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Summer 2014 Projects

We have a bunch of interns working on the ERGO Project this summer in Miami.  Our main tasks are:
1.  Test and build a few Beta ERGO pixels using the last remaining circuit boards from last summer.  Sloane is leading the team to build these “Beta” units which are the same as the units now placed around the world.
2.  William is leading the team to build a few Generation 3 ERGO pixels using the Freescale Ethermega processor board and a custom ERGO “shield” which contains the Geiger counter and GPS systems.  These pixels are functionally the same as our existing “Beta” units now placed around the world.  We have built a few of these.  One is online in the map at www.ergotelescope.org as pixel 333.  We’ve built three others that have the internet connections disabled, so they can be used in balloon payloads.  We’ve sent two of these to experimental groups in Italy, and one more is being tested for a balloon launch in Latvia.  The Generation 3 board has a couple of disadvantages, though:  it only works on local area networks that have DHCP enabled and no security; and, they’re expensive (the Ethermega board costs around $120).  That’s why we’re also working Generation 4 and 5.
3.  Generation 4 uses a Raspberry Pi processor board along with our custom ERGO Geiger-counter/GPS circuit board.  Since the Raspberry Pi is actually a linux desktop computer, it includes all the hardware and software to enable connections to any kind of LAN you can imagine, including WiFi!  The Raspberry Pi is amazingly inexpensive, too:  about US$35, which will bring the total cost of parts for an ERGO pixel down to under $150.  We’ve designed the custom board for the Raspberry Pi, and bare boards are now being fabbed in China.  We hope to have a manufacturer build complete boards that can be purchased by anyone who wants to build their own pixel.
4.  Generation 5 is a totally self-contained ERGO pixel on a single circuit board.  Simon and his team are breadboarding that system, and we hope to have software developed and the first boards being assembled by the end of the summer.  Generation 5 will be the lowest possible cost, because it is only one circuit board, so we don’t have to buy a Raspberry Pi or Ethermega board to build a complete pixel.  Simon’s team is also working to develop a better muon detector for future ERGO pixels.  They are trying to build a PIN-diode detector with a plastic scintillator, and they are setting up a vacuum-coating system to attempt making our own silicon detector wafers.
5.  Another team, led by Steven, is working on ERGO data analysis.  They are developing apps and techniques to look at the very large database of information we have built up over the last few years.  We expect to find patterns in time and spatial distributions, some of them random, some caused by our pixel’s, themselves, and perhaps some caused by natural physics.

Coolest Thing Ever?

Khan Academy is an online set of videos that constitute much of a university education, free to all. But, what if you don’t have an internet connection? What if you don’t have electricity? Imagine a tiny “intelligence hot spot” that can be solar powered and serves all of Khan Academy (as well as the school version of Wikipedia) to any device that can connect with wifi. It’s really small. Total installed cost (not including solar panel) is $50. Fifty bucks. Where in the world would you send such a thing?
Here’s my first one, working at the Syntheon lab. Let’s build a bunch and send them out into the world. http://pi.mujica.org/howto.html

ka pi

ERGO Balloon Update

We got the balloon payload from the August 17 launch back, courtesy of the National Park Service!  We’re still analyzing data, but the picture below tells you where it started and ended up.  The data above 39,000 feet were scrambled and unusable, but you can fill in the middle with your imagination.  In MY imagination, it must have gone very, very high.  With some math and science we hope to calculate the actual maximum altitude.

balloon path

ERGO Balloon Launch

The first (planned) ERGO Balloon Launch happened 8am (EDT) Saturday morning, August 17, 2013.  Many of the ERGO interns where there to help and share the excitement at the Virginia Key causeway launch site east of Miami.  The balloon quickly rose as it headed toward Miami, reaching a final reported altitude of 40,000 ft.  The actual altitude was expected to be 60,000 ft, but altitude data was limited by a firmware setting in the GPS receiver.  We tracked the balloon over Miami and out into the Everglades, when signals were lost around 11am.
A lot of things worked, and we learned a lot of lessons to improve the next launch:
What worked:
1.  The 900MHz telemetry radio worked pretty well with an omnidirectional receiving antenna in the van.  A directional antenna could improve reception a lot.
2.  The 434.920MHz ham-radio beacon (beeper) transmitter worked perfectly, sending data to a handheld transceiver with only a short “rubber duck” antenna.
3.  The 433.920 MHz ham-radio APRS (automated position reporting system) sent out data which was easily received with a directional yagi antenna, though we were unable to record much of the data.
4.  The balloon worked great (5-ft diameter weather balloon filled with helium)
5.  The batteries worked for at least three hours
6.  The Virginia Key Launch site worked well, though it would be nice to launch farther east, out in the bay.
What needs to be improved:
1.  The APRS system needs to be set up properly, so a track can be recorded on the ham-radio APRS system
2.  The payload box needs to be bright orange and bigger (but not heavier).
3.  The parachute needs to be smaller (or replaced by a streamer) to reduce drift on descent
4.  The GPS units need to be set up for aeronautical use rather than automotive mode to eliminate 40,000-ft altitude limit.
5.  We should have extra data-receiving stations farther west, along the  projected track.
6.  Wouldn’t a helicopter be great?!
Here’s the Google Earth track of the ERGO Balloon:  Download the file “Path A.kmz”:  https://www.dropbox.com/s/7lo292me7ykn4mr/Path%20A.kmz.

Then, open it with Google Earth installed.

balloon takeoff 2

News From the ERGOnaut Team!

First trial of the capsule for the ERGOnaut Mini at the Euclid Labs dock (check us out on the ERGO map: http://data.ergotelescope.org/map/google_earth).

What they figured out:
1.  The ERGOnaut Mini can be much simpler–just a G-M detector with clicker and an audio MP3 recorder.  Simple, cheap, and small.

2.  The first trial of the steel pipe fitting design worked great, except for one thing:  after four days submerged at 2 meters it had about a half inch of water inside.  That should be similar to an hour at 200 meters, so we need to make that better (but they’re close!).

ergonaut 2

Enclosure Cabinet for Gen3 and Gen4 Pixels

Alex Mattaway (RISD ’19) has been working on the industrial design for the enclosure for our next-generations pixels.  Here’s the first try.  It’s a 3D-printed model, but the final version will be a custom aluminum extrusion and molded front and rear covers.  It’s going to look very slick, and will be a stylish and durable enclosure for pixels to come.


Working ERGO EtherMega Pixel

Well, with lots of help from Jim and Daniel, we have the first, complete ERGO EtherMega pixel (the Gen3 configuration) up and running, supplying data to Jim’s experimental database.  This is a major step forward for Gen3.

ethermega pixel

Muon Detectors

We’re experimenting with a new particle detector, based on a special light-sensitive “PIN” diode.  We’ve adapted a circuit from Elektor, and we’ve started to experiment with it.  We’re hoping to develop an inexpensive, low-power detector that works as well as or better than the Geiger-Müller tubes we’ve been using in all the pixels.  If we can achieve reliable operation (not yet, but we’re trying), we’ll build a prototype board with an array of PIN diodes, trying to achieve a sensitive area similar in size to the G-M tubes.
Additional experimentation is being done to see if we can shield the G-M tubes to reduce their sensitivity to Earth-based radiation.  That might reduce the number of event detections that aren’t really cosmic-ray muons.


muon detectors

Cosmic Rays and Lightning

We have a big team working on the Lightning project this summer.  We’re trying to establish experimental evidence that lighting is triggered by cosmic-ray muon showers.  We finally gave up on the lightning detector boards we have been using, and we’re going with a custom-designed detector board based upon a known working design.  The team has prototyped it, and we’re starting to test.  So far, we know it works with a high-voltage spark transformer “Jacobs Ladder,” but we haven’t successfully recorded actual lightning strikes yet.
We have all the parts we need for the new design, and Simon is designing a custom PCB.  (see the article in Physics Today:  “Runaway Breakdown and the Mysteries of Lightning”)


The ERGOnaut Mini: Our New Deep-Sea Diver


Those of you following the project will remember the ERGOnaut deep-sea diver pixel that we lost off the coast of Florida last November.  We realized that with all the technology we’ve developed lately (Arduinos, shields, and detector circuits) we could make a new ERGOnaut that is WAY smaller (and less expensive to build).  Matt C and his intern team is building a new ERGOnaut Mini using standard high-pressure pipe fittings, Simon’s tiny ERGOduino, and a compact battery to make a diver capable of a few thousand feet depth and weighing only ten pounds or so.

ergonaut 2