Professor Boyes-Dennison was the creator of the impeller engine — described by the Doctor as an early form of reactionless drive, which humanity would only perfect two centuries later — that was used to create the three ships of the British Imperial Spacefleet, which were flown to the Moon in 1878. Their names were Cygnus, Lynx and Draco. His daughter was Emily Boyes-Dennison, who acted as his assistant more than his daughter ever since the death of her mother some years ago.
He accompanied Captain Richard Haliwell and a group of soldiers to investigate the surface after finding civilisation. He suffered from a heart attack after his daughter was taken by the inhabitants. He was buried near the ships' landing-site, as they had no means of taking the body back to Earth.
In the course of their time with the expedition, the Fifth Doctor and Vislor Turlough determined that Boyes-Dennison had created the impeller engine after the Vrall were able to send an RNA-encoded spore of some sort to Earth with the necessary instructions to create one, explaining how Boyes-Dennison could have made such a massive technological leap on his own. With his death and the near-calamity of the Vrall attack, the British space program was abandoned. (PROSE: Imperial Moon)