- 07.03.98: Launch
- 12.09.03: End of Mission
- Status: In Heliocentric Orbit
- MIC visible camera
- MGF magnetometer
- ESA energetic electrons experiment
- ISA energetic ions experiment
- IMI energetic ion mass experiment
- EIS high-energy particles experiment
- TPA thermal ion drift experiment
- PET electro, UVS ultraviolet spectrometer
- PWS sounder/HF waves experiment
- LFA plasma waves experiment
- NMS neutral gas mass spectrometer
- MDC dust counter
- XUV EUV spectrometer
- USO ultra-stable oscillator/radio science experiment
Nozomi means hope in Japanese. Before launch, it was known as Planet-B.
The orbiter weighed 541 kg (1,193 pounds), including fuel.
After launch on an M-V-3 launch vehicle Nozomi was put into an elliptical geocentric parking orbit with a perigee of 340 km and an apogee of 400,000 km. The spacecraft used a lunar swingby on 24 September and another on 18 December, 1998 to increase the apogee of its orbit. It swung by Earth on 20 December 1998 at a perigee of about 1000 km. The gravitational assist from the swingby coupled with a 7 minute burn of the bipropellant engine put Nozomi into an escape trajectory towards Mars. It was scheduled to arrive at Mars on 11 October 1999 at 7:45:14 UT, but a malfunctioning valve during the Earth swingby resulted in a loss of fuel and left the spacecraft with insufficient acceleration to reach its planned trajectory. Two course correction burns on 21 December used more propellant than planned, leaving the spacecraft short of fuel. Nozomi's originally planned mission had to be completely reconfigured.
The new plan was for Nozomi to remain in heliocentric orbit for an additional four years, including two Earth flybys in December 2002 and June 2003, and encounter Mars at a slower relative velocity in December 2003. On 21 April 2002 as Nozomi was approaching Earth for the gravity assist maneuver, powerful solar flares damaged the spacecraft's onboard communications and power systems. An electrical short was caused in a power cell used to control the attitude control heating system which allowed the hydrazine fuel to freeze. The fuel thawed out as the craft approached Earth and maneuvers to put the craft on the correct trajectory for its Earth flyby were successful. Another Earth flyby within 11000 km occurred on 19 June 2003. The fuel had completely thawed out for this manuever because of the spacecraft's proximity to the Sun.
However, on 9 December 2003, efforts to orient the craft to prepare it for a 14 December main thruster orbital insertion burn failed, and efforts to save the mission were abandoned. The small thrusters were fired on December 9 moving the closest approach distance to 1000 km. The spacecraft flew by Mars on 14 December 2003 and went into a roughly 2-year heliocentric orbit. It was sent into orbit around our Sun to avoid the possibility of a collision with Mars.
