NASA delays launch of world's biggest space telescope until 2020

NASA has delayed the launch of its much awaited, USD 8 billion James Webb Space Telescope - set to be the world's biggest space observatory - until at least May 2020.

The telescope is currently undergoing final integration and test phases that will require more time to ensure a successful mission, the US space agency said.

The James Webb Space Telescope will be complementing the scientific discoveries of NASA's Hubble Space Telescope and other science missions.

The observatory will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it, according to NASA.

After an independent assessment of remaining tasks for the highly complex space observatory, Webb's previously revised 2019 launch window now is targeted for about May 2020.

"Webb is the highest priority project for the agency's Science Mission Directorate, and the largest international space science project in US history," said Robert Lightfoot, acting NASA Administrator.

"All the observatory's flight hardware is now complete, however, the issues brought to light with the spacecraft element are prompting us to take the necessary steps to refocus our efforts on the completion of this ambitious and complex observatory," said Lightfoot.

Testing the hardware on the observatory's telescope element and spacecraft element demonstrate that these systems individually meet their requirements.

However, recent findings from the project's Standing Review Board (SRB) indicate more time is needed to test and integrate these components together and then perform environmental testing.

NASA will work with its partner, ESA (European Space Agency), on a new launch readiness date for the Ariane 5 vehicle that will launch Webb into space.

Once a new launch readiness date is determined, NASA will provide a cost estimate that may exceed the projected USD 8 billion development cost to complete the final phase of testing and prepare for launch.

This year the 6.5-metre telescope and science payload element will be joined with the spacecraft element to form the complete observatory.

The spacecraft element consists of the tennis-court-sized sunshield, designed by Northrop Grumman, and the spacecraft bus, which houses the flight avionics, power system, and solar panels.

Due to Webb's large size, engineers had to design components that fold origami-style into the Ariane 5 rocket's fairing configuration.

Webb has already completed an extensive range of tests to ensure it will safely reach its orbit at nearly one million miles from Earth and perform its science mission.

"Considering the investment NASA and our international partners have made, we want to proceed systematically through these last tests, with the additional time necessary, to be ready for a May 2020 launch," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate.

After the successful test performance of Webb's telescope and science payload in 2017 at NASA's Johnson Space Flight Center in Houston, the telescope element was delivered to Northrop Grumman earlier this year.

Both halves of the observatory now are together in the same facility for the first time.

The spacecraft element will next undergo environmental testing, subjecting it to the vibrational, acoustic and thermal environments it will experience during its launch and operations.

These tests will take a few months to complete. Engineers then will integrate and test the fully assembled observatory and verify all components work together properly.