Discussion Forum » General »

Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all!

Telecon tomorrow (Nov. 3 in North America, Nov. 4 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 22.00 European, 8 am Eastern Australia). Andrew has finally fixed the noise in Board 2 of the newly-populated ALTAIR photodiode readout / transimpedance amplifier boards!!! And the ORCASat cubesat is still ready for launch on CRS-26 in just over 2 weeks on Nov. 18 !:
https://spaceflightnow.com/launch-schedule/ and
https://en.wikipedia.org/wiki/SpaceX_CRS-26
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. 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
VII) AOB

Talk to you all tomorrow, thanks!!!
justin

-- Justin Albert - 2022-11-03

Hi all,

My apologies for the delay! -- here's the update on recent ALTAIR balloon work, minutes of the telecon 2 weeks ago on Oct. 20 (attendees Arnold Gaertner [NRC], Liviu Ivanescu [Sherbrooke], and me), and a reminder of the telecon in 12 mins from now (!) :

Andrew Macdonald finally has successfully fixed the noise problem in the second of the populated ALTAIR photodiode readout / TIA boards !!!!!!! This was a long battle for him (about 6 months), but unsoldering and re-soldering all the ICs on the board (after previously having done that with all the resistors and caps on the board) finally did the trick! Andrew is not sure which of the ICs was the problem, but his guess (probably correct) is that it was the core op-amp of the TIA itself, the AD8638, that had been the somehow-mis-soldered IC that had been causing the noise. (A previous year-ago instance of mis-soldering causing noise on an analogous ORCASat board had, in that earlier case, been due to one of the many SMT resistors on that board, but that definitely wasn't the case this time.) Anyway, Andrew is now populating half of an ORCASat board for the purpose of performance comparison with these two ALTAIR boards (and with the also-soon-to-be-populated third ALTAIR board) -- here's a photo of Andrew at work on this ORCASat board today:

After those boards (i.e. half of the ORCASat board, and the third ALTAIR board) are 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 those new boards.

Over these next two weeks, I'll finally get a chance to make additional updates to the AIFCOMSS code that I committed a few weeks ago ( https://github.com/ProjectALTAIR/AIFCOMSSwithCUPredictorTest ) in order to start adding station-keeping algorithms to AIFCOMSS.

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:

https://particle.phys.uvic.ca/~jalbert/ALTAIR_M8S_Colton8dec21/

(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 12 minutes from now!!! -- see below for Skype instructions.

Cheers, talk in 12 mins (!!!) from now -- thanks all!

justin

-- Justin Albert - 2022-11-03

DiscussionTopicForm
Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg ALTAIR_AndrewMacdonaldPhotodiodeReadoutBoardTIAPopulatingORCASatBoardForComparison_3nov22.jpg r1 manage 3046.2 K 2022-11-03 - 20:35 JustinAlbert Photograph, taken 3 Nov 2022 by me, showing Andrew at his station populating (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: r3 < r2 < r1 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r3 - 2022-11-03 - 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