The magnitude of the momentum of an object is given by:
[tex]p=mv[/tex]
where m is the mass of the object, and v is its velocity.
In our problem, the mass of the ship is [tex]m=6.9 \cdot 10^7 kg[/tex] while its velocity is [tex]v=9 m/s[/tex], so the momentum of the ship is
[tex]p=mv=(6.9 \cdot 10^7 kg)(9 m/s)=6.21 \cdot 10^8 kg m/s[/tex]