Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (July 23 in North America, July 24 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). More updates on the design of our further-improved (lower noise) transimpedance amplifier board for the photodiodes, on updates of AIFCOMSS, and on the 144 MHz transcevers (Raveon and Radiometrix). We now (as of just today) have an account for the new CSA FAST grant, and UVic is now starting to work on the subgrants. 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 - 2020-07-23

Hi all,

Apologies for the delay! -- here's an update on recent ALTAIR balloon work, minutes of the meeting two weeks ago (attendees Arnold Gaertner [NRC] and Liviu Ivanescu [Sherbrooke]), and a reminder of the telecon in 15 minutes(!) from now:

Electrical engineering student Evan Moore has completed a new draft of his updated version of the low-noise transimpedance amplifier circuit for both ALTAIR and ORCASat (to further reduce noise in that circuit). Here is the most recent version of Evan's schematic:

and here are renderings of the board layout and (in images 5 and 6) its RF shielding:

Evan is now adding some RF shielding on the back of the board as well, and is modifying the connectors to the photodiodes. When that is completed, he's planning to get a couple of copies of the board fabricated for testing.

Radiometrix has our four SHX1-144 transceiver modules (they arrived there on Apr. 6) and is doing their firmware update that solves the BUSY output issue. They'll then test them out and send them back to us. Due to the COVID-19 situation in the UK, they've been taking a while. Very fortunately, the COVID situation is slowly starting to improve in the UK (although everyone is of course very wary of a likely second wave). I asked them about the status a few days ago, and they replied that they will hopefully be able to do this next week. We've also been doing more connecting up and testing out of our two new 144 MHz Raveon M8S data modem transceivers here in Victoria:

After checking them out with Raveon's Windows-based Radio Manager software, I've started to connect the radios up to Arduino Megas -- in the next few weeks I'm planning to get them talking to one another, and then I'll check out their effective ranges.

Once we get those 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.)

Since there exist a couple of miniature lightweight low-cost atmospheric aerosol particle size sensors that one can purchase and that could easily fit within our balloon gondola, for example the Alphasense OPC-R1: http://www.alphasense.com/WEB1213/wp-content/uploads/2019/08/OPC-R1.pdf and the DFRobot SEN0177: https://www.dfrobot.com/product-1272.html , I asked Liviu Ivanescu at Sherbrooke which of those sensors he would suggest we might possibly add to our payload, as having the additional info from such a sensor could potentially be quite useful to us. Liviu suggested we might try the DFRobot SEN0177, and thus I purchased one of those. It is now here -- on the bottom right of the photo below:

together with a Sharp GP2Y1010AU0F dust sensor SEN0144 and an MQ8 hydrogen gas sensor SEN0133, as well as adapters and cables, and will be tested out here this coming week.

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 - 2020-07-24