This year's NASA Centennial Challenge for a space elevator climbing machine, held in Las Cruces, New Mexico, ended without a winner as wind and time defeated teams for the third day in a row. The companion tether competition also failed to produce a winner because the baseline material broke the horizontal test rig.

To win the Challenge's $150,000 first prize, a climber had to travel 50m (165ft) up a crane-hoisted tether at a speed of 1m/s (198ft/min) and return in a 2min controlled descent. Of the dozen teams that competed, only four climbers reached the top of the tether. They were from the University of Michigan, the University of Saskatchewan, Californian school Westmont High and Germany's Max Born College, Ruhrarea. Michigan's Climber 1 achieved the fastest climb at 58s, but that was 8s too slow to win the challenge and its descent took longer than the required 2min.

Four teams entered the $200,000 challenge to produce a tether that could be used for a space elevator. Three of the four were disqualified for not meeting the requirement for a tether no less than 2m long. Only California-based Aerojet's team was eligible to compete and its tether broke when pulled with a force of 5.94kN (1,336lb).

The baseline tether material, supplied by space elevator advocate the Spaceward Foundation, was made of commercially available Zylon coated with epoxy resin. It did not fail, but broke the test rig at 7.37kN. However, at just under 3g, the material was 50% heavier than the 2g goal set for the challenge, which was met by all the teams.

The competitions were held close to the Wirefly X Prize Cup event at New Mexico's Las Cruces International airport. Next year the tether prize money will be $500,000, and NASA's challenge may require teams' climbers to travel up a 91.5m ribbon.

Blog: Read Rob Coppinger's account of the arduous three day NASA Centennial Challenge space elevator, tether and climber competitions in the sweltering heat of the New Mexico desert.

Source: Flight International