In the centuries that followed humankind's giant leap to Luna, scientists, engineers and scholars in almost all of Planet Earth's disciplines probed ever deeper into space. Explorers studied and charted the surfaces, depths and atmospheres of each of the Solar System's bodies, and scrutinized the dynamics and constituents of space matter out to the Kuiper Belt and Oort Cloud. They ventured into the void beyond Pluto's aphelion for hundreds of millions of kilometers -- although not yet the stars. The first landing on Luna in Year 1969 of the then Common Era was judged to be among humankind's grandest achievements. At the Luna landing's Tercentenary a universal calendar was ordained to commemorate the Event as New Year's Day, Year 0, formally beginning humankind's Interplanetary Era. By then, populated Moon and Mars bases were well established. Construction cadres had ventured into and beyond the Asteroids. Their experiences, surface and strata tests and studies influenced the selection of sites for mining operations and strategic outposts along the space frontiers. Advance construction battalions built basic habitat and, having attained 'shirt sleeve' environments, conceptualized, planned, gathered local materials, and designed and built infrastructure and industries that, in time, blossomed into enormous encapsulated cities, social orders, cultural adjustments and civilizations. Explorers became teachers and mentors. Initially in Earth orbit, later in lunar space and on Luna itself, they guided settlers in developing new lifestyles and colonizing skills, and showed them how to wrest and refine usable elements and minerals from nearby sources. They devised and tested methodologies to convert crude space matter into forms with which to create and integrate structures, and manufacture and operate machines and networks that would sustain surface and contiguous space and inter-satellite and interplanetary navigation and logistics systems. The emigrants procreated and populated their cities in the void. Their disparate ancestries blended through a natural vitality that accelerated human evolution so as to survive in a radically new environment. In so doing, they turned away from traditional conventions still deeply ingrained in their common species. Adjusting over time to the novel experience of space, they conceived new ways or adapted their ancient qualities and prospered in wholly enclosed artificial worlds. Organ modifications, genetic engineering and cloning gave impetus to human transformation. Instinctively, humankind-in-space prepared for an eventual voyage to the stars.