Adelaide Brooke

Captain Adelaide Brooke was a short-lived companion of the Tenth Doctor. She was head of Bowie Base One on Mars in the late 2050s. In the year 2059, the base came under siege by a water-based entity called the Flood.

Early life
Adelaide was born in Finchley, North London on 12 May 1999. She was a child during the Daleks' abduction and invasion of Earth in 2009. Her father told her to stay in the house while he searched for her mother, but neither of her parents were ever seen again (possibly becoming victims of the Daleks' Reality bomb test) and were presumed dead. The young Adelaide was spotted by a lone Dalek, but for an unknown reason it deliberately spared her. The event inspired Adelaide to go into space travel. She was later raised by her grandmother. (DW: The Waters of Mars)
 * The Doctor believed the Dalek recognised her as she was a "fixed" point in history.

Colony on Mars
She studied at Cambridge University, and achieved a first honours degree in combined Physics and Mathematics. She transferred to Rice University in 2017, where she earned her doctorate degree in Physics. Following her fellowship at Rice, she began working at NASA's Johnson Space Center in Houston, Texas. Brooke became the first NASA candidate selected that was not a citizen of the United States. After an intense two year training programme, she served on numerous shuttle missions.

Despite her young age and relative inexperience within NASA, she was selected to head up the Project Pit Stop, a project which would use the moon as a re-fuelling base for further planetary exploration. The project was highly successful and exploratory, unmanned shuttles were dispatched to Neptune & Jupiter via the moon and the data they obtained has increased our knowledge of these planets significantly.

At the age of 42 (presumably in the year 2041), she was part of a three-person mission to Mars. She was the first woman to land on the planet. Afterwards, she campaigned to have Mars chosen as the location for colonisation.

In 2058, when Adelaide was now a mother, and a grandmother, she led an international team to Mars, the first human colony on the planet. She found fame on Earth as a result. She had contact with Earth due to video link. (DW: The Waters of Mars)

Meeting the Doctor
In 2059, after the first 17 months of success, two of her crew were taken over by the Flood. At that very same moment, the Doctor had arrived at Bowie Base One. She tried to contain the infection, and after realising this was impossible, ordered the evacuation of the base. Adelaide soon became suspicious of the Doctor's actions and comments, especially the mention of how her granddaughter would follow her into space travel and human history would be shaped by the Brookes. She eventually forced him to tell her the truth: Bowie Base One was going to be destroyed, and the crew killed. As this was a "fixed" point in time, he could not save her.

Though she struggled desperately to save the colonists, when the Doctor returned to help she resigned herself to her fate and set the base's self-destruct timer. However, the Doctor successfully saved her, Mia Bennett, and Yuri Kerenski, returning them all to Earth in front of her house. Realising that her survival would alter her granddaughter's life and thus human history, she became angry with the Doctor, especially after he arrogantly dismissed the problem and referred to her fellow survivors as "little people." She then went into her home and commited suicide to preserve the timeline. (DW: The Waters of Mars)

Legacy
Her granddaughter, Susie Fontana Brooke, would be inspired by her memory and go into space, later piloting the first lightspeed ship to Proxima Centauri. The rest of her family would follow as well, with one descendant falling in love with a Trandorian prince and creating a new species. (DW: The Waters of Mars)

Though the Doctor still managed to save three people from Bowie Base One, Adelaide's suicide ensured that the timeline was not altered significantly as she was the fixed point in time. The only evident change is that history now recorded that she died on Earth, rather than on Mars and that she had committed suicide under "unexplained circumstances." Mia and Yuri told the world the story of Bowie Base One and hailed her as a hero. This, and not the mystery of her death on Mars, was what inspired her granddaughter.

Personality
Adelaide Brooke was a strict and serious woman who often showed other people a cold demeanor only really acting warmly towards her family when they contacted her from Earth. Though she cared about her crew she treated them in a professional manner and would boss them around if she felt it was necessary. One of her crew noted that she only gave compliments if the situation was serious.

Adelaide was a selfless woman and sacrificed herself to prevent history from being changed too much. Though she only knew the Doctor for less than a day she quickly grew to accept that he was a time traveller even before she travelled in the TARDIS. She was angry with the Doctor when he rescued her telling him that "the Time Lord victorious is wrong" and also pointing out that he could have changed the history of the entire human race.

Behind the scenes

 * Adelaide is one of only a few companions in the revived series to die and the second to die without being "reborn" somehow in the new series (such as Captain Jack or Astrid Peth).
 * The details of her career can be briefly seen in her obituary.
 * Adelaide was one of the oldest human companions, until Wilfred Mott.
 * Adelaide was the first companion to commit suicide while not in the process of directly protecting others or defending herself (as was the case with Katarina and Sara Kingdom (DW: The Daleks' Master Plan), Adric (DW: Earthshock) and Astrid Peth (DW: Voyage of the Damned)).
 * Adelaide went to the same university as Liz Shaw.
 * When initially sketching out the story, Davies considered Helen Mirren as a potential actress to play the character that eventually became Adelaide. In an early draft, the character that became Adelaide was Russian, but this was changed when, still thinking of Mirren as a potential guest star, Davies felt it would have been too close to the character played by Mirren in the film 2010: The Year We Make Contact. (REF: Doctor Who: The Writer's Tale - The Final Chapter)