It is online in several segments at youtube and googlevideo or in 2 parts at guba.
part 1 of 2:
part 2 of 2:
Silent Running is considered a genre classic. It was never a huge success when it was initially released, but has garnered quite a well-liked reputation among sf fans subsequently.
But outside of its status as a fan favourite, Silent Running is a rather loopy film.
Roger Ebert gives an overview of the plot and then says,
All of this is told with simplicity and a quiet ecological concern, and it makes "Silent Running" a movie out of the ordinary -- especially if you like science fiction.
The New York Times review describes it as
no jerry-built science fiction film, but it's a little too simple-minded to be consistently entertaining. This is especially true when it is drumming home its perfectly reasonable pleas for sane conservation policies by having the voice of Joan Baez, on the soundtrack, belting out space-folk songs that sound as if they had been composed by a rotten computer. They more or less match the movie's theme, which is more like an editorial policy.
StompTokyo says it's a slow starter but "If you can make it through the first half-hour, you'll be rewarded."