The LaserMotive team
I often think of Seattle as a small town, but maybe it's only in a city that I would not have known one of my neighbors on the next block was "freelance rocket scientist" Jordin Kare. He's been living on Capitol Hill since March 2003, though his first visit to Seattle was back in 1979.
Previously at Lawrence Livermore, he moved up from the Bay to consult on a commercial satellite project at Boeing. Now he's associated with Bellevue's Intellectual Ventures, though it's his side project, LaserMotive, that brought him to my attention.
A weary but suddenly richer version of Kare greeted me at the Victrola last week to discuss LaserMotive's $900,000 win at the Space Elevator Games, held November 2 to 6, 2009.
"So, what can I do for you?" Kare asked. He's unprepossessing at first glance, clad for Seattle's cold and rain, unruly gray hair longer on the sides and back, and slightly reserved. After the interview he was off to catch a late show of 2012 with his wife, with whom I had a quick discussion about Joss Whedon's Buffy, Firefly, and Dollhouse. (She's still angry at Whedon for the way he killed off "Wash"--really, a shock for all of us Fireflyers.)
This is just proof that you can't tell by looking at someone that he's devoted his professional life to laser propulsion; Kare has been a leader in his field pretty much since he got into it as a post-grad in 1986. It is the power-beaming aspect of space elevators that got him into the Games. As it happens, it's a great, high profile way to demonstrate that you can beam power over a kilometer's distance in a challenging setting.
LaserMotive was founded, essentially, as a part-time enterprise that would have one product, or goal: to create a laser-powered climber that would win the Space Elevator Games power beaming competition. First prize, for a climber that could travel one kilometer vertically at speeds of five meters per second or more, was $2 million, provided by NASA.
LaserMotive's climber set a world record, doing the kilometer twice at an average speed of four meters per second (topping out at 4.13 m/s), which netted them $900,00. "Hopefully we'll pick up the spare next time we go back down there," said Kare, cheerful at the prospect of holding another huge novelty check, this one for $1.1 million.
This is not precisely the space elevator you've seen on NOVA, with carbon nanotubes. For the competition, pilot Doug Uttecht's helicopter hauled aloft a 3/16-inch steel cable, 4300 feet long, that weighed about 300 pounds. (The people with this niche expertise are Northwest Helicopters, who also flew the cables in for the Tacoma Narrows Bridge.)
There's another "tether strength" competition that is supposed to yield a ribbon that can stretch from earth to geostationary orbit, which is over 35,000 kilometers. Since there are no 35,000-km extension cords, and onboard-gas-tank technology is already represented in rocketry, beaming the power via lasers is the preferred method.
"Some of the people who are competing are very much believers in the space elevator--Tom Nugent and I, who started the LaserMotive team, are pretty skeptical," admitted Kare. "It's one of these things where it's a lovely idea, and it may be physically possible--which I wouldn't have said a decade ago--but it's a very long jump drawing pretty pictures and writing basic equations to being able to build something a hundred-and-some-odd-thousand kilometers long."
Laser power beaming, in contrast, is "closer and closer to being something you could do practical work with," said Kare. Satellite solar power arrays, for instance, with 24-hour, unobstructed exposure to the sun, "are enormously more efficient" than ground-based solar power.
"The two problems are always, How much does it cost to get a satellite up there, and how do you get the power back down," explained Kare. "The laser system that we demonstrated in the climber competition are the first ones that are efficient enough that you could talk about sending the power down on a laser beam."
Terrestrial power beaming is just now becoming competitive on both the amount of power delivered and cost, in special instances. A laser power beaming system "delivers" about 20 percent of its electrical intake--about 50 percent of the incoming electricity is converted to light, and about 50 percent of that light is converted by photovoltaic sells back to electricity.
"It's not what you'd call efficient compared to an extension cord across the room," said Kare, but in remote areas without power infrastructure, it could be cost effective to beam power in. Or, he suggested, electric drones could "refuel" in flight.
The LaserMotive team in their command module
These are high-powered laser beams, of course: LaserMotive's climber is powered by their own infrared 4-kilowatt laser, while its two competitors relied on an 8-kilowatt Trumpf TruDisk 8002. You weld metal with the Trumpf, so safety is not just about not looking into the beam.
"Stepping in front of a high-powered laser beam is generally a bad idea," confirmed Kare. "Our beams will cook hot dogs very nicely but they will take a few minutes to do it," he said, adding a second later that this was confirmed in a LaserMotive test. (While LaserMotive has a great safety record, they also have a sense of humor about working lasers--a sign at their Kent workspace reads "1 Days Without Shark-Related Accidents.")
It meant more work to develop their own laser system, but LaserMotive banked on getting more power from their 4-kilowatt system because the photovoltaic cells that could handle the 8-kilowatt Trumpf's slightly longer wavelength were simply not as good. The Kansas City Space Pirates, despite having 8,000 watts to burn, could only get around 100 watts out of the standard solar cells they used. LaserMotive's high-efficiency cells produced more with less area.
(In an ironic development, LaserMotive used a manual joystick to direct the laser beam, while its two competitors went with automated guidance. "Other people had problems with radio interference and computers crashing, we didn't have any of that, we just had a guy who could cope," said Kare.)
The LaserMotive climber
On their climber's final run at the competition, a single, missing 1/4-inch titanium nut and Murphy's Law meant the stripped-down climber appeared slow, baffling the admittedly sleep-deprived LaserMotive crew, who had just lightened it of protective material. A rod missing that nut had jammed into the backstop that would arrest the climber's descent, and the climber was towing the backstop up. Unaware of the problem, LaserMotive "stepped on it," transmitting 1,000 watts to the climber, and burnt out a DC-to-DC converter.
"We're pretty sure we can do the five meters per second next time," Kare said. The rematch is, tentatively, May 10, 2010.
After that? Possibly exploring power beaming to one of those "remote areas" he mentioned earlier. LaserMotive has been talking to NASA about the prospect of beaming power to robot rovers on the moon or Mars. (The incredibly hardy Mars rovers Spirit and Opportunity have been sleeping through Martian winters, when not enough sunlight arrives to power them.)
Kare, who has worked out not one but two methods of interstellar travel, perked up at this idea. $2-million prizes are one thing. Space exploration, that's where the excitement is.
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