From left, Starliner Flight Crew Integration Manager Tony Ceccacci, and NASA astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams participate in a mission rehearsal at Boeing’s Avionics and Software Integration Lab in Houston.

NASA astronauts Barry “Butch” Wilmore and Sunita "Suni" Williams visit the Commercial Crew and Cargo Processing Facility at Kennedy Space Center in Florida on Dec. 17, 2020. The astronauts are at Kennedy to prepare for their flights to the International Space Station on Boeing’s CST-100 Starliner, as part of the agency’s Commercial Crew Program. Wilmore and Williams will command the Crew Flight Test and the Starliner-1 mission, respectively.

NASA astronauts Barry “Butch” Wilmore, left, and Sunita "Suni" Williams visit the Commercial Crew and Cargo Processing Facility at Kennedy Space Center in Florida on Dec. 17, 2020. The astronauts are at Kennedy to prepare for their flights to the International Space Station on Boeing’s CST-100 Starliner, as part of the agency’s Commercial Crew Program. Wilmore and Williams will command the Crew Flight Test and the Starliner-1 mission, respectively.

The Starliner team works to finalize the mate of the crew module and new service module for NASA's Boeing Crew Flight Test that will take NASA astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams to and from the International Space Station.

NASA's Boeing Crew Flight Test (CFT) astronauts Barry "Butch" Wilmore and Sunita "Suni" Williams pose for a picture during T-38 pre-flight activities at Ellington Field.

Astronaut Sunita Williams gives a talk at NASA's Plum Brook Station. In June, NASA Glenn hosted an Open House at Plum Brook Station in Sandusky to celebrate the 75th anniversary of the Center. Thousands of people attended, and some lucky kids got to see awesome experiments and meet astronaut Suni Williams.

NASA astronauts arrive aboard T-38 jet aircraft at the Launch and Landing Facility at Kennedy Space Center in Florida on Dec. 17, 2020. The astronauts are at Kennedy to prepare for their flights to the International Space Station on Boeing’s CST-100 Starliner, as part of the agency’s Commercial Crew Program. At right is Sunita “Suni” Williams. At left is Barry “Butch” Wilmore. Wilmore and Williams will command the company’s Crew Flight Test and the Starliner-1 mission, respectively.

NASA astronauts Barry “Butch” Wilmore and Sunita "Suni" Williams arrive aboard T-38 jet aircraft at the Launch and Landing Facility at Kennedy Space Center in Florida on Dec. 17, 2020. The astronauts are at Kennedy to prepare for their flights on Boeing’s CST-100 Starliner. Wilmore and Williams will command the Crew Flight Test and the Starliner-1 mission, respectively. The crew members will fly to the International Space Station as part of the agency’s Commercial Crew Program.

NASA astronaut Sunita “Suni” Williams, commander of Boeing’s Starliner-1 mission, arrives aboard a T-38 jet aircraft at the Launch and Landing Facility at Kennedy Space Center in Florida on Dec. 17, 2020. She is at Kennedy to prepare for her flight to the International Space Station on Boeing’s CST-100 Starliner, as part of the agency’s Commercial Crew Program.

NASA astronauts Josh Cassada, left, and Sunita “Suni” Williams, far right, view the Orion spacecraft with Adam Leppek, Spacecraft Offline deputy element operations manager with ARES Corporation (KLXSIII), inside the Multi-Payload Processing Facility (MPPF) during a visit to NASA’s Kennedy Space Center in Florida on April 6, 2021. During their time at Kennedy, Cassada and Williams also had the opportunity to view the Interim Cryogenic Propulsion Stage for the Space Launch System (SLS) rocket – this and Orion being serviced inside the MPPF ahead of the Artemis I launch. The first in a series of increasingly complex missions, Artemis I will test Orion and SLS as an integrated system prior to crewed flights to the Moon.

NASA astronauts Josh Cassada, left, and Sunita “Suni” Williams, center, view the Orion spacecraft with Adam Leppek, Spacecraft Offline deputy element operations manager with ARES Corporation (KLXSIII), inside the Multi-Payload Processing Facility (MPPF) during a visit to NASA’s Kennedy Space Center in Florida on April 6, 2021. During their time at Kennedy, Cassada and Williams also had the opportunity to view the Interim Cryogenic Propulsion Stage for the Space Launch System (SLS) rocket – this and Orion being serviced inside the MPPF ahead of the Artemis I launch. The first in a series of increasingly complex missions, Artemis I will test Orion and SLS as an integrated system prior to crewed flights to the Moon.

NASA astronauts Josh Cassada, left, and Sunita “Suni” Williams pause for a photo during a tour of the Multi-Payload Processing Facility (MPPF) at NASA’s Kennedy Space Center in Florida on April 6, 2021. In the background is the Interim Cryogenic Propulsion Stage for the Space Launch System (SLS) rocket. During their time at Kennedy, Cassada and Williams also had the opportunity to view the Orion spacecraft – this also being serviced inside the MPPF ahead of the Artemis I launch. The first in a series of increasingly complex missions, Artemis I will test Orion and SLS as an integrated system prior to crewed flights to the Moon.

NASA astronauts Josh Cassada, left, and Sunita “Suni” Williams pause for a photo during a tour of the Multi-Payload Processing Facility (MPPF) at NASA’s Kennedy Space Center in Florida on April 6, 2021. In the background to the left is the Interim Cryogenic Propulsion Stage for the Space Launch System (SLS) rocket, and to the right is the European-built service module, topped with the crew module. During their time at Kennedy, Cassada and Williams also had the opportunity to view the Orion spacecraft – this also being serviced inside the MPPF ahead of the Artemis I launch. The first in a series of increasingly complex missions, Artemis I will test Orion and SLS as an integrated system prior to crewed flights to the Moon.

NASA astronauts Josh Cassada, left, and Sunita “Suni” Williams add their signatures to an Artemis “We Are Going” banner inside the Multi-Payload Processing Facility (MPPF) during a visit to NASA’s Kennedy Space Center in Florida on April 6, 2021. During their time at Kennedy, they also had the opportunity to view the Orion spacecraft and Space Launch System’s (SLS) Interim Cryogenic Propulsion Stage – both being serviced inside the MPPF ahead of the Artemis I launch. The first in a series of increasingly complex missions, Artemis I will test Orion and SLS as an integrated system prior to crewed flights to the Moon.