A 36-year-old NASA spacecraft, still largely in working condition, will zip through Earth’s neighborhood on Sunday for the first time in decades before receding again into the solar system.
The craft – the International Sun-Earth Explorer-3, or ISEE-3, better known as the zombie spaceship that was revived by a scrappy band of space enthusiasts – will pass about 9,700 miles from the surface of the moon at 1:16 p.m. Central time.
The enthusiasts had hoped to nudge it much closer to the moon, just 30 miles from its surface; the moon’s gravity would then have swung the spacecraft into orbit around Earth, from which it could have been catapulted on a new mission.
But when they tried the course change on July 8, the thrusters sputtered. The craft’s nitrogen tanks, needed to pressurize the propulsion system, had somehow emptied.
Although ISEE-3 and many of its scientific instruments are still working, there is now no way to steer the spacecraft.
“Obviously, we were very, very disappointed,” said Dennis Wingo, an engineer and entrepreneur who is a leader of the ISEE-3 Reboot Project.
But the enthusiasts did not give up. They have commanded the craft to continue collecting scientific measurements and sending them back to Earth, an interplanetary exercise in “citizen science” that they hope will show NASA how to tap into the expertise of people outside the space agency.
A website started Friday with help from Google, spacecraftforall.com, offers an interactive history of the mission and an archive of the science data, including of the magnetic fields in space and the number of protons from the sun streaming by. The team will hold a live video chat on Sunday afternoon from its mission control, a former McDonald’s at an old Navy airfield north of San Jose, California, that is now part of a research park run by NASA Ames Research Center.
The propulsion failure was a disappointment to Robert W. Farquhar, the flight director for ISEE-3 when it was launched in 1978. When he last fired the thrusters, in 1987, he deliberately set the spacecraft on a course to fly by Earth on Aug. 10, 2014.
“I’m going to wave goodbye to the spacecraft,” said Farquhar.
The craft’s looping orbit around the sun will again put it in the vicinity of Earth 17 years from now. Might he plot something for it then?
“Hah,” said Farquhar, now 81. “No.”