Thanks Vasile. It would be hard to get a more EE subject than this one! > http://www.rdmag.com/ShowPR.aspx?PUBCODE=014&ACCT=1400000100&ISSUE=0804&RELTYPE=MS&PRODCODE=0000000&PRODLETT=IH&CommonCount=0 Note that this is NOT a solar light sail, which is what is usually envisaged when "solar sailing" is talked about. Pressure per area is about 5000 times smaller !!!. The reason that this is potentially more useful is ... why not read the article. That 2 milliNewton per square kilometre of "sail" is useful is interesting. Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist