Gagarin Station

Gagarin Station (named after the first human to orbit Earth and colloquially known as Jump Zero) used to be the furthest human-made structure from Earth in the decades before discovery of the Mass Relay. It was used for deep space telemetry, exploration, and for conductin experiments too dangerous to do near more expensive assets.

The station came to be known as Jump Zero because it was the launching point for early failed attempts at light speed travel before knowledge of the mass effect was discovered. It was the jump point to nowhere.

After humans discovered the mass relays and joined the galactic community, the station was partially disassembled and moved to the other side of the near-Earth relay. There it serves as the gateway to human space, both as ajumping point outward and a receiving point inward. It remains "Jump Zero", as it is now the first jump to expanding human territory.

In the early years of biotic research, the station served as a safe place to evaluate emergent biotic humans. In rare circumstances, alien experts were brought in to assist in training, as humans lacked experience in the field, although that was not common knowledge.

Gagarin Station remains a PR beacon as the gateway to the human homeworld.

Source

 * Galactic Codex: Essentials Edition 2183, p.31.