Want to be part of operating a spacecraft? Now is your chance, with NASA's decision to hand a decommissioned probe over to a group of scientists and engineers and anyone willing to put in some money to support the idea, or donate some processing power to analysis.
"Our plan is simple: we intend to contact the ISEE-3 spacecraft, command it to fire its engines and enter an orbit near Earth, and then resume its original mission," wrote Keith Cowing, a former NASA engineer who is part of the team taking over the craft. "If we are successful it may also still be able to chase yet another comet."
In 1978, when the International Sun/Earth Explorer-3 (ISEE-3) was launched its task was to study the solar wind, the stream of particles that flow from the sun and cause aurora when they interact with the atmosphere. ISEE-3 was the first spacecraft to spend time in one of the Earth's Lagrangian points. These are five spots where the gravity of the Earth and Sun combine so that an object can remain stationary relative to us. ISEE-3 sat at L1, between the Earth and Sun.
For four years ISEE-3 examined the way the solar wind interacts with Earth's magnetic field, and the shock-wave created when they meet. In 1982 it was renamed International Cometary Explorer and given a new mission, to study comets. To do this it was sent on a series of complex orbits around the Earth and Moon until by 1983 it was orbiting the sun directly. On this orbit it passed through the tails of Comets Giacobini-Zinner's and Halley.
When that was done the spacecraft formerly (and subsequently) known as ISEE-3 spent time watching the sun for coronal mass ejections. Then in 1997 NASA decided it had new and more exciting toys to play with, and shut the spacecraft down. By this time the craft which had once transmitted at 2048 bits/second (a lot for the 70s) was going in the opposite direction from every other communication technology known to humanity and had progressively stepped down to 64 bits/s. NASA donated the craft to the Smithsonian, although the value of the gift was questionable since it was not only in space but gradually getting further and further from Earth.
With an orbital period just slightly shorter than that of Earth's ISEE-3 gradually got further and further ahead of us, until for a while it was on the other side of the sun, making communication impossible. But now that slightly faster orbit is causing to catch up with us. In 2008 NASA did a check in and was able to locate the prodigal spacecraft and found 12 of its 13 experiments were functioning.
For a while NASA considered reactivating ISEE-3, but eventually decided the cost of doing so was not worth the information to be gained.
A combination of the romance of giving a new lease of life to such a veteran, and the scientific potential has led to a global campaign known as the ISEE-3 Reboot Project.
Part of the reason NASA lost interest was that the Deep Space Network equipment that transmitted signals to ISEE-3 was such down in 1999. It was thought that no suitable equipment existed, and rebuilding from scratch would be prohibitively expensive. However, it is amazing what can be found out the back of old laboratories. The reboot team came up with a suitable power amplifier and modulator/demodulator. These were installed a week ago on the giant Arecibo dish in Puerto Rico. http://en.wikipedia.org/wiki/Arecibo_Observatory
The team estimated it would cost $125,000 and set about running a crowdsourcing campaign, eventually bringing in $159,502 before the deadline last Friday.
Two days earlier NASA announced they are handing the craft over to the citizen scientists, who will attempt to swing it round the Moon into an orbit that will allow it to go on doing many years' fruitful research. "We have a chance to engage a new generation of citizen scientists through this creative effort to recapture the ISEE-3 spacecraft as it zips by the Earth this summer," said John Grunsfeld, NASA's associate administrator for science.
The announcement came in the nick of time. ISEE-3 has drifted somewhat from its expected orbit, and recent observations reveal it is in danger of hitting the Moon if evasive action is not taken. It is thought to still have enough fuel for a corrective maneuver, but only if action is taken soon.