Nasa Contacts Lost Satellite Control Teams Discover New Mystery: Fuel Tank Empty, Computer Was Turned Off
NASA ground control teams established periodic radio contact with the lost tethered satellite on Tuesday, finding to their surprise that its computer was dormant and its fuel tank empty.
Controllers successfully commanded the 1,500-pound satellite into a “safe” mode - a form of electronic hibernation - moments after the spacecraft and the more than 12 miles of thin tether attached to it broke free of the shuttle Columbia on Sunday night.
When they lost contact 30 minutes after the snap, the computer was on, the fuel tank filled with more than 90 pounds of nitrogen gas and the valves that secure the propellant tank closed.
The satellite’s computer software was specifically compiled in such a way that it could not command the opening and closing of the fuel valves.
Now, ground teams acknowledge, there are at least two mysteries - why the long tether snapped and how the satellite could have been so radically altered.
The space agency said its formal investigation into the satellite loss will include the possibility of a connection between all the events.
“It’s a very interesting puzzle,” said NASA’s Tony LaVoie, the satellite system’s chief engineer. “We don’t have all the answers right now.” About the only thing experts are willing to rule out is extraterrestrial intervention.
The purpose of the unusual experiment was to determine if long space tethers could be controlled to generate an electrical current while speeding through Earth’s ionosphere and magnetic field.
Researchers said they saw more than the expected voltage across the tether, a voltage surge on one satellite instrument and high-energy electrons around the spacecraft before the break. The current flow, however, had been intentionally interrupted by ground commands several minutes before the break.
Contact with the renegade satellite was first re-established through the Electronic Signal Test Laboratory at the Johnson Space Center in Houston. It sent commands that re-awakened the spacecraft’s scientific gear for electrical measurements and reactivated gyroscopes for stability.
The satellite and the mass of fabric tether suspended from it are circling Earth in an egg-shaped orbit with high and low altitudes of 254 and 195 miles. The satellite is expected to fall and re-enter Earth’s atmosphere within 20 to 30 days, burning up before it reaches the ground.
Some people on the ground should be able to see it.
One of the commands transmitted to the satellite Tuesday turned on a set of flashing lights.
“It will be an absolutely awesome sight,” astronaut Jeff Hoffman said of the opportunities to see the satellite in parts of the Northern Hemisphere next week.