NASA astronauts Bob Behnken and Doug Hurley will be geared up for the long haul when they launch from the Kennedy Space Center on a SpaceX Crew Dragon spacecraft later this month, but they won’t know exactly how long they will be in orbit until they are already aboard the International Space Station.

A week after scrubbing a launch attempt to evaluate an issue with an oxygen sensor, Rocket Lab launched a mission Wednesday to deliver 10 small commercial Earth observation satellites to orbit. Liftoff of the Electron booster from Rocket Lab’s spaceport in New Zealand occurred at 5:21 p.m. EDT (2121 GMT).

A European-built Ariane 5 rocket launched Tuesday with a U.S.-made communications satellite for Tokyo-based Sky Perfect JSAT and a South Korean environmental observatory. The heavy-lift Ariane 5 launcher took off from the Guiana Space Center in Kourou, French Guiana, at 5:18 p.m. EST (2218 GMT; 7:18 p.m. French Guiana time).