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 The U.S. space agency NASA bypassed escape systems for the
now-retired space shuttle fleet, believing the spaceships to be far
safer than they turned out to be. The illusion was shattered on Jan.
28, 1986, when gas leaking from a solid-fuel booster rocket doomed
the shuttle Challenger and its seven crew about 72 seconds after
liftoff from the Kennedy Space Center in Florida.
Taking a page from design books for the 1960s-era Mercury and Apollo
capsules, the National Aeronautics and Space Administration’s next
manned spaceship, Orion, will include a rocket-powered tower
attached to the top of the spacecraft that can separate from a
troubled launch vehicle and parachute the crew to safety.
The so-called Launch Abort System can activate in milliseconds,
catapulting the crew capsule about 1 mile (1.6 km) in altitude in
seconds.
“We proved in shuttle that it was a bad idea to not have a launch
escape system ... so there’s been a lot of work to build this really
Cadillac version of a launch escape tower that they’ve got on
Orion,” said Wayne Hale, a former NASA space shuttle program manager
who oversees human space flight for Colorado-based consulting firm
Special Aerospace Services.
“It’s a big, heavy capsule that requires a big, heavy rocket that
steers you all over the sky to get away from problems with the big
rocket booster. It’s a huge system,” Hale said.
While Orion is intended for deep-space missions beyond the
International Space Station, which flies about 260 miles (418 km)
above Earth, NASA is requiring commercial companies hired to taxi
astronauts to and from the orbital outpost to have launch escape
systems as well.
Privately owned Space Exploration Technologies, or SpaceX as the
California-based firm is known, next year will test an alternative
technology that uses its capsules’ own steering thrusters to boost
it away from a malfunctioning rocket.
Boeing plans to use a similar pusher abort system for its CST-100
capsule. SpaceX and Boeing last month won contracts worth a combined
$6.8 billion to finish development of their passenger spaceships,
test them and fly up to six operational missions each for NASA
beginning in 2017.
Currently station crew members fly on Russian Soyuz capsules
equipped with Apollo-style rocket-powered launch escape towers. In
47 years of Soyuz rocket flights, the escape system has been used
once in an actual emergency.
On Sept. 26, 1983, a fuel leak sparked a fire on the launch pad that
engulfed a Soyuz rocket about a minute before liftoff. Seconds
before the booster exploded, the rocket’s launch abort system
ignited, carrying cosmonauts Gennadi Strekalov and Vladimir Titov to
safety.
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“The interesting thing on the Soyuz then and even today is the crew
can’t initiate the launch escape tower, unlike the American designs.
The ground control has to actually initiate it,” Hale said. "I
would tell you that just because you've got a launch escape tower on
your rocket doesn't mean that you're guaranteed safety," he added.
NASA wants its commercial space taxis to be 1,000 times safer than
the shuttle, which had two fatal accidents out of 135 flights.
The cause of the Orbital Sciences Antares rocket explosion remains
under investigation. The accident, which occurred about 10 seconds
after liftoff from the Wallops Flight Facility on Wallops Island,
Virginia, claimed a cargo ship bound for the space station, which is
a $100 billion research laboratory owned and operated by 15 nations.
The Antares rocket, which previously made four successful flights,
has been grounded pending results of the investigation.
Orbital Sciences uses refurbished Soviet-era motors for the rocket’s
first stage and already had been planning to replace the engines,
known as AJ-26, due to technical concerns and supply limitations.
“It is possible that we may decide to accelerate this change if the
AJ-26 turns out to be implicated in the failure, but this has not
yet been decided,” Orbital Sciences President and Chief Executive
David Thompson told analysts in a conference call on Wednesday.
“Under the original plan we were, as of now, about two years away
from conducting the first launch of Antares with the
second-generation propulsion system ... I certainly think we can
shorten that interval, but at this point I don’t know by how much,”
Thompson said.
 (Reporting by Irene Klotz; Editing by James Dalgleish)
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