The Rescue Rangers, at Gadget's request, visit a human space center in the Ranger Plane to watch the launch of the space plane. The Rangers end up inside the astronaut training area of space center. Gadget states her admiration for astronauts. Naturally, both Chip and Dale decide to go through astronaut training exercises to impress her. They undergo exposure to twelve gravities of force, a simulated emergency water landing, and finally space plane flight simulator training. Chip tries the simulator first, fails to fire the simulator's retrorockets, and crashes into the simulated space center. Dale goes second and manages to fire the retrorockets, which delays his crash slightly.
As the space plane's launch is imminent, the Rangers leave astronaut training area. Dale becomes distracted by a storage room while the Rangers are walking through a hallway. While exploring, he falls into an open space suit. Chip jumps in after him with a grappling hook. Before Chip and Dale can exit the suit, however, two human workers take the space suit to the space plane. Gadget, Monty, and Zipper attempt to stop the launch by distracting or moving the humans in the control room, but the space plane launches on schedule with Chip and Dale inside.
In space, Chip and Dale finally escape the suit and experiment with zero-gravity in the space plane's cargo hold. During their exploration, they manage to remove their space suit from a rack of suits. The astronauts open the cargo hold to deploy a weather satellite. The decompression sucks Chip, Dale, and the loose space suit along as the satellite. Chip and Dale take shelter inside the suit.
On Earth, the rest of the Rangers learn from Stan Blather that the space plane accidentally left a space suit floating in orbit and that the astronauts plan on retrieving the suit at the end of their two-week mission. Gadget, knowing that chipmunks cannot survive two weeks in a space suit, finds a nearby junkyard and constructs dynamite-powered. During the construction, Monty removes a parachute and rubber raft from Gadget's invention in order to fit more dynamite. The garbage can spacecraft reaches space flawlessly and snags the abandoned space suit using a tow rope. Gadget planned on returning to Earth immediately and making a water landing, but Monty's removal of the parachute and raft means they will have to return to the space plane and ride it back to Earth. The Rangers catch up with the space plane; Gadget dons a space suit made from a glove and opens the cargo bay doors by hotwiring a control panel on the plane exterior. The Rangers land in the space plane.
As the astronauts sleep and the Rangers avail themselves of the plane's food supplies, a small meteor strikes the space plane. The astronauts briefly awaken, but a broken pipe in the cockpit releases a gas and puts the astronauts out cold. Launch control contacts the plane to report that they have lost remote flight control and have detected a major oxygen leak. Launch control reports that the astronauts must land immediately or risk complete oxygen depletion. After the Rangers try to wake the astronauts and try to communicate with launch control, Gadget determines that they'll have to land the plane themselves. She reminds them that Chip and Dale are the only ones present with astronaut training.
Between the two of them, Chip and Dale manage to get the plane back into the atmosphere and pointed toward the space center. It soon becomes apparent that they are not only headed toward the space center, but directly at the space center's control tower. Gadget then directs the Rangers in avoiding the tower and landing the space plane on the runway. After the plane stops, the human astronauts awaken and assume that they were responsible for the successful landing. The astronauts star in a parade, and the Rescue Rangers perch on the astronauts' car and enjoy the applause.
- The space plane was probably an experimental model. Stan Blather refers to the astronauts as the "first space-plane astronauts" during the parade. Unlike real-world spacecraft, the space plane does not separate from or eject any fuel containers or other parts; the entire craft returns from space. It is also notable that the space plane launches and lands horizontally rather than vertically.
- After the Ranger's feast in the space plane's food storage, we see an apple core floating with the rest of the garbage. Supplies for a space mission would not include fresh fruit.
- One of the few episodes were there was no real villain.
- The title is a pun on the phrase “out to lunch”.
- The Spacesuit Chip and Dale were inside had a sticker on its shoulder, which is the Ukranian flag, but upside down.
- Corey Burton as Dale, Zipper, Technician, Ship Computer
- Peter Cullen as Monterey Jack, Mission Control, Buzz Airfields
- Jim Cummings as Stan Blather, Radar Operator, Remote Mock-up Voice, Roger Houston
- Tress MacNeille as Chip, Gadget Hackwrench, Female Technician, Joy Rider
- Chip 'n Dale Rescue Rangers: Super Sleuths
- Chip 'n Dale Rescue Rangers: Volume 1