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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Telecon tomorrow (Apr. 16 in North America, Apr. 17 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 7 am Eastern Australia). Some more successful outdoor drop tests have been done; Radiometrix is presently updating and testing our SHX1 144 MHz transceiver modules; and engineering students Josh Gage and Evan Moore are presently testing out some new laser diodes and photodiodes. Also, some more testing of the new Raveon M8S data modems in the lab, new Hamamatsu and Thorlabs photodiodes are here in Victoria and ready to be tested, and progress on AIFCOMSS station-keeping prediction/simulation software. 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

Talk to you all tomorrow, thanks!!!

-- jalbert - 2020-04-15

Hi all,

Apologies for the delay! -- here are minutes of our last telecon on Apr. 2 (attendees Karun Thanjavur [UVic] and me, and apologies from Arnold Gaertner [NRC] whose home computer is currently missing a microphone), an update on ALTAIR balloon work, and a reminder of the telecon in 5 minutes(!!!) from now:

I did a couple more drop tests, one to confirm that basically perfect drop test done 2 weeks ago with the yellow parafoil, by using the same setup except with the red parafoil, i.e. with a full spar frame including diagonal cross-spars as well as a center cross-brace. This confirmed that successful test, as you can see in the video here:

as compared with the test from 2 weeks ago:

I also did another 2-parafoil drop test, again with no diagonal spars on the spar frames (because I am only presently in possession of 4 of the long 10' fiberglass rods, and we would need 8 of those to have full spar frames on both of the two parafoils), but with center cross-braces added to both parafoils. That confirmed the need for also having the diagonal cross-spars (and thus I'll need to get more fiberglass spars when possible):

In the drop tests back on Mar. 31, 1 of our 4 long fiberglass spars suffered some damage:

I repaired it, using a short hollowed nylon rod (to act as a "cast" around the breakage) and a pair of M3 set screws, as can be seen here:

but this further indicates that I need to get more fiberglass spars! The reason that I think that spar suffered its breakage is that the steel set screws that I need to use to affix the spars into the plastic gusset plates can (and do) create little nicks in the fiberglass, which can weaken that spot in the spar, and make the spar much more likely to break in that spot when the spar bends a lot. The solution to this is to get a good set of nylon (or other plastic) set screws and use those instead of the standard steel set screws. However, somewhat similar to 10' long 1/8" diam fiberglass rods, short M4 nylon set screws are not something one tends to find a good stock of in one's local hardware store, so I'll need to order those from McMaster-Carr, or other, as well. Remembering back to when I ordered the spars in the first place, the spars themselves were only about $5 apiece, but McMaster-Carr charged me about $250 USD in shipping to get them here to Victoria. So, I think it would be best to wait a couple months (until the pandemic subsides) and then ship them to Washington State instead and pick them up there -- that would likely save over $200. So I think it's time to have a temporary hiatus on drop tests -- declare success for the time being -- until I can more easily pick up some more spars in a couple months from across the border.

Radiometrix now has our four SHX1-144 transceiver modules (they arrived there in Harrow on Apr. 6) and is doing their firmware update that solves the BUSY output issue. They'll then test them out, and then send them back to us hopefully before the end of this month.

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 successfully 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.

Engineering students Josh Gage and Evan Moore are working on testing out some new laser diodes of ours this week -- here is the testing procedure that they developed: https://wiki.heprc.uvic.ca/twiki/pub/Forum/ForumGeneral0052/LaserWingsAndOpticalStopsTestPlan.docx

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 (new engineering student) to try out -- he's taking a few weeks to ramp up, and will produce some linearity, etc., plots from them soon.

I'm also working with another undergraduate student on the actual station-keeping algorithm for AIFCOMSS. Presently the "station keeping" code in AIFCOMSS just turns on the propellers in the simulation at full power, and propels the gondola in a single direction until the battery runs out (it's presently most certainly not actual "station keeping"). I added some hooks for adding actual station keeping algorithms into the code, and we're developing the algorithms and will implement them.

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 5 minutes from now (see below for Skype instructions).

Cheers, talk in 5 minutes(!!!) from now -- thanks all!


-- jalbert - 2020-04-30

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg ALTAIRBrokenLongFiberglassParafoilSparNeedsFixing_6apr20.JPG r1 manage 4326.5 K 2020-04-16 - 05:52 JustinAlbert A broken long (10') thin (1/8" diam) fiberglass parafoil spar (damaged in a Mar. 31 drop test), in need of repair
JPEGjpg ALTAIRBrokenLongFiberglassParafoilSparRepaired_6apr20.JPG r1 manage 3706.5 K 2020-04-16 - 05:54 JustinAlbert The broken fiberglass spar repaired using a short hollowed nylon rod (to act as a "cast" around the breakage) and a pair of M3 set screws
Quicktime moviemov ALTAIRDropTestRedPfoilWithFullSparFramePlusCenterCrosstie6Apr20.MOV r1 manage 3187.4 K 2020-04-16 - 05:43 JustinAlbert A second (and also successful) drop test with a center cross-tie spar added to the full spar frame (first test with this setup, but on the yellow parafoil, was on Mar 31 a week earlier), this time on the red parafoil
Quicktime moviemov ALTAIRDropTestWith2ParafoilsCenterCrosstiesButNoDiagCrosslinksAndSemiBrokenSparOnRedPfoil5Apr20.MOV r1 manage 6860.5 K 2020-04-16 - 05:40 JustinAlbert A second drop test with both parafoils (first was the previous week on Mar 31), both with spar frames but no diagonal crosslink spars (because we only have 4 long fiberglass rods at present), but this time with center cross-tie spars added. One of the long fibreglass spar frame rods was partially broken and repaired prior to test (see photos also attached).
Unknown file formatdocx LaserWingsAndOpticalStopsTestPlan.docx r1 manage 617.3 K 2020-04-16 - 05:35 JustinAlbert Engineering students' procedure plan for laser diode tests of optical stops and observation of tails of light output distributions
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Topic revision: r3 - 2020-04-30 - JustinAlbert
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