Rosetta third Earth approach on schedule
Although time will be short, several science observations are planned around the swing-by.
Provided by ESA, Noordwijk, Netherlands
November 9, 2009
After the trajectory correction maneuver October 22, Rosetta has lined up on a near-perfect Earth approach path. The maneuver was so precise that flight dynamics and mission control experts have decided not to use the additional maneuver slot that was available November 6.
Rosetta's orbit has been determined using radiometric data received from European Space Agency (ESA) and NASA ground stations, and estimates show that it will pass within a few miles of the planned point of closest approach during this week's Earth swing-by. If necessary, additional maneuver slots are available at 24 and 6 hours prior to closest approach.
On November 13, Rosetta will pass over a watery point just south of the island of Java in the Indian Ocean at an altitude of 1,542 miles (2,481 kilometers) at 8.29 miles/second (13.34 km/second) relative to Earth. This estimate will be updated in the coming days.
Although time will be short, several science observations are planned around the swing-by to use Rosetta's unique perspective and powerful instrument suite.
The planned observations include imaging with the Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS), an attempt to look for water on the Moon with the Microwave Instrument for the Rosetta Orbiter (MIRO), study of the magnetosphere with the suite of Rosetta plasma instruments, and observations of Earth's atmosphere and a search for aurorae.
The instruments were turned on one by one beginning November 6 and will stay on through the swing-by.
The goal of the swing-by is to assist Rosetta to reach Comet 67 P/Churyumov- Gerasimenko for its prime mission. Accordingly, spacecraft operations will have priority over the science activities November 13.
During the two nights before closest approach and one night afterwards, members of the Rosetta team will conduct observations from ESA's Optical Ground Station in Tenerife, Spain. They will also carry out an experiment to investigate whether a laser beam can be detected by OSIRIS.