Less than two weeks into its journey, the James Webb Space Telescope reached its first major milestone this week when the team deployed a 70-foot sunshield.
Folded to fit inside the payload area of an Ariane 5 rocket’s nose cone prior to launch, the screen successfully opened on Tuesday to about the size of a tennis court.
“Unfolding Webb’s sunshield in space is an incredible milestone, crucial to the success of the mission,” Webb’s program director Gregory L. Robinson said in a statement. “Thousands of parts had to work with precision for this marvel of engineering to fully unfurl. The team has accomplished an audacious feat with the complexity of this deployment—one of the boldest undertakings yet for Webb.”
The five-layered sunshield aims to protect the telescope from the heat and light of the Sun, Earth, and Moon. Each plastic sheet—about as thin as a human hair and coated with reflective metal—provides protection on the order of more than SPF 1 million. Together, all five layers reduce Sun exposure from more than 200 kilowatts of solar energy to only a fraction of a watt.
This protection, according to NASA, is crucial to keep Webb’s scientific instruments at temperatures of 40 kelvins (or minus 380℉)—cold enough to see faint infrared light in the cosmos.
Named after former NASA Administrator James E. Webb, who played an integral part in the Apollo program, the space telescope is a joint NASA/European Space Agency (ESA)/Canadian Space Agency (CSA) project set to succeed the Hubble Space Telescope as the world’s premier science observatory.
Launched on Christmas morning from Europe’s Spaceport in French Guiana, South America, the telescope began a month-long journey to its intended orbit—nearly 1 million miles from Earth. Webb has five and a half months of setup still to come, including deployment of the secondary mirror and primary mirror wings, alignment of telescope optics, and calibration of science instruments. Its first images are expected this summer.
