WASHINGTON, Jan. 17 (Xinhuanet) -- The National Aeronautic Space Administration (NASA) on Friday trimmed the course of Opportunity,a second Martian spacecraft after Spirit, to put it on track to land on Red Planet.

    NASA said its engineers fired the spacecraft's rockets three times for a total of 30 seconds to put it on track to land within its target ellipse. This was the first time Opportunity's course was adjusted within the past 4 months.

    The so-called trajectory correction maneuvers help steer a spacecraft to its destination and are akin to the multiple strokesa golfer typically makes when playing a hole.

    According to a plan, there are two other chances to correct Opportunity's path a week before it touches the Red Planet on Jan.25, but NASA intends to skip those chances unless needed.

    The Spirit rover successfully landed on Mars on Jan. 3 and Opportunity is scheduled to land on the opposite side of the planet.

    Spirit is searching for evidence that frozen, dry Mars was oncea wetter planet capable of supporting life and the arrival of Opportunity will add to the efforts of such search. Its landing site is near a mineral called gray hematite, which is associated with liquid water.

    NASA wants to park the Spirit rover for the three days immediately following the new rover's arrival so that controllers involved in the double mission can focus on Opportunity. Enditem