NASA presses ahead with Webb space telescope sunshield deployment

Engineers activating the James Webb Space Telescope fine-tuned its electrical power system to better cope with the actual space environment and cooled down slightly warmer-than-expected motors before pressing ahead Monday with final deployment of the observatory's critical sunshade.

Bill Ochs, the NASA project manager, said tightening up the sunshade's five hair-thin layers, carefully pulling them taut with motor-driven cables running through multiple pulleys, likely would take three days to complete. But by Monday night, three of the five layers had been pulled into shape, with the final two awaiting tightening Tuesday.

The sunshade deployment has long been considered one of Webb's most challenging hurdles, but "I don't expect any drama," Ochs said.