The TARDIS lands on an Earth spaceship orbiting the Sense-Sphere, its crew held prisoner by the telepathic Sensorites. The time travellers are able to make peaceful contact with the reclusive Sensorites, and learn that there has been a wave of deaths on the Sense-Sphere ever since another human expedition landed ten years earlier. The Doctor sets out to discover what has been killing the Sensorites... and his need becomes all the more urgent when Ian's health begins to fail. At the same time, he must contend with the machinations of a Sensorite who sees the chaos as the chance to seize power for himself.

Peter R Newman was in the process of moving into television, following several years writing scripts for Hammer Films, when he began discussing a contribution to Doctor Who with story editor David Whitaker. During January and February 1964, Newman developed a storyline which was commissioned as The Sensorites on February 25th. With William Hartnell and Carole Ann Ford taking two-week holidays in the stories which would precede The Sensorites in the schedule, it was agreed that Jacqueline Hill would be given a break during Newman's serial. As such, the writer was asked to omit Barbara from parts four and five.

Meanwhile, the Controller of Programmes for BBC One, Donald Baverstock, had not yet approved a full second season of Doctor Who. One of the issues complicating the programme's long-term future was its studio assignment. For some time, producer Verity Lambert had been negotiating to move Doctor Who out of the cramped and technologically unsophisticated confines of Lime Grove Studio D in Shepherd's Bush, London. On April 30th, Lambert finally secured permission to make use, whenever possible, of Studios 3 and 4 in BBC Television Centre. When TC3 and TC4 were unavailable, Lime Grove Studio G was offered as an alternative venue. However, its elongated dimensions made it generally unsuited to Doctor Who. In particular, it was noted that the spacious sets needed for The Sensorites -- originally scheduled for Studio D -- would be largely incompatible with Studio G.

It was felt that Mervyn Pinfield could achieve a visually impressive production, despite the minimal budget for The Sensorites

The director assigned to The Sensorites was Mervyn Pinfield, Doctor Who's associate producer. Pinfield had briefly been a candidate to make Inside The Spaceship earlier in the year, but this would now be his first directorial outing on the series. It was felt that Pinfield had the experience necessary to achieve a visually impressive production, despite the minimal budget accorded to The Sensorites. Later, it was agreed that Pinfield would make way for Frank Cox on the fifth and sixth installments; as a result, he received his normal associate producer's credit only on these episodes. Cox was a junior BBC director who had also handled part two of Inside The Spaceship.

A small amount of filming for The Sensorites, involving model shots and back-projection, was undertaken on either May 7th or 8th at the BBC Television Film Studios in Ealing, London. Part one, Strangers In Space, was then recorded on May 29th at BBC Television Centre Studio 3 in White City, London; as usual, the following episodes were taped on successive Fridays. TC3 was also home to the second installment, before part three was taped in Lime Grove Studio D. On June 19th, the fourth episode, A Race Against Death, brought Doctor Who to BBC Television Centre Studio 4 for the first time.

Despite its unsuitability, Lime Grove Studio G was the venue for part five on June 26th, with Cox now taking over as director. Finally, it was back to Studio D for the concluding installment on July 3rd. One scene, apparently the insert in which the Earth spaceship was seen on the TARDIS scanner in part six, was remounted in Studio D on July 10th, just prior to the start of recording on the following story, The Reign Of Terror.

Meanwhile, unhappiness with the studio situation had escalated. BBC Head of Drama Sydney Newman, who had been instrumental in the creation of Doctor Who, wrote to Donald Baverstock on May 20th to suggest that his brainchild should be cancelled if a satisfactory solution could not be found. Newman did not want to see Doctor Who's potential compromised as a result of inadequate facilities. In early June, Newman suggested that Doctor Who might be shifted to the diminutive Television Centre Studio 2, with each episode being taped over two days instead of one. Lambert nixed this idea because of the extra cost and effort which the change in recording scheme would entail. Shortly thereafter, the dilemma was finally settled when it was agreed that Doctor Who's new home would be Riverside Studio 1 in Hammersmith, London. These facilities had previously been deemed inappropriate for the programme because they lacked the video inlay technology necessary for various visual effects, but this was no longer the case. The new arrangement would take effect with The Dalek Invasion Of Earth, the final serial of Doctor Who's first production block.

The Sensorites was originally intended to close Doctor Who's first season

The Sensorites was originally intended to close Doctor Who's first broadcast season, although production would continue for several additional weeks to build up a stockpile of episodes which would air following a proposed six-week break in transmission. However, Baverstock decided in late May that Doctor Who would not go on hiatus until the early autumn, and that the gap between new episodes would only be four weeks long. As a result, the next serial to be recorded, The Reign Of Terror, would become the new season finale.

Episode one of The Sensorites, Strangers In Space, was broadcast on June 20th. The following week, The Unwilling Warriors was delayed by twenty-five minutes due to the overrun of Summer Grandstand. One week later, on July 4th, an extended edition of the sports showcase caused Doctor Who's first-ever break in transmission. Although a late 7.10pm slot (ultimately filled by Juke Box Jury) was contemplated for Hidden Danger, the third installment was ultimately preempted until the following Saturday. Unusually, the rescheduled part three and part five were both immediately preceded by Summer Grandstand, with The Telegoons still leading into the remaining episodes of The Sensorites.

• Doctor Who Magazine #248, 12th February 1996, “Archive: The Sensorites” by Andrew Pixley, Panini UK Ltd.
• Doctor Who Magazine Special Edition #7, 12th May 2004, “Do You Want To Know A Secret?” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who: The Complete History #3, 2016, “Story 7: The Sensorites”, edited by Mark Wright, Hachette Partworks Ltd.
• The Doctor Who Production Diary: The Hartnell Years by David Brunt (2024), Telos Publishing Ltd.
• Doctor Who: The Handbook: The First Doctor by David J Howe, Mark Stammers and Stephen James Walker (1994), Virgin Publishing.
• Doctor Who: The Sixties by David J Howe, Mark Stammers and Stephen James Walker (1992), Virgin Publishing.