**1. Introduction**

It is now obvious that the Moon is renewed in its aura of the Earth's first harbor to the solar system and the first non-Earth scientific playground [1], even though it was recognized so more than 60 years ago already [2], alongside the now very reliable Earth orbiting International Space Station (ISS). The Global Exploration Roadmap [3] is a multi-governmental (USA, Canada, Japan, EU, Russia) roadmap to renew space exploration by integrating the Planet Earth inorbit activities with the Deep Space Gateway in lunar orbit to facilitate sequential and relayed access to both the Moon and Mars, but also potentially the asteroid belt (**Figure 1**).

To foster such a push in space, an accompanying financial support to the economics of space engineering has to be unrolled by the main governments involved in the space race. It turns out that the last few years have seen just that and more. Boosted by the long strides of privately funded commercial ventures to reduce cost to LEO, a new influx of trust sentiment has developed, from both private and public bodies.

This introductory chapter aims at developing the actual state of the '*Access to space*' renewed race. In this highly evolving topic, it will venture into the place of the Moon as *Earth's first spaceport* and as the *solar system exploration gateway*, but also into the *changes of perspective* that need to happen to enable this outward expansion of humanity.

**Figure 1.** *The global exploration roadmap [3].*
