The 10 Most Dangerous Moments in Space Shuttle and Station History
Astronauts are even braver than you think. Here's a list of NASA's closest calls during the history of the agency's shuttle program
The 10 Most Dangerous Moments in Space Shuttle and Station History
- 10. ORBITAL BULLETS--JUNE 28, 2011 Space above Earth is a lethal junkyard littered with countless scraps speeding by at tens of thousands of kilometers per hour. The trash runs the gamut from pieces of explosive bolts to farings from rocket nose-cones and, lately, bits of a satellite deliberately blown up by China. All pose serious threats to even the toughest spacecraft, so the U.S. National Reconnaissance Office sometimes alerts NASA if their top-secret system detects something getting dangerously close to a manned spacecraft. On June 28, the space station had its closest-ever encounter with orbital junk, at about 250 meters away. The object, traveling about 46,700 kph, forced six crew members on board the space station into two docked Soyuz spacecraft ready for a quick escape. The all-clear came a few minutes later, and orbital life went on as normal. The last time crew members were sent scrambling for the lifeboats was March 12, 2009, when a hunk of a satellite’s motor zipped by the ISS. In the end, says Hale, these and other dangerous events are a fact of life in spaceflight. NASA
- 9. SNAGGED SOLAR ARRAY--NOVEMBER 3, 2007 The space station’s four pairs of solar arrays, each close to a football field long end to end, provide all of the orbital laboratory’s electricity. During the STS-120 space shuttle mission, astronauts moved one of the station’s solar-array pairs to a new location, then unfurled them. But when the deployment was about 80 percent finished, one of the golden wings jammed up and ripped. With a damaged and only partially unfurled sail, the station could not support soon-to-be-delivered rooms and equipment. So Mission Control engineered a daring repair starring astronaut Scott Parazynski—a medical doctor. He ventured outside the space station, clipped onto the end of the space shuttle’s inspection boom (which was itself attached to a robotic arm) and sewed up the rip with tools wrapped in tape to prevent electrocution. "It was at the absolute limit we could reach out there, and we sent out our tallest astronaut. He could barely reach," Hale said. "For a moment, the entire space station hung in the balance. It was pretty dramatic." NASA
- 8. EXPLOSIVE LANDING--DECEMBER 8, 1983 Hydrazine is a nasty fuel that smells like ammonia and can ignite spontaneously when exposed to air. When the ninth space shuttle mission landed at Edwards Air Force Base in California, hydrazine leaked from an auxiliary power unit on the shuttle and caught fire—but no one at NASA knew until the next day. Technicians found the scorched area only after detaching the rear panel of the spacecraft during post-flight inspection. It is believed the fuel leaked on orbit but immediately froze. Once Columbia and it crew of six touched down on the warm ground, the hydrazine ice melted and the leak resumed. NASA/JSC Digital Image Collection
- 7. SOLAR FLARE--JANUARY 20, 2005 Space weather is a looming threat for any space flier. Even those cradled in a spacecraft within the Earth’s protective magnetic shield can feel the wrath of solar radiation storms.
On January 20, 2005, a giant sunspot exploded and flung an X-class solar flare toward the Earth. As high-speed protons arrived at the International Space Station, space fliers on board—including Chiao—hunkered down in well-insulated nooks and crannies of the space station. Over the next few days, Chiao and cosmonaut Salizhan Sharipov retreated to their hideouts about every 90 minutes—each time the space station completed an Earth orbit. The precaution cut their radiation levels to a modest 1 rem, or one CAT scan’s worth. Radiation levels of 50 rems outside the ISS during the flare could have sickened a space-walking astronaut. Inside, the worst Chiao and Sharipov probably met was an increase in their lifetime cancer risks. "It was kind of eerie seeing radiation levels 10 times higher than they should be, and there was nothing you could do about it," Chiao said. "It wasn’t pleasant." NASA/Earth Observatory - 6. SEVERE TILE DAMAGE--DECEMBER 1988 The space shuttle's thermal protection system is an armor of heat-resistant tiles that diverts super-heated plasma during reentry. And as NASA was forced to address with the loss of Columbia and its crew in 2003, damage to those tiles is a life-threatening situation. Nearly 15 years before, however—just two flights after the Challenger disaster—a Columbia-like problem occurred: Insulation from the right solid rocket booster of space shuttle Atlantis fell out 85 seconds into the launch and scraped tiles on its starboard side. The crew inspected the shuttle’s undercarriage in space with a TV camera on the spacecraft’s robotic arm. After seeing the images, shuttle commander Robert Gibson thought he was "going to die" during atmospheric reentry, according to Spaceflight Now[http://spaceflightnow.com/shuttle/sts119/090327sts27/]. Because the mission was to deliver a top-secret satellite to space, transmission of TV images to Mission Control was encrypted, low-resolution and slow. When mission managers saw imagery of the tiles they dismissed the anomalies as poor lighting. The crew had a much clearer view and repeatedly voiced their concerns, but found no recourse. NASA would not break encryption for clear TV imagery and reiterated its engineers' assessment. The extreme nature of the damage became fully apparent once on the ground. One tile was completely missing, and a total of 700 were damaged. The reentry even scorched sections of the orbiter’s thin aluminum skin. A panel assembled by NASA reviewed the incident and made 10 recommendations, including that the agency should conduct more thorough inspections and improve communication about damage to the thermal protection system. NASA
- 5. FLAT TIRE, FAILED BRAKES--APRIL 19, 1985 The last thing you want when landing 100 tons of the most complex machine ever built by humans is a flat tire. Or a brake failure. Both happened to the seven-person crew of the STS-51-D space shuttle mission when they landed at Edwards Air Force Base in California—with U.S. Senator Edwin Garn (R-Utah) aboard.
- 4 LAUNCH PAD FIRE--JUNE 26, 1984 Technical glitches plagued the first launch of space shuttle Discovery. After the crew of six (shown here participating in fire training exercises) climbed into the spacecraft for the third time at Launch Pad 39A, a fuel valve in one of the Discovery’s three main engines failed to open four seconds before launch. Liquid hydrogen leaked onto the launch pad, lit on fire and burned for 12 minutes while the crew evacuated the space shuttle. The blunders compiled, as water from the launch pad drenched the astronauts and mission managers failed to order the six-person crew to use the pad’s zip-line-like escape system (it had transported only dummies up to that point in time). NASA/JSC Digital Image Collection
- 3. SOYUZ LOSES CONTROL--OCTOBER 16, 2004 When necessary in the past decade or so, NASA has ferried its astronauts to the space station aboard Russia’s Soyuz spacecraft (an option it will be stuck with after Atlantis’s final launch and until the advent of mature commercial vehicles). Chiao’s arrival at the ISS in 2004 aboard a Soyuz was a little more exciting than he liked. Normally a flight computer and docking system automatically line up and lock the Soyuz in place at the space station. But as Chiao’s spacecraft drew near the ISS, the Soyuz began to accelerate instead of slow down. "All sorts of alarms were going off, and we started to yaw and lose sight of the space station," Chiao said. The crew took manual control and stabilized the Soyuz, then stopped it about 50 meters away from the space station—an incredibly close call in the vastness of space. "After we docked and had a moment to relax, the danger of what happened really hit us," Chiao said. "We could have collided, killed ourselves and maybe even everyone on board the station." Engineers quickly traced the problem to automated docking system, which supplied incorrect information to the main flight computer. NASA
- 2. BAD DIRECTIONS--JANUARY 1990 Several times during a space shuttle mission, controllers in Houston beam up instructions called a "state vector." The coordinates tell the spaceship exactly where it is above the Earth so it can make extremely precise docking, undocking and reentry maneuvers.
During the STS-32 mission, however, Mission Control sent up a funky set.
Space shuttle Columbia was in orbit to retrieve a long-duration experiment (shown) from space, and communications noise garbled a state vector sent by Mission Control. The spacecraft beamed back an incorrect confirmation to Houston, and computers there flagged the errors for review. A mission controller looked at the data but inexplicably determined everything was fine and uploaded them to Columbia.
The garbled instructions made Columbia "think" it was close to Earth's core. In response, it fired its thrusters and began to spin about once every couple of minutes. The movement was harmless (no space station existed at the time for Columbia to bang into), but Mission Control woke up the five-person crew led by commander Daniel C. Brandenstein to right the errant yaw. NASA quickly changed its state vector procedures to prevent a similar mishap in the future.
"Uploading the wrong state vector at the wrong time could have serious consequences," Chiao said. "If this happened while an orbiter was at the space station, they could collide." NASA/exploitcorporations - 1. O-RING EROSION--NOVEMBER 26, 1985 The launch of space shuttle Atlantis on November 26, 1985, would emerge as a haunting close call in the shadow of the Challenger disaster three months later. Rubber O-rings serve as a seal between segments of the shuttle’s solid rocket boosters and prevent hot gases from escaping as the rocket fuel burns. During Atlantis’s chilly night launch, the cold winter air likely hardened the ring and allowed hot gases to escape through a crack. The mission went off without a hitch, however, and NASA reported no anomalies even after retrieving the rockets from the ocean and inspecting them. A similar failure caused space shuttle Challenger to disintegrate 73 seconds into its flight on January 28, 1986, ultimately killing all seven crew members. NASA
