Boeing is set to relaunch its Starliner crew capsule (with no humans on board) for a second attempt at docking with the International Space Station this Tuesday, Aug.

"The International Space Station team will use the time to continue working checkouts of the newly arrived Roscosmos Nauka multipurpose laboratory module (MLM) and to ensure the station will be ready for Starliner's arrival," said NASA in a statement.

Software defects and a communications link problem led to a premature end to the original Boeing test flight in 2019, though the CST-100 Starliner capsule landed safely back on Earth.

The upcoming Orbital Flight Test-2 (OFT-2) mission is a chance for Boeing to thoroughly vet its hardware and software before a crew of three American astronauts flies on Starliner.

Both Boeing and SpaceX are part of NASA's Commercial Crew Program, which is all about sending astronauts to the ISS from American soil.

"OFT-2 will provide valuable data that will help NASA certify Boeing's crew transportation system to carry astronauts to and from the space station," NASA said in a statement July 22 after successfully concluding a flight readiness review.