Answer
The length is contracted by $~~0.00000105~~$ of its proper length.
Work Step by Step
We can find $\gamma$:
$\gamma = \frac{1}{\sqrt{1-(v/c)^2}}$
$\gamma = \frac{1}{\sqrt{1-(\frac{630~m/s}{3.0\times 10^8}~m/s)^2}}$
$\gamma = 1.00000105$
We can find an expression for the contracted length:
$L = \frac{L_0}{1.00000105}$
$L = 0.99999895~L_0$
The length is contracted by $~~1 - 0.99999895~~$ which is $~~0.00000105~~$ of its proper length.
