Dengeki Sentai Changeman (1985)

It's the very first Super Sentai series what made many of it's successors possible. If you want to watch the original first season of the Super Sentai series.

Both are series with a surface level space theme while changeman does more with having the go into space in the end while super-1 was training to be a astronaut before he became a cyborg

It's the 8th sequel of the series from Super Sentai right after Choudenshi Bioman which is the 7th sequel. If you would like to watch the super sentai series chronologically.

It's the 9th sequel of the series from Super Sentai right after Dengeki Sentai Changeman which is the 8th sequel. If you would like to watch the super sentai series chronologically.