The idea is to again use the Swedish Viking satellite as a platform to mount the beaming experiment on. The beam would first be directed in space 1 km away to a rectenna mounted on the Ariane third stage Ariane Structure for Auxiliary Payloads (ASAP). The solar panels will be body mounted on the Viking bus. A preliminary drawing of the concept is given below. The Viking platform as well as the Ariane third stage need to be in the same orbit. Both the Viking satellite and the Ariane third stage are spin stabilized. Because of the changing nature of the orientation of the spinning satellites with respect to each other, the rotation axis of both satellites have to be aligned at the moment of power beaming. This implies that the beaming can only be performed for a short duration, once per orbit. After the space to space experiment the beam could be pointed to earth. This means that at the moment of power beaming the satellite's rotational axis must be perpendicular to the equatorial plane. This should happen at the south pole (rectenna site). In this case the power beaming can also be performed for a limited duration. A initial calculation was made to look at the order of magnitude of power beaming possible. This preliminary example shows that about 250 W are available for power beaming from the Viking spacecraft. Given a 1 km distance, 35 GHz frequency and the antenna diameter of 1.2 m (Viking) and 4 meters (ASAP) the efficiency is 20%. The resulting maximum received power is approximately 50 watts. Due to power conversion the actual received power would be 10 watts. For the space to ground the received power is unclear. The main purpose is to make a technology demonstration of beaming efficiency at different angles and distances over a time of some months at a power level substantially above previous experiments. Another technical issue in pointing accuracy. Objectives of second order priority are scientific issues. An example of on such issue is the 35 GHz influence on upper atmosphere The Viking platform The size of the Viking satellite bus is 2 meter octagonal and has a height of 1 meter. The mass is 550 kg, with a possibility of being increased. The load carrying structure is a 1.2 meter aluminum cylinder 6.1 mm thick and 0.525 meters high. The ASAP ASAP is a ring with an internal diameter of 2060 mm and external diameter 2900 mm. The maximum total mass available is 200 kg placed at 4 to 6 positions. Maximum dimension of the equipment's placed on the ring is 450x450x450 mm (can be 700 mm high by waiver). It is electrically connected to the Vehicle Equipment Bay (OBC). The mission costs An example of the first cost break-down is as follows : Launch 10 M$ Viking platform 20 M$ ASAP rectenna 5 M$ Experiment 10 M$ Ground segment 3 M$ Operations 1 year 5 M$ Total - 50-60 M$ Acknowledgements During the work of this student working group two persons contributed especially. Thank you Dieter Kassing of ESA and Sven Grahn of Swedish Space Corporation.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==