October 20, 2009

Last Visit Home For Rosetta

ESA's Rosetta comet chaser will swing by Earth on November 13 to pick up orbital energy and begin the final leg of its 10-year journey to the outer Solar System. Several observations of the Earth"“Moon system are planned before the spacecraft heads out to study comet 67/P Churyumov-Gerasimenko.

This will be the third Earth swingby, the last of Rosetta's four planetary gravity assists. Closest approach to Earth is expected at 08:45 CET. The swingby will provide exactly the boost Rosetta needs to continue into the outer Solar System. The craft is scheduled for a close encounter with asteroid 21 Lutetia in July next year. 

Rosetta is expected to arrive at its final destination in May 2014. There, it will release the Philae lander for in-situ studies on the surface. The spacecraft will then escort the comet on its journey toward the Sun, studying it closely for up to two years.

As it closes in on Earth next month, Rosetta will have traveled almost 4500 million km since launch. It will speed past Earth at 13.3 km/s, passing above the Indian Ocean at 109°E, 8°S, just south of the Indonesian island of Java. The gravity-assist will increase the spacecraft's speed by 3.6 km/s with respect to the Sun.

Instruments in action

While the swingby is critical for achieving the velocity required to reach its ultimate destination, the close encounter will also be used to study the Earth"“Moon system from Rosetta's unique perspective.

Several instruments that usually hibernate during the long trek will be turned on in the week before the swingby.

Follow the swingby live

The Rosetta Blog will be updated regularly for this final planetary swingby. Follow crucial events live via the blog and the dedicated ESA Rosetta mission website.

Critical swingby events

Closest approach is scheduled for 08:45 CET on 13 November, but mission operators will perform a number of critical actions before and after the swingby to ensure that Rosetta is on the right trajectory.

One of the most important will be a trajectory correction maneuver (TCM), scheduled for 22 October at 14:30 CET. Results of this maneuver will be analyzed to determine whether additional TCMs are required to achieve the correct approach trajectory.

# Notes: All times are in Central European Time (CET/CEST)

# TCM: Trajectory correction maneuver

# DSN: Deep Space Network (NASA)

# DSA: Deep Space Antenna (ESA)

October 22

14:30 "“ 21:30 - TCM slot

November 5

12:30 "“ 19:30 - Slot for TCM if needed

November 6

Beginning 22:45 - Instruments switched on to begin observations of the Earth-Moon system

November 12

10:30 "“ 17:30 - Slot for TCM if needed

November 13

01:00 "“ 08:00 - Slot for TCM if needed

08:45 - Earth closest approach

09:04 - 10:55 - Swing by confirmation via Maspalomas ground station, Canary Islands

11:00 "“ 21:00 - Start science data download via NASA DSN Goldstone, California

16:41 - Moon closest approach

21:13 - 5:04 (November 14) - ESTRACK DSA New Norcia ground station pass, Australia

November 19

By 12:05 - Instruments turned off

All times are subject to change.


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