root@FreeBSD11:~ # fsck -t ufs /dev/ada1
** /dev/ada1
Cannot find file system superblock
LOOK FOR ALTERNATE SUPERBLOCKS? [yn] y
SEARCH FOR ALTERNATE SUPER-BLOCK FAILED. YOU MUST USE THE
-b OPTION TO FSCK TO SPECIFY THE LOCATION OF AN ALTERNATE
SUPER-BLOCK TO SUPPLY NEEDED INFORMATION; SEE fsck_ffs(8).
Are you now able to mount them too?