A pullback system to install or replace underground utilities that is used with a hammer used in horizontal directional drilling operations. A segment of the track can be folded for transportation and deployed when the rolling radar array system is to be in an operational mode. The compositions of the present invention will be useful in the inhibition of angiogenesis and lymphangiogenesis. The simulation engine feeds the request packet to a display engine that has the ability to treat the request packet as though the display engine itself originated the request packet.