See inside Russia’s Soyuz capsule

Orbital ATK’s seventh Antares rocket stands ready for launch with a Cygnus supply ship Saturday on a two-day flight to the International Space Station.

When the countdown hit zero last Friday and the engines powering a previously flown Falcon 9 first stage roared to life for takeoff, the four astronauts strapped into a SpaceX Crew Dragon some 21 stories up started laughing.

A $110 million NASA science instrument twice targeted for cancellation by the Trump administration is set for launch Tuesday inside the trunk of a SpaceX Dragon cargo capsule for delivery to the International Space Station, where it will spend three years charting changing carbon dioxide concentrations in Earth’s atmosphere.