It's a step toward landing it back at the launch site for rapid reuse.
The project's long-term objectives include returning a launch vehicle first stage to the launch site in minutes and to return a second stage to the launch pad following orbital realignment with the launch site and atmospheric reentry in up to 24 hours. Both stages will be designed to allow reuse a few hours after return.
— https://en.wikipedia.org/wiki/SpaceX_reusable_launch_system_development_program
1) Why is it important that the rocket that just landed take off again so soon? I've always had the impression that space missions aren't too frequent.
2) Does transporting the rocket from the ocean back to the launch site cost a lot of money? Is avoiding this a big benefit of the reusable launch system?
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