Space Elevator Tethers

The Space elevator blog discusses the needed tether strength based on work by Ben Shelef, CEO of the Spaceward Foundation:

A tether which has a tensile strength of 30 GPa-cc/g would be strong enough to create a useful Space Elevator provided the Climber power system can generate at least 1.5 kWatt/kg. If the tensile strength of the tether is only 25 GPa-cc/g, the power system needs to generate at least 3.5 kWatt/kg.

Space Elevator tethers must have extra strength for safety margin and enough strength to do three things

1. add replacement material to handle tether degradation
2. add material to increase the tether’s carrying capacity
3. hold a spare seed ribbon.

The stronger the power system is, the weaker the tether can be and a weaker the power system needs a stronger tether.

The faster your climbers climb then they can get high enough so that gravity weakens so you can launch another significant Climber.

– at 2,624 kilometers in height, a climber is one half of its ground weight
– at 6,400 kilometers in height, a climber is one quarter of its ground weight

The latest tether work is discussed at the 2008 Euro Spaceward Conference

The abstracts from the second day of the 2008 Euro Spaceward Conference are here

Outlook on tethers from the 2008 Euro Spaceward Conference