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Report: Russian Spacecraft’s Off-Target Landing Fraught with Risk

April 22, 2008

This
story was updated at 3:23 p.m. EDT.

The
off-target landing of a Russian Soyuz spacecraft during its return to Earth on
Saturday posed a serious risk to the three astronauts aboard, Russian space
officials and reports suggest.

An apparent
malfunction in a mechanism designed to jettison the Soyuz TMA-11 spacecraft’s
propulsion module from its crew-carrying descent capsule threatened the lives
of the three astronauts aboard, Russia’s Interfax News Agency reported
Tuesday.

The Soyuz landed
on Saturday
about 260 miles (420 km) short of its intended target in the
arid central Asian steppes of Kazakhstan returning to Earth under a backup,
ballistic reentry path.

NASA space
operations chief Bill Gerstenmaier said that while an investigation is still
under way, the most likely cause of the atypical landing is a faulty cable,
which may have had an electrical short that commanded the ballistic descent. The
Soyuz astronauts also reported experienced unusual shaking and buffeting during
reentry, suggesting a module separation malfunction as well, Gerstenmaier said.

“The
Russians immediately set up a commission,” Gerstenmaier said. “They’re going to
go off and investigate this, they’ll get the capsule back and they’ll
understand the data.”

The
steeper-than-usual landing subjected Soyuz cosmonaut commander Yuri
Malenchenko, returning U.S. astronaut – and Expedition 16 commander – Peggy
Whitson
and South Korea’s first spaceflyer So-yeon Yi to higher than normal
gravitational loads that peaked at about 8-Gs for about one minute,
Gerstenmaier said.

Yi described
the descent
as frightening in a post-landing press conference in Russia.

“At
first I was really scared because it looked really, really hot and I thought we
could burn,” she said, according to the Associated Press, adding that
later she noticed that it wasn’t even warm inside the Soyuz. “I looked at
the others and I pretended to be OK.”

Russia’s
three-segment Soyuz spacecraft are made up of an engine-carrying propulsion
module, central crew capsule with a bottom-mounted heat shield and an orbital
module. The orbital and propulsion modules are designed to be discarded during
reentry, leaving the bell-shaped crew capsule to land under parachutes and
retrorockets on the Kazakh steppe.

Citing an
unmanned space official close to Russia’s post-landing investigation, Interfax
reported that the propulsion module did not jettison properly, preventing the
Soyuz’s heat shield from bearing the brunt of the fiery temperatures during
reentry.

Instead,
the spacecraft’s hatch side was facing forward and suffered some heat damage
before the propulsion module separated for good and allowed a successful
landing, the news agency reported.

“It is
a great success that the crew are safe and sound. The whole thing could have
ended much worse. You can say that the situation was on the edge of a
razor,” Interfax quoted its source as saying.

Saturday’s
landing marked the second consecutive Soyuz landing to return to Earth on a
ballistic trajectory, falling like a cannonball until the parachutes open.

Expedition
15 cosmonauts and a Malaysian astronaut also experienced
a ballistic reentry
during their Oct.  21, 2007 landing, as did the
crew of Expedition 6 – which included U.S. astronaut Don Pettit – in May 2003. The
2007 event also included a module separation malfunction early in the reentry
process , Gerstenmaier said.

“You’re
always concerned about the crew on any reentry vehicle,” NASA space station program
manager Mike Suffredini said in a post-landing interview on NASA TV. “We had a
few minutes there where we weren’t sure whether they had a ballistic landing,
or something else.”

Russia has
had additional experience with Soyuz module separation problems in the past. In
January 1969, a returning Soyuz 5 spacecraft with Soviet cosmonaut Boris
Volynov failed to separate immediately from its crew capsule. It eventually
pulled free to allow Volynov’s Soyuz to perform a ballistic reentry and make a
rough landing, according to the European spaceflight site Encylopedia
Astronautica.

Russia’s
Interfax News Agency and the Associated Press contributed to this report.

 


Source: imaginova



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