Earlier this month, the world was excited to hear that NASA had scheduled the first-ever "all-female spacewalk". Now, an annoying equipment problem has disappointed many #WomeninSTEM enthusiasts.

Expedition 59/60 flight engineers Christina Koch and Anne McClain were going to venture outside the International Space Station (ISS) on March 29 to continue upgrading batteries on one of the station's solar arrays.

Despite wide media coverage, the scheduling of these crew members - including the fact that women would be at key flight controls down on Earth as well - was a happy coincidence, not a pre-meditated event (the maintenance jobs weren't even planned until later in the year).

"It was not orchestrated to be this way," NASA spokeswoman Stephanie Schierholz said when the news first broke.

But given the fact female astronauts have, without a doubt, been underrepresented in ISS missions and spacewalks over the years, of course everyone got super-excited.

That said, NASA did explicitly warn us that things might still change regarding this excursion.

"Spacewalk assignments may be adjusted if the flight operations team deems it necessary," Schierholz wrote in the original press statement about the latest spacewalk schedule.

Now they have, with one of the astronauts swapped out for a male colleague due to a spacesuit sizing issue. On March 26, NASA announced that McClain would be replaced by flight engineer Nick Hague - together, they started the work on the battery upgrade in a previous spacewalk on March 22.

Some more shots of the #spacewalk on Friday – was privileged to work with my friend and colleague @NASA_Astronauts @AstroHague pic.twitter.com/KueUo7HXFm — Anne McClain (@AstroAnnimal) March 25, 2019

The 'cancellation' of the all-female spacewalk has come down to the fact that during that March 22 foray McClain discovered her best spacesuit torso fit is a medium, not large as the team previously thought.

NASA's extravehicular activity (EVA) suits are actually considered to be "personal spacecraft" designed to keep a human alive in the harsh environment of space. They don't have male and female versions, but consist of a mix-and-match collection of parts - torso, arms, gloves etc. - that come in several sizes, to ensure proper fit for each astronaut.

For the March 29 spacewalk, only one medium-sized torso piece was ready to go, and so it will be donned by Koch, according to NASA's announcement about these updated assignments.

Public reactions on social media have sounded a lot like this: "Omg, how does NASA not have enough suits sized for female astronauts!? How did they not see this coming!? How embarrassing!"

Not so fast, though.

While it's a shame that this historical event now can't happen due to what is essentially an equipment shortage, the current state of affairs is more complicated than just alleging that NASA doesn't sufficiently cater for female astronauts due to, say, implicit sexism.

In fact, the ISS even has another medium-sized torso onboard. But donning a spacesuit and getting out the airlock is nothing like the breezy process we're used to seeing in sci-fi movies.

While it does take only 15 minutes to get the suit on, the crew actually spends considerable time doing suit checks and preparing for the EVA in the days before it's scheduled.

According to a tweet by Schierholz, McLain actually trained in both sizes of spacesuit and the fit issue was only discovered late in the spacewalk schedule. Besides, the job involves a lot more crew than just two people popping out of the ISS, so NASA went with the fastest and easiest solution - replace the astronaut, not the suit.

We have another medium size spacesuit segment on the station; Anne trained in M and L and thought she could use a large but decided after Friday's spacewalk a medium fits better. In this case, it's easier (and faster!) to change spacewalkers than reconfigure the spacesuit. — Stephanie (@schierholz) March 25, 2019

On top of that, it's not like NASA doesn't have enough suits just for female astronauts. They barely have enough suits, period.

In 2017, the agency released an audit of the suits currently used on the ISS, outlining concerns about the age of the equipment which might not even last until the station's planned retirement in 2024.

"Of the 11 remaining complete and functional spacesuits, 4 are kept on the ISS and the remaining 7 are on Earth in various stages of refurbishment and maintenance," the audit stated. Yikes.

New suits are in the works, but these things involve extraordinary costs and time to produce, with funding cuts eating into the development of replacements, the Z-Series Pressure Garment System.

The crew change certainly makes the March 29 spacewalk less exciting for the public, but ultimately, most spacewalks are just another highly complicated station maintenance trip. Getting the job done properly and safely remains the main priority for everyone involved.

We can only hope that soon enough another ISS mission with plenty of amazing female astronauts can set this milestone in human space exploration.