Complex sentence: Saudek and Macourek prepared the album to be published in 1970, but in the atmosphere of Husakian "normalization", official publication of a comic whose main theme was an invasion of monsters from the Orange Planet would have been "political suicide".
Split into simpler sentences: Saudek and Macourek prepared the album to be published in 1970, however, the publishing in the atmosphere of Husakian "normalization" was unconceivable. Publishing a comic whose main theme was an invasion of monsters from the Orange Planet would be a "political suicide".