SMART-1 lunar mission: from capture to impact
- Paper number
IAC-06-A3.6.06
- Author
Mr. Jurriaan De Bruin, European Space Agency/ESOC, Germany
- Coauthor
Mr. Octavio Camino, European Space Agency/ESOC, Germany
- Coauthor
Dr. Per Bodin, Swedish Space Corporation, Sweden
- Coauthor
Mr. Peter Rathsman, Swedish Space Corporation, Sweden
- Coauthor
Mrs. Maria Alonso, European Space Agency/ESOC, Germany
- Coauthor
Mr. Johannes Schoenmaekers, European Space Agency/ESOC, Germany
- Year
2006
- Abstract
SMART-1 is the first of the European Space Agency’s Small Missions for Advanced Research in Technology. It demonstrated orbit raising from geostationary transfer orbit to the Moon using solar-electric propulsion. In November 2004 SMART-1 successfully manoeuvred into Moon orbit. Since January 2005 SMART-1 has been in its operational orbit performing scientific operations that were interrupted only by a one-month reboost phase in September 2005 to re-optimise the orbit. Without orbit control, natural degradation of the orbit causes the spacecraft to impact the Moon on the far side by mid-august 2006. With orbit control, the impact date and location can be influenced such an Earth observation campaign can be organised to observe it.
This paper will present the approach ESA and industry have been taking for operations close to Moon impact. It will highlight how the orbit evolved towards the end of the mission, and discuss the unconventional way or orbit control that has changed the impact to be early September on the near side of the Moon. It will present the special operations that were done at low altitude and around the time of impact, and discuss how the different spacecraft sub-systems were affected by the changing orbit and close proximity of the Moon. Examples are:
- Thermal. When getting closer to the Moon the thermal balance of the spacecraft will increasingly be affected by albedo and infrared radiation. Of special concern are spacecraft units or parts that are exposed to radiation directly, such as the solar arrays. To avoid overheating Ground Control may well decide to turn the solar arrays away from the Sun and Moon around the lower perilunes before Moon impact.
- Power. As the spacecraft will be out of eclipse season towards the end of the mission it is not expected to have power problems, as long as the solar array temperatures are kept under control. Note that overheating of the solar arrays results in power loss and possible collapse of the power bus.
- Attitude Control. The attitude sensors are affected by the proximity of the Moon. An example is the effect of Moon induced straylight on the startracker cameras as a large part of the spacecraft hemisphere will be filled by the Moon. It is planned to turn the spacecraft away from its nominal attitude to have at least one valid startracker camera when close to the Moon.
- Payload. It will need to be assessed whether the scientific instruments can perform meaningful science in the last couple of orbits before impact. At low altitude and high relative speed a special pointing might have to be adopted to avoid for instance smear-effects on images taken by the onboard camera (AMIE).
- Abstract document
- Manuscript document
IAC-06-A3.6.06.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.