The four oldest galaxies in the universe. A nebula where stars are born. A new exoplanet shrouded in silicate clouds. Since its launch in December 2021, the Webb Space Telescope has been delivering an array of awe-inspiring images—with incredible clarity. But the US$10 billion path from project launch to space pad launch was lengthy and complex. Led by nasa with support from europeanspaceagency and canadianspaceagency, the project required a team of about 20,000 engineers, astronomers, technicians, and administrators. Knowing that once the telescope was in orbit there would be no way to correct any issues, the team relied on lots of testing, iterating, and retesting. When engineers vetted the telescope’s ability to withstand the vibrations of launch, screws holding its sun shield popped loose. Fixing that pushed back the launch date by 10 months—and increased the project’s budget by US$800 million. Finally, after two decades of timeline slips and tumultuous setbacks, Webb is now ...