The International Space Station (ISS) orbits the Earth at an altitude of 250 miles. That doesn't sound like much. You can drive 250 miles in a cheap sedan in about four hours or take an hour-long flight (if that).

It's taken Boeing (BA 1.61%) five years to reach the ISS, however. And when they finally arrived, they found SpaceX already got there four years ago.

Third time's the charm?

Boeing's first attempt to launch a Starliner spacecraft to ISS in 2019 ended in failure when an on-board clock error caused the spacecraft to fire its engines at the wrong time, putting it on a wrong course, and eventually requiring the spacecraft to come back to Earth without ever reaching its goal.

Three years later, Boeing made its second attempt to reach ISS -- Orbital Flight Test 2 -- and despite some bugs encountered along the way, it succeeded in both docking the unmanned capsule with its target, and then returning it to Earth.

Earlier this month, it was time for Boeing to try once more, this time with astronauts on board. On June 5, Boeing launched its Crew Flight Test mission. On June 6, Starliner once again docked with ISS.

With caveats.

Even before Starliner blasted off from Cape Canaveral, troubles were evident in the form of sticky valves and a persistent helium leak that delayed launch by about a month. By the time Starliner arrived at ISS, the spacecraft was starting to resemble cosmic Swiss cheese, with three separate leaks detected in the propulsion system and at least four thrusters malfunctioning. Two more leaks have been detected since the docking.

NASA has twice postponed Starliner's departure for its return flight to Earth, with the latest target date being June 25, without giving a specific reason -- although I think we can guess.

Unconfirmed media reports say NASA is now contemplating the potential need to organize a "rescue mission" to retrieve its astronauts in the event the capsule is deemed unsafe to travel in.

Adding insult to injury

Whether things deteriorate to that point remains to be seen, but Starliner's malfunctions have combined to further injure an already mangled Boeing reputation for quality. And that reputation looks all the worse when stacked up against the stellar performance of SpaceX, Boeing's rival on the Commercial Crew Transportation contract ferrying astronauts to and from ISS -- and the likely provider of a spacecraft for any potential rescue mission.

Boeing and SpaceX first won Commercial Crew contracts in 2014, with Boeing receiving 61.5% more money for its work because it was considered the more reliable company. Since then, SpaceX has sent astronauts to ISS on its Crew Dragon capsule 10 times without incident, versus Boeing's record of zero times without incident (or perhaps one time with lots of incidents). If NASA has to fly a rescue mission, it's pretty clear which spacecraft it would use.

And even if no rescue is needed, just Boeing knowing SpaceX would have been NASA's rescuer of choice has to sting a bit.

Best-case scenario

We'll keep our fingers crossed, though, and hope everything works out for Starliner in the end. And what then?

As Payload Space reminds us, Starliner's mission to ISS is still just a test flight. The spacecraft hasn't yet been "certified" for operational (i.e., regular) use, and it won't be certified until Boeing has gone over the design with a fine-toothed comb, figured out what's going wrong with its leaky vessel and glitchy space jets, and gotten all of this fixed.

After that, Boeing's still got a contract to fulfill, and six crewed, operational missions to fly in order to receive the $4.2 billion it was awarded under its original Commercial Crew contract.

With six years remaining until ISS is removed from service, and NASA flying crews to ISS about twice per year, there's still time for Boeing to claim the cash -- but only if it's quick in getting the bugs ironed out of Starliner. And beyond 2030, when ISS retires, it's still unclear what use -- if any -- might be found for Starliner.

One way or another, I'm afraid this spaceship's days are numbered. And Boeing may be out of the human-rated space race for good.