In article <1993Apr15.051746.29848@news.duc.auburn.edu> snydefj@eng.auburn.edu writes: > >I am looking for any information concerning projects involving Solar > Sails  I was at an interesting seminar at work (UK's R.A.L. Space Science Dept.) on this subject, specifically on a small-scale Solar Sail proposed as a student space project. The guy giving the talk was keen to generate interest in the project. I'll typein the handout he gave out at the meeting. Here goes :   			The Microlight Solar Sail 			-------------------------  1. Introduction The solar sail is a well-established concept. Harnessing the pressure of sunlight, a spacecraft would have unlimited range. In principle, such a vehicle could explore the whole Solar System with zero fuel consumption.  However it is more difficult to design a practical solar sail than most people realize. The pressure of sunlight is only about one kilogram per square kilometer. Deploying and controlling the large area of aluminized fabric which would be necessary to transport a 'conventional' type spacecraft is a daunting task. This is why, despite the potential of hte idea, no such craft has actually been launched to date.  2.Design Recent advances in microelectronics make possible a different concept: a tiny sail just a few metres in diameter which could be controlled purely be electronics, with no mechanical parts. Several attitude control methods are feasible: for example the pressure sunlight exerts on a panel of solar cells varies according to whether power is being drawn.  The key components of the craft will be a minute CCD camera developed at Edinburgh University which can act as both attitude sensor and data gathering device; solar cells providing ~1 watt power for control and communication; and a directional radio antenna etched onto the surface of the sail itself. Launched as a piggyback payload, the total cost of the mission can be limited to a few tens of thousands of dollars.  3.Missions The craft would be capable of some ambitious missions. For example: a) It could rendezvous with a nearby asteroid from the Apollo or Amor groups. Closeup pictures could be transmitted back to Earth at a low bit rate. b) It could be steered into a lunar polar orbit. Previously unobserved areas around the lunar poles could be viewed. By angling the sail to reflect sunlight downwards, polar craters whose bases never receive sunlight could be imaged. Bright reflections would confirm that volatiles such as water ice have become trapped in these locations.[Immensely valuable information for setting up a manned lunar base, BTW] c) It could be sent to rendezvous with a small asteroid or comet nucleus. Impacting at low speed, a thin wire probe attached to the craft causes it to rebound while capturing a tiny sample is a sharp-edged tube, like performing a biopsy. Returning to Earth, the sail acts as an ideal re-entry parachute: load per unit area 20 gm/m2 ensures that heat is reradiated so efectively that the sail temperature cannot exceed ~300 deg C. The material sample is recovered, enclosed in a small insulating container.  Contact: Colin Jack                              Tel. 0865-200447 Oxford Mathematical Designs, 131 High Street, Oxford OX1 4DH, England  --------------------------------  This guy would love to hear from anyone interested in this project or seeking details or anything, and would be most happy to send you more information.  	Andy    --