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Telecon tomorrow (Thursday) @ 5 pm Eastern time

Hi all,

Lots of new info to show, so please join and give social distancing a temporary teleconferencing taunt tomorrow (Apr. 2 in North America, Apr. 3 in Australia) at the regular time: 5 pm Eastern (2 pm Pacific, 11 am Hawaii, 23.00 European, 8 am Eastern Australia)! Two new drop tests were done yesterday, one of which (using an additional short spar as a center cross-tie) was especially successful and should form the basis of a "foolproof" recipe to ensure good parafoil behavior on opening. Also yesterday our four Radiometrix SHX1 144 MHz transceiver modules were shipped to Radiometrix in England for a firmware update to finally fix the BUSY output issue. 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 - 2020-04-01

Hi all,

Apologies for the delay! -- here are minutes of our last telecon on Mar. 5 (attendees Arnold Gaertner [NRC] and me), an update on ALTAIR balloon work, and a reminder of the telecon in 20 minutes(!) from now:

On Tuesday we had a very successful -- essentially perfect -- drop test, done by adding a center cross-tie to the parafoil spar frame, as shown in the following photo:

and here you can see the video of the drop test itself:

As mentioned the parafoil spar frame is made from our 10' long thin (1/8" diam) white fiberglass rods from McMaster-Carr, the little plastic corner clips (aka mini gusset plates) that I had machined a month ago, and green bamboo garden stakes for the short spars (I've been using those for the short spars just because I happened to have them around, and because they fit perfectly, however any wood or plastic dowels would do for those). The test above added a short bamboo cross-tie spar across the middle of the spar frame, as shown in that first photo above.

I also did a different (and rather less successful) drop test earlier on Tuesday using two parafoils instead of one (in hope of a more gentle / slower descent to Earth), but 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). Here is a photo of the setup of the two parafoils, and their semi-frames, prior to the drop:

and here is the video of that drop test itself:

I will be doing more drop tests, with a variety of configurations, this weekend, to see if the configuration in the first drop test above is very consistently as good as in that test; as well as trying other configurations that I haven't tried yet, just to see how they turn out.

A month ago I got the wonderful news that Radiometrix has developed a firmware update that solves the BUSY output issue with their/our SHX1-144-5 144 MHz transceivers. They sent me the following message:

Dear Justin,

Yes, we have now implemented BUSY function on SHX1. Please find attached oscilloscope screen capture showing Transmit Data, Received Data and BUSY output.

BUSY normally stays low, goes high when there is data in the Receive buffer, which need to be emptied before transmit data is fed into SHX1.


great! -- and here are Saba at Radiometrix's oscilloscope screen captures showing the oscilloscope traces of those respective outputs, during short and long messages sent from the transceiver:

The above traces look excellent to me. This module firmware update requires the transceiver modules to be sent back to Radiometrix for them to do the update (it requires access to the inside of the module), so we unsoldered the SHX1 modules from our boards and packaged them up:

and on Tuesday we shipped them back to Radiometrix in England (they're in Harrow on the outskirts of London). It should arrive there late next week, so we should have them back sometime around the end of this month, after Radiometrix does the update, tests them out, and sends them back to us.

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.

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

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


-- jalbert - 2020-04-02

Title Telecon tomorrow (Thursday) @ 5 pm Eastern time
Forum ForumGeneral
Topic attachments
I Attachment History Action Size Date Who Comment
JPEGjpg ALTAIRBothParafoilsButNoCrosslinksForDropTest31Mar20.JPG r1 manage 2591.8 K 2020-04-01 - 23:36 JustinAlbert Both parafoils, with spar frames but no diagonal crosslink spars (since we only have 4 long fiberglass rods at present), nor center cross-tie spars
Quicktime moviemov ALTAIRDropTestWith2ParafoilsNoCrosslinkSpars31Mar20.MOV r1 manage 4191.5 K 2020-04-01 - 23:39 JustinAlbert A first drop test with both parafoils, both with spar frames but no diagonal crosslink spars (because we only have 4 long fiberglass rods at present), nor center cross-tie spars
Quicktime moviemov ALTAIRDropTestWithFullSparFramePlusCenterCrosstie31Mar20.MOV r1 manage 3641.8 K 2020-04-01 - 23:40 JustinAlbert A first (and very successful) drop test with a center cross-tie spar added to the full spar frame on the yellow parafoil
JPEGjpg ALTAIRYellowParafoilWithFullSparFramePlusCenterCrosstie31Mar20.JPG r1 manage 2696.9 K 2020-04-01 - 23:25 JustinAlbert ALTAIR yellow parafoil with center cross-tie (bamboo stake in the center) added to the spar frame
JPEGjpg All4SHX1TransceiversForShippingBackToRadiometrixForFirmwareUpd29mar20.JPG r1 manage 1612.0 K 2020-04-01 - 23:28 JustinAlbert All four of our Radiometrix SHX1 144 MHz transceiver modules packed for shipping to Radiometrix for firmware update to fix the BUSY output
PNGpng RadiometrixSHX1-144BUSY1byteOscilloscopeScreen.png r1 manage 549.4 K 2020-04-02 - 01:33 JustinAlbert Oscillioscope traces sent by Saba at Radiometrix showing a 1-byte message with associated BUSY output sent by an SHX1 module with updated firmware
PNGpng RadiometrixSHX1-144BUSYDelayInDetailOscilloscopeScreen.png r1 manage 401.8 K 2020-04-02 - 01:32 JustinAlbert Oscillioscope traces sent by Saba at Radiometrix showing the BUSY output, with a detailed view of the time delays, in a message sent by an SHX1 module with updated firmware
PNGpng RadiometrixSHX1-144BUSYLongMessageOscilloscopeScreen.png r1 manage 356.5 K 2020-04-02 - 01:31 JustinAlbert Oscillioscope traces sent by Saba at Radiometrix showing a long message withy BUSY output sent by an SHX1 module with updated firmware
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Topic revision: r3 - 2020-04-03 - JustinAlbert
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