Enlarge / Technicians at NASA's Kennedy Space Center in Florida prepare Boeing's Starliner spacecraft for fueling. (credit: Boeing )

HOUSTON—While it doesn't have the same relevance to public consciousness as safety problems with commercial airliners, a successful test flight of Boeing's Starliner spacecraft in May would be welcome news for the beleaguered aerospace company.

This will be the first time the Starliner capsule flies into low-Earth orbit with humans aboard. NASA astronauts Butch Wilmore and Suni Williams are in the final stages of training for the so-called Crew Flight Test (CFT), a milestone running seven years behind the schedule Boeing said it could achieve when it won a $4.2 billion commercial crew contract from NASA a decade ago.

If schedules hold, Wilmore and Williams will take off inside Boeing's Starliner spacecraft aboard a United Launch Alliance Atlas V rocket after midnight May 1, local time, from Cape Canaveral Space Force Station in Florida. They will fly Starliner to the International Space Station for a stay of at least eight days, then return the capsule to a parachute-assisted, airbag-cushioned landing in the western United States, likely at White Sands, New Mexico.

Enlarge / A Falcon 9 rocket with SpaceX's Crew Dragon Endeavour spacecraft stands on Launch Complex 39A ahead of a launch attempt Sunday night. (credit: Chandan Khanna/AFP via Getty Images)

SpaceX's oldest Crew Dragon spacecraft is about to launch on its fifth mission to the International Space Station, and engineers are crunching data to see if the fleet of Dragons can safely fly as many as 15 times.

It has been five years since SpaceX launched the first Crew Dragon spacecraft on an unpiloted test flight to the space station, and nearly four years since SpaceX's first astronaut mission took off in May 2020 . Since then, SpaceX has put its clan of Dragons to use ferrying astronauts and cargo to and from low-Earth orbit.

Now, it's already time to talk about extending the life of the Dragon spaceships. SpaceX and NASA, which shared the cost of developing the Crew Dragon, initially certified each capsule for five flights. Crew Dragon Endeavour , the first in the Dragon fleet to fly astronauts, is about to launch on its fifth mission to the space station.

Enlarge / SpaceX's Crew Dragon Endurance spacecraft, seen here last week, has been integrated with its Falcon 9 rocket for liftoff Friday. (credit: SpaceX )

SpaceX is launching a mission about once every four days, and most of those flights are going to space to deploy Internet satellites for the company's own Starlink broadband network. But this week is different. Aside from two more missions carrying Starlink satellites, SpaceX is preparing to send a four-person crew to the International Space Station early Friday.

The crew launch from the Kennedy Space Center in Florida will deliver NASA commander Jasmin Moghbeli, European Space Agency astronaut Andreas Mogensen, Japanese astronaut Satoshi Furukawa, and Russian cosmonaut Konstantin Borisov to the space station for a half-year stay. This mission, known as Crew-7, will be SpaceX's 11th astronaut flight and the company's seventh operational crew rotation mission for NASA using a Crew Dragon spacecraft.

Bill Gerstenmaier, SpaceX's vice president of build and flight reliability, says these crew missions are special. SpaceX and NASA managers met Monday for a flight readiness review, a customary milestone before every crew launch, to deliberate on any problems that could affect the upcoming mission.

Enlarge / The Boeing CST-100 Starliner spacecraft is seen after it landed in White Sands, New Mexico, Sunday, Dec. 22, 2019. (credit: NASA/Bill Ingalls)

NASA confirmed Wednesday that it has awarded five additional crew transportation missions to SpaceX, and its Crew Dragon vehicle, to ferry astronauts to the International Space Station. This brings to 14 the total number of crewed missions that SpaceX is contracted to fly for NASA through 2030.

As previously reported by Ars , these are likely the final flights NASA needs to keep the space station fully occupied into the year 2030. While there are no international agreements yet signed, NASA has signaled that it would like to continue flying the orbiting laboratory until 2030, by which time one or more US commercial space stations should be operational in low Earth orbit.

Under the new agreement, SpaceX would fly 14 crewed missions to the station on Crew Dragon, and Boeing would fly six during the lifetime of the station. That would be enough to fill all of NASA's needs, which include two launches a year, carrying four astronauts each. But NASA has an option to buy more seats from either provider.