Live coverage: Soyuz crew lands in Kazakhstan

Three years and a billion miles past Pluto, NASA’s New Horizons probe is on the verge of at least one more pioneering, once-in-a-lifetime milestone: a New Year’s Day flyby of a small body known as 2014 MU69, unofficially dubbed Ultima Thule — “beyond the known world” — in a NASA naming contest.

Blue Origin plans to launch its single stage New Shepard suborbital booster Wednesday as the commercial space company moves closer to flying people to the edge of space.

Two NASA astronauts and an Italian flight engineer are sheltering in the space station’s Russian segment as mission control analyzes a possible leak of toxic ammonia coolant aboard the complex.