Simon Willison’s Weblog

2 items tagged “spacescience”


Inside the Globus INK: a mechanical navigation computer for Soviet spaceflight (via) Absolutely beautiful piece of Soviet spacecraft engineering, explained in detail by Ken Shirriff. # 21st January 2023, 7:53 pm


GPS and Relativity (via) GPS satellite clock ticks need an accuracy of 20-30 nanoseconds. The satellites move fast enough that their clocks fall behind by 7 microseconds a day due to time dilation, but orbit high enough that the curvature of spacetime due to the Earth’s mass puts them forward by another 45 microseconds. GPS receivers have to perform relativistic calculations to determine their location! # 11th January 2010, 9:17 am