NASA's Starshade Concept Aims to Directly Image Earth-like Exoplanets

• A NASA-led team is developing a "Hybrid Observatory for Earth-like Exoplanets" (HOEE) that uses an orbital starshade to allow ground-based telescopes to directly image rocky, Earth-sized worlds.
• The project aims to overcome the limitations of current space-based instruments by blocking stellar glare before it enters the Earth's atmosphere.

The HOEE Technology

• Architecture: A hybrid system pairing a space-based starshade—positioned 175,000 km away in elliptical orbit—with next-generation ground telescopes like the Extremely Large Telescope (ELT) in Chile.
• Design: The occulter features a 50-meter diameter central disk with 48 petals, each 24.5 meters long.
• Maneuverability: Uses microthrusters powered by hot hydrogen gas to maintain 6-meter positioning accuracy.
• Portability: The design utilizes an inflatable structure to keep launch mass under 1,500 kg, allowing it to fit into standard launch vehicles.

Scientific Goals and Capability

• Targets: Rocky, Earth-like planets orbiting solar-type (F, G, and K) stars within 20 light-years of Earth.
• Detection: The system aims to reveal planets that are a billion times fainter than their host stars, potentially identifying an exo-Earth within the first minute of observation.
• Bio-signatures: Scientists hope to detect spectral lines from red and green auroras, which would indicate atmospheres capable of supporting nitrogen and oxygen, potentially signaling life.

Project Status

• Funding: The team has applied for NASA Innovative Advanced Concepts (NIAC) Phase B funding, with a goal of receiving it by 2027.
• Cost: Estimated in the billion-dollar range.
• Timeline: Designed to align with the first scientific light of the Extremely Large Telescope, expected by late 2030.