 Which term best describes the ease of space travel within the context of the passage?
[Transcriber's Note: This etext was produced from Fantastic Stories of Imagination May 1962. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed.] Then he knew he was being marooned on a planet of endless terrors. The plans were thrashed out very painstakingly, in formal conference on the space-yacht Nadine , with Moran present and allowed to take part in the discussion. The Nadine was out of overdrive and all the uncountable suns of the galaxy shone steadily, remotely, as infinitesimal specks of light of every color of the rainbow. Two hours since, the sun of this solar system had been a vast glaring disk off to port, with streamers and prominences erupting about its edges. Now it lay astern, and Moran could see the planet that had been chosen for his marooning. The ice-cap, by its existence and circular shape, proved that the planet rotated at a not unreasonable rate. A water-ice ice-cap said that there were no poisonous gases in the planet's atmosphere. Sulfur dioxide or chlorine, for example, would not allow the formation of water-ice. It would have to be sulphuric-acid or hydrochloric-acid ice. Its size, too, told about temperature-distribution on the planet. A large cap would have meant a large area with arctic and sub-arctic temperatures, with small temperate and tropical climate-belts. A small one like this meant wide tropical and sub-tropical zones. The fact was verified by the thick, dense cloud-masses which covered most of the surface,—all the surface, in fact, outside the ice-cap. But since there were ice-caps there would be temperate regions. In short, the ice-cap proved that a man could endure the air and temperature conditions he would find. Moran observed these things from the control-room of the Nadine , then approaching the world on planetary drive. Two of the Nadine's four-man crew watched out the same ports as the planet seemed to approach.
 strict
 complex  evolving  strict  flexible