Three years ago I wrote about a BBC link about how to build your own Sputnik. Well, this week I read about Hojun Song who has built his own little satellite 10×10x10cm in size. One side contains four LEDs which are powerful enough to be seen from earth and its via these that his satellite will be able to communicate messages back to earth via Morse code. Just watch the video. You can even download a PDF of instructions to build your own here.