NASA spacecraft ready for Pluto flyby after glitch

Washington: The recent computer glitch that triggered communication breakdown with NASA's New Horizon spacecraft has been rectified and the probe is ready for its epic Pluto flyby next week. The mission is returning to normal science operations after a July 4 anomaly and remains on track for its July 14 fly by of Pluto, NASA said. The investigation into the anomaly that caused New Horizons to enter "safe mode" on July 4 has concluded that no hardware or software fault occurred on the spacecraft.

The underlying cause of the incident was a hard-to-detect timing flaw in the spacecraft command sequence that occurred during an operation to prepare for the close flyby, NASA said. No similar operations are planned for the remainder of the Pluto encounter. "I'm pleased that our mission team quickly identified the problem and assured the health of the spacecraft," said Jim Green, NASA's Director of Planetary Science. "Now with Pluto in our sights we're on the verge of returning to normal operations and going for the gold," said Green.

Preparations are ongoing to resume the originally planned science operations on July 7 and to conduct the entire close flyby sequence as planned. The mission science team and principal investigator have concluded that the science observations lost during the anomaly recovery do not affect any primary objectives of the mission, with a minimal effect on lesser objectives.

"In terms of science, it won't change an A-plus even into an A," said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder. Adding to the challenge of recovery is the spacecraft's extreme distance from Earth. New Horizons is almost 3 billion miles away, where radio signals, even travelling at light speed, need 4.5 hours to reach home.

Two-way communication between the spacecraft and its operators requires a nine-hour round trip, said NASA.