We describe the operation of a cold atom clock in reduced gravity. We have recorded the cesium hyperfine resonance signal at a frequency near 9.2 GHz in the ∼10 g gravity environment produced by jet plane parabolic flights. With a resonance width of 7 Hz, the device operated in a regime which is not accessible on earth. In the much lower gravity level of a satellite, our cold cesium clock would...

Since 2008 the main geodetic activities at the national level in Poland concentrated on maintenance of the national gravity control, gravity survey for geodynamic research, continuing operational work of permanent IGS/EPN permanent GNSS stations, conducting GPS data processing on the regular basis at the WUT and MUT Local Analysis Centres, activity within the EUREF-IP Project, works towards mon...

Can a gravitational lens magnify gravity? Leading theories of gravity likely indicate “no”, but the possibility might be testable by using our Sun as a gravitational lens and carefully aligning a satellite past the minimum transparent focal distance of about 25 AU. Here the magnitude of a maximal effect is estimated and found potentially observable. Subject headings: gravitation – gravitational...

A technique for satellite formation flying modelling in LEO is applied at L2. Analytical solutions to the equations of motion of a hub satellite relative to L2 are used to define a halo reference orbit. An expression for the gravity gradient is obtained at the hub and the linearised equations of motion of the mirror satellites relative to the hub are derived. The relative motion model is implem...

A higher-order perturbation theory for the rotation of a uniaxial satellite under gravity-gradient torque demonstrates that known special configurations of the attitude dynamics at which the satellite rotates, on average, as in a torque-free state, are only the result of an early truncation of the secular frequencies of motion. In addition to providing a deeper insight into the dynamics, the hi...

Stephen Hodgart received a Ph.D. degree from the University of Surrey. He has been with the Surrey Space Centre, since its inception and the launch of their first satellite, UoSAT-1 in 1981. He is currently visiting Reader at the University of Surrey. He was responsible for the first practical low-cost active magnetic and passive gravity gradient control attitude system for a low earth orbiting...