Rosetta timeline: countdown to comet arrival
A timeline of the most crucial steps leading to Rosetta’s arrival at its target comet on Wednesday. Mission operations and science teams at ESA and scientists from multiple countries will be following progress closely.
After completing a complex series of nine orbital manoeuvres since the end of hibernation on 20 January, Rosetta is finally in position to rendezvous with the comet.
Orbit entry will take place on 6 August, and will be triggered by a small but crucial thruster firing lasting just 6 min 26 sec, starting at 09:00 GMT (11:00 CEST). The commands were uploaded during the night of 4 August.
This burn will tip Rosetta into the first leg of a series of three-legged triangular paths about the comet. The legs will be about 100 km long and it will take Rosetta between three and four days to complete each one.
Orbit entry timeline
5 August
| GMT/CEST | Event | Details |
| 08:04/10:04 | BoT New Norcia tracking station | ESA 35 m station, Australia |
| 19:41/21:41 | EoT New Norcia tracking station | |
| 20:00/22:00 | BoT DSS-63 tracking station | NASA 70 m station Madrid |
6 August
| GMT/CEST | Event | Details |
| 00:05/02:05 | EoT DSS-63 | |
| 00:10/02:10 | BoT Malargüe tracking station | ESA 35 m station, Argentina |
| 02:41/04:41 | EoT Malargüe | |
| 02:50/04:50 | BoT DSS-15 | NASA 34 m station, Goldstone, USA |
| 07:35/09:35 | EoT DSS-15 | |
| 08:00/10:00 | BoT New Norcia tracking station AoS telemetry data flow (see below) | |
| Rosetta slews into position for thruster burn | ||
| 09:00:01/11:00:01 | Start: Comet Approach Trajectory – insertion thruster burn | Start of orbit entry manoeuvre. Must wait 1-way light time for confirmation on ground |
| 09:06:27/11:06:27 | End: thruster burn | Rosetta now on first leg of cometary orbit |
| Rosetta slews back to comet-pointing mode | ||
| 09:22:30/11:22:30 | Start of thruster burn confirmed on ground | |
| 09:28:56/11:28:56 | End of thruster burn confirmed on ground | |
| 19:43/21:43 | EoT New Norcia | |
| 19:48/21:48 | BoT Malargüe tracking station | |
Note:
- All times subject to change
- BoT: Beginning of track
- EoT: End of track
- AoS: Acquisition of signal
- LoS: Loss of signal
- One-way signal time 6 August: 22 min 29 sec
- Thruster burn set to run 6 min 26 sec
