ISEE 3 --> ICE

Launch data: Designation  11004 / 78079A Launch date  12 Aug 1978 - 15:12 UT Launch site  CC, LC-17B Launch vehicle  Delta-2914 (#633/D144) Mission   Earth orbit on 1978 Aug 12.7: Perihelion / Aphelion  180 x 1151664 km Eccentricity  0.989 Inclination  28.89 deg Period  73702 min Heliocentric orbit Perihelion / Aphelion  0.973 x 1.006 A.U. Eccentricity  0.017 Inclination  0.0 deg Period  359 days Heliocentric orbit on 1990 Jan: Perihelion / Aphelion  0.93 x 1.03 A.U. Eccentricity   - Inclination  0.1 deg Period  355 days

Spacecraft data:

Description:

• ISEE 3 was developed by NASA-GSFC and was the first spacecraft at the Earth-Sun L1 Lagrange point.

Mission details:

• Entered heliocentric orbit - a 'halo' orbit around the Sun-Earth/Moon libration point, at distance of 1.6 million km from Earth on Earth-Sun line and maintained location by use of microthrusters.
• During early Oct 1982, manoeuvred from this 'dayside' libration point, back across the Moon's orbit (1982 Oct 16), and out to a 'nightside' apogee of about 1.6 million km on 1982 Dec 22.
• Several manoeuvres in 1983 led to close Moon passages and finally on 1983 Dec 22.78 to a 119.4 km 'slingshot' pass towards the comet 21P/Giacobini-Zinner and name changed to International Cometery Explorer. It passed through the tail of the comet, 7870 km from its nuclues on 1985 Sep 11.46.
• Made observations of comet 1P/Halley from 35 million km on 1986 Mar 22.
• The International Sun-Earth Explorer 3 spacecraft, after its trip to P/Giacobini-Zinner in 1985, is returning to the vicinity of the Earth in August 2014 following 30 years in solar orbit.
  On Apr 18, 2014 ISEE 3 was in a 0.927 x 1.034 AU x 0.06 deg solar orbit at a distance of 28.9 million km from Earth. Current orbital data suggest that on Aug 9, 2014 at 1145 UTC the probe will pass only 397000 km from Earth and then return to a solar orbit with slightly higher period and inclination.
• Aug 2014: ISEE-3 continues to approach its lunar flyby as the Reboot Project begins science operations with it. The probe's propulsion system is not working and attempts to recapture the satellite in the Earth-Moon system have been abandoned.
  ISEE-3 was in a 0.927 x 1.035 AU x 0.1 deg orbit around the Sun before its Earth approach; the burn in early July 2014 did not significantly affect this. It entered the Earth's sphere of influence on Aug 3, 2014 on a 42.5 deg inclination trajectory and will pass through a 178400 km perigee on Aug 9 before entering the lunar sphere of influence at about 1015 UTC Aug 10. Perilune is 15938 km at 1927 UTC Aug 10, 2014; ISEE-3 will leave the Earth-Moon system on Aug 14, passing the L1 radius on Aug 17 and entering a 1.012 x 1.190 AU x 1.17 deg solar orbit, having increased its solar orbital period by 66.9 days to 422 days. (Data calculated from the ephemeris on JPL HORIZONS).
• ISEE-3 flew past the Earth after over 20 years out of contact and 35 years in space. ISEE-3 became the first vehicle to utilize the Sun-Earth Lagrangian point 1 (L1) to monitor the Solar wind. Several vehicles followed, specialized probes even clusters were developed to understand the complex interaction between the Sun and the Earth’s magnetic field and atmosphere.