Efforts to return a 1978 space probe to active service have ended in disappointment, as former Nasa engineers have
confirmed it won’t be able to return to Earth.
The vintage probe, named ISEE-3, was launched in 1978 to measure
solar winds and decommissioned in 1997 as it drifted further away
from Earth. But in 2008 the Deep Space Network found that it was
still issuing a signal. Nasa admitted that the craft was too far
away when the mission ended to issue a shutdown command.
However, it was also discovered that the probe would fly past
Earth again in 2014, so a group of former Nasa employees raised
$160,000 (£93,427) to try and return it
to active duty. That cash was spent on ground stations at Morehead
State University and the Arecibo Observatory in Puerto Rico, which
houses the world’s largest and most powerful radio telescope.
Things were looking up when the probe was successfully persuaded to fire its thrusters for the first
time in 20 years. But attempts to alter its trajectory to keep it
close to Earth failed, as the craft’s nitrogen tanks are either
empty or not operational.
The thruster firings that occurred July 3 and 8 were “probably
the result of residual hydrazine that was already in the system
that had pressure,” said Keith Cowing, a former Nasa employee
working on the project, in an interview with NPR. “We were a little misled that we
got this perfect burn.”
Cowing added: “At this point we’re sort of scratching our heads.
We may take one last run at the spacecraft but this may be it for
an attempt to bring it back to Earth.”
Instead, its new operators have switched it into a mode that’ll
allow its instruments to collect and send data to receivers back on
Earth. That’s expected to last another three months.
After that, the craft will have travelled too far into the inky
blackness of space to ever be rescued again.