DART (satellite)

Demonstration for Autonomous Rendezvous Technology (English for demonstrator for autonomous docking ), short DART, was funded by the NASA project. It had to develop objective automatic navigation and docking systems and test them on the basis of military satellites MUBLCOM. Here, the satellite should automatically approach the target satellite. To perform this operation, DART had laser rangefinder and a camera whose data he used for calculating the convergence rate.

The DART satellite was built, launched and operated by the U.S. company Orbital Sciences Corporation. DART was launched on 15 April 2005 with a Pegasus XL rocket that was launched from an L -1011 on the Point Arguello Western Air Drop Zone. DART approached as planned to its destination at, but consumed more fuel than planned and broke the 24 hours planned for a duration mission already after 11 hours.

NASA press release on 15 May 2006 an investigative report for failed DART mission. It was announced that the satellite is its first rendezvous partner MUBLCOM, a military satellite officially undisclosed function, which was also operated by Orbital Sciences Corporation, approached as planned. Switching from GPS navigation on a video sensor was also carried easily, although already more fuel had been used as planned at this time. The video sensor delivered as intended direction information for the target satellite. It was only later, distance and location data should be transmitted. However, this was not because the software performed a reset due to a large deviation between measured and planned data. After the reset was again the GPS receiver in operation, however, was relatively inaccurate and control could not provide you with exact data. This resulted in intervals of three minutes on repeated resets the control software, which between the controller tried measured by igniting the engines and bring planned position in line. While still jumped a system that should prevent a collision, but because of inadequate data, it could not prevent the clash of the two satellites. MUBLCOM was thus thrust into a slightly higher orbit, but suffered no damage and was after a system reboot again ready for operation.

DART detected then that the fuel supply was nearly exhausted and headed the unforeseen withdrawal maneuvers and used the remaining fuel to lower the orbit and to shorten the time spent in orbit. In April 2012, DART was still in orbit.

The project cost $ 110 million.

A similar task as DART had the same time as developed by the U.S. Air Force satellite XSS 11