This week I was approached with a question. Why don’t passenger aircraft have emergency parachutes? Whole plane emergency parachutes are available for light aircraft, and have been used to great effect in many light aircraft engine failures and accidents.
But the truth is that while parachutes may be effective for light aircraft, they don’t scale. There are a series of great answers on Quora which run the numbers of the size a parachute would need to be for a full size passenger jet. I recommend reading the full thread, but suffice it to say a ballpark estimate would require a million square feet (92903 square meters) of material. This clearly isn’t very feasible, and the added weight and complexity would no doubt bring its own risks.
Last spring [Mike] built a foam rocket launchpad which was a hit with the kids in his neighborhood. But the launch system was merely a couple of buttons so the early enthusiasm quickly wore off. He went back to the drawing board to make improvements and really hit the jackpot!
The original launch system had one button for building up air pressure with a second big red button of doom for launching the rocket. The problem was a complete lack of user feedback; all the kids could do is guess how long they needed to hold the button to achieve the highest launch. This revision adds flashing LEDs to hold the attention of the wee ones but to also function as a gauge for the new pressure control system. The visually fascinating control board also includes a removable key to prevent accidental launches.
The particulars of this are as you’d expect: it’s a bunch of plumbing to manage the air pressure, an Arduino to control it all, and additional electronics in between to make them work together.
We’re especially impressed by the leap in features and quality from the first version to this one. It’s a testament to the power of quick proofs-of-concept before committing to a more involved build. Great work [Mike]!
For as much as we enjoy rockets, explosives, and other dangerous things, we haven’t said a word about the works of [Richard Nakka]. He’s the original hacker rocketeer with thousands of words dedicated to the craft of making things move straight up really fast. One of his more interesting builds is his series on building rocket engines out of PVC pipe written in conjunction with [Chuck Knight].
For the propellent grains, the PVC rocket didn’t use the usual potassium nitrate and sugar mixture of so many homebrew solid rockets. Instead, it uses Sorbitol, an artificial sweetener. While melting and casting the Sorbitol-based propellant grains is much easier than a sugar-based concoction, the Sorbitol had much less thrust than a typical sugar rocket, making it the perfect candidate for a PVC engine.
For those of you wondering about the strength of a PVC engine casing, [Richard] does say making larger rocket engines out of 2 or 3-inch PVC may not make much sense due to the increased chamber pressures. There is a fairly clever reinforcement method for these PVC rockets (PDF warning) that involves using PVC couplers, but the experiments into the strength of these casings have yet to undertaken.
The rocketery-oriented part of LVL1 spawned from a University of Louisville’s group. The goal of the group is to compete in the NASA University Student Launch Initiative, dedicated to competing against other teams to launch a scientific payload to 1 mile AGL. At the competition last May, the team placed 5th out of 42 teams and won the award for best website. We can’t wait to see what they come up with next year.
In response to the Carmack Prize to launch an amateur rocket above 100,000 feet, [Derek Deville] and the rest of the Qu8k team launched a 320 pound, 14-foot-long rocket through 99% of the Earth’s atmosphere.
Unlike our little toy rockets from years ago, more than half of the entire rocket is fuel. This isn’t a plastic or salami-powered hybrid rocket, though. It’s an entirely solid fuel rocket. The fuel grain is specially made for this rocket in a cylinder-with-fins shape that ensures an even burn through the entire flight.
The payload included 2 timers, an accelerometer, a cosmic ray detector (check out the Geiger tube) and 4 GPS units required of the Carmack Prize. The video from the on-board camera shows a fantastic flight, only partially obscured by the plastic aeroshroud that melted when the rocket was going about Mach 3.
Videos of the entire flight and a ‘highlights’ reel are available after the break.
Some researchers in Japan are hard at work building a 3D volumetric fog display that would allow you to live out some of your Leia-related Star Wars fantasies. Using a column of fog and three projectors, they were able to create a display that looks three-dimensional from any angle. It might be a while before the technology hits your living room, so don’t clear your calendar just yet, Obi Wan. [via Neatorama]
The Claw – a three-fingered robotic gripper
Instructables user [AntMan] has been hard at work revising his robotic claw gripping mechanism. Laser cut from wood, this servo-driven claw can easily grasp small objects with little effort. We can’t wait to see someone build a version from milled aluminum!
Ben Heck’s retro Xbox 360
[Ben Heck] is at it again, and has recently given the Xbox 360 a sweet retro makeover. Taking inspiration from gaming consoles of the 70’s, he converted an Xbox 360 into a laptop-style portable (again), but this time with the look and feel of an old Atari 2600. Retro gamers rejoice, you can now get your Xbox on while enjoying the sweet simulated wood-grain you grew up with.
Rocket-based ice fishing notification system
What fun is ice fishing if you have to sit outside freezing your butt off? We’re assuming that was the driving thought behind [Mike’s] rocket-based ice fishing rig. A model rocket is attached to his fishing sledge, which is triggered when a fish is detected on the line. Using a low-tech detonator, the rocket lets him know it’s time to check the lines. Now only if we could get the fish to fillet themselves…
Case modding video series hits the web
The “Mod Men” is a fairly new web series that takes you out of the basement and into the garage for some professionally constructed case mods. Described as “American Chopper for geeks with a dash of This Old House”, the creators aim to showcase over-the-top case mods with a professional flair. They already have three episodes under their belt, all of which are available on their site.
Launching model rockets is a good time, but more often than not, it’s hard to tell how high the rocket went or how fast it moved – both essential facts when bragging about your latest flight. [Chris] recently built a GPS-based altimeter for the USC Rocket Propulsion Lab, so that they could track the performance of their latest project. The circuit is based off a Picaxe 18x and uses a GPS module to obtain NMEA altitude data. Once the data is obtained, it is stored on an external EEPROM to be read back after the rocket has been recovered.
[Chris] unfortunately does not have any pictures of the board he built, but he has made his circuit diagram and source code available. He reports that the logger worked perfectly aside from a small bit of time where the GPS module temporarily lost its satellite lock.
If you are interested in reading more about flight data recording and telemetry, be sure to check this out.