Wind
Wind — a NASA solar-wind observatory, launched on 1 November 1994. It first swung past the Moon on long loops around Earth, then flew to the Sun–Earth L1 point, out to distant orbits ahead of and behind Earth and to the L2 point; since 2004 it has stayed at L1, about 1.5 million km sunward of Earth, watching the solar wind before it reaches Earth.
Key facts
Mission & specifications
Mission
- Operator
- NASA
- Launched
- November 1, 1994
- Status
- Active
Trajectory
- Speed rel. Earth
- 349 m/s
- Computed from the cached state vector, relative to Earth
- Distance from the Sun
- 0.987 AU
- Computed from the cached position
- Distance from Earth
- 2,469,248 km
- Computed from cached positions
- Distance from Venus
- 0.267 AU
- Computed from cached positions
Mission
Wind was launched on a Delta II on 1 November 1994, one of the spacecraft of the International Solar-Terrestrial Physics programme, alongside Geotail, Polar and SOHO. For its first nine months it flew a looping orbit near the plane of Earth's orbit, using the Moon's gravity to keep its far point on the day side of Earth, between 80 and 250 Earth radii out. It then went to a small halo orbit around the Sun–Earth L1 point, and later ranged further: a distant orbit that took it about 300 Earth radii ahead of and behind Earth in 2001 and 2002, and the L2 point, beyond Earth's night side, from November 2003 to February 2004. A last lunar gravity assist in June 2004 sent it back to L1, where it has stayed. In 2020 three manoeuvres moved it into a halo orbit, to keep it out of the zone around the Sun's disc where solar radio emissions interfere with its radio link. At L1 it measures the solar wind, magnetic fields and particles about an hour before they reach Earth. According to JPL, it has the fuel to continue there into the 2070s.
- 1994Wind launches on a Delta II rocketLaunch
Into looping orbits that use the Moon's gravity.
- 2004Back at the L1 pointArrival
After a last lunar gravity assist; it has stayed at L1 since.
- 2020Into a halo orbitMilestone
The first of three manoeuvres keeping it out of the Sun's radio glare.
Images
Images from open archives · credit shown per image