are in a Lissajous orbit until decommissioned, when they are sent into a heliocentric graveyard orbit. Past probes 2001 – 2010: NASA's Wilkinson Microwave Anisotropy Probe (WMAP) observed the cosmic microwave background. It was moved to a heliocentric orbit to avoid posing a hazard to future missions. 2003 – 2004: NASA's WIND. The spacecraft then went to Earth orbit, before heading to . 2009 – 2013: The ESA Herschel Space Observatory exhausted its supply of liquid helium and was moved from the Lagrangian point in June 2013. 2009 – 2013: At the end of its mission ESA's Planck spacecraft was put into a heliocentric orbit and passivated to prevent it from endangering any future missions. 2011 – 2012: CNSA's Chang'e 2. Chang'e 2 was then placed onto a heliocentric orbit that took it past the near-Earth asteroid 4179 Toutatis. Present probes The ESA Gaia probe The joint Russian-German high-energy astrophysics observatory Spektr-RG The joint NASA, ESA and CSA James Webb Space Telescope (JWST) Planned probes The ESA Euclid mission, to better understand dark energy and dark matter by accurately measuring the acceleration of the universe. The NASA Nancy Grace Roman Space Telescope (WFIRST) The ESA PLATO mission, which will find and characterize rocky exoplanets. The JAXA LiteBIRD mission. The ESA Advanced Telescope for High ENergy Astrophysics (ATHENA) The ESA ARIEL mission, which will observe the atmospheres of exoplanets. The joint ESA-JAXA Comet Interceptor The NASA Large Ultraviolet Optical Infrared Surveyor (LUVOIR) which would replace the Hubble Space Telescope. Cancelled probes The ESA Eddington mission The NASA Terrestrial Planet Finder mission (may be placed in an Earth-trailing orbit instead) Sun–Earth L3 is the Sun–Earth Lagrange point located on the side of the Sun opposite Earth, slightly outside the Earth's orbit. There are no known objects in this orbital location. Sun–Earth L4 is the Sun–Earth Lagrange point located close to the Earth's orbit 60° ahead of Earth. Asteroid is the first discovered tadpole orbit companion to Earth, orbiting ; like Earth, its mean distance to the Sun is about one astronomical unit. Asteroid is the second Earth trojan, confirmed in November 2021, oscillating around in a tadpole orbit and expected to remain there for at least 4000 years, until destabilized by Venus. STEREO A (Solar TErrestrial RElations Observatory – Ahead) made its closest pass to in September 2009, on its orbit around the Sun, slightly faster than Earth. OSIRIS-REx passed near the