In outer space, an uncrewed,
intelligent life-searching
NASA space probe,
Infinity, is dragged into an intergalactic
wormhole and crash-lands on the other side of the galaxy. It lands on an Earth-like alien planet named Malgor, populated by colorful alien beings. Zartog, an inhabitant, accidentally discovers how to take manual control of the onboard machinery and uses it to enslave the population. Faced with the possible extinction of
Infinity and their budget, the scientists hire multiple chimpanzees as astronauts to regain contact with the probe and retrieve it: technical genius Comet, lieutenant Luna and commander Titan. The Senator adds Ham III, grandson of
Ham, the first chimpanzee in space to the team, who works as a
cannonball at a circus in company of Houston, a friend of Ham III's grandfather. Ham III is uninterested in the mission, but despite his best attempts to escape, he is launched into space. Ham, Luna and Titan enter the
wormhole, where the latter two pass out from the pressure, leaving Ham with the task of getting the ship out and landing it. The ship and Titan are taken by the henchmen of a tyrannical
fishmen-like
alien named Zartog, and Titan, unaware of Zartog's agenda, teaches him about the probe's features. Ham and Luna journey to Zartog's palace. Ham reveals that he believes Space Chimps is a joke which makes Luna angry at him. They arrive in the planet Malgor and meets a big-headed alien named Kilowatt, who glows when she gets scared. They go into a valley of the aliens' food where they meet some small, spherical creatures called globhoppers, which arrange themselves into a duplicate of Ham and copy his every move, and then they go into the cave of the Flesh-Devouring Beast. Kilowatt volunteers to distract the beast so Luna and Ham can escape, and is devoured in the process. They then go inside the Dark Cloud of Id, which they fall out of. Once at the palace, they rescue Titan and plan to leave. However, Ham, Luna and Titan alter their course of action after noticing Zartog torturing the inhabitants by having them frozen in a pool of freznar, feeling they owe it to Kilowatt to stop Zartog. They abandon the ship, which returns home on autopilot. Zartog attacks the chimpanzees with the probe and threatens to freeze them all, but Titan tricks him into activating the probe's ejection mechanism, which launches Zartog into the pool of freznar and freezes him. Kilowatt, who has survived, frees the chimps. The chimps re-establish contact with Houston and Comet to discuss their prospects on leaving. By Ham's suggestion and with help from Malgor's inhabitants, they manage to engineer a ship from the probe's constituents, launching it through a volcanic eruption while using the frozen Zartog as their nose cone. Before they re-enter the wormhole, Titan hands the controls over to Ham. Though Ham becomes skeptical once more, he is reassured by a vision of his grandfather and steers it out of the wormhole. Comet advises him to decrease the ship's entry angle, and the ship starts spinning out, though Luna recovers in time to aid Ham. The repurposed mechanical arms soon fail, and the Zartog nose cone detaches in the atmosphere, damaging one of the ship's fins while Comet and Houston appropriate an
HEMTT to prepare for the ship's arrival. Since Ham needs to fly and Titan is still out, Luna climbs out to repair it. She succeeds and Ham regains control as the ship passes a media conference, but Luna loses her grip and is seemingly killed. Ham nearly crashes the ship and one of the arms break off, but he manages to successfully land it on the HEMTT. He leaves the ship and finds Luna merely knocked out. Moments later, Houston, Comet and Titan catch up with them. Attracted by the commotion, the scientist, Senator and media discover the ship and the chimps. Under pressure from the press, the Senator decides to dramatically increase the space program's funding instead of cutting it. Subsequently, the scientists celebrate their return. Zartog is later revealed to have landed in front of a suburban residence, as a
Dachshund then urinates on him after he leaves the ship. == Cast ==