Students at Enfield County School will be up early on Saturday, June 9 - their high altitude balloon transmitting on 434.314 MHz launches at 03:30 GMT (04:30 BST)
Teacher Steve Mounsey says the early start is mandated by the many aircraft flights in the area.
The call sign is ECS_18 and they are using a Raspberry Pi In The Sky system on 434.314 MHz USB 300/600 ASCII-8 RTTY.
Steve says: "Last time we did this, it was great for the kids to see that we had people as far away as Germany able to track our balloon as it went up! Sadly none of them managed to fish it out of the North Sea for us. Lessons were learned, and this launch should go much more smoothly."