Banjul International Airport (formerly Yundum Airport) was the primary TAL site for 28.5 degree (low) inclination launches because of its in-plane location. It was selected in September 1987, replacing a TAL site at Dakar, Senegal, that NASA concluded was unsatisfactory due to runway deficiencies and geographic hazards. Banjul was closed in November 2002.

The Republic of The Gambia is a former British colony that gained independence in February 1965. The Gambia, the oldest English-speaking country in West Africa, is surrounded on all sides except its seaboard by Senegal. It reaches 300 miles inland, but is never wider then 15 miles on either side of the Gambia River. Ocean-going vessels can navigate as far us as Kuntaur, 150 miles inland. The international airport, located adjacent to the country's capital, Banjul, is located on a flat plain seven miles inland from the Atlantic and six miles south of the Gambia River. The Gambia has a dry season that extends from November to May, during which weather conditions are generally good, the only difficulty being lowered runway visibility due to airborne dust.

NASA completed four phases of construction projects at Banjul international Airport (BIA). These include improvements to the runway, adding of shuttle-unique visual landing aids and a Microwave Landing System (MLS), a Tactical Air Control and Navigation (TACAN) system and a Shuttle Orbiter Arresting System (SOAS) or barrier net located in the overrun of the runway.

Also included were a remote weather tower, operations and storage buildings, an orbiter de-service and turn-around pad, and utility and personnel transport vehicles. The airport lies almost directly below the 28.5-degree flight path, hence its designation as an in-plane contingency landing site.

After extending the existing overruns to 1,000 feet, the site was declared a full-up TAL site in April 1990. The runway is 11,811 feet long by 150 feet wide with 25-foot paved shoulders.

Communications included three INMARSAT satellite circuits and Gambian commercial telephone lines. Internet capability was available through GAMTEL, the local telephone company. Other communications options were available through the American Embassy located nearby.