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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all!

Telecon tomorrow (Jun. 2 in North America, Jun. 3 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). Regarding the ALTAIR-relevent ORCASat news from two weeks ago: The reason that only a single photodiode read out on each of the flight spacecraft and prototype when we did the calibration at NRC 3 weeks ago (following the vibration tests the prior week), was indeed due to the handmade cable assemblies within ORCASat that Alex had suspected -- and he thinks that he can completely fix, and is presently working on fixing, those cables so that they will each function reliably and robustly, even after the vibrations of ORCASat launch. So we're tentatively planning for ORCASat calibration at NRC in Ottawa again (this time of both photodiodes, again on both the flight spacecraft and functional prototype) 3 weeks from now on June 23 - 24 (and integration into the Nanoracks deployer at CSA hq just outside Montreal the week after that, June 27 - 28 -- with launch from KSC in FL in October). The ORCASat handmade cable assemblies are fortunately not an issue for ALTAIR: ORCASat cannot use standard PVC cable assemblies (or any PVC parts) due to PVC outgassing in space -- which is not considered a problem for ALTAIR, we have no such restrictions at all on high-altitude balloons. We thus intend to just use these little USB-mini-B male to male cable assemblies on ALTAIR:


between the photodiode readout/digitization boards and the photodiode front-end modules on the integrating sphere (whereas using PVC-containing cable assemblies like that is not possible on ORCASat -- handmade cable assemblies made with Kapton tape are instead required).

Andrew Macdonald has made a bit more progress testing his ALTAIR photodiode readout / transimpedance amplifier boards. I have some further updates on (and some quite successful results with!) some new large lightweight flexible solar panels (for future balloon-top usage!) that have arrived here for testing, and 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 plots 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 - 2022-06-02

Hi all,

My apologies for the delay! -- here's the update on ALTAIR balloon work -- and on closely related ORCASat issues, from the past couple of weeks, and a reminder of the telecon in 15 mins from now (!) :

As mentioned yesterday, Alex Doknjas (ORCASat project manager) figured out last week, by opening up the ORCASat functional prototype and checking the USB-mini-B cable assemblies between the photodiode readout board and the photodiode front-end modules, that those cable assemblies did indeed appear to be at fault: when the functional cable assembly was used to replace the non-functional one, the photodiode read out via that cable began reading out just fine again. A short between the photodiode anode readout line and ground within that faulty cable assembly in the prototype appears to be the problem. (A different short or disconnect is almost certainly the problem in the bad cable assembly within the flight spacecraft, due to the fact that its readout gives very different values that are more indicative of a disconnect -- Alex is working on the flight spacecraft right now.) Alex is confident that he and student Ben Kellman can make much better cable assemblies within the next 2 weeks (that will still, of course, satisfy the ORCASat requirement of using space-qualified, ultra-low-outgassing materials; which fortunately is not a requirement for ALTAIR, where we can just use simple purchased commodity little USB-mini-B cable assemblies), and then carefully test, install on both the ORCASat prototype and the flight spacecraft, and then carefully test them again together with the whole ORCASat system during that brief time. We're tentatively planning for ORCASat calibration at NRC in Ottawa again -- this time of both photodiodes, again on both the flight spacecraft and functional prototype -- likely 3 weeks from now on June 23-24 -- and then integration into the Nanoracks deployer at CSA hq just outside Montreal the week after that, June 27-28 -- with ORCASat launch to the ISS from Kennedy Space Center in Florida in October (and then deployment from the ISS into orbit around the very beginning of 2023).

Again, ALTAIR very fortunately doesn't need to use those handmade, space-qualified material, low-outgassing cable assemblies, and can/will instead just use the following little commodity USB-mini-B cable assemblies, of which I've ordered 30: https://www.aliexpress.com/item/32826885322.html . (Note that previously, ALTAIR has always just been using little SMA cable assemblies from the readout board directly to the photodiodes on the integrating sphere for this purpose -- but we all definitely want to switch to using ORCASat-like photodiode integrating sphere front-end modules that are thermally-monitored right at the PD, and easily interchangeable between PD types, etc. -- hence these little USB-mini-B cable assemblies.)

And, we're all very greatly looking forward to going back to NRC soon to do calibration, with Arnold Gaertner there of course! (and of course Eric Cote there too, together with all the other critical NRC staff!) again when we have these cable assemblies fixed and thus both ORCASat photodiodes working on both the flight spacecraft and functional prototype.

Andrew Macdonald has still been having issues in testing the ALTAIR photodiode readout boards, and specifically in fixing a mysterious latch-up problem that appears to occur with them when turning on the reverse bias (but that has never occurred with the ORCASat boards) -- but which hopefully can be avoided via good firmware procedures (specifically in only setting the reverse bias on or off before board power-up, and always maintaining that bias setting [either on or off] for as long as the board is powered up). More on Andrew's latch-up topic, etc, in a couple of 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 30 weeks ago, and thus I pinged them 28 weeks ago to follow up, and again 19 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 - 2022-06-02

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
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