D.E.C.A. is the onboard computer aboard the Astro Megaship.
- D.E.C.A. allows the crew of the Astro Megaship to run it more smoothly by continuously monitoring the Megaship's status and its sensors.
- Cameras located in every room and major hallway of the Megaship allow D.E.C.A. to monitor the interior of the ship.
- D.E.C.A. responds to voice commands and can also make reports in speech.
- D.E.C.A. can perform retinal scans on people whose eyes can be seen by D.E.C.A.'s cameras even without the subject knowing about it.
- D.E.C.A. is capable of speaking 3000 languages.
- In the event that the crew feels the need to silence D.E.C.A., there is a control on the bridge of the Megaship that can silence D.E.C.A.