…The first burn lasted for ten minutes; then Hal reported that Discovery had entered the transfer orbit. As soon as Leonov’s radar and optical tracking confirmed that, the other ship injected itself into the same trajectory. Two minor in-course corrections were made; then, three hours and fifteen minutes later, both arrived uneventfully at the first Lagrange point, L. 1 – 10,500 kilometres up, on the invisible line connecting the centres of Io and Jupiter…

2010: Odyssey Two – Arthur C. Clarke