Skystriker was a rocket developed by Magrik under the command of Vorus and built on Voga to destroy the Cybermen who sought to destroy Voga because of its gold which was lethal to the Cybermen's chest units. Vorus hoped the victory it brought would free the Vogans from the genocidal threat of the Cybermen and allow them to once more live on the surface of Voga instead of living underground where they had survived for centuries after the Cyber-War.
Vorus paid Kellman to lure the Cybermen to Nerva Beacon, which he planned to destroy with the rocket. The rocket was constructed by Magrik and his team of scientists and engineers, but they had problems constructing it and there were delays in fitting the bomb head.
The Cybermen attacked before the rocket was ready, however. When the preparations were finished, the Fourth Doctor asked Chief Councillor Tyrum to delay the launch while he rescued Sarah Jane Smith from the beacon.
When Vorus saw Nerva Beacon was on a collision course with Voga, he launched the rocket, despite having been shot by Tyrum. His dying words were, "My Skystriker, my glory!" Following directions from the Doctor, Captain Stevenson redirected the rocket into the Cyber-ship, destroying it. (TV: Revenge of the Cybermen)