Tim Furniss/LONDON

NASA has rectified major computer and antenna faults that occurred on its $1.3 billion Terra spacecraft shortly after its launch last month.

The Terra, the flagship of NASA's Earth Observing System (EOS) programme, was launched into polar orbit on 18 December on an Atlas IIAS operated by International Launch Services (ILS).

The main computer shut down shortly after launch because of a bug in the navigation software, according to NASA.

The failure happened 1min before the winter solstice, when the sun is furthest from the equator, while the sun's position in the navigational software was being updated by the computer.

In addition, the craft's antenna, which may have been damaged by the South Atlantic anomaly where radiation is trapped in the magnetosphere, was repaired by alterations to the software, according to the US space agency.

The Terra's flight was the first Atlas Centaur-based launch from Vandenberg AFB, California. The SLC-3E former Atlas H launch pad was modified by ILS at a cost of $330 million.

The 4,645kg (10,230lb) spacecraft - the largest to be carried on an Atlas - is the first in a series of EOS vehicles to be launched over the next five years to study the Earth's environment.

Source: Flight International