June 15, 2001

 Station arm hits outpost during test

 Officials unable to pinpoint cause of arm's problems

 By Todd Halvorson
 SPACE.com
 and Steven Siceloff
 FLORIDA TODAY

 CAPE CANAVERAL, Fla. - Two American astronauts performed a major test of
 a balky $600 million robot arm at the International Space Station on
 Thursday, inadvertently banging the outpost with the high-tech
 construction crane in the process.

 Though no damage apparently was done, ground engineers are no closer to
 pinpointing the cause of recent troubles with the arm, and that's crucial
 to clearing shuttle Atlantis for NASA's next station assembly mission in
 July.

 The problem: The operating system performed well. That has engineers
 wondering whether to trust the system during a complex shuttle mission
 slated to begin July 12.

 The $600 million arm, built in Canada, is central to construction and
 maintenance of the $96 billion station. Atlantis and its $165 million
 station airlock cargo cannot launch until controllers are confident in
 the arm because the device is needed to swing the airlock into place.

 Mission planners already delayed Atlantis' mission by several weeks to
 give station controllers a chance to analyze the arm's problems. The
 delay will leave the three members of Alpha's second crew in space
 another month.

 Ground controllers are to meet again Monday to decide whether Atlantis
 should launch in July, or wait until late September.

 If Atlantis moves to September, Discovery will launch Aug. 5 to deliver a
 new crew to the station. The new crew would use the crane to move an
 airlock from Atlantis onto the outpost. The crew began training for the
 task this week.

 Had the arm's flaw re-emerged, analysts were hopeful they could diagnose
 it and transmit a computer fix telling the arm to work around the
 trouble.

 Evaluations of the arm were to last four hours Thursday, but astronauts
 Jim Voss and Susan Helms spent the first hour getting the correct videos
 on the three screens of the arm workstation. Astronauts rely on video to
 see where the arm is going as they move it with joysticks.

 The test got off to a rocky start when the tip of the 57.7-foot arm
 suddenly sprang away from an external anchor and rebounded, striking the
 outpost.

 The mishap clearly troubled ground engineers, who sounded dismayed during
 a space-to-ground radio debriefing with Helms and Voss.

 "I'm a little stressed out," flight controller Ian Mills told Voss from
 NASA's Mission Control Center in Houston, after the test.