That isn't as simple as it sounds either. Hundreds of meters of drill sections must be pulled up, disconnected and stored. A deep shaft can take many hours or days to clear. A better way was needed. When such weapons are fired, a spool of fine wire is played out from the rear of the rocket, enabling operators to make corrections in the flight and guide the missile to its target.
Similar systems are also in use for certain types of torpedoes.
Holcomb realised the same technology might be applied to well drilling. Although using fiber optic telemetry had often been considered as way of relaying drilling data, it was always regarded as being much too expensive. With the intention always being to re-use the line, a bulky armoured sheath was required to protect the delicate optical fiber, and deploying the resulting thick composite cable interfered with drilling. Holcomb s revelation was to disregard the longevity of the fiber. His system uses an unarmoured filament, protected only by a thin plastic coating.