Space Flight, the fourth Flight <l:6,66>Advance<e>, opens <l:5,13>space<e> to mankind - to visit, but not to stay. Despite the successful <l:3,25>Moon Landing<e>, without better launch vehicles the cost of constructing a complete <l:6,106>Space Colony<e> remains prohibitive. However, the improved rocketry engines and advanced construction materials find their use in certain military applications, such as the <l:1,133>Interceptor<e>.