The story of the little satellite that could took an unfortunate turn on Tuesday, when a team of young scientists and former NASA engineers trying to rescue the defunct International Sun-Earth Explorer-3 (ISEE-3) announced that they suspected that the craft may have run out of nitrogen.
On July 2, the team of scientists jumpstarted ISEE-3 after the decommissioned spacecraft had spent the last 27 years languishing in a somnambulant state of inactivity. The craft was first launched in 1978 with the task of measuring the solar winds that the Sun propels into Earth’s magnetic field. After an encounter with a comet in 1987, the satellite’s batteries failed and it fell into an orbital path that would see it circling the Sun in perpetuity.
The group of scientists looking to break ISEE-3 out of its orbit received approval from NASA in May, and has raised nearly $160,000 through crowdfunding. They are hoping to bring the satellite into a gravitationally stable orbit approximately 932,000 miles (1.5 million kilometers) from Earth, at which point ISEE-3 would be able to restart its original mission. Thanks in part to the offer of free use of the telescope at Puerto Rico’s Arecibo Observatory, the team was able to contact ISEE-3 on May 29. Last week, the team managed to fire the craft’s thrusters and slightly alter its rate of rotation in preparations for efforts to change its orbit.
Attempts to shift the craft’s trajectory began on Tuesday, but ISEE-3 failed to accelerate. The team first thought that the craft suffered from a stuck valve, but after investigating further, they began to suspect that it did not have enough nitrogen left to provide pressure to its fuel system. If the team is unable to change ISEE-3’s course, then the craft will fly around the moon on August 10 before resuming its orbit around the sun.
The volunteer engineers look to gain more information about the craft’s condition during Friday’s radio communications session. Even if they fail to bring ISEE-3 into a stable orbit, the team still hopes to use it for scientific purposes while it is in the inner solar system.