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, which returned to Earth twelve days later, in the first Indian attempt to recover a satellite after re-entry.

Several carrier rockets made their maiden flights in 2007; the PSLV-CA, Long March 3B/E, Shavit-2, Zenit-2M, Proton-M Enhanced. These were all modernised or upgraded versions of existing systems. The RS-24 missile also conducted its first launch, and the Atlas V made its first flight in the 421 configuration. The first Colombian and Mauritian satellites, Libertad 1 and Rascom-QAF 1 respectively, were launched in 2007, although a helium leak reduced Rascom's operational lifetime by thirteen years.

Several spacecraft were launched to explore the Moon. Japan's Kaguya orbiter, along with the smaller Okina and Ouna relay spacecraft, was launched on 14 September. The spacecraft entered Selenocentric orbit on 3 October. China launched its first Lunar probe, Chang'e 1, on 24 October, with the spacecraft entering Selenocentric orbit on 5 November. In 2009, two satellites launched into highly elliptical Earth orbits in 2007 as part of the THEMIS mission were also sent to the Moon. They are expected to arrive in October 2010.

In August, the NASA Phoenix spacecraft was launched towards Mars, followed by the Dawn mission to the Asteroid belt in September. Cassini continued to make flybys of the moons of Saturn, mostly focussing on Titan. In November, Rosetta flew past Earth, where it was mistaken for an asteroid, and given the provisional designation 2007 VN₈₄.

Five crewed flights were launched in 2007, two by Russia and three by the United States. Russia flew two Soyuz missions to the International Space Station for crew rotation. Soyuz TMA-10, launched on 7 April, carried the Expedition 15 crew to the Station. Space tourist Charles Simonyi was also launched on this flight, and landed aboard Soyuz TMA-9 a few days later. When TMA-10 returned to Earth in October, it made the first of two consecutive ballistic re-entries of Soyuz spacecraft, due to problems with separation bolts. Soyuz TMA-11, launched on 10 October, carried the Expedition 16 crew, and the first Malaysian in space, Sheikh Muszaphar Shukor, who was selected for flight under the Angkasawan programme. He landed aboard Soyuz TMA-10. When TMA-11 landed in 2008, it also made a ballistic descent.

2007 also saw the continued assembly of the International Space Station, by US Space Shuttle flights. On 8 June Atlantis made the first Shuttle launch of the year, STS-117, with seven astronauts, and the S3/4 truss segment of the ISS. It was the first Shuttle to launch from Complex 39A at the Kennedy Space Center since STS-107 in 2003. Launch had previously been delayed from February due to Hail damage to the External Tank, which required a rollback to repair in the Vehicle Assembly Building. In August, Endeavour launched on its first mission since 2002, STS-118. This carried the S5 truss segment, and marked the final flight of the Spacehab module, which was used to carry supplies. NASA's first Educator Astronaut, Barbara Morgan flew aboard STS-118. Morgan had previously been a backup for Christa McAuliffe, who was killed in the Challenger accident in 1986. STS-120, launched on 23 October using Discovery, carried the Harmony node, the first pressurised ISS component to be launched since Pirs in September 2001. Attempts to launch Atlantis in December on STS-122 were scrubbed, and the launch was delayed to 2008 after ECO sensors in the External Tank failed.

Three orbital launch attempts in 2007, involving a Zenit, a Falcon 1, and a Proton failed, and two others, an Atlas V and a GSLV, resulted in partial failures. On 30 January, a Sea Launch Zenit-3SL exploded on the Ocean Odyssey launch platform, seconds after ignition. The failure destroyed the NSS-8 satellite, and caused considerable damage to the Odyssey platform. It was later determined that the failure had been caused by debris in the turbopump. As a result of downtime to conduct repairs, and bad sea conditions at the end of the year, Sea Launch did not conduct another launch until 2008.