NASA Contractor on why Space Shuttle smelled bad when ground crews got aboard after a flight to clean and unload

Key Points:

• NASA's Space Shuttle, formally known as the Space Transportation System (STS), consists of an orbiter, two solid rocket boosters, and an external fuel tank, with a total liftoff weight of 2000 tonnes and a height of 56 meters.
• The Shuttle's main engines and boosters generate 30.16 MN of thrust during launch, and while the orbiter, boosters, and main engines are reusable, the external fuel tank burns up in the atmosphere after each flight.
• The Space Shuttle fleet included orbiters such as Columbia, Challenger, Discovery, Atlantis, and Endeavour, with Challenger and Columbia lost in tragic accidents in 1986 and 2003 respectively; Enterprise was used only for testing and never flew in space.
• After missions, the Shuttle's cabin air quality deteriorated significantly due to reduced environmental control system effectiveness once the vehicle was no longer in a vacuum, leading to a strong, unpleasant odor from stagnant air and decomposing food and waste.
• The onboard environmental system ran for about 45 minutes to an hour after landing until the coolant ammonia was depleted, after which the air inside the crew module became increasingly foul, making post-flight cleaning unpleasant for ground crews.