Problems for
Intermediate Methods in Theoretical Physics

Edward F. Redish

The Orbital Tower

One suggestion for putting satellites into orbit cheaply without using rockets is to build a tower tall enough so that the top of the tower, by virtue of the rotation of the earth, would be traveling at orbital velocity for that height. The tower would contain an elevator. One would put the payload in the elevator, lift it to the top, and just step out into orbit.

(a) Estimate how tall the tower would need to be.

(b) Ignoring other problems (such as structural strain on the tower), estimate the weight of such a tower if its base were the size of Washington DC and it were made of steel. (Steel is about 5 times as dense as water, which has a density of 1 gm/cm3.)

This page prepared by

Edward F. Redish
Department of Physics
University of Maryland
College Park, MD 20742
Phone: (301) 405-6120
Email: redish@umd.edu

Last revision 19. September, 2004.