Below you'll find two pictures of the antennas for our weather balloon experiment. The red one is the balloon side antenna. It looks big, but most of it is just foam. It will have to be mounted "upside down" on the balloon. The larger, colourful thing is the feeder for the ground antenna. It will be combined with a parabolic reflector to (hopefully) achieve the required gain. The four colourful antenna elements will each look into a slightly different direction, which will increase the reliability of the connection and make it easier to track the balloon (i.e. adjust the antenna direction towards the balloon). The WLAN adapters of the ground station will be attached directly to the back of the feeder, i.e. there will be no RF cables at all. This minimizes signal loss and also simplifies the cabling quite a bit. The transceiver system is developed by Dr. Lampe from Siemens, Beijing. Thanks again at this point! The launch is scheduled for August. Will we be the first team who reaches at least an altitude of 40 km :P?