Why is the Swift Boost mission exceptional?

Because it's the first attempt to rescue a space observatory not designed for maintenance, opening the field for future space maintenance services.

How long is the mission expected to take from launch until the telescope is captured?

The LINK vehicle will take months to gradually adjust the orbit, and the exact time of capture has not been announced.

The 'Swift Boost' mission is the first of its kind to rescue a space observatory in low orbit before it re-enters the atmosphere.