December 10th, 2009
A few weeks ago, Brian Turner (captain of the Kansas City Space Pirates - KCSP) sent out this email to his mailing list. This email, detailing “What Went Right”, is a follow-up to his “What Went Wrong” email I posted here.
In my last email I talked about what went wrong. In this one I will cover what went right. The glass is half full point of view. Sorry if I get a bit technical. And I must point out that all numbers are estimates.
Keeping all the power of the laser on target is no small task. We were the only team with a fully functional and automatic tracking system. The performance was spectacular. We were able to keep the laser on target 99.99% of the time for the first 500 meters. That performance dropped to 99.7% or so from 500 to 700 meters. At that point the .3% was driving our motor controller and power tracking nuts. This was markedly better than the manual tracking that the other teams were using. USST’s automated systems were down. Probably because of the same radio interference issues that we were suffering from. LaserMotive was using manual tracking that utilized 2 expert video game players with lots and lots of practice. Some time ago I had estimated that the cable would not be as stable as it was and that manual tracking was at the edges of human ability. So I was wrong in that the cable was really very docile. But I was right in that it is at the edge of human ability as Lasermotive was only able to keep it on target about 93% of the time from what I could see in our tracking camera. We do still have room for improvement here and I already know ways to make it better. I will be talking to National Instruments about a bigger and faster FPGA processor in our Compact Rio so we can improve the tracking even further.
All three of the top teams did well in creating a competitive optics system. One that could handle the power while directing it quickly and accurately. This was however a major stumbling block for the teams that did not qualify. I would like to thank Thor Labs for providing the bulk of the high quality components needed to pull this off.
Our climber was 1.2 Kg with payload vs 8.8 for USST and 5.4? for Lasermotive. We were less than 1/4 the weight of our nearest competitor. The climber was also simpler. We were the only team willing to run without added structure to save the climber from damage from landing mishaps. I suspect that we will be seeing lighter climbers from the other teams in the next round.
We had a peak power transfer of 190 watts. For our lightweight climber that is enough to do 5 m/s. In our field testing we had power conversion of more than 200 watts at the full Km distance. LaserMotive had a peak of 1000 watts in the competition. USST was boasting 1200 watts at 800 meters in their testing. This puts us at just under 1/5 the power levels of our competitors. What is impressive is that we are in the hunt with them using only 1/5th the power. The reason for this disparity is the cost of the solar panels. USST commented that their panel cost $120,000. That exceeds our entire cash budget. We do get over that number counting Sponsors like TRUMPF, but clearly our competitors are much better funded than us. LaserMotive is using experimental cells that have no price on them. I would estimate that they are around $60,000 in value because they are less exotic than USST’s cells. Our cells cost less than $4000 per climber. I think this illustrates that no team does more with a watt or a buck than we do.
Although we can probably eek out a 5 m/s run with our current system we clearly can’t be competitive with the power levels of the other teams using our current PV(solar) panels. We also crossed the finish line running well into the red on our finances. Although I have seen a few ideas that might have potential, I have to assume that there are no silver bullets to give us $75,000 PV panel performance from $4,000 panels.
I had “The Talk” with my wife and she pointed out that the basement is full of this stuff, either sell it or use it. With the usual provisions about not losing any major items the house or cars. I really love how understanding she is. So now I need to talk with the team and work out details with them. Then I need to switch to fund raiser mode and raise enough to buy and build the PV panel that we need to be competitive.
So if anyone knows a company that would like to sponsor a high profile, underdog, high tech team, be sure and let me know.
KC Space Pirates
Let’s hope they succeed in their funding efforts. I expect they will and further expect to see them at the next round of competition (May, 2010) ready and loaded for bear…