Beyonce shuttle sample angers Nasa
Nasa officials have criticised Beyonce's use of an audio grab from the 1986 Challenger space shuttle disaster, saying the event "should never be trivialised".
In the grab, which features on a new Beyonce song, a NASA official describes a "major malfunction".
The space agency issued a statement after the popstar first received criticism from the families of the seven crewmembers who died when the shuttle broke apart on takeoff.
"The Challenger accident is an important part of our history; a tragic reminder that space exploration is risky and should never be trivialised," NASA said in the statement.
"Nasa works every day to honour the legacy of our fallen astronauts as we carry out our mission to reach for new heights and explore the universe."
Nasa's response comes after the popstar explained the use of the short snippet in a statement that stopped short of an apology.
Among those critical of the sample was June Scobee Rodgers, widow of Challenger commander Dick Scobee.
She said in a statement that she was disappointed and described the use of the sample as "emotionally difficult".
"My heart goes out to the families of those lost in the Challenger disaster," Beyonce's statement said.
"The song XO was recorded with the sincerest intention to help heal those who have lost loved ones and to remind us that unexpected things happen, so love and appreciate every minute that you have with those who mean the most to you.
"The songwriters included the audio in tribute to the unselfish work of the Challenger crew with hope that they will never be forgotten."
XO is about a failing relationship and making sure you take the time to appreciate what you have in the moment because life changes.
The 1986 Challenger accident was the worst in NASA's history.