Space Station X-7 is overrun by a previously unknown but deadly alien fungus that originated in ice caves on the Moon and was inadvertently brought back by astronauts returning with lunar samples.

As a swarm of meteors approaches the space station, Cromwell is unable to give the order to take evasive action until prodded to do so by X-7's communications officer, Lt. Connie Engstrom.

But when Cromwell looks at the body in the isolation chamber, he calmly says, "There's nothing unusual in there" and refuses to report to Gen. Knowland at Earth Control Center that the fungus has killed Dan.

He insists that Dan's demise was caused by "pressure shock" and warns Gordon, Faith, and Hoffman to say nothing about the fungus because it might panic X-7's crew.

Cromwell orders Connie to send a message to Knowland about the mutiny and to say in it that Gordon held the crew at gunpoint until he was overpowered.

No one can understand why the fungus is spreading on X-7's exterior until one of Knowland's staff officers says that it must be due to the "high temperatures generated by the unshielded blazing sun" beating down on X-7.

This gives Knowland the idea of launching a rocket that will explode and form a huge cloud of ice crystals for X-7 to pass through.

"[5] Mutiny in Outer Space was theatrically released in the US as the bottom half of a double feature with The Human Duplicators.

[11] Writing on May 12, 1965, "Whit," a reviewer for Variety, said that Mutiny in Outer Space "stacks up as a suitable minor entry".

But he went on to praise "Grimaldi's direction of the Arthur C. Pierce script" and said that the film was "deftly lensed" by cinematographer Archie R. Dalzell and that "George White's editing is a plus".

[13][14] Like Westphal, Bryan Senn, an American film critic, sees both good and bad in Mutiny in Outer Space.

He writes that "Richard Garland gives a good performance as the stressed-out space skipper" and refers kindly to the rest of the cast as "overworked [and] presumably underpaid".

The film was chosen for its unusually high number of women cast as astronauts aboard X-7 and as military personnel on Earth.