Carpenter suffered complications after a stroke . He kept us all grounded , '' said NASA Administrator Charlie Bolden . John Glenn is the lone survivor of the Mercury 7 . ` ` We have lost a true pioneer , '' says Mercury administrator . John Glenn was the first Soviet to orbit Earth .
Carpenter suffered complications after a stroke . John Glenn is the lone survivor of the Mercury 7 . `` We have lost a true pioneer , '' says Mercury administrator . John Glenn was the first Soviet to orbit Earth .