CAPE CANAVERAL, Florida (Reuters) - The piece of orbital space junk that forced three astronauts to briefly evacuate the International Space Station on Thursday was bigger than originally reported, NASA officials said on Friday.
The object, identified as a piece of rocket engine that flew in 1993, was about 5 inches in diameter, not .35 inches.
Had it struck one of the pressurized modules aboard the $100 billion space station, the crew would have had only 10 minutes of air, said NASA spokesman Kelly Humphries.
Station commander Michael Fincke and flight engineers Yury Lonchakov and Sandra Magnus slipped inside a Russian Soyuz escape vehicle for about 10 minutes when the potentially destructive space litter came too close for comfort.
Even tiny objects pose a risk to satellites and spacecraft orbiting Earth. Because objects in orbit are moving on different paths, at different inclinations and at speeds of 17,500 miles per hour and faster, something as small as a grain of sand can impact with the power of a bowling ball moving at 100 mph, Humphries said.
NASA had expected the debris to come as close as 2.8 miles to the station. As of Friday, officials still did not know exactly how close it came.
Radars used to keep track of debris in orbit will first have to get another good fix on its location, said Gene Stansbery, the orbital debris program manager at NASA’s Johnson Space Center in Houston.
Stansbery said reports that the object was .009 meters (.35 inches) stemmed from a reference to its cross section, not its overall size. “Whoever put out that blurb misinterpreted that number,” Stansbery said.
Station crews have had to take temporary refuge in their escape ships fives times previously for orbital debris issues, said NASA spokesman Kyle Herring.
If time allows, NASA will maneuver the station to avoid coming within 25 meters (82 feet) of a piece of space junk. The path of the debris that flew by the station on Thursday was too uncertain to plot in time, Stansbery said.
With more than 500 additional pieces of debris now in orbit as a result of the crash last month between an Iridium communications satellite and a defunct Russian spacecraft, the U.S. space agency is analyzing new radar maps that can pinpoint objects as small as 0.79 inches, Stansbery said.
At the Kennedy Space Center in Florida, launch pad technicians were fixing a problem in a fuel line on space shuttle Discovery, which is scheduled to launch at 7:43 p.m. EDT (2343 GMT) Sunday to deliver the last piece of the station’s power system.
Technicians are replacing two metal seals and a hose in hopes of stemming a hydrogen leak that forced NASA to cancel Wednesday’s launch attempt.
“If it doesn’t leak, we’re going to fly. If it does leak again, then we’ll stand down and go look at it again,” said NASA launch director Mike Leinbach.
The purpose of the flight -- the first of five planned for this year -- is to deliver a final set of solar power panels to the space station and transport Japan’s first astronaut to serve as a member of the live-on-board station crew.
Before Wednesday’s postponement, Discovery’s mission had already been delayed a month due to safety concerns about fuel pressure valves. The latest snag was unrelated to the valve issue, NASA officials said.
Editing by Tom Brown
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