Engineering Challenges

Although no new materials or fundamental technology is required, the engineering challenges of building the first space cable are formidable. Fortunately, it is possible to build small-scale prototypes before making a full-scale commitment.

1. Wind management and stabilization, particularly coping with buffeting cross winds: The theoretical work shown on this web site (see Stabilization and Cross Winds) and elsewhere needs to be validated in working prototypes.
2. Failure scenarios: Exhaustive reviews and testing will be needed (see Failure Scenarios).

Laboratory validation is needed, followed by field trials at increasing scales.

Ideally a first application will be away from the public for such applications as communications, astronomy and the testing of ramjets and scramjets.

Failure Scenarios

The space cable has multiple pairs of tubes; five pairs are proposed in most of the preferred designs. This gives redundancy in case one tube pair fails or has to be taken out of service. The following scenarios require further study, and there may be others:

1. Ejection of bolts: If there is a breakage, high-speed bolts will move through the atmosphere and burn up. Clearly, this would be very hazardous for anyone near and in the line of fire.
2. Loss of vacuum in the tubes: This is readily detectable because it will cause a drop in bolt speed. The space cable can continue to operate but with loss of energy (see Vacuum).
3. Attacks or collision: Fixed infrastructure is susceptible to terrorist action or to acts of war, mainly at the lower altitudes. This will be a serious concern. To reduce risks, passenger vehicles will be designed so that they can glide back to earth in an emergency.