Astronomers at the Smithsonian Astrophysical Abservatory are not trying to "think up novel forces" to explain slight deviations in the orbital behavior of the Russian third stage rocket. These deviations have not been explainable thus far in terms of known forces acting on the object.

Dr. Fred L. Whipple, director of the Observatory, said "We can't say these forces don't exist, but at the moment we are trying to explain the rocket's behavior by air drag and other known forces."

He poitned out that scientists are just beginning to get really reliable observations on the object's path, so that accurate determinations may yet explain the behavior of the rocket.

The possibility that certain unpredicted irregularities may be explained by a difference between the actual and theoreretical mass distribution of the earth was not totally discarded by Whipple. He said that the IGY project hopes to gain information about the earth's mass distribution and that these present discrepancies might be a start towards such information. However, he added that it was still too early to tell.