This is a timeline of known spaceflights, both manned and unmanned, sorted chronologically by launch date. Owing to its large size, the timeline is split into smaller articles, one for each year since 1951. There is a separate list for all flights that occurred before 1951.
The 2017 list, and lists for subsequent years, contain planned launches which have not yet occurred.
For the purpose of these lists, a spaceflight is defined as any flight that crosses the Kármán line, the officially recognised edge of space, which is 100 kilometres (62 miles) above mean sea level (AMSL). The timeline contains all flights which have crossed the edge of space, were intended to do so but failed, or are planned in the near future. Some lists are further divided into orbital launches (sending a payload into orbit, whether successful or not) and suborbital flights (e.g. ballistic missiles, sounding rockets, experimental spacecraft).