The group released its debut album as King's X, entitled Out of the Silent Planet, in 1988. Despite being hailed by music critics, the album did not fare well commercially, peaking at No. 144 on the Billboard album charts. The songs "King" and "Shot of Love" were released as singles, but failed to garner much attention. The album derives its name from the C. S. Lewis novel Out of the Silent Planet. This appears to be the band's first of multiple references to the British author.  In 1989, the band released Gretchen Goes to Nebraska. Considered by many fans to be their landmark album and most creative period, the album fared only slightly better from a commercial standpoint than Out of the Silent Planet. The band played with a wide variety of acts while touring in support of it, including Anthrax, Suicidal Tendencies, M.O.D., Living Colour, Billy Squier and Blue Murder. The album contains many fan favorites such as "Summerland", "Mission", and "The Burning Down". The song "The Difference (In the Garden of St. Anne's-on-the-Hill)" appears to be another C.S. Lewis reference, this time to a scene in the book That Hideous Strength, third and final installment of the "science-fiction" trilogy begun by Out of the Silent Planet. The song "Pleiades" is credited by Ty Tabor as being the genesis of the King's X sound when he presented the demo to the other band members a few years earlier. Significantly, the song "Over My Head" received moderate airplay on MTV and radio.  The increase in exposure would prove beneficial when the band released their third album, Faith Hope Love, in late 1990. It was the group's first album to crack the U.S. Top 100, with the help of the successful single "It's Love". Another track, the funk-rock "We Were Born to Be Loved", enjoyed a long life on Late Show with David Letterman as a commercial bumper instrumental favorite of Paul Shaffer's CBS Orchestra. King's X was featured in the February 1991 issue of Rolling Stone (RS598). Still, with major mainstream success continuously eluding them, King's X began questioning Sam Taylor's management vision for the group.  The band landed the opening slot for Iron Maiden in Europe on their No Prayer for the Dying tour in late 1990, and AC/DC in the U.S. and Europe for the first half of 1991. They also toured with Living Colour, themselves near the peak of their popularity. In the middle of that year, their song "Junior's Gone Wild" appeared on the soundtrack to the movie Bill & Ted's Bogus Journey.

Answer this question "When was it released" by extracting the answer from the text above.
in 1988.