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. Design of the bolts for magnetic coupling to the tube and to travelling vehicles: Although we have shown general feasibility, more design work is needed on the detail.
2. 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 must be augmented and validated.
3. Failure scenarios: Exhaustive reviews and testing will be needed (see Failure Scenarios).

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

Failure Scenarios

The space cable has multiple pairs of tubes; three pairs are proposed in the preferred design. 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.