Shuttle's clock could mean bad time for space program
- By Aliya Sternstein
- Nov 09, 2006
The computers aboard Space Shuttle Discovery, which is set to launch in December, will not know what time it is back on Earth come Jan. 1, 2007. This scenario has prompted NASA officials to devise a series of work-around plans that involve either advancing the launch date, launching in 2007 or reinitializing the computer software in flight on Jan. 1.
The shuttle software code was designed 30 years ago to operate periodically, not for years at a time, so the computer does not recognize the end of a calendar year, NASA spokesman Kyle Herring said.
On Jan. 1, 2007, the computer will think it is the 366th day of 2006.
Discovery is scheduled to launch Dec. 7 on a 12-day mission to work on the International Space Station. But poor weather conditions could cause delays.
Herring said that if the agency cannot avoid launching at the end of the calendar year, then the astronauts will have to take about four to six hours to reprogram the computers.
“There’s a procedure to do all that but it’s time consuming,” he said. “It is not a safety of flight issue.”
Adjusting the clock on Jan. 1 is necessary to ensure that the shuttle computer is synchronized properly with the ground computers in mission control.
Before this year, NASA did not have a reason to reconfigure the computer’s software because the agency had always had enough time to avoid flying during the holiday season, Herring said. But now the agency has a limited amount of time to assemble the space station before retiring the shuttle in 2010. NASA is trying to accomplish three shuttle missions this year, he added.
Boeing spokesman Ed Memi said because of budgeting, NASA chose not to redesign the software when the agency ramped up the space program in 2004.
“Every time you change the software it’s a recertification process and it’s very costly,” he said.