VU3DTT, VU2PEP and S21HMX on Space Station with Antenna Rotation by Wind!

Set out to work amateur radio on international space station by setting the antenna towards the direction of maximum elevation of the pass as usual. I could hear VU2PEP from Hyderabad working VU3DTT in Bhilai. Soon I could hear S21HMX at a distance of over 2000 km exchanging reports with VU2PEP. Waited for the contact to be over and called, but heard nothing. Went outside and checked the antenna. It had rotated about 90 degrees on its own, possibly driven by wind! Could not hear anything afterwards and the pass was over for me!