Short answers, pulled from the story.
The International Cometary Explorer was launched on the 12th of August 1978 as the International Sun-Earth Explorer 3, designed to study the interaction between Earth's magnetic field and the solar wind from a halo orbit at the Sun-Earth Lagrange point, about 1.5 million kilometers from Earth. Its instruments measured energetic particles, plasma waves, and electromagnetic fields; it carried no camera.
On the 11th of September 1985, the spacecraft passed through the plasma tail of comet Giacobini-Zinner at a distance of approximately 7,800 kilometers from the nucleus, becoming the first spacecraft to visit a comet. It also flew between the Sun and Comet Halley in late March 1986, at a minimum distance of 28 million kilometers from Halley's nucleus.
Beginning on the 10th of June 1982, the spacecraft executed fifteen propulsive maneuvers and five lunar gravity assists over roughly eighteen months. Its closest lunar pass, on the 22nd of December 1983, brought it just 119.4 kilometers above the Moon's surface, providing the final gravity boost needed to eject it from the Earth-Moon system toward comet Giacobini-Zinner.
The ISEE-3 Reboot Project was an unofficial team that crowdfunded US$159,502 on RocketHub and used software-defined radio techniques with the 305-meter Arecibo dish to reestablish two-way contact with the spacecraft in May 2014. They successfully fired the thrusters on the 2nd of July 2014, but subsequent firings failed due to loss of nitrogen tank pressure, preventing the planned orbit change; contact was lost on the 16th of September 2014.
NASA ended the ICE mission on the 5th of May 1997, leaving only a carrier signal broadcasting. The spacecraft had been donated to the Smithsonian Museum, though it continued in a heliocentric orbit. A 2008 status check found 12 of its 13 scientific instruments still functioning and enough propellant for 150 meters per second of delta-v.
ICE is a barrel-shaped cylindrical spacecraft covered with solar panels, with four long antennas protruding equidistantly around its circumference spanning 91 meters total. It has a dry mass of 390 kilograms, generates a nominal power of 173 watts, and carries 13 scientific instruments including a plasma wave instrument, vector helium magnetometer, and cosmic ray detectors, but no camera.