No. 33 - SMART-1 Closing in on the Moon
| Event | Day and Time (UTC) | Period (h) |
| Perilune Passage 1 | 15-11-2004 @ 17:47:38.762Z | 89 |
| Perilune Passage 2 | 19-11-2004 @ 11:01:02.127Z | 75 |
| Perilune Passage 3 | 22-11-2004 @ 14:29:38.449Z | 69 |
| Perilune Passage 4 | 25-11-2004 @ 11:36:11.520Z | 59 |
| Perilune Passage 5 | 27-11-2004 @ 22:42:28.011Z | 59 |
| Perilune Passage 6 | 30-11-2004 @ 01:59:00.054Z | 51 |
| Perilune Passage 7 | 01-12-2004 @ 23:25:21.011Z | 46 |
| Perilune Passage 8 | 03-12-2004 @ 16:05:27.002Z | 41 |
| Perilune Passage 9 | 05-12-2004 @ 05:08:18.135Z | 37 |
| Perilune Passage 10 | 06-12-2004 @ 15:08:27.116Z | 34 |
| Perilune Passage 11 | 07-12-2004 @ 22:40:07.437Z | 31 |
| Perilune Passage 12 | 09-12-2004 @ 04:08:57.443Z | 29 |
From the above it can be seen that the period of the orbit is continuously reduced due to the thrust provided by the electric propulsion system, which reduces the semi-major axis and hence the orbital period.
Since the first start of the electric propulsion engine in the gravitational field of the Moon on 15 November at 05:23 UTC, it has been working well and has fired 20 pulses with a total ON time of 333 hours.
The following table shows the last activities of the electric propulsion engine:
| Event | Day and Time (UTC) | Duration (s) |
| EPP Start | 03-12-04 @ 03:18:33.000Z | 68306 |
| EPP End | 03-12-04 @ 22:16:59.000Z | 0 |
| EPP Start | 04-12-04 @ 09:13:08.000Z | 8983 |
| EPP End | 04-12-04 @ 11:42:51.000Z | 0 |
| EPP Start | 04-12-04 @ 16:49:09.000Z | 67185 |
| EPP End | 05-12-04 @ 11:28:54.000Z | 0 |
| EPP Start | 05-12-04 @ 20:32:52.000Z | 8182 |
| EPP End | 05-12-04 @ 22:49:14.000Z | 0 |
| EPP Start | 06-12-04 @ 03:27:37.000Z | 62096 |
| EPP End | 06-12-04 @ 20:42:33.000Z | 0 |
| EPP Start | 07-12-04 @ 04:59:52.000Z | 7456 |
| EPP End | 07-12-04 @ 07:04:08.000Z | 0 |
| EPP Start | 07-12-04 @ 11:17:21.000Z | 58287 |
Orbital/Trajectory information
The following osculating orbital elements have been determined by a tracking campaign:
|
EPOCH (UTC) 2004/12/04 10:37:47.3 Elements WRT Moon and its equator of date |
|
| Pericentre Distance (km) |
5 454.925035 |
| Apocentre Distance (km) |
20 713.095288 |
| Semi Major Axis (km) |
13 084.010162 |
| Eccentricity |
0.583085 |
| Inclination (deg) |
83.035497 |
| Asc. Node (deg) |
239.659898 |
| Arg. of Pericentre (deg) |
291.239623 |
| True Anomaly (deg) |
180.000986 |
| Osc. Orbital Period (h) |
37.304959 |
These elements are for the 9th apolune passage (true anomaly = 180°) which also marks the start of the 9th orbit as determined by the ESOC. In the previous two reports the perilune passage (true anomaly = 0°) was taken as the starting point of the orbit.
In the below diagram the 9th osculating lunar orbit (around apolune 9) is compared to the first one (around perilune 1). It shows the influence of the firings of the electric propulsion system on SMART-1's lunar orbit.
- the semi-major axis has decreased by 16 872 km
- the perilune height has decreased by 1249 km
- the apolune height has decreased by 32 495 km
- the orbital period has been reduced by 92 hours
 |
|
SMART-1 first and ninth lunar orbit |
Contact Points
Giuseppe Racca
SMART-1 Project Manager
ESA/ESTEC - SCI-PD
Keplerlaan 1- 2200 AG Noordwijk, The Netherlands
E-mail: Giuseppe.Racca
esa.int
Bernard H. Foing
SMART-1 Project Scientist
ESA/ESTEC - SCI-SR
Keplerlaan 1- 2200 AG Noordwijk, The Netherlands
E-mail: Bernard.Foingesa.int
