Picture caption: An earlier picture of the laser motive climber. Mostly solar cells that absorb the laser light that power a motor that climbs the cable. On the right is a screenshot of Lasermotive’s climber from the ustream video
3:00:39 PM PST:
LaserMotive Climber is climbing! Live at http://ustre.am/4mZA
First climb was 4 minutes, 2 seconds – officially. They qualified for the $900K prize. Live at http://ustre.am/4mZA
Now trying a second climb Live at http://ustre.am/4mZA
Second climb completed – unofficially also 4:00 or so. These guys HAVE to be happy… Live at http://ustre.am/4mZA
If neither the University of Saskatchewan or the Kansas City Space Pirates can beat that time over the next few days then Laser Motive will win the prize.
But in 2009 there will be a winner of the laser beaming space elevator contest.
Youtube Video of the Actual Climb
(H/T to reader Jriskin)
Vertical Distance: 1 km
Speed: 2 m/s, 5 m/s
$900,000 for 2-4.99 meters/second
$1.1 Million for 5+ meters/second
Lasermotive’s climber went 1000 meters in 242 seconds is about 4.13 meters/second
A climb faster than 3 minutes and 20 seconds is needed to win the 5 meter per second prize for $1.1 million.
LaserMotive (Tuesday, Nov 3, 2009) beamed roughly 400 watts of laser power to a moving target at a distance of 1 kilometer, as part of the vertical laser alignment procedure. The target was a retro-reflective board a little larger than 1 meter on a side. I don’t know offhand if that is a record; I will have to check once things calm down. (It’s a record that will likely be broken tomorrow by one or more teams, of course.)
Summarizing Space Elevator Feasibility Articles
For a Carbon Nanotube tether that is 30 MYuri [A MYuri is the name we gave the SI equivalent of N/Tex, or GPa-cc/g] strong, and a characteristic time constant (CTC) of 1 year the Feasibility Condition requires that the climbers will have a power density of at least 1.0 kiloWatt/kg.
So where do the competition requirements stand in respect to this?
It is easy to show that when moving straight up, the power density of the climber is directly proportional to its speed (mgv/m), and so a 5 m/s speed in 1 g gravity corresponds to 50 Watt/kg, or about 5% of a real commercial scale Space Elevator climber.
The Space Elevator will function a lot better with a ~35 MYuri material, but this is the bare minimum that we need. Keep in mind that successive 50% improvements in material strength are very large steps, but that we already know that CNT molecules are measured at ~50 MYuri, and fabricated CNT micro-bundles have been produced by several labs at 10 MYuri, so this challenge is not impossible.