The crew of the Orion spacecraft embarked on a historical voyage last Wednesday, April 1, when they blasted off from Florida to make a journey around the moon.

Astronauts Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen made history when they became the humans to have flown furthest from the earth's surface.

On Tuesday, April 7 they completed a flyby of the moon, passing by its far side and losing contact with Mission Control in Houston, Texas for 40 minutes.

All told, the mission has thus far been a roaring success, though there was a rather grim – and wholly unexpected – malfunction that occurred shortly after lift off last week.

The astronauts had not long left Florida when they told mission control: "Toilet is powered, waste tank emerged."

An amber warning light subsequently appeared on the loo, but the crew were able to patch things up to ensure it remained in working order.

Those onboard the Orion reported a 'blinking fault light and mission control teams successfully assessed the data and worked with the crew to troubleshoot and resolve the issue'.

Reports claim that Mission Specialist Christina Koch was the astronaut who addressed the issue, though it now appears there were lingering problems.

Artemis II Flight Director Rick Henfling explained in a press conference yesterday (Tuesday, April 7) that the crew can use the toilet, but things aren't perhaps working exactly as they should.

"The toilet remains operational," Henfling explained. "The challenge that we're working through is evacuating the tank. The vent is a lot less than we were expecting, and so we're having to fall back to some other alternate means, other than the toilet."

NASA had previously revealed in a statement that the capsule's toilet system had a jammed fan which prevented normal urine disposal.

It's also been reported that the astronauts themselves noticed a burning smell coming from the toilet system, with Hansen providing an update on the situation last Friday (April 3).

"For me, it was some sort of burning odor, and then it was definitely in the hygiene bay," Hansen explained.

"And when I opened up the hygiene bay, the rest of the crew could smell it pretty much immediately."