Discussion Forum » General »

Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all!

Very happy New Year!!! -- and our first telecon of 2023 tomorrow (Jan. 5 in North America, Jan. 6 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 22.00 European, 9 am Eastern Australia). The ORCASat cubesat was deployed out of the ISS into its own orbit at 1345 UTC on Dec. 29; and then on New Year's Day, our project managers Alex Doknjas and Levente Buzas successfully detumbled ORCASat and put it into a "Y-Thomson spin," in preparation for putting ORCASat into nadir-pointing mode. (If you happen to not be familiar with this particular aspect of orbital dynamics -- as I also wasn't as well a couple of years ago! -- Y-Thomson spin is described very well in
.) ORCASat will need to be in nadir-pointing mode (rather than its current Y-Thomson spin) in order for the ORCASat light source to be optimally viewable by the telescope(s) that ORCASat calibrates; but ORCASat will remain in Y-Thomson spin this week, in order to get a week's worth of telemetry that shows nothing unexpected is happening. Next week (barring the unexpected), Alex and Leve plan to move forward with getting ORCASat into nadir-pointing mode. Each ORCASat attitude determination and control system (ADCS) aspect has to be commissioned one at a time, so this is a bit of a slow process ... but that is perfectly OK! -- since ORCASat overpasses of Chile (where the nominal source-on overpass location is located) don't start to be at nighttime until near the end of this month! -- so we have until around Jan. 25 to commission the ADCS and other aspects of ORCASat before starting to eat into any possible observing time of ORCASat! (And we presently appear to be easily on target for that!) First optical ground observations (with DECam on the Blanco 4m on Cerro Tololo in Chile) are still planned for near the end of this month!

Air Canada has presently stranded me in Toronto, but I'm supposed to get back to Victoria late tonight. I'll send more on ALTAIR status in the progress report just before the telecon tomorrow. 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; ALTAIR gondola and payload solid models; computing / website / TWiki forums and e-mails; grant applications; and recap of schedules.

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 - 2023-01-04

Hi all!

My apologies for the delay! -- here's the update on recent ALTAIR balloon work, minutes of the telecon 3 weeks ago on Dec. 15, 2022 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 20 mins from now :

First, just one sentence on ORCASat summarizing the info in the telecon announcement from yesterday (message quoted below): ORCASat is presently in a Y-Thomson spin, in preparation for being put into nadir-pointing mode next week for observations later this month -- telemetry so far looks excellent / nominal!

I returned to Victoria late last night to very happily find this morning that Andrew Macdonald has made excellent progress in the past few days on populating the half of an ORCASat photodiode readout board for the purpose of performance comparison with the two ALTAIR photodiode readout boards: he's completed that population (and now he just needs to electrically test the board)! Here's a photo of that board:

on Andrew's workstation:

Additionally, Andrew has made more progress with writing/debugging Arduino code to get the data from the ADCs. Thus, after the third ALTAIR board is also populated, we'll be able to re-make Adithi Balaji's nice plots of transimpedance amplifier linearity:

in order to fix the problems with the reverse-bias plots in the above, as well as make new versions of the plots for the newer boards.

Over these next two weeks, I'll finally get a chance to make additional updates to the AIFCOMSS code that I committed approximately three months ago ( https://github.com/ProjectALTAIR/AIFCOMSSwithCUPredictorTest ) in order to start adding station-keeping algorithms to AIFCOMSS. (Teaching plus organizing local events for the ORCASat launch, etc, had been swamping me!!! But I should finally have a respite which allows me to get this task done by late next week.)

The two 144 MHz Raveon M8S data modem transceivers are still here in my office (together with the LiPoly batteries that power them). I got a chance to do some initial tests of 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/ ), and there were some issues -- I'll also be working on those over the next 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 a year 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 about a year ago, and thus I pinged them 11 months ago to follow up, and again 10 months ago -- and Radiometrix hasn't replied to those yet either. I will be pinging Radiometrix on this yet again next 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:

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 20 minutes from now! -- see below for Skype instructions.

Cheers, talk in 20 mins (!) from now -- thanks all!


-- Justin Albert - 2023-01-05

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg ALTAIR_ORCASatHalfBoardForComparisonPopulatedByAndrewMacd1_5jan23.jpg r1 manage 2698.5 K 2023-01-05 - 21:21 JustinAlbert Photograph, taken 5 Jan 2023 by me, showing the populated half of an ORCASat TIA board (populated by Andrew Macdonald), which will be used for comparison with the new ALTAIR photodiode readout boards
JPEGjpg ALTAIR_ORCASatHalfBoardForComparisonPopulatedByAndrewMacd2_5jan23.jpg r1 manage 2621.3 K 2023-01-05 - 21:22 JustinAlbert Photograph, taken 5 Jan 2023 by me, showing Andrew Macdonald's workstation with the populated half of an ORCASat TIA board, which will be used for comparison with the new ALTAIR photodiode readout boards
Edit | Attach | Watch | Print version | History: r2 < r1 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r2 - 2023-01-05 - JustinAlbert
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    Altair/Forum All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2023 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback