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Danger in Space - Space Shuttle Tragedy

The recent Space Shuttle tragedy has refocused our minds on the perils of space travel. In this article we take a broader look at the history of space disasters over the last four decades.

by Stuart Carter

Space is an airless vacuum of burning heat and searing cold. It’s the most hostile environment imaginable. Yet reaching out into this lifeless void is man’s ultimate dream – and the ultimate challenge. We have been redefining our place in the universe since 1961. We have broken the bonds of gravity and we have walked on the moon.

But conquering the final frontier often comes at a price. January 1997:Russia’s MIR space station was setting records as the only continuously occupied man-made structure in space. It had been in orbit for 11 years when American astronaut Jerry Linenger joined the crew. During the crew exchange, the space station’s compliment doubled from three to six. MIR’s aging oxygen generators were pushed to their limits. A simple spark became a raging fire. Linenger: “All of a sudden I heard the master alarm. The fire was blasting across the entire module. Fire was shooting this way, molten metal flying this way, getting splattered on the far bulkhead, sparks flying and smoke billowing out.”

The smoke was acrid and incredibly dense. The crew’s first priority was the desperate search for breathable air. “I grabbed the oxygen mask. Activated it. Got nothing. At this point I felt like I had been swimming under water for maybe 25 metres and needing air. Grabbed the second oxygen mask, put it on, sort of kept my fingers crossed, said a quick prayer and I got oxygen.” It took 14 minutes before Linenger and Tsibliev finally got the situation under control.

Official portrait of Astronaut Jerry M. Linenger as taken in 1992

America’s worst fire didn’t happen in space but here on Earth on a launch pad on Friday January 27, 1967.This was supposed to have been a run through of America’s first Apollo capsule. Instead Apollo 1 claimed the lives of astronauts: Gus Grissom, Ed White and Roger Chaffee. Six hours into their exercise, a spark from faulty wiring ignited the capsule’s pure oxygen environment, instantly turning the spacecraft into a furnace. After the Apollo 1 tragedy, NASA replaced the 100% oxygen atmosphere with a safer, non-flammable mixture of oxygen and nitrogen.

For shuttle crews, the eight-minute ride to orbit is intensely dangerous. While the solid rocket boosters, the SRBs, are firing, stresses on the vehicle make it impossible for the crew to escape. The spacecraft’s three main engines burn liquid fuel at a ton every second. The SRBs, are the workhorses of the system, blasting shuttles into orbit since the early 1980s. SRB’s are 450 tons of pre-packed high explosive. Once lit an SRB can’t be turned off.

On an unseasonably cold day in January 1986 an enthusiastic shuttle crew began their trip to the launch pad. Although shuttle launches had become routine, a shuttle had never been flown in such cold conditions. Ignition was perfect, lift-off flawless. 2,000 tons of hardware accelerated through a clear blue sky towards 25 times the speed of sound. But a tiny leak from a frozen rubber ‘O’ ring seal on one of the SRBs was allowing burning gas to escape and melt a supporting strut. The strut gave way --- and the booster hit the external tank containing half a million gallons of liquid hydrogen. Challenger’s 10th flight was to be her last.

When a shuttle does finally take off, it is protected by millions of safety systems. And sometimes these systems abort the launch with just seconds to lift off. Once the SRBs are jettisoned, there’s still the chance of a main engine malfunction. At this stage the three main engines are still burning propellant at over 1,000 gallons a second. For a human working in the vacuum of space, personal protection is vital. Each space suit is in reality a miniature spacecraft. As the numbers of men and women living and working in space grow, so will the numbers of space walks. But a space walk is not to be taken lightly - space is quite simply the most inhospitable environment any living creature could possibly face. Linenger: “You open that door without a space suit on and essentially you will come apart.”

Challenger wreckage remains and boxes of debris being lowered into abandoned Minuteman Missile Silos at Complex 31 on Cape Canveral Air Force Station.

A tear big enough to expose you to the full vacuum of space would be one of the most painful deaths imaginable. All the air would be sucked from your lungs. Blood would feel as if it was boiling in your veins, and your internal organs would go into seizure. A space walker must keep tethered to his spacecraft. There are no second chances...

But perhaps those astronauts who dared leave the relative safety of Earth orbit took the greatest risks of all. On April 20th 1972, Charlie Duke became one of only 12 human beings to ever set foot on a world outside our own. “The lunar surface was to me incredibly beautiful – lifeless, hazardous, it was the most desert you could ever imagine and yet you felt right at home. It’s hostile, I mean there’s no atmosphere up there, you depend on that suit. If the zipper splits open you’re dead. If a glove pops off you’re dead…”

In its quest for the moon NASA’s Apollo program proved man could reach for other worlds. But long-duration missions are still a major challenge. Russia’s MIR space station was suspended in Earth orbit for 15 years - a fragile bubble of life in the vacuum of space. It had already suffered a major fire but worse was still to come.

In May 1997, the next NASA astronaut (person) to step on board MIR was British born Michael Foale. Foale’s Russian crewmates Vasiliy Tsibliev and Sasha Lazutkin, had already served a total of six months aboard MIR. Little did these three men know that they were about to endure the worst on-orbit collision accident in space history. Just like Linenger before him, Foale was surprised by the conditions he found on board the space station. Much of this clutter was waste that had to be stowed until it could be disposed of on regular visits by ‘Progress’, MIR’s unmanned supply ship. The radar system used to pilot ‘Progress’ from the ground was expensive. To save money a cash strapped Russian mission control decided the crew on board MIR should guide ‘Progress’ in manually. This near impossible task fell on the shoulders of MIR’s commander - Vasiliy Tsibliev.

Tsibliev was expected to manually dock two spacecraft traveling at 18,000 miles an hour. Tsibliev’s only visual aid was a single, low-resolution video camera mounted on ‘Progress’ itself. To help their commander judge the distance of the approaching spacecraft, Foale and Lazutkin took turns shouting instructions from portholes around the space station. It was an impossible task. As ‘Progress’ closed Tsibliev lost control. 7 tons of hurtling spacecraft - the size of a small bus - collided with MIR’s ‘Spektr’ module...

The MIR Space Station

The impact ruptured the ‘Spektr’ module. The hiss of escaping air rushed through MIR. The space station tumbled out of control. Foale rushed through the station. It was a race to seal the hatch that led to the crippled module and contain the leak before all of MIR de-pressurized.

17 minutes after the impact, they managed to seal the hatch. MIR was tumbling out of control, its solar panels damaged and no longer pointing at the sun. With no power the crew worked in dark, dead silence for 14 hours. Finally the crew managed to stabilize the space station and regain control.

Having helped avert a major catastrophe Foale was safely returned to Earth on NASA’s space shuttle. But bad luck continued to plague the exhausted Tsibliev and Lazutkin on their return to Earth. The retro rockets designed to fire and cushion their capsule’s hard landing malfunctioned. Lazutkin injured his back, and Tsibliev was about to become a political scapegoat. The ageing space station limped on for a few more years. MIR finally tumbled back to Earth and crashed in to the pacific in March 2001.

Re-entering the Earth’s atmosphere is no mean feat. Most objects that fall through the atmosphere such as small asteroids or space debris never make it at all. They burn up by friction when they collide with the atmosphere 60 miles above the surface.

Astronaut Virgil I. "Gus" Grissom wishes Alan B. Shepard a safe flight just before insertion into the Freedom 7 spacecraft

Once the astronauts fire their retro rockets, you drop into the Earth’s atmosphere. There is no turning back. Traveling at 5 miles a second - that’s 18,000 mph - the early Mercury astronauts were reaching into the unknown. There was no margin for error - the angle at which they hit the planet’s atmosphere was the most critical part of the whole journey. And when a capsule starts to re-enter the Earth’s atmosphere, the crew are on their own...The capsules were engulfed in a huge fireball and during that time no one could talk to them from the ground. In fact the most dangerous part of the Mercury capsule’s journey was not re-entry but splashdown. In 1961, 6 years before he died in the Apollo 1 accident, Gus Grissom nearly drowned when his hatch blew open on splashdown. He was saved by the waiting rescue services, but his Mercury capsule sank thousands of feet to the bottom of the Atlantic Ocean.

For cosmonauts, capsule re-entry is still their only way home. But touchdown on land rather than water can be lethal. In 1967, a Soyuz capsule pile drived into the ground. It’s lone occupant, cosmonaut Vladimir Komorov made it through the perils of launch and orbit, only to die because of a faulty parachute.

To make re-entry as safe as humanly possible, NASA designed the Space Shuttle, with many new, groundbreaking technologies. They equipped the outer skin with a lightweight, re-usable heat shield that would protect both vehicle and crew. These Thermal tiles are so heat insulating that even at 1, 300 degrees centigrade, they can be picked up with your bare hand. Each shuttle has a total of 25,000 tiles on its outer surfaces. The shuttle begins its descent at a staggering 5 miles a second. To slow down it performs a series of ‘S’ shape turns that create extra drag - the tiles becoming hotter than a blast furnace as the shuttle smashes through the atmosphere.

STS107-S-002 (October 2001) - The seven STS-107 crew members take a break from their training regimen to pose for the traditional crew portrait. Seated in front are astronauts Rick D. Husband (left), mission commander; Kalpana Chawla, mission specialist; and William C. McCool, pilot. Standing are (from the left) astronauts David M. Brown, Laurel B. Clark, and Michael P. Anderson, all mission specialists; and Ilan Ramon, payload specialist representing the Israeli Space Agency.

We remember them.

A shuttle can lose one or two thermal tiles and survive, but if a whole section broke free...

We may never know what caused the break up of the Columbia Shuttle. Whatever the cause it seems almost certain now that the thermal insulation layer was insufficient to counter the heat. Did something damage the tiles on lift off? Was there a computer malfunction? It may take NASA years to know. One thing is almost for sure the Shuttle will have to fly again; if only to provide proper support to the three astronauts left stranded on the ISS. But its days are surely limited. In just over 100 flight two orbiters have been lost.

When the next shuttle launch does take place it will be under incredible scrutiny as it appears over the skies of Florida. At this point of its journey the Shuttle is an unpowered glider and the commander will have just one shot to hit the runway.

Each completed mission challenges us to take the next step forward. Humans are an adventurous species, facing the unknown, is nothing new. No-one knows what other dangers will confront the men and women who venture into space but one thing is certain, their stories will inspire a whole new generation to explore the final frontier.

Click Here for a follow up article to this one, Men in Space? Where Sir Martin Rees reflects on the recent space tragedy, and ponders the question of the dangers of men travelling into space.


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