Vanguard I satellite, a component of the Vanguard Project, is a small aluminum sphere designed to partake in the International Geophysical Year (IGY) — a series of coordinated observations of various geophysical phenomena during solar maximum, spanning July 1957 through December 1958.
Image credit: NASA
Back in 2022, it turns out that the longest-lived object in Earth orbit and a Russian rocket body passed within roughly 0.8 miles (1.3 kilometers) from each other.
That U.S. non-operational payload was Vanguard 1, according to Darren McKnight, a senior technical fellow of LeoLabs, a group dedicated to space domain awareness.
In a conjunction review of the situation, McKnight notes that on August 29, 2022, an SL-14 Russian rocket body launched in 1986 and Vanguard 1 found themselves in close collision at an altitude of approximately 590 miles (950 kilometers) altitude above Earth.
Close-call events
“This conjunction was discovered when searching for events with the oldest object in Earth orbit: Vanguard 1,” McKnight reports.
Built by the Naval Research Laboratory (NRL), Vanguard 1 was launched in March 1958 into a highly elliptical orbit (currently at roughly 3,800 kilometers by roughly 650 kilometers).
“As such, it spends most of its time outside of low Earth orbit (LEO). However, despite this non-treacherous orbit relative to most of the LEO population,” McKnight adds that the old Vanguard 1 has had a trio of close-call events since January of 2022.
Instrumentation onboard Vanguard 1 included a set of mercury batteries, a transmitter, two temperature sensors, and a beacon powered by six square solar cells — the first satellite on-orbit to be powered by photovoltaic cells. It remains the oldest artificial object orbiting Earth to this day.
Image credit: Naval Research Laboratory
Transiting space
“While the satellite has been orbiting the Earth for more than 67 years, the battery-powered transmitter onboard the spacecraft only lasted three months and its solar-powered transmitter remained functional for six years,” McKnight explains.
Transiting the space environment all these decades, Vanguard 1 has chalked up a distance equal to two roundtrips from the Earth to Pluto, McKnight notes.
Save Vanguard 1?
Recently, there was a new push to save Vanguard 1, snagging the tiny satellite and safely returning it to Earth.
A team that includes aerospace engineers, historians and writers recently proposed “how-to” options for an up-close look and possible retrieval of Vanguard 1.
Go to my Space.com story earlier this year – “Vanguard 1 is the oldest satellite orbiting Earth. Scientists want to bring it home after 67 years” – at:
Vanguard 1 launches in March 1958 from the Atlantic Missile Range in Cape Canaveral Florida.
Image credit: Naval Research Laboratory