Butch Wilmore, Mike Fincke and Suni Williams are all military test pilots and NASA astronauts, and they’re eager for Boeing’s new spacecraft to prove itself so they can climb aboard. NASA held a press conference Wednesday (May 18), a day before the planned launch of Boeing’s Starliner spacecraft on a crucial uncrewed test flight to the International Space Station (ISS). Agency leaders, including NASA associate administrator Bob Cabana and human spaceflight chief Kathy Lueders, were joined by the three astronauts, who have been training as future Starliner crewmembers. The coming mission, called Orbital Flight Test 2 (OFT-2), is scheduled to launch Thursday (May 19) at 6:54 p.m. EDT (2254 GMT) from Cape Canaveral Space Force Station in Florida. If all goes according to plan, Starliner will rendezvous and dock with the ISS, showing it can provide what Cabana referred to as the “dissimilar redundancy that we need in our ability to get crews to the International Space Station .” Live updates: Boeing Starliner Orbital Flight Test 2 mission to ISS The redundancy he’s referring to will complement the capabilities of SpaceX’s Falcon 9 rocket and Dragon capsule, which have already launched four NASA crews to the ISS. Boeing and SpaceX both hold NASA contracts to fly astronauts to and from the space station, and Starliner’s success is poised to bring an increased cadence to the number of crewed missions flying out of Florida’s Space Coast. All three astronauts at Wednesday’s briefing joked about their jealousy of OFT-2’s sole passenger, Rosie the Rocketeer , a mannequin strapped into Starliner’s command seat, but each was very clear in his or her focus on making this flight a success. “We’re going to be focused on the flight test objectives and getting ready for the flight test objectives for the crew flight test,” Fincke said in the press conference, “with the goal of certification at the end so that we, as NASA, can regularly schedule dissimilar redundant flights to the International Space Station … so that we can go up one flight with Boeing, one flight with SpaceX . In order to get there, we’re going to be paying attention on this mission to the artificial vision system called VESTA that we didn’t get to see in action on the first orbital flight test.” VESTA is Starliner’s Vision-based Electro-optical Sensor Tracking Assembly, and it’s designed to allow the spacecraft to see and differentiate features on the space station in the same way a human would. That visualization is then used with star tracking data to enable Starliner to rendezvous, approach and dock with the ISS. “We are part of the testing processes, both hardware and software, development of the procedures, and the list goes on and on,” Wilmore said of the astronauts’ relationship with the program leading up to the first crewed Starliner flight. “We need to go up to fly the spacecraft without humans on it, demonstrate the systems and come back safely,” Wilmore continued. “We wouldn’t be here right now if we weren’t confident this will be a successful mission.” Related: The science and cargo of Boeing’s OFT-2 Starliner test flight to the space station Though OFT-2 is uncrewed, the three astronauts will be very involved. “We are covering all of the mission,” Wilmore said. “We’ll be in mission control.” Once Starliner docks, crews aboard the ISS will empty over 400 pounds (180 kilograms) of cargo from the capsule and conduct tests on the vehicle itself. Station crew hope to test signals from hardline and radio systems in order to confirm communication capabilities between Starliner and the space station. The Boeing spacecraft will stay docked to the ISS for five to 10 days before departing for a parachute-aided landing in the western United States. According to Williams, “that’s when the rest of the work will start to happen.” “One of the things that Rosie doesn’t do, she doesn’t breathe,” Williams continued. “So we will be the first ones when we get in it to be the breathers, the creators of carbon dioxide, so we want the spacecraft to get back so we can start testing the environmental control system’s interaction with people. So there’s a lot of work ahead of us before we get to the crewed flight, but we’re chomping at the bit.” — Boeing’s 1st Starliner flight test in photos — Boeing to launch 2nd test flight of Starliner spacecraft for NASA on May 19 — NASA reassigns 2 astronauts from Boeing’s Starliner to SpaceX’s Crew Dragon Another thing that will be determined following a successful OFT-2 is which astronauts will actually get to fly on Starliner’s first crewed flight, and when. “We are getting our crewed test vehicle ready to go by the end of the year,” Lueders said in the briefing. She didn’t say, however, who would make up that crew. Lueders explained that the crew complement and mission duration are two of the things uncrewed missions like OFT-2 help determine. The original plan was for Crew Flight Test 1 (CFT-1) to have three astronauts aboard, with the potential for an “extended mission” to the space station. Now, Lueders said, the mission will carry a minimum of two people. Lueders also pointed out the “high potential for crewed launches next year,” emphasizing the complications that come with scheduling crew rotations with backup crews and test flight crews, all on multiple launch vehicles. Lueders said CFT-1 would likely last between five to seven days but pointed out that crew returns are weather-dependent, highlighting the near week-long delay in the return of the private Ax-1 mission last month. Lueders said a final crew selection for CFT-1 will be decided after “the schedule is more determined this summer.” Following the briefing Wednesday, Fincke and Williams headed back to join Starliner on the launchpad to perform “checks and switches” for the communications in the capsule before ground teams officially close the hatch, a tradition for astronauts before the launch of a test vehicle, according to Fincke. Williams hinted at the two leaving a good-luck note for the station crew, while Fincke also mentioned giving Rosie a high-five on the way out. Follow us on Twitter @Spacedotcom or on Facebook .