NASA's abandoned International Sun-Earth Explorer 3 (ISEE-3) spacecraft is officially down for the count. The probe, which was re-activated recently by a crowdfunding effort, recently flew by the moon and kept on going, back into deep space.
The probe launched in 1978, with a mission to study the Earth's magnetosphere. Once it completed that, it received a second mission: chasing down comets. In 1997, NASA shut the spacecraft down. Since then, ISEE-3 has been sleeping, while orbiting the Sun.
Earlier this year, a crowdfunded effort to revive ISEE-3 raised nearly $160,000 to bring the probe back from the dead. The plan was to turn the spacecraft back on and get it to fire an engine, placing it on a new trajectory to fly by the Moon, where it would carry out new missions, perhaps even chase down more comets. NASA approved of the effort and handed over the spacecraft's controls.
All seemed well, at first. The team behind reactivating ISEE-3 established contact with the spacecraft and ordered it to go through a series of testing. The team even managed to get the craft's thrusters to fire for the first time since 1987. However, they soon discovered ISEE-3 had a major problem: its fuel tanks were low on nitrogen gas.
Unfortunately, this meant that ISEE-3's propulsion system eventually stopped functioning and the team behind its reactivation had no control over its trajectory.
"Obviously, we were very, very disappointed," says Dennis Wingo, an engineer and one of the leaders of the ISEE-3 Reboot Project.
Although ISEE-3 recently did its Moon flyby, it will continue into deep space and orbit the Sun. It will take it nearly 17 years before it is close to Earth again.
All, however, is not lost. The good news is that ISEE-3's on-board scientific instruments are not only intact, but are also functioning. The spacecraft is still measuring Earth's magnetosphere, as well as solar winds and cosmic radiation.
Because of this, the group behind ISEE-3's reactivation have teamed up with Google to make the spacecraft's data available to the public via its website.
"The main feature of this is a new website developed by Google Creative Lab in collaboration with the ISEE-3 Reboot Project team that features a history of the ISEE-3 mission as well as a presentation of data currently being received from ISEE-3," says co-founder Keith Cowing.
The ISEE-3 team is calling this a Citizen Scientist Program and it is the first of its kind.
