Here are minutes of our meeting on Thursday -- please just reply with (or let me know) any corrections -- thanks!:
Phoning in: Arnold Gaertner (NRC), Yorke Brown (Dartmouth), Cordell Grant and Houman Hakima (UTIAS-SFL), and our 3 JHU students working with Nathan & Susana
The latest drop tests with the new parafoil and modular cutdown system are now uniformly successful, and Yorke believes that he and Cynthia are ready for a flight as soon as the weather clears up in Hanover. (The forecast and current weather are not so great, lots of rain and clouds there, but hopefully there will be some clear days/nights before snow starts to stick.) Yorke is working on some updates to his diffused-LED-based low-cost light source, and has a few needed software updates to make prior to the next flight (and also he'll shortly work on the back-up telemetry card with a second DNT transceiver, but will work with the current system in the meantime).
Houman and Cordell are progressing well with the 3-D modelling of the nanosat payload, and of the multicolour laser module. Houman has some new solid-model renderings, and now is working on a light-tight shroud to go around the light path between the laser and the integrating sphere.
Our three JHU senior undergraduate engineering design students working with Nathan and Susana had some more excellent questions regarding cutdown and light source. They have moved from considering hot-wire-based cutdown to motor-based cutdown. Advice for JHU includes having telemetry be an even higher priority than cutdown, i.e. not simply depending on a "launch-and-forget" return-to-home system without some form of tracking the balloon in real time throughout the flight, because if one is without any real-time tracking, the chance of just losing it is extremely high, and then one would learn little to nothing from the flight or where one went wrong (except in the fairly small chance of someone serendipitously recovering it and contacting the launch team) -- telemetry really is key. Regarding light source, JHU using one of Yorke's diffused-LED light sources is suggested (either that, or just one, or a set, of bare LEDs). Yorke's new sources will have an integrated photodiode, but require a stable 5V power supply and the correct readout for the photodiode.
We now finally have a ballpark quote from Buoyant Aircraft Systems (actually from the sealing company they are using, which is in fact a specialty garment manufacturer in Winnipeg) -- a superpressure balloon meeting our specs will be $5k, which is not cheap, but is not crazy either. We will continue to move forward with getting one made for us to test out. It will have an electronic bleed valve at the bottom, so instead of descending by parachute/parafoil, we would release helium from the balloon and descend that way, so the balloon (and even much of the helium) will be reusable. (Note that parafoil-like control, as well as control at operating altitude, could be achieved with small motors / propellers.)
We have some more progress on the photon scattering in a diffusive medium study (a few plots at https://particle.phys.uvic.ca/~jalbert/photontoymc.pdf) and I'll be sending more soon on this, as well as on analytic photon scattering calculation results, and comparison between the two methods, very shortly. Additionally I'm working on a proposal for an Ericsson-Canada grant program due by the end of this month (http://www.uvic.ca/hsd/current/facultystaff/rcpd/centres/Ericcson%202014%20Invitation%20Letter.doc) for a long-range optical transceiver for very long-range (up to 100 km and beyond) ground-to-balloon, as well as ground-to-LEO and ground-to-ground (as Ericsson is interested in those), nighttime communication.
That's all I remember, please send things that I forgot. Next telecon in two weeks, on Thursday, Nov. 6 at 1:30 pm Eastern time (Skype again).
cheers, thanks all! justin
On Thu, 23 Oct 2014 00:52:11 GMT, Justin Albert wrote:
> Hi, > > Telecon tomorrow (Oct. 23) at the usual time: 1:30 pm Eastern (10:30 am > Pacific, 19.30 European). Discussion items include: operations status > and upcoming flights, light source modelling, goniometric and pre- and > post-flight calibration, nanosat and new laser module design, > computing/website, grant applications, and recap of schedules. A > reminder of the CSA project timeline is attached. > > I will try Skyping-out, rather than your having to Skype in, to the > conference tomorrow -- I will Skype-call the group containing everyone > on ALTAIR whom I have as a contact. So here's how to connect tomorrow: > > 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 call you at the > usual time (1:30 pm Eastern, 10:30 am Pacific). 4) If there is any > trouble, or if you don't get a call for some reason and would like to > join, just send me an e-mail ( jalbert@uvic.ca ). > > Here's the tentative agenda: > I) Progress toward flights, drop tests, robustness improvements, other operational work > II) Light source studies and modelling, pre- and post-flight calibration, and goniometric calibrations > III) Nanosat, new integrating spheres, and multicolour laser module designs > IV) Computing/website > V) Grant applications > VI) AOB > > Talk to you all tomorrow, thanks! > justin > > Attachments: > http://projectaltair.org/HyperNews/get/AUX/2012/11/12/18.02-43361-Schedule-20120702_hqp.pdf >