A Spacecraft Is Measured by a Scientist on the Ground $81 \mathrm {~m}$

A spacecraft is measured by a scientist on the ground to have a length of $81 \mathrm {~m}$ as it flies overhead with a speed $2.4 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s }$ . The spacecraft then lands and its length is again measured by the scientist at rest on the ground. What result does he now get for the Iength of the spacecraft? $\left( c = 3.0 \times 10 ^ { 8 } \mathrm {~m} / \mathrm { s } \right)$