Space.com's 56-year-old NASA satellite expected to fall to Earth this weekend says:
"OGO-1 is predicted to re-enter on one of its next three perigees, the points in the spacecraft's orbit closest to our plant, and current estimates have OGO-1 re-entering Earth's atmosphere on Saturday, Aug. 29, 2020, at about 5:10 p.m. EDT [2110 GMT], over the South Pacific approximately halfway between Tahiti and the Cook Islands," NASA officials wrote in an update Thursday (Aug. 27).
"The spacecraft will break up in the atmosphere and poses no threat to our planet — or anyone on it — and this is a normal final operational occurrence for retired spacecraft," they added.
The new observations come courtesy of the University of Arizona's Catalina Sky Survey (CSS) and the University of Hawaii's Asteroid Terrestrial-impact Last Alert System (ATLAS), both of which independently detected a small object on an apparent impact trajectory.
Analyses by researchers at the CSS, the Center for Near-Earth Object (NEO) Studies at NASA's Jet Propulsion Laboratory in Southern California and the European Space Agency's NEO Coordination Center revealed that the object in question was not an asteroid but rather OGO-1, NASA officials said.
Why does OGO-1's trajectory information come from "the University of Arizona's Catalina Sky Survey (CSS) and the University of Hawaii's Asteroid Terrestrial-impact Last Alert System (ATLAS), both of which independently detected a small object on an apparent impact trajectory" rather than from normal satellite tracking systems? It's perigee is only about 350 km and it's a well-known US-launched spacecraft.
It's not small, and its orbit should have been quite predictable, was it dropped from tracking or somehow lost for years?
For more information see:
- OGO program summary; NASA-SP-7601
Images of OGO-1 captured during asteroid survey operations on Tuesday, August 25 by University of Arizona’s Catalina Sky Survey, funded by NASA’s Planetary Defense Coordination Office. Credits: Catalina Sky Survey/University of Arizona/NASA