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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all!

Telecon tomorrow (Jul. 14 in North America, Jul. 15 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). Andrew Macdonald now has an Arduino Mega-based tester board all ready for students Adithi Balaji and Nisheth Eluri to test the two populated ALTAIR photodiode readout / transimpedance amplifier boards, and Adithi and Nisheth will be testing the gain and linearity of the board at different settings and under different conditions over the next few weeks. Also, more progress has been made with operation of the two Raveon M8S 144 MHz transceiver boards. As for ORCASat, the cubesat is down at Nanoracks HQ in Houston, awaiting its October launch to the ISS! More discussion items for tomorrow's telecon include: flight/telescope plans and tests; construction and lab tests of the new gondolas/payloads; light sources and light source modelling; goniometric and pre- and post-flight calibration; propulsion work; nanosat bus and payload solid models; computing / website / TWiki forums and e-mails; grant applications; and recap of schedules. I'll send the progress report and photos before the telecon tomorrow.

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 (5 pm Eastern, 2 pm Pacific, etc).
4) If there is any trouble, or if you don't get a Skype-call for some reason and would like to join, please just send me an e-mail (jalbert@uvicNOSPAMPLEASE.ca).

Here's the tentative agenda:

I) Flight & telescope plans, and upcoming tests
II) Construction, drop tests, and other tests of the new gondola and payload
III) Diffused light source and its modelling, pre- and post-flight calibration, and goniometric calibrations
IV) Solid modelling
V) Computing/website, including recent flight control and simulation progress
VI) Grant applications

Talk to you all tomorrow, thanks!!!

-- Justin Albert - 2022-07-14

Hi all,

My apologies for the delay! -- here's the update on ALTAIR balloon work from the past few weeks, minutes of the telecon 4 weeks ago on June 16 (attendees: Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 15 mins from now (!) :

In order for students Adithi Balaji and Nisheth Eluri to test the two ALTAIR photodiode readout boards that Andrew Macdonald has populated, Andrew made the Arduino shield board pictured below for them to use:

The shield board (red) sits over an Arduino Mega board (almost entirely hidden underneath it -- but green-coloured), and the blue clock board for the photodiode readout boards is attached to its top, as shown. Adithi and Nisheth should be using this to test the photodiode readout boards over the next few weeks. Andrew is now making the circuits for the battery-powered "femtocurrent source" per the diagrams sent a couple of months ago:

also for Adithi and Nisheth to test the linearity and gain of the photodiode readout boards.

Regarding solar panels that can go atop ALTAIR balloons -- as mentioned in the progress report back on May 20, we have, and have successfully tested, three Renogy 100 W flexible solar panels (and a controller which came with them) -- with photos of the panels and controller at:



But, these solar panels are just rather heavier and bigger than I'd like (even though I definitely don't regret having purchased them -- they were an excellent deal!). This is also because there are only two 11.1 V LiPoly batters aboard ALTAIR, and realistically, 6 amps for charging these two batteries is all we would want or need -- thus a maximum of 90 watts in total from the solar panels (rather than 300 watts!) will be more realistic. So, I spent awhile looking around for the very lightest possible solar panels, and found that three of these:


would be perfect. (They are each about 6 times lighter than a 100 watt Renogy solar panel! -- so about twice the power per mass.) They weren't cheap (about $270 USD per 30 watt panel, as compared with about $150 CAD per Renogy 100 watt panel), but I think they will be worth it, so I purchased 3 of them. I'll pick them up when I'm in the U.S. near the beginning of August (and will bring them back to Victoria).

The two 144 MHz Raveon M8S data modem transceivers are still here in my office (together with the LiPoly batteries that power them), and hopefully this weekend I will get a chance to test Colton Broughton's most recent code updates for them, which can be found in:


(as compared with his older code within https://particle.phys.uvic.ca/~jalbert/ALTAIR_M8S_Colton17nov21/ ).

Our new summer NSERC USRA student Adithi Balaji, Colton Broughton, Sarah Alshamaily, and Will Stokes have also completed installing AIFCOMSS ( https://github.com/ProjectALTAIR/AIFCOMSSwithCUPredictorTest ) on their laptops. I've updated AIFCOMSS to work with the recent Cesium v1.83, as well as the instructions, and they all report success with this update and those instructions. The next two things that we know most definitely will need updating (or, rather, creating) are the station-keeping software for AIFCOMSS, and the online command-handling within the onboard Arduino software -- and I'll also be working on those over the next 2 weeks.

Regarding the latest news on our four Radiometrix SHX1 144 MHz transceiver modules that were returned to us from Radiometrix (following their firmware update to fix the BUSY output):

and the problems that Colton found with them (i.e., that of the 12 radio TX to radio RX permutations between those 4 boards, only 3 of the 12 permutations work, 3 of the other permutations give spotty connections -- e.g. only around 1 out of every 5 characters gets successfully transmitted -- as if one is transmitting and the other is receiving on neighbouring channels, but not the same channel..., and the remaining 6 permutations do not successfully receive any transmitted characters) -- we sent an e-mail to Radiometrix to ask about this about 8 months ago. They then sent back an e-mail a week later asking for more information, and Colton replied to them the next day providing the info (just a query about what logic voltages we were using -- we've being using 5V TTL from our Arduino Megas). Radiometrix has not replied to us since that e-mail reply sent to them 32 weeks ago, and thus I pinged them 30 weeks ago to follow up, and again 21 weeks ago -- and Radiometrix hasn't replied to those yet either. I will be pinging Radiometrix on this yet again next week.

We also still need to test out our new DFRobot SEN0177 payload aerosol monitors that we have here -- and Adithi Balaji is presently working on that! :

Engineering students Josh Gage and Evan Moore found that the "wings" that Josh had found in the laser diode light output distributions:

were due to how the diode was mounted in the heat sink. When the diode is mounted properly and carefully, the wings go away.

We also have our 10 Hamamatsu S12698-01 photodiodes and 3 Thorlabs FDS100-NOCAN photodiodes (those Thorlabs ones have their windows removed) here in Victoria:

<a href="https://twiki.cern.ch/twiki/pub/Altair/Forum/ForumGeneral0045/PhotodiodesHamamatsuS12698-01AndThorlabsFDS100-NOCAN.JPG">

and all that remains to be done is to finish the 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 landing gear has been started and 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.

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.

Next grant application will be a NATO "Science for Peace and Security" application (together with Australian colleague partners).

Our next telecon is in 15 minutes from now! -- see below for Skype instructions.

Cheers, talk in 15 mins (!) from now -- thanks all!


-- Justin Albert - 2022-07-14

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
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JPEGjpg ALTAIR_TesterArduinoShieldForTestingPhotodiodeReadoutBoards_13jul22.jpg r1 manage 2567.6 K 2022-07-14 - 01:42 JustinAlbert Photograph, taken 13 July 2022 by me, of Andrew's Arduino board shield for Adithi and Nisheth to test the ALTAIR photodiode readout boards
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