Launch of James Webb Space Telescope postponed to spring 2019
Delay is due to difficulties integrating various parts of the telescope and will not increase its budget.

By Laurel Kornfeld | 4 hours ago

Delays in integration of various instruments on the James Webb Space Telescope (JWST) have led NASA to postpone its launch from October 2018 to sometime between March and June of 2019.

NASA announced this latest of multiple launch delays for the Hubble Space Telescope's successor in a press release on Friday, September 29.

With an 18-segment, 6.5-meter mirror along with infrared instruments, JWST will have unprecedented capabilities, among them probing the atmospheres of exoplanets, directly imaging exoplanets, looking back to the earliest days of the universe to witness the formation of the first stars and galaxies, and observing new stars being born in stellar nurseries.

The telescope and its various instruments are currently undergoing tests in a simulated space environment, both to assure their survival and to determine the extent of their capabilities, in a process known as cryovacuum testing.

A special sunshield made up of five layers designed to protect the telescope's infrared detectors through cooling it by 300 degrees Celsius has already completed testing and successful integration into the spacecraft.

To assure its capability of surviving launch, the sunshield will now undergo vibration, accoustic, and deployment tests. Once those are completed, testing will start on integration of the entire telescope and its instruments.

Scientists and engineers will not be able to fix any problems JWST experiences after launch, as the telescope will orbit the Sun in the L2 Lagrangian point at a distance of 1.5 million kilometers from Earth.

Lagrangian points are positions between the orbits of two celestial objects where a smaller object, such as JWST, which is affected only by gravity, can hold a stable position between the two large objects (in this case, the Earth and Sun).

Initially scheduled for a 2011 launch, JWST has experienced multiple delays and cost overruns. While its cost was first estimated at $1.6 billion, the total price tag has now risen to $8.8 billion.

On several occasions, cost overruns caused Congress to threaten cancellation of the project.

JWST program director Eric Smith emphasized the launch delay will not further increase its budget.

"The Congressional cap is on the development (through commissioning) cost of Webb and not the launch date. No new funding for Webb will be required even with the launch date change. Assuming the remaining integration and test steps proceed as planned for Webb, and no long launch delays are encountered in French Guiana, the Webb program has sufficient funds to stay in its planned budget," Smith said.

French Guiana is the the site from which JWST will be launched.

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