identify this movie - Strange and haunting Science Fiction Film

I put together the timeframe, spacesuit, and greenhouse to come up with this suggestion, a great movie - essentially High Noon in space.
I think you might mean Outland from 1981, with Sean Connery. Connery plays a Marshall on an off-world mining colony, not a spaceship, who annoys the local company President, played by Peter Boyle. When the annoyances get too deep, since the President is involved in a conspiracy to increase profits, he hires an assassination team to deal with the marshall, Connery. The showdown scenes involve a hide-and-seek in the colony's massive glass greenhouse, which is hundreds of feet high and wide, multiple stories. Outside the glass, of course, is a starfield. The assassins are inside with Connery outside in a pressure suit.

Otherwise, I agree you mean Silent Running, also.