Robotech is an 85-episode animated science-fiction television series about three successive extraterrestrial invasions of Earth. Within the context of the show, "Robotech" refers to robotechnology, the advances in science and technology that came about from studying an alien starship that crashed on a South Pacific island. Robotechnology made possible the creation of giant robotic mecha, or fighting machines, many of which were capable of transforming into vehicles (especially fighter planes) for greater battlefield mobility.
Robotech was one of the first anime televised in the United States that largely managed to preserve the complexity and drama of its original Japanese source material. Produced by Harmony Gold USA, Inc. in association with Tatsunoko Prod. Co., Ltd., Robotech is a story adapted with edited content and revised dialogue from the animation of three different mecha anime series: The Super Dimension Fortress Macross, Super Dimension Cavalry Southern Cross, and Genesis Climber Mospeada. Harmony Gold's cited reasoning for combining these unrelated series was its decision to market Macross for American weekday syndication television, which required a minimum of 65 episodes at the time (thirteen weeks at five episodes per week). Macross and the two other series each had fewer episodes than required since they originally aired in Japan as weekly series. (Wikipedia)
The Second series, Robotech the Next Generation was adapted from the Japanese series Genesis Climber Mospeada.