Europa Clipper, NASA's upcoming flagship mission to the outer solar system, has passed a significant milestone, completing its Critical Design Review. During the review, experts examined the detailed design of the spacecraft to ensure that it is ready to complete construction. The mission is now able to complete hardware fabrication and testing, and move toward the assembly and testing of the spacecraft and its payload of sophisticated science instruments.

With an internal global ocean twice the size of Earth's oceans combined, Jupiter's moon Europa carries the potential for conditions suitable for life. But the frigid temperatures and the nonstop pummeling of the surface from Jupiter's radiation make it a tricky target to explore: Mission engineers and scientists must design a spacecraft hardy enough to withstand the radiation yet sensitive enough to gather the science needed to investigate Europa's environment.

The Europa Clipper orbiter will swoop around Jupiter on an elliptical path, dipping close to the moon on each flyby to conduct detailed reconnaissance. The science includes gathering measurements of the internal ocean, mapping the surface composition and its geology, and hunting for plumes of water vapor that may be venting from the icy crust.

NASA's OSIRIS-REx mission is on the brink of discovering the extent of the mess it made on asteroid Bennu's surface during last fall's sample collection event. On Apr. 7, the OSIRIS-REx spacecraft will get one last close encounter with Bennu as it performs a final flyover to capture images of the asteroid's surface. While performing the flyover, the spacecraft will observe Bennu from a distance of about 2.3 miles (3.7 km)—the closest it's been since the Touch-and-Go Sample Collection event on Oct. 20, 2020.

The OSIRIS-REx team decided to add this last flyover after Bennu's surface was significantly disturbed by the sample collection event.

NASA's Nancy Grace Roman Space Telescope will create enormous cosmic panoramas, helping us answer questions about the evolution of our universe. Astronomers also expect the mission to find thousands of planets using two different techniques as it surveys a wide range of stars in the Milky Way.

Roman will locate these potential new worlds, or exoplanets, by tracking the amount of light coming from distant stars over time. In a technique called gravitational microlensing, a spike in light signals that a planet may be present. On the other hand, if the light from a star dims periodically, it could be because there is a planet crossing the face of a star as it completes an orbit. This technique is called the transit method. By employing these two methods to find new worlds, astronomers will capture an unprecedented view of the composition and arrangement of planetary systems across our galaxy.

Scheduled for launch in the mid-2020s, Roman will be one of NASA's most prolific planet hunters.