We have received authorization from NASA to communicate with (and command) ISEE-3 until 25 June. Meanwhile, analysis of telemetry from ISEE- 3 shows that *ALL* of its science instruments are still powered on. Telemetry also shows that ISEE-3 has a power margin of +28 watts – after 36 years. It is important to note that ISEE-3 has not had a functioning battery for decades. Indeed, this power capacity is what was projected for the spacecraft to have had in 1982 after 4 years in space.
Power System Status
– main bus voltage >= 28 volts
– solar array current >= 5.2 amps
– essential bus current <= 0.25 amps
– non-essential bus current = 4 amps
– shunt dump current >= 1 amp
– transponder A RF power = 5 watts
– transponder B RF power = 5.25 watts