2007 in spaceflight 2007 in spaceflight The year 2007 contained several significant events in spaceflight, including a Chinese ASAT test, the launches of the US Phoenix and Dawn missions to study Mars and Asteroid belt respectively, Japan's Kaguya Lunar orbiter, and the first Chinese Lunar probe, Chang'e 1. The internationally accepted definition of a spaceflight is any flight which crosses the Kármán line, 100 kilometres above sea level. The first recorded spaceflight launch of the year occurred on 10 January, when a PSLV, launched from the Satish Dhawan Space Centre, placed four spacecraft into low Earth orbit. One of these spacecraft was SRE-1,
Orbital station-keeping track it is also necessary to make out-of-plane manoeuvres to compensate for the inclination change caused by Sun/Moon gravitation. These are executed as thruster burns orthogonal to the orbital plane. For Sun-synchronous spacecraft having a constant geometry relative to the Sun, the inclination change due to the solar gravitation is particularly large; a delta-v in the order of 1–2 m/s per year can be needed to keep the inclination constant. For geostationary spacecraft, thruster burns orthogonal to the orbital plane must be executed to compensate for the effect of the lunar/solar gravitation that perturbs the orbit pole with typically 0.85