Here are minutes of our telecon Thursday Sept. 15, my apologies for the delay! -- as well as some work done since then -- please just reply with (or let me know) any corrections -- thanks! :
Attendees: Arnold Gaertner (NRC) and me
Over the past few weeks I've been working on building up the initial ALTAIR-Victoria gondola and payload, with some photos at:
http://projectaltair.org/HyperNews/get/AUX/2016/09/28/17.38-92075-assembly1.jpg http://projectaltair.org/HyperNews/get/AUX/2016/09/28/17.38-80271-assembly2.jpg http://projectaltair.org/HyperNews/get/AUX/2016/09/28/17.38-2180-assembly4.jpg http://projectaltair.org/HyperNews/get/AUX/2016/09/28/17.38-83675-assembly6.jpg
Other than of course large amounts of both testing and resultant fixing, one of the relatively few things that remains payload-construction-wise is the power distribution board, which is nontrivial due to the propulsion motors (and the vastly higher currents they require compared with all the other electronics -- up to around 50 A sum total at absolute max, at the 11.1 volt supply voltage), and desire to have full redundancy regarding the battery supply: 2 batteries will of course be carried, but instead of, for example, just powering the propulsion from one and everything else from the other (which would be fairly similar to how previous ALTAIR gondolas have implemented power distribution -- however then, if the "everything else" battery is the one that happens to die -- that hasn't happened yet, but it of course could -- in that case being stuck with no telemetry and no means of control of anything), to instead nominally power everything from one of the two batteries, but entirely and transparently switch, either automatically (upon death, or large undervoltage, of the active battery), or be able to do so manually at any time (via telemetry), to being fully powered by the other battery instead. Doing so requires a high power MOSFET switch design (I'm using these Infineon half-bridges: http://www.infineon.com/dgdl/Infineon-BTN8982TA-DS-v01_00-EN.pdf?fileId=db3a30433fa9412f013fbe32289b7c17 ) which I'm currently testing (only a few minor transistor explosions have been suffered so far) on a breadboard that has so far been reasonably patient with my occasionally putting 10's of amps through it, just emitting a few small sad wisps of smoke when so tested.
Yesterday Mark Lenckowski (TRIUMF staff member at UVic) and I did a test setup on an athletic field of the PVC pipe structure we'd like to use to do future Victoria drop testing of ALTAIR -- a photo at:
http://projectaltair.org/HyperNews/get/AUX/2016/09/28/17.38-16804-DropTestStructure.jpg
However, this 10-meter-high structure was too flexible (and its connections were too fragile) for us to fully lift the structure to vertical (using a winch) -- when we attempted to do so, the connections between the pipes very clearly threatened to break -- thus we need to rethink how to raise this structure. Mark and I have some ideas (Mark's idea is likely better than mine).
The hardware for the pre- and post-flight photometry cross-check device -- the 12" aluminum sphere (a photo of it is attached in a link at the bottom of this message, http://www.sharpeproducts.com/store/aluminum-12-dia-sphere) as well as the white "Avian-B" Lambertian reflective paint for its interior -- is in the machine shop here at UVic for machining and painting. This will be a field photometry check device to, in the field immediately before launch, and right after recovery, cross-check photometry information from the ALTAIR gondola (to an accuracy and precision of about 1% or so. Note that photometry checks which will be more precise than that will be done in the lab, most precisely at NRC, and/or NIST -- however we want to have the ability to do quick cross-checks in the field immediately before and after flight.) Some renderings (of the upcoming device) are also attached in the attachment links at the bottom of the message. Student Tyler Makaro and machinist Jeff Trafton coated a small test hemisphere:
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-99000-AvianBTestHemisphere.jpg
The large sphere should be coated and completed in approximately a month or two.
The survey-tripod-mounted device to cross-check yaw-pitch-roll information from the gondola (e.g., on days before/after flights) is mostly constructed now, thanks to Mark Lenckowski -- photo at
http://projectaltair.org/HyperNews/get/AUX/2016/08/31/18.15-24048-wPitchRollCalibDevice.jpg
and all that remains to be done is a small fitting between the device and the bottom of the payload. The purchased hardware in it includes both the survey tripod (http://www.cpotools.com/cst-berger-60-alwi20-o-aluminum-tripod-with-quick-release--orange-/cstn60-alwi20-o,default,pd.html), two adjustable angle mounts (http://www.thorlabs.com/thorproduct.cfm?partnumber=AP180), and a rotation mount (https://www.thorlabs.com/thorproduct.cfm?partnumber=RP01). That last fitting to attach (temporarily, pre- or post-flight) the upper adjustable angle mount to the payload feet will be completed here in the next couple weeks.
We're currently revising the draft initial contractual agreement from our colleagues at Globalstar Canada regarding 2 initial SPOT Trace devices (and their service plans) for the educational side-project for the upcoming NATO SPS application, in which classrooms in elementary and high schools could launch company-donated SPOT Traces using party balloons (or a more environmentally-friendly version thereof), and track them to learn more about winds at different levels in Earth's atmosphere.
A screenshot outline of the new flight control system (which I'm starting to call by the name AIFCOMSS: ALTAIR Integrated Flight Control Operation, Monitoring, and Simulation System) which merges Google Maps, Cesium (http://cesiumjs.org), and Processing P5.js (http://p5js.org) monitoring and control, can be seen at:
http://projectaltair.org/HyperNews/get/AUX/2016/09/28/17.38-26596-MSS_screenshot28sep16.png
It's Javascript-based, thus runs in a web browser in a platform-independent way, and communicates with the flight telemetry via a serial port connection through USB to an Arduino connected to a DNT900P transceiver and antenna.
Regarding the simulation part of AIFCOMSS, James Hartwick (senior undergrad here at UVic, who has done an enormous amount for ALTAIR, including much of the current projectaltair.org website, light source work, etc) has written an ALTAIR flight propulsion control and simulation program, which includes GFS (global forecast system) file input, for both forecast and real-time information of winds at all points in Earth's atmosphere. We'll have plots, images, and data from his software coming up very soon. I'm developing a visualization interface for the simulation within AIFCOMSS, which will display the real-time (as well as forecasted) winds within the Cesium frame of AIFCOMSS in a way that is somewhat similar to this site:
https://earth.nullschool.net
Here you can see the first attempt at a movie within Cesium of a proto-ALTAIR flying 200 meters above someplace in Kansas:
https://particle.phys.uvic.ca/~jalbert/ALTAIRCesiumDemo.mov
and also a first attempt at displaying some ersatz wind streaks across the Earth here:
https://particle.phys.uvic.ca/~jalbert/WindyWorldCesiumDemo.mov
A next step, software-wise, is to establish telemetry communication between the main ALTAIR-Victoria board:
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-32651-ectronicsBoard17aug16.jpg
and the Betelgeuse test-box:
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-68004-Betelgeuse1.jpg http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-53104-Betelgeuse2.jpg
and to update the control and monitoring software to incorporate the telemetered info, and also implement onboard SD card data storage, as well as storage of the telemetered info.
Houman will send Cordell and/or us updated sections of his master's thesis soon -- that information will be extremely useful to us going forward. Also, Susana and Nathan, it would be very helpful for us all to get the JHU students' final writeup when you have a chance.
Our next grant application will be a NATO "Science for Peace and Security" application, together with Australian colleague partners.
That's all I remember, please send things that I forgot. Next telecon tomorrow(!) (Sept. 29), at 6 pm Eastern time.
cheers, thanks very much all! justin
On Thu, 15 Sep 2016 01:21:21 GMT, Justin Albert wrote:
> Hi! > > Telecon tomorrow (Sept. 15 in North America, Sept. 16 in Australia) at > the regular time: 6:00 pm Eastern (3:00 pm Pacific, noon Hawaii, > midnight European, 8 am Eastern Australia). Discussion items include: > flight/telescope plans and tests; construction, drop testing, and other > forms of tests of the new gondolas and payloads here in Victoria; light > sources and light source modelling; goniometric and pre- and post-flight > calibration; propulsion work; nanosat bus and payload solid models; > computing/website; grant applications; and recap of schedules. > > Here's how to connect: > > 1) Open Skype on your computer (note that of course, you should first install Skype, http://www.skype.com , on your machine if you haven't already). > 2) In the "Contacts" menu, add me ( jalbertuvic ) as a contact, if you haven't already. > 3) Just wait for me to Skype-call you at the usual time (4 pm Eastern, 1 pm Pacific). > 4) If there is any trouble, or if you don't get a Skype-call for some reason and would like to join, just send me an e-mail (jalbert@uvic.ca). > > Here's the tentative agenda: > > I) Flight & telescope plans, and upcoming tests > II) Construction, drop tests, and other forms of tests of the new gondolas and payloads here in Victoria. > III) Diffused light source, and its modelling, pre- and post-flight calibration, and goniometric calibrations > IV) Nanosat solid models & Houman's thesis > V) Computing/website, including new flight control and simulation progress. > VI) Grant applications > VII) AOB > > Talk to you all tomorrow, thanks! > justin
Attachments:
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-32651-ectronicsBoard17aug16.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-99000-AvianBTestHemisphere.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-30898-TopPlate.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-7894-CutdownSystem.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-38576-tdownAndSteeringSetup.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-68004-Betelgeuse1.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.30-53104-Betelgeuse2.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.32-41770-DropTestSetup1.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/20.32-76024-DropTest4.jpg
http://projectaltair.org/HyperNews/get/AUX/2016/08/17/17.21-74532-tSetup_draft11aug2016.pdf
