National Geographic announced three new documentary specials during its session Tuesday at TCA. One focuses on Princess Diana, another is a companion doc to upcoming scripted series The Long Road Home and the third is an event special marking the 20th anniversary of the blockbuster Titanic film. The network also revealed the guest star lineup for the upcoming fourth season of StarTalk with Neil deGrasse Tyson.

Diana: In Her Own Words stems from a series of secret interviews with Diana, Princess of Wales, recorded in 1991 inside London’s Kensington Palace, with her permission by a close friend on behalf of journalist Andrew Morton. The documentary reveals Diana’s thoughts and feelings at a very specific point in her life in her own voice, weaving in archival footage and photography. Diana: In Her Own Words premieres Monday, August 14, at 9/8c on National Geographic. Peabody-winning filmmaker Tom Jennings of 1895 Films executive produces.

Nat Geo, Martha Raddatz, and Lincoln Square Productions announced the greenlight for a companion documentary special to the network’s upcoming drama, The Long Road Home, based on Raddatz’s best-seller. The scripted series and its companion documentary special will air globally in November.

The Long Road Home companion documentary will tell the story of how the First Cavalry Division came under surprise attack in Sadr City on April 4, 2004 — now known as “Black Sunday.”

The docu will be produced by Lincoln Square Productions for National Geographic.

Titanic: 20th Anniversary from Nat Geo and James Cameron, commemorates the 20th anniversary of the blockbuster film which became not only the highest-grossing movie in history, but also a watershed for researchers of the Titanic, inspiring dives to the wreck, a host of books and countless documentaries. It’s set for premiere this December.

Titanic: 20th Anniversary will look back at the critical choices made during the film and put them to the test against a wealth of new sources — including new underwater footage, computer-generated simulation and scholarly research.  Cameron will take audiences through his personal journey in making the film, giving context to the choices he made during production based on the historical facts and science that was available at that time.

Titanic: 20th Anniversary is executive produced by James Cameron and Maria Wilhelm and directed by Tom Grane of Los Angeles-based Mob Scene.

Nat Geo also announced the guest cast for the upcoming fourth season of StarTalk with Neil deGrasse which premieres in October. Guests on the new season include Oscar-winning director James Cameron, Alan Alda, Arati Prabhakar (technologist, U.S.Department of Defense), Jane Goodall (primatologist) Janelle Monáe (Hidden Figures), Ted Melfi (director, Hidden Figures) and Margot Lee Shetterly (author, Hidden Figures), Kareem Abdul-Jabbar (former NBA star), Katie Couric, pop star Katy Perry, filmmaker Kevin Smith, Lance Armstrong, astronaut Mae Jemison, Nainoa Thompson (celestial navigatior), Salman Rushdie (author), Sam Harris (neuroscientist), Sylvia Earle (oceanographer) and Fabien Cousteau (conservationist).

StarTalk, which just picked up its third Emmy nomination for Outstanding Information Series or Special, is recorded in front of a live studio audience at the American Museum of Natural History in New York City. It’s derived from Tyson’s popular radio show and podcast of the same name — the first and only space-based popular commercial radio show.

StarTalk is produced by Curved Light Productions and National Geographic Studios for National Geographic.