Our vehicle group recently performed a battery-powered endurance test of our prototype vehicle drive sub-system on our upgraded treadmill to see how it would perform over long distances. We’re not releasing exact details just yet, but suffice it to say that the test exceeded the speed and distance requirements set by the Spaceward Foundation for the full $2 million NASA-sponsored prize for this year’s Power Beaming Challenge. According to the rules of the competition, the winning entry must power a vehicle up (and back down) a steel cable a vertical distance of 1 km at a minimum speed of 5 m/s using only power beamed from a station on the ground. Here’s a video of parts of the test:

As you can see, the drive system is very robust, having run for quite a long time at a high speed. We’re working to improve the drive system by making it lighter and more efficient, but as it stands right now we have a drive system we could use today. It’s an important milestone to have reached because of the entirely different nature of this year’s steel cable from last year’s flat ribbon.

We are, of course, building and testing the other sub-systems as well. A video showing a voltmeter measuring output of a photovoltaic array is probably not nearly as exciting to watch as one of the drive system, but we’ll see what we can post as we get other results.

UPDATE: We have issued a press release about the endurance test.

The LaserMotive team has been very active preparing for this year’s power beaming competition. Because so many elements of the competition have changed from last year, there has been a lot of redesigning going on. One of the biggest changes was when Spaceward switched the vertical “racetrack” from a rubber ribbon to a steel cable. We looked at many possible methods of gripping and climbing the cable, and prototyped a couple of them.

We don’t want to disclose our choice for gripping the cable just yet, but we’d like to show that we have been “throwing cable” quite a bit. The video below was originally taken in early May. We may not have stated it explicitly before, but we are aiming for the full $2 million prize in 2008, which means we need to travel 5 m/s on average. So this video shows our prototype throwing roughly 100 feet of cable in about 6 seconds, which translates to approximately 5 m/s.

Even more progress has been made since that video, and I’m planning to post more about what’s happened next week. We’re excited with all of the progress we’ve been making on the vehicle, as well as other components, and we’re looking forward to the competition!

As we mentioned back in June, the BBC came out and videotaped some of our early vehicle work. Lucky for us, the portion of the video about Carbon Nanotubes and the Space Elevator is now at YouTube (the part with LaserMotive starts roughly 7 minutes in):

Thanks to Ted at The Space Elevator Blog for highlighting the video!

Before the competition, we didn’t talk much about our optics, for obvious reasons. But now that it’s over, we feel more comfortable showing off parts of our system. For example, we had an automated tracking vehicle system which was hooked up to the laser optics, changing the focus of the optics as the vehicle moved further away. Below is a video showing the focus rails being moved by manual control, at varying speeds. The mirrors are wrapped in brown tissue paper to protect them during testing. The movement is quite smooth and reproducible, and certainly makes an interesting sound.

You can also download the movie as a Quicktime version (2.9MB, Quicktime 7 required).

As promised, here is a video (courtesy of Dan from the Space Pirates!) of our vehicle on our treadmill test rig in Utah. We’d made some modifications and were testing the braking systems right before going to do the indoor qualification (this was Wednesday, 10/17).

We hadn’t had much practice with the mechanical brake, and as you can see in the video, the first time we pull up the vehicle, it then promptly free-falls back to the base. It scared us for a few minutes, but the vehicle was very robust and survived the fall without a problem! Then we practiced getting the brake right, and ran things up a number of times. At the end, we’re all heading off to do the indoor qualifying run.

Now that I’m starting to deal with the various video snippets we took while in Utah, I’m also looking to see what Ted Semon and others posted online. I posted our pre-competition qualifying video yesterday. Then today I discovered that Ted had posted his video of our second qualifying run, the indoor one in Utah.

Although the video only shows one run, we actually ran it twice. Once I download my own video of it, I’ll try and post it. And in the next couple of days, I’ll post a video of our vehicle free-falling 6+ feet down a ribbon mere minutes before the event shown in the above video happened.

Below is the interesting part of the qualifying video we submitted to Spaceward back at the beginning of October. (The entire video is about 5 minutes long, but watching us mount and dismount the vehicle is less interesting.) Note that the PV array was only a portion of our final array, and similarly we were only using some of our lasers. There are silver lines every one meter on the ribbon, and you can barely see them as they go along. We start by “locking” the test rig rollers so that the ribbon does not move (this is done by grabbing onto one of the rollers with a gloved hand). The vehicle climbs to the top of the treadmill, where we then start letting the rollers turn. The vehicle continues to “climb” for about 20 seconds, and then we let it come back down. Total ribbon distance travelled is between 50 and 60 feet at roughly 1 m/s.

It’s a shame that last-minute wiring changes on the vehicle motor controller at the competition itself prevented us from showing what the full system was capable of. With luck, we will be able to make some alternate kind of demonstration to show in the not-too-distant future.

A video team from the BBC brought along Michio Kaku to interview us and to video some of LaserMotive’s early hardware during May as part of a documentary they’re working on about future technhology (the episode we’re featured in also talks about carbon nanotubes, for example). The series will air sometime this fall; we’ll post more info once we have it.

The interviews were focused more on the space elevator than power beaming itself, but we were proud that they thought LaserMotive would be the best group for them to showcase power beaming technology. Dr. Kaku had some very good questions, and for someone whose prime work is in string theory, he was very professional in his job as a TV interviewer – he easily handled multiple takes, making it always appear fresh.

Regardless of what the focus of the filming itself was, having media guests come from overseas was a great way to give us a hard deadline, and we accomplished a lot of work. I was too busy throughout the day to do much photography, but I did manage to capture their video guy and audio guy doing some prep shots:

During the day of filming, we were able to borrow a neat contraption from their videographer to mount our own camcorder to our vehicle and get some video of the vehicle’s ascent of the ribbon, from the vehicle’s perspective (1.8 MB, Quicktime 7 required). The ribbon height is only about 15 feet or so; it’s limited by the height of the building we’re in.

We want to thank the BBC for their visit, and their patience (the producer commented about TV, “Never work with animals, children, or scientists!”). We’re looking forward to seeing the episode, probably around the same time we’re heading to this year’s Power Beaming competition!

We don’t want to release too much information about our entry just yet, but in these blog posts we try to show a little bit of what we’re working on and/or to discuss relevant issues (e.g., laser safety). This post will talk about our vehicle.

The basic vehicle design was drafted at the beginning of the year, and fabrication of the first version was completed in the spring. We expect that we’ll produce a revised version in early summer, after extensive testing of the current version. We have designs for attaching the beam receiver, cargo, etc. on the vehicle, but early testing of it looked only at the core chassis.

Here’s a short video (398kB, Quicktime 7 required) of the first run of our vehicle. We just threw together the mount for the ribbon – real testing obviously requires a longer ribbon (which we have). Heck, this setup wasn’t even tall enough to give the vehicle time to get up to full speed (yes, Steve only pushed the control to half throttle, but it did not have time to get up to half speed). These tests showed, though, that the vehicle was certainly robust and did not have any problem mounting nor tracking on the ribbon.