Q&A with Scott Bolton, principal investigator on NASA’s Juno mission

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.

SpaceX scrubbed the planned launch from the Kennedy Space Center of a Falcon 9 rocket Friday with the company’s next 57 Starlink Internet satellites and a pair of commercial Earth-imaging surveillance satellites. Officials did not immediately confirm a new target launch date.

Heino Falcke, an accomplished radio astronomer at Radboud University in the Netherlands, leads a team of European scientists and engineers who developed a scientific receiver flying on China’s Queqiao spacecraft flying to a point in space beyond the far side of the moon.