Space Rock is a subgenre of Rock, with the name originally referring to a group of early (mostly British) 1970s Progressive Rock and Psychedelic Rock artists, for example, the likes of Hawkwind, Gong and Pink Floyd, these bands were mostly characterised by slow, lengthy instrumental passages and dominated by electronic organs, synthesisers, and experimental guitar work.
The term Space Rock was revived in the late 20th century and early 21st century to refer to a new wave of bands including; Comets on Fire, Monster Magnet and Flotation Toy Warning, who diversely drew upon the ideas and sounds of this genre's founders.
Mankind's exploration into outer space provided loads of subject matter for the Rock n Roll and Rhythm and Blues artists of the 1950s and early 1960s. It also inspired new sounds and sound effects to be used in the music itself. A prominent early example of space rock is the 1959 concept album "I Hear a New World" by British producer and song writer Joe Meek. The album was inspired by the space race and concerned man's first close encounter with alien life forms.
Meek then went on to have a UK and US #1 success in 1961 with the song "Telstar", named after the newly launched communications satellite and thus intended to commemorate the new space age. Its main instrument was a "clavioline", an electronic forerunner of synthesizers.
1960s and '70s
Pink Floyd's early albums contain pioneering examples of Space Rock, their 1967 debut album "The Piper at the Gates of Dawn" is another great example. Their second album "A Saucerful of Secrets" contained further examples: "Let There Be More Light" and "Set the Controls for the Heart of the Sun" with explicit science fiction themes, then their third, "Soundtrack from the Film More" in 1969 had Cirrus Minor.
In early 1971, Pink Floyd began writing the song that would become known as "Echoes", from the 1971 album Meddle. The song was performed from April until September 1971, with an alternate set of lyrics, written about two planets meeting in space. Before the Meddle album released, the lyrics were changed to an aquatic theme, because of the band's concern that they were being labelled as a Space Rock band.
David Bowie's "Space Oddity", from 1969 is, apart from Telstar, probably the best example of a Space Rock song achieving mainstream recognition, "Space Oddity" probably being the most well known of them all.
Quite possibly the most well known, and most defining album in the history of Space Rock was Hawkwind's "Space Ritual" from 1973, this was a two-disc live album advertised as "88 minutes of brain-damage" documenting Hawkwind's successful 1972 tour that included a "liquid light show", lasers, nude dancers, wild costumes and psychedelic imagery. This live experience, attracted a large collection of dedicated of psychedelic drug users, science-fiction fans and bikers.
Hawkwind even collaborated with the science fiction writer "Michael Moorcock" on many occasions to write the lyrics for many of the spoken-word sections on "Space Ritual".
By the early to mid 1990s, the term Space Rock came to be used when describing numerous American and British Rock bands of the time, bands such as Kyuss, The Flaming Lips, Orange Goblin, Spacemen 3, Spiritualized, and Monster Magnet.
The sonic experimentation and emphasis placed on texture by these bands led them to be dubbed by some as Space Rock, although most would more readily be categorized in other genres such as "Shoegaze" or Stoner Rock. With a lot of these bands drawing influence from the late 1980s, Rave and Indie crossover sounds.
The Strange Daze festivals from 1997-2001 showcased the American Space Rock scene in 3 day outdoor festivals. These shows were headlined by Hawkwind and Nik Turner in 1997 and featured the major players of American Space Rock.
The 21st century
Original Space Rock bands like Hawkwind and Gong, continue to perform live in the 2000s. The likes of Kyuss, The Flaming Lips, Orange Goblin, and Monster Magnet are still going strong, with new albums being released right into the 2010s. Plus new bands, on an underground circuit, gigging around the globe, bands like "Samsara Blues Experiment".  in fact, Hawkwind even released a new album in 2014 
NASA Astronaut, Commander Chris Hadfield, whilst on board the International Space Station, in 2013, successfully bought Space and Rock together in a stunning way, with this interpretation of David Bowie's Space Oddity.