CAPE CANAVERAL, Fla. — The first rail system in space hit a snag during its inaugural run on Monday, but after several hours of brainstorming NASA resumed its test of the International Space Station’s new railway, according to a wire service.
The rail system’s origins may be in the Industrial Age, but it was a Space Age problem that halted the test — a computer shut down the nine-foot (2.7-metre) trolley and put it into safe mode after it moved about 17 feet (5.1 metres) along its 32 feet (9.7 metres) of track.
“As you can imagine. We’re having a big discussion,” Mission Control told the astronauts.
Later, ground controllers said the likely culprits were some magnetic sensors that lost contact with the rail car, perhaps by no more than 1/50,000 of an inch (0.00005 cm), but enough to send bad information to the computers.
After several hours, the trolley was moving again and NASA declared success.
“I can officially say that our space rail system is in service,” Ben Sellari, a NASA mission manager, told reporters.
The Mobile Transporter, as it is known, may not be as grand as the Orient Express but it cost a lot more — $190 million.
Ultimately, the trolley will have a run of more than 300 feet (91 metres) along a truss under construction atop the space station.
Its purpose is to move the station’s giant robot arm, a kind of construction crane with a computer brain, from one work site to another as construction continues on the orbiting outpost.
STRAIGHTFORWARD FIX
The problem that cropped up during Monday’s test came after the rail car had latched itself down at one of the work sites.
At first, NASA considered leaving it in place, since that was the site where it would be needed for the next bit of assembly work. Later, the space agency decided that even if the problem repeated itself — and it did — the fix was straightforward enough to complete the test.
The space trolley has a top speed of about 1 inch (2.5 cm) per second but NASA did not want to push it on this test run, so astronaut Carl Walz, a member of the station’s resident crew operating the trolley from inside, kept the speed to a modest 0.1 inch (0.25 cm) per second.
When finished, the truss will be the longest fixed structure in space and sport about an acre (0.40 hectares) of solar panels sending electrical power throughout the station.
Soon, a handcart for astronauts will be added to the rail system, helping spacewalkers move tools and equipment from the station air lock to the various work sites.
The centerpiece of the truss, known as the S-Zero segment, rode to space last week aboard the shuttle Atlantis and was installed by teams of spacewalking astronauts. The truss will grow to 130 feet (40 metres) by the end of the year as two new segments are added by shuttle crews.