Kenneth Chang

An interruption in the flow of helium to the upper stage may require that the rocket be removed from the launchpad for repairs.

Technical and oversight problems left two astronauts aboard the International Space Station for months longer than had been expected.

The New Shepard rocket from Blue Origin, which brought 92 people on trips to the edge of space, will cease flying for at least two years as the company prioritizes NASA contracts.

The Space Launch System and Orion capsule are being transported to the launchpad before an astronaut mission that could launch as soon as Feb. 6.

A professor at the University of California, Santa Cruz, he was a key contributor to a landmark paper that laid out how the universe came to look like it does today.

The members of Crew-11 — two American, one Russian and one Japanese — splashed down after one became ill, prompting an early return.

Four astronauts are leaving the outpost about a month earlier than scheduled because a crew member, who was not identified, has an undisclosed medical issue.

Eric and Wendy Schmidt are backing a start-up-like approach to building a giant space telescope and powerful ground observatories.

Two papers challenged the existence of theorized particles called sterile neutrinos that might account for mysteries like the cosmos’s dark matter.

The ability of Russia to launch astronauts to the International Space Station remains in limbo after an incident last week at the Baikonur base in Kazakhstan.