The launch of a NASA research satellite built to probe conditions along the boundary between Earth’s atmosphere and space has been tentatively rescheduled for no earlier than Wednesday, pending the conclusion of a review of unexpected data signatures discovered on the first stage of the mission’s air-launched Pegasus XL rocket.

Rocket Lab called off a launch attempt Tuesday, U.S. time, in New Zealand after encountering a technical problem during the countdown for the company’s first commercial satellite launch. Tuesday’s countdown came after a four-day delay to resolve problems with a downrange tracking station and wait for improved weather.

Spaceflight Now editor Stephen Clark spoke live to International Space Station astronauts Shane Kimbrough and Megan McArthur about their mission Friday.