HERACLES (Human-Enhanced Robotic Architecture and Capability for Lunar Exploration and Science) is a planned robotic transport system to and from the Moon by Europe (ESA), Japan (JAXA) and Canada (CSA) that will feature a lander called the European Large Logistic Lander (EL3, or Argonaut), a Lunar Ascent Element, and a rover.^[2] The lander can be configured for different operations such as up to 1.5 tons of cargo delivery,^[3] sample-returns, or prospecting resources found on the Moon.^[4]

The system is planned to support the Artemis program and perform lunar exploration using the Lunar Gateway space station as a staging point.

As of 2023, the HERACLES project has been superseded by the European Large Logistics Lander (EL3) project, and is no longer actual.^[5]

The HERACLES architecture was outlined by 2015.^[6] ESA approved the HERACLES project in November 2019.^[3][7] Its first mission is expected to launch in 2030.^[8] The project will be the next phase of ESA's exploration program Terrae Novae (known as European Exploration Envelope Programme (E3P) before 2021).^[9]

The HERACLES transport system will leverage the Lunar Gateway as a staging point.^[10] The architecture involves dispatching the EL3 lunar lander from Earth aboard an Ariane 64^{[11]: slides 7, 9 and 10 [12][2]} which would land on the Moon with a disposable descent module.

The EL3 lander will have a landing mass of approximately 1,800 kg (4,000 lb)^[13] and will be capable of transporting a Canadian robotic rover to explore, prospect potential resources, and load samples up to 15 kg (33 lb) on the ascent module.^[14] The rover would then traverse several kilometers across the Schrödinger basin on the far side of the Moon to explore and collect more samples to load on the next EL3 lander.^[15][13] The ascent module would return each time to the Lunar Gateway, where it would be captured by the Canadian robotic arm and samples transferred to an Orion spacecraft for transport to Earth with the returning astronauts.^[16] The ascent module would then be refueled and paired with a new descent module dispatched from Earth.

The second and third landings would each have 500 kg (1,100 lb) payload available for alternate uses such as testing new hardware, demonstrating technology and gaining experience in operations. The 4th or 5th lander mission will provide a sample return.^[13]

The project will require the development of a reusable lunar ascent engine, four of which could be clustered to power a reusable crewed or robotic lander in the future. Later missions will include a pressurised rover driven by astronauts and an ascent module for the crew to return to Earth.^[13][16]

The HERACLES EL3 lander concept will consist of the Lunar Descent Element (LDE), which will be provided by Japan's JAXA,^[1] the ESA-built Interface Element that will house the rover, and the European Lunar Ascent Element (LAE) that will return the samples to the Lunar Gateway.^[14]

The rover, to be developed by the Canadian Space Agency (CSA), will have a mass of 330 kg (730 lb) and will feature a "radioisotope power system" that will permit operations during the long and frigid lunar nights.^[14] The total spacecraft mass will be ≈8,500 kg (18,700 lb) including fuel, with a payload of ≈1,500 kg (3,300 lb).^[1]

Nammo have been awarded a contract to evaluate engine performance requirements and 'find' the best engine design.^[17] The engine may be fed by electrically driven pumps, from low pressure propellant tanks, which may enable in-space refueling.^[17]

• Artemis program – NASA-led lunar exploration program
• Commercial Lunar Payload Services – NASA program contracting commercial transportation services to the Moon
• Chandrayaan programme – Indian Lunar exploration programme
• Chinese Lunar Exploration Program – Lunar research program (2004 – present)
• Luna-Glob – Moon exploration programme by the Russian Federal Space Agency