UNFOLD
A FIELD GUIDE TO THE JAMES WEBB SPACE TELESCOPE
Ten chapters on a telescope too large to launch fully built — folded like origami into a rocket fairing, unpacked over two weeks a million and a half kilometres from any repair crew, and now rewriting how early the universe got interesting. Scroll to begin the mission.
BEGIN — CHAPTER 01 →A parking spot a million miles out
Hubble orbits Earth at 535 km, crossing in and out of daylight every 95 minutes. Webb doesn't orbit Earth at all — it orbits the Sun, parked in a large halo around the second Sun-Earth Lagrange point, roughly 1.5 million km out, where gravity from the Sun and Earth balances just enough to hold a stable position while staying in line with Earth as both move around the Sun.
That position lets a single sunshield block the Sun, Earth, and Moon all at once, keeping the telescope in permanent, deep shadow — essential for an instrument that has to stay colder than almost anything else humans have ever built.
A 330°C temperature drop, five layers thin
Roughly the size and shape of a tennis court, the sunshield is five layers of a reflective polymer film, each thinner than a human hair, spaced apart to let heat radiate away between them.
Eighteen hexagons, one mirror
At 6.5 metres across, Webb's primary mirror was too large to fit any rocket fairing whole, so engineers built it from 18 gold-coated beryllium hexagons that fold flat for launch and unfold into a single optical surface in space, each one individually adjustable to within a fraction of a wavelength of light.
An observatory, not just a telescope
Four instruments, a mirror, a sunshield, and a spacecraft bus — every piece with no possibility of a repair mission. Select a component.
Two weeks of unfolding, no rehearsal in space
Engineers counted 344 mechanisms that had to work correctly — hinges, motors, and releases — with no way to test the full sequence in real conditions until it actually happened, a million and a half kilometres past any rescue mission's reach. Step through the sequence.
Five images, six months in the making
Seeing through dust, and back through time
Infrared light passes through the dust clouds that block visible light, letting Webb see stars being born inside nebulae that would otherwise look like solid dark walls.
It also solves a problem unique to the very edge of the observable universe: the expansion of space stretches light from the earliest galaxies so much that it shifts out of visible wavelengths entirely and into the infrared — exactly the band Webb was built to see.
The early universe looks nothing like predicted
Two eyes, two kinds of light, one target
Astronomers regularly point both telescopes at the same object, combining Hubble's ultraviolet-through-visible view with Webb's infrared one to build a far more complete picture than either could alone.
Built for decades, not years
Webb launched with enough propellant for a mission well beyond its planned ten years — and it is already shaping what the next generation of observatories will need to answer next.