June 29, 2011
First ARTEMIS Spacecraft Successfully Enters Lunar Orbit
The first of two ARTEMIS ("Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun") spacecraft is now in its lunar orbit.
On June 22, ARTEMIS P1 began firing its thrusters to move out of its kidney-shaped "libration" orbit on one side of the moon, where it has been since January. Three successive maneuvers were used to kick the spacecraft out of its orbit and send it on a trajectory toward the moon.
This is the culmination of a complex, two-year journey that relied predominantly on gravity boosts and used minimal fuel. The path from its orbit around Earth to the moon was developed and orchestrated by engineers at the NASA's Goddard Space Flight Center in Greenbelt, Md., NASA's Jet Propulsion Lab in Pasadena, Calif., and University of California at Berkeley.
The engineers will watch the ARTEMIS P1 orbit closely over the next few days in case additional adjustments are required. Engineers are set to move the second spacecraft, ARTEMIS P2, into position on July 17.
ARTEMIS is the first mission ever to orbit the moon's Lagrangian points "“ points on either side of the moon where the moon and Earth's gravity balance perfectly. It is also the first to attempt to move from the Lagrangian to lunar orbit.
The ARTEMIS mission uses two of the five in-orbit spacecraft from another NASA Heliophysics constellation of satellites called THEMIS that were launched in 2007 and successfully completed their mission in 2010. The ARTEMIS mission allowed NASA to repurpose two in-orbit spacecraft to extend their useful science mission.
Karen C. Fox, NASA's Goddard Space Flight Center
Image Caption: The predicted path for ARTEMIS P1 as it enters lunar orbit. Credit: NASA/Goddard/D. Folta
On the Net: