space. Students filled classrooms at McAuliffe's Concord High in New Hampshire to cheer on one of their own. Only Cable News Network and anchor Tom Mintier, a close friend with Smith, carried the launch live internationally to the public as it happened.
One future astronaut followed the live coverage from his office in New Jersey. "I was surprised to hear NASA was proceeding with an on-time launch," said Dr. Don Thomas, who joined NASA in 1987 and later flew aboard four shuttle flights. "I fully expected NASA to scrub the launch that day because of the cold temperatures and all the ice that had formed on the shuttle launch tower."
At the Johnson Space Center, the home of NASA astronaut corps., Dr. Seddon prepared for her second space shuttle mission. "My next crew and I took a break from our training to watch this one go," she said looking up to pause. Her eyes began to tear. "The engines started. The boosters ignited. They went off into an intensely clear blue sky."
As the twenty-fifth space shuttle mission rose from its ice-covered launch complex, cheers throughout classrooms erupted on that January morning at 11:38 a.m. EST. On Challenger's flight deck, Resnik also cheered as the three main engines roared to life, "All right... Aaallll riiight!" Several miles away at the space center's VIP viewing site, McAuliffe's parents watched and applauded the launch with several of the crew's family members.
NASA cameras around the launch site perimeter began clicking in rapid fashion remotely triggered by the extreme vibrations of lift-off. As 6.7 million pounds of thrust passed through the space shuttle's twin solid rocket boosters and Challenger's three liquid fueled main engines those cameras began to record the "smoking gun" of her demise.
Several puffs of black smoke blew out from the lower section of the right side booster as the boosters were ignited. Later, engineers determined that fire singed the frozen rubber O-ring seal located where the booster's casings were stacked together at the aft strut.
Seconds later the black smoke puffs stopped and the shuttle cleared the launch tower and streaked out over the Atlantic waters. Cheers turned to conversations within the schools as both school officials and students spoke about the powerful launch they witnessed.
As Challenger began her eastward dart out over the Atlantic Ocean the entire shuttle stack rotated on cue into a heads down position. Seconds later, pilot Smith radioed his commander, "Looks like we've gotta lot of wind here today." Scobee agreed, "Yeah. It's a little hard to see out my window here."
As the spacecraft passed the speed of sound, Scobee and Smith throttled the main engines down to 65% of rated thrust as not to tear the spacecraft apart due to extreme forces as it flew faster through earth's dense atmosphere. moments later, Smith asked Scobee to throttle the engines back to 104%.
According to NASA, the crew encountered several "high altitude wind shear conditions" which occurred for twenty-seven seconds during Challenger's first minute of flight. The guidance and navigation system combined with the rocket boosters steering system corrected for the excessive winds. NASA added, "The wind shear caused the (boosters) steering system to be more active than on any previous flight."
One minute into the ascent, the view from close up cameras on NASA TV trained on Challenger's launch provided no insight of the trouble underway. The orbiter and crew were traveling faster and higher in a heads down attitude. However, Air Force tracking video cameras recorded the earlier O-ring breach reappearing as a massive flame forcing its way through the booster's same failed seal.
Seventy seconds into the flight, the last audio from Challenger's cockpit is heard as Scobee acknowledged mission control's command, "Roger, go at throttle up." The main engines were once again at 104% of thrust as they helped push the space shuttle toward orbit.
The breach of the booster's joint was determined to be caused by the forces of launch and the shuttle's movement through the high wind speeds of the Jet Steam. The booster's weakened rubber seal began to shift allowing the O-ring failure.
As the flame continued to intensify, it began to lick the side of the massive rust colored external fuel tank loaded with several hundred thousand gallons of super cold liquid oxygen and liquid hydrogen. On the mid deck, McNair, McAuliffe and Jarvis were likely all smiles as they soared closer to space.
It took only a few seconds for that blow torch effect to punch a hole in the tank and mix with the hypergolic fuel causing a disastrous chain reaction. The dome base of the tank broke free dumping thousands of gallons of liquid hydrogen. This "created a sudden forward thrust of about 2.8 million pounds, pushing the hydrogen tank upward into the intertank structure," NASA added.
Smith commented, "Uh-oh!" as the main engines lost thrust. In milliseconds, the lower strut attachment holding the ailing right booster to the tank broke off forcing the top of the booster to steer into the upper tank. The external fuel tank then exploded 73 seconds after launch.
The force of the explosion caused Challenger to shatter into thousands of pieces. The blast threw the crew cabin upward fully intact. Onizuka and Resnik on the flight deck survived the break up and were alert to activate Scobee and Smith's oxygen units behind their seats.
In Mission Control near Houston, public affairs officer Steve Nesbitt had spent the last 73 seconds updating the public on NASA-Select with altitude and velocity calls. "One minute, 15 seconds, Velocity 2,900 feet per second," he said not having seen the video immediately. "Altitude nine nautical miles. Downrange distance seven nautical miles."
Nesbitt suddenly found himself without words as he looked up and the entire control center gasped after witnessing the fireball. Pausing to collect new information from nearby flight controllers, he said, "Flight controllers here are looking very carefully at the situation. Obviously a major malfunction."
The students at Concord High continued to cheer unaware of the disaster until one student near the TV shouted "Shut-up... they just said there was a malfunction!" The room grew silent and the radio static originating from mission control became a chilling moment.
"I listened intently hoping to hear some report that Challenger had flown free of the blast and would be flying back to KSC or ditching in the Atlantic," Thomas said as his voice grew soft. "But that report never came. It took a few minutes to sink in that all was lost, the crew, Challenger -- the entire vehicle was lost."
Seconds passed before Nesbitt spoke the line which echoed through the hearts of the public watching both on TV and in the grandstands of the space center, "We have a report from the flight dynamics officer that the vehicle has exploded." Nesbitt added, "The flight director confirms that. We are looking at checking with the recovery forces to see what can be done at this point."
As the memories of that morning rushed past Dr. Sheddon, she said, "It was unbelievably horrible to see seven friends perish in an instant. It was even more difficult to see what their families would have to endure."
The twin rocket boosters soared off and away from the explosion, higher and erratic they flew as they burned propellant, and without Challenger's guidance computer to control them. Seconds later, the Range Safety Officer at Cape Canaveral Air Force Station pressed the destruct button to destroy them.
There was no hope for the crew inside the freed cabin as gravity drew it back toward earth in a dizzying spin before slamming into the Atlantic Ocean at nearly 300 m.p.h. It then settled on the ocean floor several miles below not to be discovered by search and recovery divers for another five weeks.
Dr. Thomas paused for a few seconds focused on one of many shuttle launch images at the Kennedy Space Center as we recalled the launch. "It was numbing later that evening when I watched the national news and could see visually for the first time the full extent of what had taken place," he said. "I joined the rest of the nation in mourning this tragic loss."
Seddon remembers her friends and the mission of Challenger in a chapter of her new book Go for Orbit. This aerospace journalist asked her, 'What does Challenger's legacy mean to you?' "The loss of the Challenger crew reminds us that the price of exploration can be high, but it must not stop us from striving to discover new worlds," she said.
A few years following the loss of Challenger, Dr. Thomas reported to the Johnson Space Center to interview for a prized selection into the astronaut corps. "During one of the interviews, I was asked why I still wanted to be an astronaut considering that NASA had lost its last vehicle and crew. My answer was easy and straight forward, 'I had been following NASA since I was six years old. I had seen other accidents... I had every confidence that NASA would fix the Challenger problem and when they moved on afterwards, I wanted to be part of that exploration'."
The families of the seven astronauts bonded together in the year following their losses to create their personal Phoenix, The Challenger Learning Center. The new center rose up to continue the educational lessons begun by the Challenger 7. Today, over 40 Challenger Learning Centers operate across America and around the globe.
"The Challenger families agreed it was important for the world to remember how the crew lived and what they were passionate about, not how they died,” said Challenger Center Chair Dr. June Scobee Rodgers, widow of Dick Scobee. “I know Dick and the crew would be so proud. They would love the enthusiasm of the children who visit our centers. They were inspiring the future 30 years ago, and we’re so pleased that the mission continues to live on today through our Challenger Learning Centers.”
The center's strong Science, Technology, Engineering and Math (STEM) focus continues to broaden both the education and outlook of today's youth. The centers support students from elementary through high school with instructors dedicated to their job.
"Every day I get to go into work and watch the eyes of our students grow wide with wonder as they work together to solve problems and accomplish goals," said Libby Norcross, a Flight Director at the Challenger Learning Center of Heartland College in Illinois. "I get to see them have that light bulb moment when they realize they can do things that seem hard."
As the veteran flight director shuffled through charts to prepare for her next session with a new flight crew, Ms. Norcross summed up her thoughts, "I have watched the incredible bravery of the 51-L astronauts, and their families, in the face of such tragedy live on and touch the lives of thousands of students. What a tremendous legacy, and what an honor to help carry their mission forward."
Americans returned to space 32 months later as Discovery carried a crew of five on a successful mission deploying NASA's third TDRS into orbit. The five day mission went trouble free, however, booster joint O-ring singe on several future space shuttle launches would create a few tense moments within the space agency.
Thomas authored a book recently detailing one of his four shuttle missions which flew in July 1995. Orbit of Discovery recounts his all-Ohio crew's delayed mission by a pesky woodpecker, and their deployment of the replacement TDRS built after Challenger. The hardcover book includes brief biographies of fellow Ohio astronauts, including Dr. Resnik and Neil Armstrong.
"One of the contributions I am most proud of as an astronaut was deploying TDRS-G, the final Tracking and Data Relay Satellite deployed from the space shuttle," Thomas said with a proud smile. "This satellite was the replacement for the one that was lost aboard Challenger, and our STS-70 crew took special pride in helping to complete one of the major objectives of the STS-51L mission."
(Charles A. Atkeison reports on aerospace and science. Follow his updates on social media via @Military_Flight.)
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