The opening shot of the TARDIS being beamed aboard the space station was the most expensive special effects shot in the show's history, costing £8,000.
Colin Baker and Nicola Bryant decided to tone down the acrimony between their characters, believing that the relationship between the Doctor and Peri would have matured between seasons.
BBC Head of Drama Jonathan Powell took issue with several aspects of The Mysterious Planet, most notably its humorous content (which had ironically been inserted following a directive from BBC One Controller Michael Grade that the series needed more humour), the level of the Doctor's involvement in the events on Ravolox, and the gradual introduction of the Trial scenario. Robert Holmes-- who by now was ill with liver-related difficulties - was frustrated by Powell's last-minute indictment of his story, as it meant he would have to suspend work on the season finale to return to a set of scripts he believed were long since finished. Eric Saward, for his part, was livid, believing that Powell was demonstrating a lack of respect for the veteran writer. Things were not helped by the fact that Saward's relationship with John Nathan-Turner was deteriorating, with the script editor feeling his producer was expending too much time wooing the show's American fan base.
The trial of the Doctor in this serial was partly meant as a metaphor for the fact the series was on trial following its 18 month hiatus.
Beginning with this story, all exteriors would be recorded using Outside Broadcast video, rather than film as had usually been the practice for the previous 22 years. The use of OB for exteriors would continue for the remainder of the original series, until its end in 1989.