The Exploration of Space

acceleration airless asteroids astronautics astronomers atmosphere body bricks build carry certainly Chapter chemical completely course crew diameter difficult distance Earth energy engineering enormous escape velocity exploration extremely fact Figure free orbit fuel Galaxy gases gravitational field gravity heat hundred hydrogen imagine important interplanetary flight interplanetary travel interstellar ionosphere journey Jupiter landing LEWIS CARROLL light light-years lunar Mars and Venus Martian means Mercury meteors miles million minutes missiles Moon Moon's motors never normal observed orbit oxygen payload perhaps planetary Plate Pluto possible pounds pressure probably problem produce propellant propulsion Proxima Centauri R. A. Smith radar radiation radio reach reason refueling rocket power satellite Saturn scientific ship Solar System space space-flight space-stations space-suits space-travel spaceship speed spinning stars stations structure sunlight surface take-off tanks telescope temperature thousand thrust trolley Uranus vehicle voyage weight weightless