Oct 19, 2010 12:58 GMT  ·  By
Our progress on the path to the Pluto system, captured near the halfway mark (in time) toward the Pluto encounter
   Our progress on the path to the Pluto system, captured near the halfway mark (in time) toward the Pluto encounter

Experts at the Johns Hopkins University Applied Physics Laboratory (JHU/APL) announce that the NASA New Horizons space probe passed the halfway mark in the number of days from launch to Pluto encounter on Sunday.

The mark was reached at 3:24 UT on October 17, and this means that the spacecraft now has fewer days of flight ahead and it does behind. It is scheduled to arrive at Pluto in 2015.

Another important milestone that was achieved recently – on July 30 – was the successful completion of the fourth annual checkout (ACO) phase. Once this was done, the probe was put back in hibernation.

The next wake-up call will be sent to New Horizons on November 9, and the ground control team will then wait patiently until the probe responds. The delay in communications is now at 5 hours.

One of the main objectives of the communication session will be to command the explorer's computers to reorient the main antenna so that it accounts for the motion of the Earth around the Sun.

The JHU/APL team is at this point carrying on with preparations for meeting up with Pluto five years from now. Efforts are oriented towards planning for the 17 days in which New Horizons will be close to its target.

The interval of closest approach will last for more than nine days, experts say, but the team also wants to prepare for the four days prior and the four days after this interval.

Mission managers are also conducting thorough reviews of the onboard fault detection and protection softwares that the prove will rely on as it carries out its flybys.

The group also announces that the American space agency has decided to move the full dress rehearsal of the Pluto encounter to the summer of 2013 from the summer of 2014.

This was requested because the group wanted to have more time available to identify any potential problem, and then devise solutions to address them.

All repairs will then be tested, if necessary, a full year before the spacecraft reaches the dwarf planet.

New Horizons was launched on January 19, 2006, aboard the Atlas V 551 delivery system. It lifted off from the Pad 41 complex at Cape Canaveral Air Force Station (CCCAFS), in Florida, SpaceRef reports.