Citations of this article
Mendeley users who have this article in their library.
Get full text


There is an interaction between gravitational tidal forces and the instantaneous moment of inertia of any massive extended body. A mechanism that changes the altitude of a spacecraft orbiting a central mass by periodically changing its instantaneous moment of inertia tensor is discussed. This can be achieved most simply by connecting two bodies with a tether of adjustable length and does not rely on any chemical propellant. By using a series of reasonable approximations, a formula for the rate of change of height is given in terms of accessible data. This formula predicts that by suitably varying the length of a 50 km connecting tether a connected system can rise at about 300 m an hour in low earth orbit. © 2002 Elsevier Science Ltd. All rights reserved.




Gratus, J., & Tucker, R. (2003). An improved method of gravicraft propulsion. Acta Astronautica, 53(3), 161–172. https://doi.org/10.1016/S0094-5765(02)00202-3

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free