PXR5 is the ninth studio album by the English space rock group Hawkwind, released in 1979. It reached No. 59 on the UK album charts. Overview Allmusic referred to PXR5 as "the last in the sequence of brittle, pop-inflected records the band launched with Astounding Sounds, Amazing Music", saying that Hawkwind "both understood and allowed themselves to absorb the energies of new wave" on PXR5. The album was recorded and mixed at Rockfield Studios in January and February 1978. "Uncle Sam's on Mars", "Robot" and "High Rise" were originally recorded on the preceding UK tour but were partly overdubbed in the studio, particularly Robert Calvert's double-tracked vocals. "Infinity" and "Life Form" were originally to have been part of a solo album Dave Brock was working on. After the album was recorded and mixed, the band split up during a US tour in March when Simon House left to join David Bowie's band and Robert Calvert suffered a bout of clinical depression. With the band in temporary hiatus and no pending promotional tour, the album's release was shelved. The band re-emerged in mid-1978 as the Hawklords to record the 25 Years On album. Two tracks were released as singles, "Psi Power" and "25 Years", which featured "Death Trap" and "PXR5" respectively on their B-sides. The PXR5 album was eventually released on 15 June 1979, and the cryptic message on the cover "This is the last but one" refers to the fact that it was recorded prior to 25 Years On. The album's cover featured a British BS 1363 mains plug wired in a dangerous way. Shortly after the album's release, the illustration of the plug was covered by a sticker obscuring the image. Lyrical references The lyrics of "Jack of Shadows" are inspired by Roger Zelazny's book Jack of Shadows. "Uncle Sam's on Mars" evolved from the Neu!-esque "Opa Loka", with a Calvert-penned anti-US rant over the top of it. Its first performance was at the Cardiff Castle Festival in summer 1976 as "Vikings on Mars", read by Calvert from his clipboard notes, and with the aid of a megaphone, on stage after "Opa Loka". "Robot" also made a brief appearance as a poem at this historic gig. The song title itself is a twist on Gil Scott-Heron's "Whitey on the Moon". "Infinity" uses a Calvert poem from Space Ritual. "Robot" references Isaac Asimov's Three Laws of Robotics. The lyrics of