The 21st NASA Extreme Environment Mission Operations got underway July 21 in the Florida Keys. NASA astronauts Reid Wiseman and Megan McArthur are part of the international crew of NEEMO-21 aquanauts performing research during the 16-day mission, which takes place about 60 feet below the surface of the Atlantic Ocean, in the Aquarius habitat – the world’s only undersea science station. Simulated spacewalks are designed to evaluate tools and mission operation techniques that could be used on future space missions. NEEMO-21’s objectives include testing a mini DNA sequencer similar to the one NASA astronaut Kate Rubins also will test aboard the International Space Station, and a telemedicine device that will be used for future space applications. The mission also will simulate communications delays like those that would be encountered on a mission to Mars. Also, Space Launch System Work Platforms, All-Electric X-Plane Arrives, Asteroid Mission Technology, and NASA @Comic-Con International.