No.41 - Preparing for Ion Drive Firing
22 Jul 2005 11:36
Overall Status
During the period 20 June to 17 July 2005, SMART-1 ground activities focused on planning and preparing for the upcoming firing of the ion drive.
It is planned to exhaust all the Xenon available in the tank going beyond the design limit of 2 kg. This has required special simulations and the development of new procedures.
The EP planned activities are summarised below:
| Thrust Starts |
2 August 10:21 |
| Thrust Ends |
14 September 18:29 |
Interuptions (to avoid double stracker blindings) |
| 7 August 13:32 |
- |
11 August 02:28 |
| 21 August 19:34 |
- |
25 August 03:32 |
| 6 September 07:21 |
- |
10 September 01:14 | |
| Orbit |
207 revolutions of about 5 hours each |
| Coast at Perilune |
49 minutes |
| Coast at Apolune |
112 minutes |
| Thrust on Ascending Arc |
68 minutes (true anomaly 62° and 144°) |
| Thrust on Descending Arc |
68 minutes (true anomaly -144° and -62°) |
| Perilune Height |
| At Start: |
430 km |
| 20 August: |
411 km |
| At End: |
462 km | |
| Apolune Height |
| At Start: |
2889 km |
| 20 August: |
2918 km |
| At End: |
2866 km | |
| Xenon |
| At Start |
6.05 kg |
| At End |
0.565 kg |
| Useage |
5.485 kg |
The moon eclipse period starts on 19 October and ends on 22 December. By then the thrust spiral must be terminated, as the EP cannot be operated during this period.
Future Activities
In the coming weeks mission activities will be focused in a number of areas including:
- Finalisation of the preparation and start of the EP orbit Re-boost in August
- Start work for next phase of ground automation activities.
Spacecraft Status
The spacecraft status is good with all functions working nominally.
Orbital Information
|
SMART-1 OD335 – Close to Apolune 912 Epoch (UTC) 2005/07/18 11:14:28.0 Elements WRT Moon and its equator of date |
| Pericentre Distance (km) |
2204.644615 |
| Apocentre Distance (km) |
4600.376088 |
| Semi Major Axis (km) |
3402.510352 |
| Eccentricity |
0.352054 |
| Inclination (°) |
90.263741 |
| Ascending Node (°) |
237.447509 |
| Argument of Pericentre (°) |
247.553315 |
| True Anomaly (°) |
180.023828 |
| Osculating Orbital Period (h) |
4.947143 |
The changes since apolune 878 are as follows:
- Semi-major axis: -0.3 km
- Perilune height: -24.8 km
- Apolune height: +24.1 km
- Orbital period: -0.0 min
Last Update: 09 Nov 2005