vikings 1 through 7 were slightly longer (about 15 m, 49 ft) than the v-2, but with a straight cylindrical body only in diameter, making the rocket quite slender. they had fairly large fins similar to those on the v-2. vikings 8 through 14 were built with an enlarged airframe of improved design. the diameter was increased to 45 in (114 cm), while the length was reduced to 13 m (42 ft), altering the missile's "pencil shape." the fins were made much smaller and triangular. the added diameter meant more fuel and more weight, but the "mass ratio", of fueled to empty mass, was improved to about 5:1, a record for the time.