Live coverage: New Horizons returns first close-up image

NASA has selected three finalists for a new Explorer-class astrophysics satellite mission scheduled to launch by the end of 2020, and two of the proposals aim to fulfill similar goals to an X-ray telescope shelved after cost overruns in 2012.

A NASA spacecraft set to explore a metallic asteroid for the first time will launch in 2022, a year earlier than originally planned, and reach its destination in 2026, four years ahead of schedule, giving ground teams a shorter wait for the mission’s scientific payoff and shaving $100 million off the project’s total cost, officials said Wednesday.

NASA plans to use a piece of a martian meteorite as a calibration target for a high-precision laser instrument aboard the agency’s Mars 2020 rover, marking the first round trip for a fragment of the red planet blasted into space during an ancient impact.