Von Braun really wanted to go to Mars. Square jawed heroes battle evil purple Martian invaders. Sounds like Barney. Aliens look just like Earthlings. Ming tries to siphon nitrogen from the Earth's atmosphere, now that's evil.
Every body needs buffer gas.
A Martian woman dressed in black leather lands in Scotland, to find a human husband. Scotland is a good Martian analog. They must have had fuel to spare. Interplanetary robot runs amuck, hey it could happen. Released on video with the more appropriate title Mars Invades Puerto Rico.