In Interstellar, they have shown that the astronauts Mann, Miller and Edmunds were sending signals to NASA (Earth) through their beacons.
Also NASA is able to send videos recorded on earth to Cooper and his team while they are in all together a different galaxy!
I want to know whether this is possible and how? How can you send data (heartbeats through beacons and videos) to and from earth and planets of unknown galaxies?