A crowd-funding effort to give an old spacecraft a new mission has been approved by NASA. The craft in question is the International Sun-Earth Explorer-3 (ISEE-3). It will be put back to work if this effort succeeds. NASA has previously shared technical details about the craft with interested parties.
NASA thought they were done with the spacecraft when its mission ended in 1997. ISEE-3 was launched in 1978 and sent the L-1 Lagrange point, a location between the earth and the sun, to study solar winds. Lagrange points are stable orbital positions between two bodies, the Earth and the sun in this case.
The craft had a name change, to International Cometary Explorer, in the 1990s before being sent to examine the two comets while it moved in a new orbit around the sun. It ended its original service life there and has been trailing the earth, transmitting a signal that NASA forgot to turn off.
The probe’s instruments are still working and it is getting closer to earth. Those facts indicate that it might be possible to return ISEE-3 to the old L-1 position and put back to work. This could be quite a challenge because NASA hasn’t kept the hardware or the communication protocols that are needed to communicate with ISEE-3. Thanks to the ongoing transmissions, in 2008 engineers determined that at least some of the instruments still worked.
Time is critical here as ISEE-3 makes its closest approach to Earth in the summer. The tiny gravitational boost associated with the close approach should give the craft the ability to fly back into the old L-1 orbital position. The upcoming approach will be the craft’s closest in 30 years.
Those issues haven’t stopped people from trying to unofficially reestablish communication with the craft in something called the ISEE-3 Reboot project. On May 21, NASA announced an agreement with California-based Skycorp, Inc., which is backing the project. The new “Non-Reimbursable Space Act Agreement” between NASA and Skycorp allows ‘rebooters’ to try and regain control of the spacecraft, and outlines conditions under which such control efforts may be attempted.
Skycorp thinks a radio telescope it owns will be capable of communicating with ISEE-3. Crowdsourcing will help it raise the money it needs to contact the probe and control. NASA lacks the funding to recreate the long-ago scrapped communication gear that the mission originally used. A group of scientists at the Arecibo, a radio telescope facility in Puerto Rico, are trying to reestablish communication.
If the project works, any new data would be put in the public domain per the agreement with Skycorp.
NASA has worked with the public on other space science initiatives. A recent project used amateur scientists to help count moon craters. Another, far more ambitious, citizen science effort has amateurs helping NASA analyze data on asteroids that professional astronomers have identified. That asteroid study was announced on May 22.
The ISEE-3 Reboot is another example of increased NASA cooperation with companies and individuals on promising technical and scientific exercises. The use of citizen scientists to save an old satellite is one more NASA effort to stretch a tight budget.
By Chester Davis