The $11bn observatory will search for Earth-like exoplanets and analyse their atmospheres for potential biosignatures, including oxygen, ozone and methane.

NASA has confirmed that its planned Habitable Worlds Observatory (HWO), the agency’s next flagship space telescope designed to search for signs of extraterrestrial life, will be built with robotic servicing as a mandatory mission requirement, marking a major shift in the design of future space observatories.

The Habitable Worlds Observatory is expected to become the first space telescope specifically designed to directly image Earth-like planets orbiting Sun-like stars and analyse their atmospheres for potential biosignatures, including oxygen, methane and water vapour, that could indicate the presence of life beyond Earth. The mission was identified as the highest-priority large astrophysics mission in the US astronomy decadal survey and is currently undergoing technology maturation ahead of a planned launch in the 2040s.

Unlike previous flagship observatories such as the James Webb Space Telescope, which was not designed for maintenance after launch, HWO will incorporate a modular architecture that allows robotic spacecraft to inspect, refuel, repair, replace instruments and upgrade hardware while the observatory operates at the Sun-Earth L2 Lagrange point, approximately 1.5m kilometres from Earth. NASA has elevated robotic servicing from a design objective to a mission-level requirement, with the aim of extending the telescope’s operational life and enabling future scientific upgrades without launching a replacement observatory.

The decision reflects NASA’s broader strategy of building more sustainable and serviceable space infrastructure. Engineers are designing every major component of the observatory with modularity in mind, allowing future robotic missions to swap instruments, replenish fuel supplies and perform maintenance as technologies evolve over the telescope’s lifetime. Officials believe this approach will reduce long-term costs, improve scientific returns and allow the observatory to remain at the forefront of astronomical research for decades.

The observatory will also introduce several technological advances needed to detect distant habitable worlds. Among them is a next-generation coronagraph capable of blocking the intense light from nearby stars, enabling scientists to directly observe much fainter orbiting planets. NASA said the mission will require unprecedented optical stability, with the telescope maintaining alignment to within the width of an atom during observations to accurately characterise exoplanet atmospheres.

Beyond its primary search for life, the Habitable Worlds Observatory will serve as a general-purpose astrophysics observatory, supporting research into galaxy evolution, black holes, stellar formation, planetary science and other areas of astronomy. NASA expects the mission to build on the scientific legacy of the Hubble Space Telescope, the James Webb Space Telescope and the upcoming Nancy Grace Roman Space Telescope.

Earlier this year, NASA selected seven companies, including Lockheed Martin, Northrop Grumman, L3Harris Technologies, BAE Systems, Astroscale US, Busek and Zecoat, to develop critical technologies for the observatory under three-year contracts. The work focuses on advancing the telescope’s optical systems, coronagraph technology and servicing capabilities as NASA moves the mission toward its next design phase.

The agency’s commitment to robotic servicing also aligns with its growing investment in commercial on-orbit servicing technologies. NASA is already supporting robotic missions capable of inspecting and extending the life of existing spacecraft, experience that is expected to inform future servicing operations for the Habitable Worlds Observatory.