Researchers simulated 30 million routes to the Moon and found a hidden detour through L1 that saves fuel and keeps spacecraft talking to Earth the whole way An international team of researchers has identified a new fuel-efficient route between Earth and the Moon that also avoids the kind of communications blackout the Artemis II crew experienced when their spacecraft slipped behind the lunar far side in April. The trajectory, published in the journal Astrodynamics by a group led by Allan Kardec de Almeida Júnior at the University of Coimbra, uses roughly 58.80 metres per second less change in velocity than the most efficient previously known route, and parks the spacecraft at the L1 Lagrange point as an intermediate waypoint with continuous line-of-sight to Earth. The savings sound modest set against the roughly 3,343 m/s total budget of the journey. They are not. In rocketry, every metre per second of delta-v translates exponentially into propellant mass at launch, which is why mission planners spend years hunting for fractional improvements in trajectory design. A hidden branch on a well-mapped highway Spacecraft rarely fire their engines for long. Most of a deep-space journey is coasting along gravitational contours that physicists collectively call the Interplanetary Transport Network — a web of low-energy pathways that connect orbits around planets, moons and Lagrange points. The underlying mathematics treats gravity as nearly free propulsion, with thrusters needed mainly to nudge a vehicle from one natural trajectory to the next. Within that network, what mission designers call a “variate” is a natural trajectory leading into a target orbit. Conventional wisdom said the cheapest entry point onto the lunar-orbit variate was the branch closest to Earth.#artemis_ii #allan_kardec_de_almeida_jnior #university_of_coimbra #vitor_martins_de_oliveira #fapesp
