No. 22 - 2000 hours of electric propulsion operations
In this phase of the mission, the electric propulsion system is again at the centre of our attention, as the main purpose is now to increase the apogee of the orbit to get closer to the Moon. The performance of the engine is still very good. At 16 April 2004, the engine had cumulated a total ON time of about 2000 hours, consumed about 32 kg of Xenon and imparted to the spacecraft a velocity increment of about 1440
ms-1.
Orbital/Trajectory information
The osculating orbital elements are periodically computed by the ESOC specialists. These elements define the so called "osculating orbit" which would be travelled by the spacecraft if at that instant all perturbations, including EP thrust, would cease. So it is an image of the situation at that epoch. In reality the path travelled by the spacecraft is a continuous spiral leading from one orbit to another. The most recent osculating elements are as follows:
|
EPOCH (UTC) 2004/04/26 07:21:36.5 Elements WRT Earth (J2000) |
|
| Pericentre Distance (km) |
22 742.301469 |
| Apocentre Distance (km) |
90 145.336906 |
| Semi Major Axis (km) |
56 443.819188 |
| Eccentricity |
0.597081 |
| Inclination (deg) |
6.936123 |
| Asc. Node (deg) |
145.673466 |
| Arg. of Pericentre (deg) |
215.074808 |
| True Anomaly (deg) |
180.076818 |
| Osc. Orbital Period (h) |
37.070895 |
 |
Since the start of the mission, the electric propulsion system has changed the orbital parameters as follows:
- The semi major axis from 24 626 km to 56 443 km
- The perigee altitude from 656 km to 16 364 km
- The apogee altitude from 35 880 km to 83 767 km
- The orbital period from 10 hours 41 minutes to 37 hours and 4 minutes
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