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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all!

Telecon tomorrow (Jun. 16 in North America, Jun. 17 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). In addition to ALTAIR-relevant ORCASat news -- we'll be at NRC in Ottawa next week from Wed. - Fri. doing the ORCASat (re-)calibration there -- this time of both photodiodes, and then at CSA HQ just outside Montreal from Mon. - Wed. June 27 - 29 doing the integration of the flight spacecraft into the Nanoracks ISS deployer -- we additionally have important new ALTAIR-specific news! Andrew Macdonald has populated a second ALTAIR photodiode readout / transimpedance amplifier board, and students Adithi Balaji and Nisheth Eluri will be testing the gain and linearity of the board at different settings and under different conditions over the next few weeks. Also some more progress has been made with operation of the two Raveon M8S 144 MHz transceiver boards. 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 - 2022-06-16

Hi all,

My apologies for the delay! -- here's the update on ALTAIR balloon work from the past couple of weeks, minutes of the telecon 2 weeks ago on June 2 (attendees: Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 15 mins from now (!) :

As mentioned yesterday in the meeting announcement, Alex Doknjas and I will be headed back to NRC in Ottawa next week to do the recalibration of the ORCASat light source and onboard photodiode montoring, and then heading to Montreal right after that to put ORCASat into the Nanoracks cubesat deployer at CSA HQ. In addition to fixing the problematic USB-mini-B cable assemblies, Alex also made fixes to a problem with the photodiode front-end modules -- as you can see in this photo:

the photodiode anode line can short against the lip on the grounded shield. (Kind of a ridiculously simple error -- that lip in the shield should just never have been there.) A better fix for this would have been to pull the modules out, take a Dremel tool, and grind/sand off that lip -- but it was not physically possible to get the modules out of ORCASat without completely disassembling the spacecraft (not possible at this point), so Alex cracked the modules open in situ, and separated the lip from the board with a thin line of epoxy. No more shorts, fortunately.

Alex and engineering student Josh are redesigning these front-end modules for ALTAIR -- which will, of course, fix this shield lip-short problem.

Regarding the (separate) issue with the USB-mini-B cables, for which ALTAIR fortunately doesn't need to use the handmade, space-qualified material, low-outgassing cable assemblies that ORCASat uses; and for which I purchased 30 of the following little commodity USB-mini-B cable assemblies: https://www.aliexpress.com/item/32826885322.html -- I received those cables yesterday, and very unfortunately these are what I got from that AliExpress order:

They were supposed to be 8 cm long, and they are really 10 inches long! -- over 3 times as long as they claim. I specifically ordered these so they would be very short 8 cm cables that would fit inside the payload -- 10" is vastly too long to fit. This sort of problem is, of course, why people avoid ordering directly from AliExpress and similar absolutely-no-quality-control sites -- the sellers on such sites simply lie about what they are selling, and there is no reasonable way to return their faulty items. But fortunately, it is only $30 -- so live and learn. I'll need to get good, short USB-mini-B cables from another supplier.

Andrew Macdonald has tested his populated ALTAIR photodiode readout board, and has come up with this fix for the latch-up problem that he was seeing:

and has implemented it and it works -- and additionally sounds reasonable to Alex and others who worked on the ORCASat version of the board, i.e. like it shouldn't cause significant differences in output between the ORCASat board and the ALTAIR boards. So, Andrew is implementing that fix.

Andrew has also just populated a second ALTAIR photodiode readout board:

and students Adithi Balaji and Nisheth Eluri will be testing its linearity and gain under different conditions over the next few weeks.

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:

I've given them to Evan to try out -- he's taking a few weeks to ramp up, and will produce some linearity, etc., plots from them soon.

The survey-tripod-mounted device to cross-check yaw-pitch-roll information from the gondola (e.g., on days before/after flights) is also constructed now, thanks to Mark Lenckowski -- photo at:

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 - 2022-06-16

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg ALTAIR_SecondPopulatedPhotodiodeReadoutBoardTIA_15jun22.jpg r1 manage 2759.3 K 2022-06-16 - 03:17 JustinAlbert Photograph, taken 15 June 2022, of the second ALTAIR photodiode readout (TIA & digitization) board to be populated, sitting in Andrew Macdonald's microscope for board soldering.
PDFpdf AndrewMacdonaldTIA_DAQTestReportALTAIR2022-06-01.pdf r1 manage 324.6 K 2022-06-16 - 03:31 JustinAlbert Report from June 1, 2022 from Andrew Macdonald regarding a fix for the latch-up problem that he had been seeing on the ALTAIR photodiode readout (TIA & digitization) board, via a 2 kHz RC low-pass filter
JPEGjpg BadUSBMiniBCablesFromAliExpress_SupposedToBe8cmLongAreReally10Inches_14jun22.jpg r1 manage 3367.1 K 2022-06-16 - 03:14 JustinAlbert Photograph, taken 14 June 2022, of the 30 bad USB-mini-B cables that I had ordered 2 weeks ago from AliExpress and received earlier in the day. They were supposed to be 8 cm long, and as can be seen, they are 3x longer: 10". They are almost certainly too big/long to fit in their place inside ALTAIR.
JPEGjpg PhotodiodeFrontEndModuleProblematicShieldLipPhoto_13jun22.jpg r1 manage 2490.3 K 2022-06-16 - 22:00 JustinAlbert Photograph, taken 13 June 2022, of the problematic shield lip on the ORCASat photodiode front-end modules (that can unintentionally short the photodiode anode line to the shield ground)
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Topic revision: r3 - 2022-06-16 - JustinAlbert
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