"Zero Hour" is the twenty-fourth and final episode of the third season of the American science fiction television series Star Trek: Enterprise; the seventy-seventh episode overall. It first aired on May 26, 2004, on the UPN network within the United States. Set in the 22nd century, the series follows the adventures of the first Starfleet starship, Enterprise, registration NX-01. Season three of Enterprise features an ongoing story following an attack on Earth by previously unknown aliens called the Xindi.
Scott Bakula said initially that there were three endings for "Zero Hour", but later explained that only one was filmed.
"Carbon Creek" is the second episode of the second season of the science fiction television series Star Trek: Enterprise, the 28th episode overall. It first aired on September 25, 2002, on the UPN in the United States. Only three of the main cast appear in this episode. It features a flashback story, and T'Pol tells how first contact between humans and Vulcans actually happened far earlier than the date officially celebrated. Three Vulcans, including her great-grandmother T'Mir, also played by Jolene Blalock, crash landed on Earth in 1957 shortly after the launch of Sputnik. It was directed by James A. Contner, his second episode of Enterprise as director. It was filmed partly on location in Crestline, California.
The episode is set in 1957, when the first man made satellite Sputnik was launched.