Russian Satellite Sends Signals After Silence of Several Hours

Radio signals from the Soviet space satellite halted yesterday for a period of about six hours, but were picked up again shortly after 10 p.m.

J. Allen Hynek, director of the Smithsonian Astrophysical Observatory's optical tracking program, revealed yesterday that three major radio installations--one in New York, one in Chicago, and one in Cambridge--which had previously been picking up the satellite's steady beep beep signal lost radio contact with the object late Monday night and yesterday morning.

Scientists could give no explanation for yesterday's break in communications, Many had suspected that the satellite's radio batteries were running down, but they were confounded by the resumption of the signal.

The U.S. Naval Research Laboratory in Washington reported that the signals faded out about 4 p.m. yesterday but were again picked up strongly at 10 p.m. There was no variation in the type or frequency of the signal.

The loss of radio contact with the satellite had caused Smithsonian astronomers to place increased emphasis on the visual spotting program organized in this country under "Operation Moonwatch."

The Cambridge "moonwatch" group, composed of amateur astronomers, planned to assemble at 7 a.m. this morning to attempt to spot the satellite when it passes over central Connecticut at about 8:03 a.m.

Approximately six sightings have been made so far--all of them either in Alaska or Australia--but Fred L. Whipple, director of the Smithsonian, is almost certain that these are contacts with the third stage of the rocket that propelled the satellite into its present orbit.

Hynek said last night that with the sighting data now assembled "it is very likely that we can work out a definite orbit within 24 hours."

The orbit, when it is established, will reveal the satellite's maximum and minimum distance from the earth. After this is determined, scientists will be able to calculate how long the satellite will stay aloft.

The Smithsonian Observatory yesterday issued an appeal for University volunteers to help in its public information section. These volunteers must be Harvard University students, either graduate or undergraduate. They should report to John White, director of public information, at 79 Garden St., between 9 a.m. and 12 midnight.