Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (May 27 in North America, May 28 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). We have some recent updates on AIFCOMSS -- a few summer students here (Colton Broughton, Sarah Alshamaily, and Will Stokes) have been working on it. Andrew Macdonald is still working on the layout for the new ALTAIR form-factor version of the ORCASat transimpedance amp board. Progress also continues to be made on optical simulation and on measuring electrical characteristics of the photodiode readout. 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 a progress report 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
VII) AOB

Talk to you all tomorrow, thanks!!!
justin

-- jalbert - 2021-05-27

Hi all,

My apologies for the delay! -- here's an update on recent ALTAIR balloon work, minutes of the last meeting on May 13 (attendees Liviu Ivanescu [Sherbrooke] and me -- btw, Arnold Gaertner [NRC], me, and ORCASat colleagues had a separate ORCASat meeting on May 19), and a reminder of the telecon in 15 minutes(!) from now:

Andrew Macdonald is still working hard on the ALTAIR form-factor version of the ORCASat transimpedance amp boards, per his schematic from 3 weeks ago:

which goes along with his spec sheet here:

) and he should finally have layout and Gerber files by next week, and will send them out for fabrication the week after.

Summer students Colton Broughton, Sarah Alshamaily, and Will Stokes are working on installing AIFCOMSS ( https://github.com/ProjectALTAIR/AIFCOMSSwithCUPredictorTest ) on their laptops, and seeing what updates need to be made on it. Two things that we know most definitely need updating (or, rather, creating) are the station-keeping software for AIFCOMSS, and the online command-handling within the onboard Arduino software -- but right now the students are seeing if there are any other issues needing fixing with AIFCOMSS on any of the 3 platforms (MacOS, Windows, Linux).

I still need to test out out Radiometrix SHX1 144 MHz transceiver modules that were returned to us last month from Radiometrix (following their firmware update to fix the BUSY output):

as well as our two 144 MHz Raveon M8S data modem transceivers:

Once we get our 144 MHz transceivers settled and back into the ALTAIR gondola, we'll do some outdoor drop testing of the actual gondola. (We've done all the outdoor drop tests I can think of doing with our dummy gondola.)

And we also still need to test out our new DFRobot SEN0177 payload aerosol monitors that we have here:

We'll finally receive our metrological 1MOhm resistor from Guildline next week (its calibration by Guildline is finally done -- they just need to ship it out to us). When that arrives next week, we can use it together with our precision 1/1000 voltage divider, using one of these precision matched combined resistors: https://www.digikey.ca/en/products/detail/caddock-electronics-inc/1776-C6815/4360753?s=N4IgTCBcDaIIwHYEDYC0BhZAOOBWVAcgCIgC6AvkA and an ultra-low-offset-voltage op-amp: https://www.digikey.ca/en/products/detail/texas-instruments/TLC2652AIP/277463?s=N4IgTCBcDa4JwDYC0BGAHOpBWJA5AIiALoC%2BQA , and also our PDVS2mini calibrated voltage source (https://www.ianjohnston.com/index.php/onlineshop/handheld-precision-digital-voltage-source-2-mini-detail), so that we can reliably and very precisely put 1 uV (or even 500 nV) through the Guildline 1MOhm resistor to have a very precise 1 pA (and/or even 500 fA) current source for calibrating the TIA boards.

I've begun to look some more at MEEP (https://meep.readthedocs.io/en/latest/) for finite-difference time domain (FDTD) simulation of integrating sphere output, but I haven't yet had time to make any significant progress there -- I'm hoping to do that in the next couple of weeks. It will be interesting to compare that with ray tracing simulations, when I can get a chance to do 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

-- jalbert - 2021-05-27