Monday, November 21, 2011

Thermal Vacuum Chamber



I finally have a thermal vacuum chmaber (TVC) design I like. It's called Near Space in a Can and it will sell for $250 as a kit plus shipping (minus the vacuum pump since it's cheaper to pick that up at the store than sell it).


The TVC has a diameter and depth of nine inches. It's exterior is packed with dry ice and it's then pumped down. Inside the environment approaches near space conditions. I'll add radioactive materials and evnetually UV sources to more faithfully replicate near space.


As long as you're willing to pay postage, I will expose experiments (not living objects, please) to the chamber at no other cost. Eventually I'd like to have several of these available for amateur testing.

Tuesday, November 15, 2011

NearSys 11N

Hard to believe, but I flew my 99th near space mission this weekend as NearSys 11N. I traveled to Valley, Nebraska to launch a ballon in conjunction with friend, Mark Conner. Mark and I go back to 1998 when we met at the St. Joe Hamfest in Missouri.

We ran into a small problem on this flight that ended up creating a bigger headache before it was all over. The helium tank we received was not properly topped off (about 20% low). As a result of the unexpectedly lower volume of helium, we were forced to remove some payloads. The reduction in payload weight also meant the parachute would descend slower, permitting a longer recovery.

To make a long story short, recovery should have occured in farm fields south of Anita, Iowa. Instead, recovery occurred in a small patch of woods near Adair. As is typical, the near spacecraft recovered on the very top of the trees. It took about an hour for Mark and me to retrieve the payload.

You can view the flight data on my website at, http://nearsys.com/arhab/flightdata/2011/n/index.htm.

Mark posted pictures at, https://picasaweb.google.com/111334632256807627139/NearSysFlight12Nov2011

Onwards and Upwards

Flight Number 99

Hard to believe, but I flew my 99th near space mission this weekend as NearSys 11N. I traveled to Valley, Nebraska to launch a ballon in conjunction with friend, Mark Conner. Mark and I go back to 1998 when we met at the St. Joe Hamfest in Missouri.

We ran into a small problem on this flight that ended up creating a bigger headache before it was all over. The helium tank we received was not properly topped off (about 20% low). As a result of the unexpectedly lower volume of helium, we were forced to remove some payloads. The reduction in payload weight also meant the parachute would descend slower, permitting a longer recovery.

To make a long story short, recovery should have occured in farm fields south of Anita, Iowa. Instead, recovery occurred in a small patch of woods near Adair. As is typical, the near spacecraft recovered on the very top of the trees. It took about an hour for Mark and me to retrieve the payload.

You can view the flight data on my website at, http://nearsys.com/arhab/flightdata/2011/n/index.htm.

Mark posted pictures at, https://picasaweb.google.com/111334632256807627139/NearSysFlight12Nov2011

Onwards and Upwards

Thursday, October 20, 2011

Introducing BalloonSats

Introducing BalloonSats



An alternative to using robotics as a vehicle for teaching STEM is the BalloonSat project. One reason BalloonSats may make a superior alternative to robotics is that robotics doesn’t involve as much science and mathematics as a well structured BalloonSat project. And while robots in competition can operate in either autonomously (independent of a human operator) or with operator control (by human control, usually over a radio), BalloonSats can only operate in autonomous mode. Students design and program their BalloonSat to operate sensors and collect data without human intervention.


Description of a BalloonSat



BalloonSats, as Linda Kehr describes them, are model satellites carried under helium filled weather balloons to altitudes in excess of 80,000 feet, a very space-like environment. In fact, BalloonSat flights reach 85,000 feet easily and can reach over 120,000 feet with lighter payloads and larger balloons.


BalloonSats are the first step in the National Space Grant Satellite Program’s strategy, “crawl, walk, fly, run”, whose ultimate goal is to send a student-designed payload to Mars. However, the first step, “crawl” is designed to encourage students to build and fly simple models of satellites, like BalloonSats. It is believed that by getting students involved in a series of more complex projects, more will graduate from STEM programs and enter into aerospace engineering fields.


Description of their construction



BalloonSats are an inexpensive way to access space while still retaining some of design and engineering challenges of satellites (Kohler 2003).


Airframe



BalloonSats are student designed from Styrofoam to carry programmable dataloggers and cameras and typically do not weigh more one pound (Kennon, Roberts & Fuller 2008). Other design challenges may involve volume (not to exceed 1000 cc), minimum datalogging capability (internal and external temperatures over the entire flight) and functional testing preflight. Adhesives used to assemble the BalloonSat airframe from foamcore include silicon rubber glue, hot glue, and JB Weld (an epoxy). Aluminum duct tape is also a popular material to seal the airframe (Koehler 2003).




Figure 1. Example of a BalloonSat. This one is constructed from a sheet of ½” thick Styrofoam, the same material used as insulation of outside house walls. It’s walls are assembled with hot glue and covered in black packaging tape. Photograph from the author’s collection.


Avionics



The datalogger used when BalloonSats were first designed is the Hobo datalogger. Scouts involved with the Glenn Research Center’s BHALF (BalloonSat High Altitude Flight) are beginning to experiment with using BASIC Stamps by Parallax – the same microcontroller used in the Boe-bot robot (BHALF). For Students in CU Boulder’s Gateway to Space course who are ready for a more advanced challenge, the timer is replaced with a programmable BASIC Stamp.


After recovery of their BalloonSat, students connect the datalogger and camera to a PC to retrieve the data and images. Students can perform their own mathematical analysis of the data and images or rely on the software used to program the dataloggers.




Figure 2. An eight-bit Hobo datalogger manufactured by OnSet Computing. This model records internal temperature and an external voltage. Photograph from the author’s collection.


A one time popular camera for BalloonSats was the Canon Elph. These APS film cameras were relatively inexpensive and very easy to modify for operation by intervalometers. The intervalometer is a 555 IC based timer kit soldered together by students. More recently, digital cameras and digital video recorders are included in the BalloonSats.


Preflight testing



Prior to flight, their designers test their BalloonSats. Even though flights cost less than $300, this is still too expensive to launch a BalloonSat that has no guarantee of functioning properly. Typical tests used in Koehler’s program include the following.


Drop Test: BalloonSats land by parachute. At touchdown, the BalloonSat’s speed can easily reach 10 mph. To ensure BalloonSats will remain in one piece during the landing, students drop their BalloonSats from a height that simulates their landing of 10 mph. The height from which a BalloonSat must be dropped to simulate a 10 mph landing can be calculated as shown below.
10 mph * 5280 ft/mile * 1 hour/60 minutes * 1 minute/60 seconds = 32.2ft/s2 * t
time of fall = 0.455 seconds
h = ½ * 32.2 * (0.445)2
height of drop = 3.34 feet


Cooler Test: Near space gets very cold (the coldest temperature the author’s BalloonSats have measured is -90O F, although -60O F is more typical). To ensure the BalloonSat is build well enough to keep its datalogger contents warm enough to function is to place the BalloonSat inside a Styrofoam ice chest filled with dry ice. The BalloonSat is left inside the cooler long enough to let the interior temperature bottom out (the author uses a time of 20 to 30 minutes).


Functional Tests: During its construction and at the competition, the BalloonSat, its datalogger, intervalometer, and camera are tested together to verify they will work without interfering with each other. This means all subsystems must fit inside the airframe without blocking access to the camera power button or the camera’s view outside the airframe.


Description of launch/recovery



BalloonSats are lofted into near space on a helium-filled weather balloon. The entire vehicle consists of a helium-filled weather balloon at the top, a recovery parachute attached below the balloon by a load line of nylon cord, one or more GPS trackers packed inside a Styrofoam enclosure, and one or more BalloonSats (Koehler 2003). The GPS tracker transmits position reports of the balloon over amateur radio frequencies. The system amateur radio operators use to track the location of items (like automobiles) is called the Automatic Packet Reporting System, or APRS. Therefore, a licensed amateur radio operator is required on each near space launch. The expendable parts of the flight are the helium and latex weather balloon and accounts for the $300 price tag for the flight. The radio tracking equipment are repaired, if necessary, so it can track another mission.
Recently, Taylor University began marketing a license-free version (900 MHz spread-spectrum) of the radio tracker. The system is called the High Altitude Research Platform (HARP) and is marketed by StratoStar. To date, over 200 flights using the StratoStar system have taken place.


The maximum weight on most BalloonSat launches is 12 pounds as long as no single item weighs more than six pounds nor has a surface density greater than one ounce per square inch. Additional FAA rules apply when these limits are exceeded (Federal Aviation Administration, FAR 101). Therefore, to avoid the application of additional FAA procedures, most schools launching BalloonSat limit their flights to 12 pounds total weight.


The typical BalloonSat launch occurs in the morning and requires between two and three hours to complete. The early morning launch permits the balloon to be filled while the winds are generally lower. After release, the typical ascent rate for the weather balloon and payload is 1,000 feet per minute. Latex weather balloons are sold by weight and frequently used balloons are 1200 and 1500 grams. Kaymont is an example of weather balloon dealer located in the United States.


A balloon filling system consisting of a regulator designed for welding gases, oxygen hose, and a length of PVC pipe. The PVC pipe attaches to the end of the oxygen hose and has a diameter less than the diameter of the balloon’s nozzle. The balloon nozzle slides over the PVC pipe and taped securely. Once secured, the balloon is filled with helium. Welding companies are the suppliers of helium required to launch a weather balloon. The helium arrives in welding tanks and they can weigh as much as 120 pounds.




Figure 5. Balloon Filler. The green oxygen hose is 12 feet long and the PVC pipe is 1.25 inches outside diameter. Photograph from the author’s collection.




Figure 6. University of Kansas students filling two latex weather balloons in preparation for BalloonSat launches. Photograph from the authors collection.


A typical flight requires 90-100 minutes to climb to peak altitude and approximately 30 minutes to descend back to the ground on its parachute. Because of the amateur radio equipment onboard, the balloon is tracked and its landing site located. Because of APRS onboard the balloon, students can track the position of the balloon carrying their BalloonSat in real time (Koehler 2003).


Near Space



According to Aerostar, near space begins at an altitude of 50,000 feet. According to the United States Air Force, near space begins at 20 km (65,600) feet, or above class A airspace.




Figure 7. Example of air pressure measured as a function of altitude by a BalloonSat. Environmental sensors from this author’s past near space flights indicate the air pressure drops to 10 mb, or 99% of a vacuum at an altitude of 100,000 feet (Data from the author’s collection).




Figure 8. Example of air temperature measured as a function of altitude by a BalloonSat. Air temperature drops to a low of -60O F in the summer and lower in the winter at the boundary between the troposphere and the stratosphere (Data from the author’s collection).




Figure 9. Example of the relative humidity measured as a function of altitude by a BalloonSat (Data from the author’s collection).




Figure 10. Example of cosmic ray flux measured as a function of altitude by a BalloonSat. The flux of secondary cosmic rays increases as the altitude increases until well into the stratosphere, where primary cosmic rays begin to be detected (From author’s personal data).




Figure 11. Example of an image returned by a BalloonSat showing the blackness of space and the curvature of the earth. A digital camera modified for operation by a programmable flight computer recorded this image of near space at an altitude of 78,000 feet (Image from the author’s collection).


Thursday, October 13, 2011

Infrared for Digital Cameras

I began an investigation into adapting the cameras in my dissertation BalloonSat kit for infrared use. If you've looked for IR filters recently, you'll find they get pretty expensive. In place of a traditional IR filter, I made one according to the directions of Bill Beatty. He recommended using several layers of Congo Blue lighting gels and one of Primary Red. The blue gels are so dense in color that they block most of the visible light trying to get through them, so only a little of the blue gets though. The red gel manages to block the small amount of blue that gets through.


Stage lighting gels must be transparent to IR or else they will get too hot and melt. So if they can be stacked to block visible light, then only IR is going to get through them.


Digital cameras are naturally sensitive to IR. In fact, they need IR blocking filters to keep the appearance of their images looking like we expect. Now the camera must adjust its exposure time to compensate for the purely IR image, but my dissertation camera can handle it. I'll have to look into the effects of increased exposure time and the unsteady tripod that a BalloonSat simulates. However, if this is not too much of an issue, I expect two cameras, one with IR filter and one without, to make a great near space experiment for students.


This is the visible image taken on Wednesday afternoon. Pretty normal looking.


This is the infrared image taken on Thursday afternoon. Notice how bright the tree leaves appear. Chlorophyll is very reflective in IR. Also note how much brighter the trees are than the apartments behind them in IR (but not visible).

Saturday, October 1, 2011

Mars and the Beehive Star Cluster

The planet Mars is traversing the Beehive star cluster. The picture below was taken the morning of September 30th, at 4:30 AM. The digital camera was set for a six power optical zoom and 15 second exposure. The resulting file was enhanced and sharpened using GIMP. It's not too bad for a camera tripod in Topeka.


Tuesday, August 30, 2011

LED Photometers

Many years ago, I read an interesting article (http://www.opticsinfobase.org/abstract.cfm?URI=ao-31-33-6965) at the Physics Department at K-State. In it, Forest Mims discussed using LEDs as frequency specific light detectors. I've played with LEDs off and on for several years before finally following Forest's recommendations and making a descent LED photometer.

While they're not quite ready yet, Nearsys will soon offer LED photometer kits for near space use. The kit comes with a PCB for two LEDs and a temperature sensor. The temperature sensor is required because the light sensitivity of LEDs is strongly dependent on their temperature. It should be an easy process to calibrate the photometer with a styrofoam box and dry ice.

This design of two LEDs and a temperature sensor permits you to compare the relative brightness of sunlight in two different portions of the spectrum. The LEDs I'm in the process of testing now are 940 nm IR and 850 nm IR. I've selected these two because according to Forest's notes, the ratio between the two can be used to measure the amount of water vapor in the air. The amount of water vapor should change dramatically during a near space flight and is an example of the remote sensing that can be performed with BalloonSats. Next up will be to find other LED combinations that will provide interesting information.

You can read more about LEDs and Forest's discovery at http://www.sas.org/tcs/weeklyIssues_2009/2009-01-02/feature1/index.html and http://www.sunandsky.org/Sun_and_Sky_Data.html.



The complete photometer kit. It comes with the photometer head (with its three sensors), transconductance amp, and easy plug for connecting to a NearSys flight computer. I want to thank Mr. Forest Mims for helping me design this photometer and encouraging me to experiment with it in near space.

Monday, August 15, 2011

Changes in the American Economy

Our economy and its interaction with the rest of the world is rapidly changing. In response to concerns expressed by several of the national academies and my interest in near space, I am preparing a research project that incorporates science, technology, engineering, and mathematics, or STEM.

The United States no longer produces the majority of its wealth by manufacturing products for local markets. Instead, services, information, and innovation are our largest sources of revenue. Even when the US does create new products, much of the manufacturing eventually moves overseas. And increasingly, more research is moving overseas as Chinese and Indian students receive good educations

In order to work in occupations involving information and innovation, future employees, that is, our students, must be adequately trained in STEM. For several reasons, this is not the case. One reason students don’t receive a strong STEM education is that there are many teachers not adequately prepared to teach an integration of science, technology, engineering, and mathematics. Even when teachers are well prepared to teach STEM, they lack the real world activities that incorporate STEM. The activities they select must be stimulating in order to prevent students from tuning out.

Rising Above the Gathering Storm: A Report
In 2005, the national academies of science and engineering, the institute of medicine and the national research council were tasked to determine issues and solutions to US prosperity in the 21st century. The commission determined there are two overarching goals to meet if we want to maintain our national prosperity

First is to create more high tech jobs.
Second, to develop additional energy sources that are clean and reliable.

To create more high tech jobs and create additional supplies of clean and dependable energy of the 21st century, The commission developed recommendations in four broad areas. To meet those recommendations, there are 20 specific actions the US needs to take. The four recommendations involve the following areas.

1. K through 12 education
2. Research
3. Higher education
4. Economic policy

I will focus on the K through 12 education recommendations and its actions

The commission concludes it will take 10,000 additional, highly qualified math and science teachers every year to create STEM literacy in the majority of the US student population within the next ten years. It takes time to train college students to become teachers. However, right now, we need 250,000 teachers able to teach challenging subjects. One way to reach this goal is to teach these teachers (in summer classes) how to teach Advanced Placement and International Baccalaureate subjects back in their schools. The United States could consider creating national STEM programs and standards. These standards would need to be taught to currently active teachers (again through summer classes). Finally, the US must invest in the classroom to create more students prepared to take STEM majors in college. The truth is that our future scientists and engineers begin in 6th grade

I want to address one way we may be able to help students prepare now

Before students can become STEM smart, they need to study STEM subjects. And they need to study them diligently. So what makes students want to study difficult subjects?

Myers and Fouts in their study “A cluster analysis of high school science classroom environments and attitude toward science” state that positive attitudes to subjects are associated with higher levels of student involvement in those classes. In other words, students must have a positive attitude toward STEM subjects in order to want to spend the time necessary to acquire a high level of STEM knowledge.

Osborne in, “Attitudes towards science: a review of the literature and its implications” states that one reason students don’t like science is that they see their science class as a history of great ideas. There aren’t enough in-class applications of how science is being done today. To them, the science class is boring. Osborne also states that three of the many factors influencing students’ attitudes towards science include the following.

1. Their enjoyment of science
2. Their past achievement in science
3. And the nature of the classroom environment

In a school district were meeting state standards is the most critical part of the school year, good extracurricular activities become a more important vehicle to positively influence student attitudes towards STEM. That’s because the regular classroom doesn’t have the time for exploration or open-ended investigation. By good after school activities, I mean those that model real world science in action, that are enjoyable, and have high levels of successful completion.

Some good STEM activities in use today include FIRST robotics, BEST Robotics, and Project Lead the Way.

So in a nutshell, the nature of the American economy is changing and has been changing fast for the last 50 or so years. If our students want high paying, stimulating careers, they need to be prepared for STEM occupations. Schools in many cases could use some help finding meaningful and interesting STEM activities. This is one reason resort to robotics. However, it seems to me that the science and mathematics aspect of robotics is lacking. Based on my experience, I have propose there is a better vehicle than robotics for STEM education.


Friday, August 12, 2011

Welcome to my Dissertation

To date, I have found several articles on near space and BalloonSats in an educational setting. Some describe how a near space program was set up, how one is operated, and some of the experiments college level students are performing. However, I have found no dissertations or studies showing the effect of a BalloonSat project on student interests in science. My plan is to address this issue.

My research plan involves creating a BalloonSat challenge similar to the successful FIRST robotics challenge. Student teams will have a limited time to design, construct, and test a BalloonSat design. There is no actual competition between teams; however, students will need to send their BalloonSat back to me before their deadline. I will launch the BalloonSats for all the teams and expect them to reach 90,000 feet. After recovery, the BalloonSats will be returned to their respective schools so that each team can download and analyze the data. Students will have two weeks to process their data and post the results in a web-based report.

Student interest in science will be measured twice, once before the project begins and then one last time after the reports are completed. I also plan to select a convenience sample of students to interview. The results of the surveys, the team reports, and interviews will be the data of my study.

I have designed the BalloonSat kit and selected the science interest inventory. Over the next couple of weeks, I discuss my plans in greater detail and continue asking for volunteers. In the hopes that I can get more classrooms to volunteer, the BalloonSat kits will be free and will the flight. After the study is complete, classrooms will be allowed to keep their BalloonSat. As long as they can find a balloon group, it can be reprogrammed and launched again and again.

Please consider being a part of this study. As I said earlier, no study like this has been done in the past.


Participating classes could get images and data like this.









Monday, June 27, 2011



NearSys is in the process of creating a complete robotics kit. The kit incorporates the CheapBot body (updated version), a robot controller, line follower, and adapter cable in a single bag of parts. The assembled robot can be programmed for maze driving and line following.


The new body uses pre-drilled and shaped Sintra, just bolt it together. New servo brackets attach the motors to the bottom deck, there is no more wood in the robot body. The CheapBot is all proper metal and plastic.


The robot body is pre-drilled for robotic arms and the smart proximity detector. Future upgrades include a radio terminal (for communicating with the robot) and a beacon locator.


The price for the complete CheapBot-14 robot kit is to be about $80 plus shipping and handling. In another week a CheapBot-18 version will be available.

Sunday, June 5, 2011

Balloon CubeSat

In preparation of my dissertation, I am experimenting with different BalloonSat configurations. Here, I am attempting to replicate a CubeSat. The requiements are a 10 cm cube weighing no more than 1 kg.




The airframe is made from 10mm thick Cellfoam 88. Since it has a hard flat surface, I was able to glue Styrene plastic to it without it melting very badly. I filled in gaps with Gorrila glue.




The Balloon CubeSat measures two temperatures, internal and external. The flight computer is based on a BalloonSat Mini and will make measurements once per minute during the mission. It is my hope that a project like this will make a great introduction to satellites.

Sunday, January 23, 2011

NearSpace UltraLight



The UltraLight kit is just about ready for sale (I'm waiting for some PICAXE-28X's and to complete the directions). I've added a bunch of new stuff to the kit, including a control panel, commit tag, audio beacon, and antenna, as you can see in the picture above.


The NearSpace UltraLight is the easiest way to begin a near space program. The kit can be assembled over a weekend. All you need to complete the kit is decide on your battery and its termination (I use Anderson Powerpoles). If you have cameras, then you'll also need to select a termination method for them (I recommend Dean's micro plugs).


NearSys sells a GPS receiver kit. It is designed for flight computers like the UltraLight. The UltraLight and GPS coupled together is a complete flight computer. Build an airframe and purchase a parachute and you can begin exploring near space.


About the Flight Computer


The UltraLight digitizes four analog sensor voltages, operates three digital experiments (like geiger counters), controls two cameras, and positions two servos (the servos have their own battery). The UltraLight's audio beacon makes enough noise that you can locate the near spacecraft in tall grass or corn fields. The control panel lets you program the flight computer and download data without having to open the airframe. You can also communicate with the flight computer while launch crews are filling the balloon (perhaps to verify sensor operation prior to launch). The flight computer's Tiny Trak is also assessible through the control panel (but not while the GPS is plugged in) The control panel indicates the near spacecraft's power status and the status of the Tiny Trak (that is, when it is transmitting and when its GPS has a lock). The bright red commit tag screams a reminder to begin the mission before releasing the balloon. That way you can power up the near spacecraft and wait for a GPS lock before recording mission data (who wants a bunch of data on the ground when you're headed to 100,000 feet?).


The Onboard Tiny Trak


The APRS tracker is built right into the flight computer. The 500 mW transmitter and dipole antenna will let you track the entire mission. Since the transmitter is set for 144.390 MHz, I-Gates can put your tracking data online, allowing everyone in the world to track your flight (very useful when your chase vehicle is located in the null of the antenna).


Mission Data


Mission data is stored in 32kB of memory. After recovery, reprogram the flight computer to download its data right into your PICAXE Editor (with its built-in terminal program). This can be done right in the field if your want (bring your netbook along). The data is then saved as a text file and opened in Excel. You can be generating results from the mission at the post recovery lunch!


It may take another week to get the kits packed and the directions in their first draft. Meanwhikle, feel free to contact me if you have questions.


I guess it's time to start a forum!

Wednesday, January 19, 2011

A Complete Near Space Flight Computer



I finally received the ten 144.390 MHz transmitters I ordered for near space flight computer kits. In the interim, I developed GPS and antenna kits. The picture above shows what a complete flight computer kits looks like.


Shortly, beginners will be able to purchase a complete near space flight computer. After assemblying the kit, all you will need is a parachute, battery, and airframe. The kit will include a control panel to communicate and control the flight computer from outside the airframe, a 2m dipole antenna, GPS receiver tested to 103,000 feet, audio locator beacon, and programmable flight computer.


The first kit is based on the PICAXE-28 and the second based on the BASIC Stamp. Check the NearSys website (nearsys.com/catalog) for information as I get my updates in order. Until then, feel free to contact me through email.

Friday, January 14, 2011

Near Space in a Can



The Near Space in a Can thermal vacuum chamber is about ready for retail. The image above is missing its vacuum gauge, which is at school. Otherwise, you now get a good idea of what it will look like. The kit should be no more than $150.


Just pack the Near Space in a Can with dry ice and let it chill before loading the test subject inside. Then pump it down with your vacuum pump. The environment inside will match near space conditions.


The stainless steel canister is 7.5 inches in diameter and 7.5 inches deep. The clear plexiglass cover lets you observe the experiment inside and even video tape the test.


A future upgrade will bring wiring inside so you can communicate with experiments inside.

Sunday, January 9, 2011

Single Axis Arm with Snare End-Effector



I completed my design of a single axis robotic arm. The servo lifts and lowers the arm like a traditional arm. What is different is the end effector that allows the arm to pick up objects. It's a wire snare, similar to the end effector on the Space Shutter robotic arm. A mini servo extends and retracts the wire snare, letting it wrap around and tighten around th object to be picked up.

Look for a magazine article (in Servo) and a kit to made available shorty.

Saturday, January 1, 2011

Near Space in a Can

I ran the first tests of a new thermal vacuum chamber. It's a stainless steel can with vacuum and cable ports. The can fits inside a plastic ice chest that can be packed with dry ice (see my Nuts and volts article on this subject).

The front of the chamber is sealed with thick acrylic plastic to permit observations of the interior of the chamber during testing. The cable port permits power to enter the chamber for its ultraviolet source and temperature sensor. Pressure inside the chamber is monitored with an analog pressure gauge.

I call the thermal vacuum chamber, Near Space in a Can. It's the second simulator NearSys will sell (the GPS simulator is the first). Near Space in a Can is large enough to test BalloonSats and CubSats.

Near Space in a Can will be available from NearSys in 2011 as an affordable kit.

Robot Terminal

I finally had time to figure out how to send AT commands to the Digi Xbee radios. I've worked with them previously, but wasn't comfortable enough with how I was setting the radios. Now I've got them working the way I want.

Therefore, I will shortly be offering a robot terminal kit. It will permit you to communicate with a robot using your PC. I've got an example robot set up right now. It drives and turns as instructed while confirming the communications. The robot carries a simple arm and video transmitters that is also controlled over the radio. The robot is smart, it attempts to carry out your commands as best it can. Since the robot is using a ChapBot-14, it is a little limited - so eventually, I'll interface the radio with a CheapBot-18 on an articulated robot body and more complex arm. Moon rover anyone?

I'll also create a kit to allow BalloonSats to communicate with each other in order to create near space constellations.