NASA’s James Webb Space Telescope (JWST) is now planning to launch between March and June 2019, following a schedule assessment of the integration and test activities that remain to be completed. Previously, the telescope was targeted to launch in October 2018.

According to NASA officials, the schedule change is not due to hardware or technical performance concerns, but reflects the time required for integration of the different spacecraft elements, including the tennis court-sized multilayer sunshield.

As part of an international agreement with the European Space Agency (ESA) to provide a desired launch window one year prior to launch, NASA recently performed a routine schedule assessment to ensure launch preparedness and determined a launch schedule change was necessary. ESA is providing the Ariane 5 launch of JWST as part of its scientific collaboration with NASA.

JWST is NASA’s next great multi-purpose observatory and will be the most powerful space telescope ever built. The 21ft (6.5m) diameter infrared-optimized telescope is designed to study a wide range of astrophysical phenomena, including the first stars and galaxies that formed and the atmospheres of nearby planets outside our solar system.