Antarctica's McMurdo Dry Valleys contain some of Earth's coldest and driest deserts. The environment there is so extreme that the Dry Valleys have been used as Mars analogs to test prototype equipment for future Mars exploration.

To survive these harsh conditions, layers of algae and bacteria in the Dry Valleys overwinter in a freeze-dried state, coming back to life in the summer when neighboring glaciers melt and water flows down the stream channels again.

NASA's Orion spacecraft is heading home after exiting the lunar sphere of influence.

Orion completed the return powered flyby burn that put the spacecraft on course for splashdown on Sunday. Earth's force of gravity is now the primary gravitational force acting on the spacecraft.

Flight controllers used Orion's cameras to inspect the crew module thermal protection system and European Service Module, the second of three planned external spacecraft inspections.

Teams conducted this survey early in the mission to provide detailed images of the spacecraft's external surfaces after it had flown through the portion of Earth's orbit containing the majority of space debris, and teams reported no concerns after reviewing the imagery.

This second inspection during the return phase is being used to assess the overall condition of the spacecraft several days before re-entry.

Cameras on the four solar array wings have captured a series of still images. Engineers and flight controllers at NASA's Johnson Space Center in Houston will review the imagery over the coming days.

A final photographic survey will be conducted Friday as Orion continues its journey home.

After 908 days in low Earth orbit, a small package on board the X-37B Orbital Test Vehicle-6 has come home to the delight of some biological scientists. Soon they will open an aluminum alloy container that holds samples of plant seeds that they hope can be used to sustain astronauts on long duration missions to the moon, Mars, and beyond.

Officially, it is known as a SEER experiment, short for Space Environment Exposure Research, a pathfinder mission supported by NASA's Biological and Physical Sciences Division (BPS) in collaboration with the US Air Force.

Unofficially, they're referred to as the "Thrive in Space" experiments—a way to underscore the stepping-stone research that scientists are undertaking to help advance their fundamental understanding of what it takes to grow and protect plants beyond our planet.