Gravitational wave observatory prototype telescope revealed

NASA has unveiled the first look at a full-scale prototype for six telescopes that will facilitate space-based detection of gravitational waves—ripples in space-time caused by merging black holes and other cosmic phenomena—in the coming decade.

NASA reveals prototype telescope for gravitational wave observatory

On May 20, the full-scale Engineering Development Unit Telescope for the LISA (Laser Interferometer Space Antenna) mission was moved within a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, still housed in its shipping frame.

The LISA mission is led by the European Space Agency (ESA) in partnership with NASA and aims to detect gravitational waves by using lasers to measure precise distances—down to picometers, or trillionths of a meter—between three spacecraft arranged in a vast triangular configuration larger than the Sun. Each side of this triangular array will measure nearly 1.6 million miles, or 2.5 million kilometers.

"Twin telescopes aboard each spacecraft will both transmit and receive infrared laser beams to track their companions, and NASA is supplying all six of them to the LISA mission. The prototype, called the Engineering Development Unit Telescope, will guide us as we work toward building the flight hardware," stated Ryan DeRosa, a researcher at NASA’s Goddard Space Flight Center.

The prototype LISA telescope undergoes post-delivery inspection in a darkened NASA Goddard clean room

The Engineering Development Unit Telescope underwent post-delivery inspection in a darkened NASA Goddard clean room on May 20. The telescope is constructed from an amber-colored glass-ceramic that resists changes in shape over a wide temperature range, with the mirror's surface coated in gold to enhance infrared laser reflection and minimize heat loss from a surface exposed to the cold of space, as the telescope operates optimally near room temperature.

Manufactured and assembled by L3Harris Technologies in Rochester, New York, the prototype arrived at Goddard in May. The primary mirror is coated in gold to improve reflection of infrared lasers and to reduce heat loss.

The prototype is made entirely from an amber-colored glass-ceramic called Zerodur, produced by Schott in Mainz, Germany. This material is extensively used for telescope mirrors and other applications requiring high precision due to its minimal shape variation across a wide temperature range.

The LISA mission is slated for launch in the mid-2030s.