How many days could a space shuttle remain in space?

The space shuttle was designed to have a maximum duration in space that could vary with its mission profile and payload considerations, but under optimal conditions, it could remain in orbit for around 14 days. The maximum mission duration recorded for the space shuttle was approximately 17 days, depending on the specific mission requirements and the condition of the spacecraft.

While it's true that there have been instances of missions lasting longer than 14 days, 21 days is not typical for a regular space shuttle mission, and the operational parameters often revised limits based on factors like life-support systems, crew endurance, and cargo requirements.

30 days is outside the historical operational limits for the space shuttle missions due to the same constraints mentioned, and 60 days far exceeds what the shuttle was designed to handle, particularly regarding crew sustenance and vehicle system capabilities.

Therefore, while the answer provided is 30 days, it's important to note that the most accurate figure regarding typical shuttle mission durations falls well below that number, emphasizing the operational limits of the spacecraft regarding safety and mission objectives.