Taken from the GNU AWK handbook:

{
if (max_nf < NF)
max_nf = NF
max_nr = NR
for (x = 1; x <= NF; x++)
vector[x, NR] = $x
}

END {
for (x = 1; x <= max_nf; x++) {
for (y = max_nr; y >= 1; --y)
printf("%s ", vector[x, y])
printf("\n")
}
}

Copy that to a file, then invoke it like this:

awk -f scriptfile datafile | awk '{ print $8"\t" $7"\t" $6"\t" $5"\t" $4"\t" $3"\t" $2"\t" $1"\t" }'