Editor's note: Undocking was delayed again on April 19, and a new timeline has not been announced. The original story is below.

After spending 12 days in space, a historic commercial space mission will splash back down on Earth this week.

Houston-based Axiom Space’s first mission Axiom mission 1 (Ax-1), which took off April 8 and connected to the International Space Station, has announced its plans for undocking and splashdown.

After some initial bad weather postponed the process, the four-member private astronaut crew now is aiming to undock at about 9 pm tonight, April 19, and then land off the coast of Florida at around 2:24 pm tomorrow, April 20. Just like launch, the coverage of both events will be available at Axiom's website.

The mission on SpaceX’s spacecraft sent four multinational private astronauts — Commander Michael López-Alegría, Pilot Larry Connor, Mission Specialist Eytan Stibbe, and Mission Specialist Mark Pathy — to the ISS to conduct research and familiarize Axiom with launch, docking, and more.

Axiom Space, which reached $1 billion valuation and joined the Houston unicorn club last year after a $130 million investment round, is working on the first commercial space station to replace the ISS. The first launch of that mission is expected in late 2024. In the meantime, Axiom has a series of commercial launches to the existing station currently in orbit in order to prepare for development and orchestration of Axiom Station.

The Ax-1 mission, which has provided daily updates, has conducted over 20 research projects and even hit a few milestones, including:

• The first-ever music duet performance in space — Commander López-Alegría and Neo-Classical Piano Prodigy BLKBOK made music and space history with their piano and keyboard duet
• The Aging and Heart Health investigation, an experiment from the Mayo Clinic — a study that analyzes human cells for genetic markers of cellular aging and explores cardiac-like cells' adaptation to microgravity
• Observation of Transient Luminous Events — Specialist Stibbe completed a space observation experiment and photographed a lightning storm over Darwin, Australia, to enhance understanding of the electrical processes in the atmosphere and to determine whether there’s a connection with climate change
• Testing of the Holoportation system — Mission Specialist Pathy set up two-way AI technology that will allow the ability of future crew members to explore deep space with the ability to virtually bring friends, family, and physicians close with them so that they can get an on-Earth experience
• Several outreach calls to Earth to STEM students from around the world — this included a call to children at Space Center Houston

Axiom shares more details on its mission research projects — which span technologies such as future space habitats, cancer research, and devices to purify air on space stations — online.

“As the first step on a path to building a diverse, thriving economy in low-Earth orbit, Axiom has partnered with leaders in academia and industry to bring new users and new investigations in research to the space station,” says Christian Maender, director of In-space Manufacturing and Research for Axiom Space, in a news release. “The collection of biological and technological tests during the Ax-1 mission represent a breadth of research that will inform everything from human health considerations to novel infrastructure and design for our future homes away from Earth, beginning with Axiom Station.”

The four-person crew spent 12 days on the ISS. Photo courtesy of NASA