Orange Lights in Sky Last Night (20 July 2009)?

Hi all - I live in Gloucester, England and last night, just after 11pm, I stepped outside my back door and saw about 6 orange lights in the sky, I called my fiance who continued to watch when I went back inside the house. I called my mum who lives about a mile away and she could see them too. These 6 lights eventually went out of view only to be replace by another 6 in the same formation heading in the same direction. This happened again and then were replaced by singular ones going in the same direction going on for over half an hour. This is not the first time I have seen these orange lights, I first saw then on Boxing day 08 and again in February 09, but they have been single lights travelling in the same direction, disappearing and then another one coming along. I saw 6 on Boxing Day and 3 in February. It's really weird, I have thought that may they are chinese lanterns, but the 3x same formation last night was really odd. I have thought too that it could be some new fangled military plane, but I have looked on internet and similar sightings seem to be occurring all across Europe. There is no engine noise from these lights at all and they don't seem to me to be any sort of plane or helicopter. Did anybody else see these lights last night, or any thoughts of an explanation?