The Albedo Line In 2048 the stratosphere above the Pacific was no longer natural. Every 72 hours, a fleet of 28 high-altitude tanker drones lifted off from six island bases—Guam, Palau, Kiribati, Hawaii, Easter Island, and the Galápagos. Each drone carried…

The Burn Window The nuclear thermal rocket Icarus Dawn left Earth-Moon L1 on 17 April 2064 at 03:42 UTC. She was a 420-tonne dry-mass transfer vehicle designed for one purpose: deliver 48 tonnes of payload to Mars surface in a single…

The Margin The habitat ring of Vanguard turned once every 42 seconds. At 8.2 rpm the spin gave 0.38 g at the outer deck—enough to keep bones from dissolving, enough to let people walk instead of float, enough to make coffee…