"Real time operation." . . . . "Spacecraft docking." . . "Rendezvous guidance." . . "International space station." . . "Global positioning system." . . "Kalman filters." . . "Space transportation system flights." . . . "Flight test results from real-time relative global positioning system flight experiment on STS-69"@en . . . . . . . . . . . . . . . . . . . . . .