Merry Xmas and Happy Holidays!!! Here are minutes of our telecon on Thursday Dec. 17 -- please just reply with (or let me know) any corrections -- thanks!:
Attendees: Yorke Brown (Dartmouth), Max Fagin (just graduated and received his Master's in Aerospace Engineering from Purdue!!!)
The three main topics of discussion this telecon were 1) the launch of the "bare" SPOT Trace (using a bunch of party balloons -- as a test for an educational side-project, in which classrooms in elementary and high schools around the world could launch SPOT Traces, thus tracking them to learn about winds in the Earth's atmosphere) the following day (Yorke and I then launched it this past Friday Dec. 18, and in 5 hours it flew from the launch site on the Green at the center of the Dartmouth campus, all the way to the middle of a forest near Canterbury, New Brunswick, Canada), 2) the status of the Meade telescope, and 3) Max Fagin graduating with his M.Eng. from Purdue this month!
Yorke and I launched the "bare" SPOT Trace the day after the telecon, as mentioned above, so here I'll give the debrief on that (and also my attempt to recover it from the forest in New Brunswick this past Sunday). This is for an educational side-project, as mentioned above, in which classrooms in elementary and high schools (both in North America and in developing countries, & possibly other developed countries) could launch company-donated SPOT Traces just using party balloons, and track them to learn more about winds at different levels in Earth's atmosphere. On Thursday I bought a bag containing 72 standard 12" party balloons from Party City in W. Lebanon, NH, as well as some kite string and a little 15" plastic parachute for an Estes model rocket (the last of which turned out to be unnecessary, as only a fraction of the balloons burst at altitude, and thus the SPOT ended up descending slowly anyway), cut 21 5' lengths of string as well as one 100-foot length of string from the spool of kite string, and looked at the HABHub site (http://predict.habhub.org) and the UWyo site (http://weather.uwyo.edu/polar/balloon_traj.html) for balloon flight path predictions for the following (Friday Dec. 18) morning (with assumptions of a launch from Dartmouth campus, 3 m/s ascent and descent rate, and a variety of different assumptions [7 km, 10 km, 20 km, and 30 km altitudes] for "burst altitude" [which in this situation, with multiple small balloons, is not actually a single altitude, rather just a vague effective approximation]). The flight predictions predicted a flight in the northeasterly direction from Hanover, with landing anywhere between northeastern New Hampshire and New Brunswick Canada, depending on the effective burst altitude. Since none of the flight predictions had it landing in the Atlantic Ocean (or any other large body of water, or very populated area), it was a go-ahead for launch on Friday morning. Yorke and I met in his lab on campus at around 8 am Friday to fill up the balloons (we already had the helium tank and regulator, from ALTAIR flights) and to tie them on the 5-foot lengths of kite string. We put the SPOT Trace on the bottom of the long 100-foot length of string, just in case the balloons got caught in a tree on landing, the SPOT in principle should have ended up on the ground. (As it ended up, the balloons did get caught in a tree on landing, but then apparently the wind freed them temporarily and dragged the balloons into another tree, which in the process dragged the SPOT up to the top of yet another tree! -- see recovery story below.) With the SPOT clipped onto 21 (helium balloons + 5' lengths of kite string), the setup was only neutrally buoyant (and at that point we hadn't added the 100-foot length of string yet), so we decided to add a second "tier" of another 21 helium balloons to the middle of the strings below each of the first 21 balloons. This added another 80 or so grams of lift, so that the setup was positively buoyant, and thus we then went outside and made completely sure that the SPOT was on, functional, and actively transmitting its current location to our account on the findmespot.com webpage. We then launched from just north of the center of the Dartmouth campus green at approximately 9:52 am Eastern time that morning Fri. 18 Dec. The surface winds were about 15 km/hr coming from the north, so the balloons started off flying nearly due south. (In fact, there was enough surface wind such that the long string only made about a 20 degree angle with the ground prior to launch, and when I let it go, the SPOT dragged along the grass for about 20 meters before the balloons actually lifted it off into the air -- no harm done certainly, although in hindsight it would have been nicer if I had run along with the SPOT Trace until the balloons actually lifted it off, so that there would be no ground-dragging.) The balloons + SPOT flew nearly due south for about 20 minutes, until they were over Lebanon NH 5 km south, and then the winds at altitude, which were coming from the southwest, caught the rising balloons, and then the balloons + SPOT made a 135-degree turn toward the northeast and began heading toward Maine very quickly as it continued to rise -- with ground track speed at literally about 100 km/hour, and its ground speed was even faster than that near the peak of its journey over the White Mountains (it flew almost directly over the summit of Mount Washington) and then Maine. As the SPOT Trace data does not (presently) report altitude (it just reports lat and long -- even though altitude information must exist since a 4-dimensional fix is of course required for it to determine its GPS location), we do not know what altitude it reached, but I surmise that it was somewhere above 2000 meters (the summit altitude of Mount Washington) and probably below 6500 meters (since that is the specification for the max operating altitude of the SPOT Trace -- although perhaps it might just continue to work above that altitude). The flight path was so long, despite its most probably not getting above 10 km altitude, since it did not ascend (or descend) at anywhere close to a 3 m/s rate -- the vertical ascent rate appeared on launch to be more like 1 m/s (or even less). But its ground speed continued to be very high through Maine until it slowed down (after it must have descended some, after some fraction of the balloons must have burst over the White Mountains and Maine) near the Canadian border, and then made a 90-degree right turn toward the southeast after it reached the St. John River in New Brunswick (over the very small town of Northampton, NB, about 10 km south of Woodstock NB). It then landed in the forest about 15 km southeast of that, about 1 km east of Charlie Lake, at 45.90624 N, 67.3643 W, at about 2:46 pm Eastern time (NB is on Atlantic time, an hour later than Eastern, but I will give all times in Eastern) with the nearest tiny town being Canterbury, NB (about 5 km west). It continued to be fairly windy over the next two days (but with no precipitation), so the balloons+SPOT continued to blow around in the trees there, which reflected itself in many small movements of the SPOT GPS location, through (but not much after) my visit there 2 days later on Sunday Dec. 20.
Yorke and I decided that I should drive up to NB and attempt to fetch it, as it appeared to be in a quite fetchable place (it was only about 100 yards away from a logging trail visible on satellite map). A long -- 7 hour + stops = 9 hour, each way -- drive from Hanover NH, but doable. Yorke was however not able to join me for that two-day event of a drive (he is building a new house near Hanover, and he is having family and guests for Xmas). On Saturday Dec. 19 morning I left Hanover for the drive up to NB, and I got to the Canadian border near Houlton ME around 6 pm that evening. It was well after dark, so there was certainly no hope of trying to find it in the forest that night (and then to drive back to NH overnight), so I found a nice cheap hotel outside Woodstock NB (about 15 km from the landing site). I set off again on Sunday (Dec. 20) morning to find it in the woods. I very fortunately was in an old 4WD Land Rover Defender (very kindly lent by my father for this trip) and thus the first part of the very pitted logging trail (with some fallen small trees) was passable by the vehicle, and thus I only had to walk about a mile at the end.
Pictures of the trip, and of the balloons and SPOT in the trees at the end, can be found in the directory:
After the mile of hiking at the end of the passable logging trail (fording through a small but fast river mid-way through the hike), the balloons and SPOT Trace were where they should have been (according to GPS) at 45.90624 N, 67.3643 W. However (as mentioned above) they were _both_ high up in separate trees, as apparently the wind must have freed the balloons temporarily after they landed, and dragged them into another tree, which in the process apparently must have dragged the SPOT up to the top of yet another tree, as it was right up there hanging at the top of a separate tree about 30 meters away, even higher up (about 40 feet above the ground) than the balloons. The SPOT itself is the (very) little thing at the very top of the tree on the right-hand side of IMG_2177.JPG, and also near the center of IMG_2179.JPG, in the photos in the directory above.
After phoning a friend (Yorke) to see if there were any bright ideas on how to get it down (both of us had none), I decided to head back down the hill to my vehicle, and to use the fact that I had purchased the "SPOT Product Replacement Plan," and thus, in principle, they should send us a replacement at no cost, no questions asked. (In hindsight, what I possibly should have done, once I found the SPOT up there, is to drive back down to the nearest town with a hardware store [Woodstock NB], gotten a little hacksaw, gone back up there, and just cut the little tree down -- since, certainly unlike the Hanover, NH area, no one would give the slightest care there if one were to cut down one small little tree in the middle of the forest in the middle of nowhere up there in NB. Anyway, c'est la vie -- that's what the SPOT product replacement plan is for in any case. And if I had gone to get a saw to cut it down, then instead of getting back to Hanover at midnight that night, I would have gotten at around 4 am.) So, the SPOT and the balloons are presently still up there at the tops of their trees at 45.90624 N, 67.3643 W, about 40 km east of Fredericton, NB, in the middle of the forest 100 yards from a rough logging path near Charlie Lake there in NB.
The ALTAIR Meade 12" LX200-GPS telescope (owned by Harvard) for which the computer control and display (which controls, and monitors, the slewing and tracking motors on its alt-az mount), stopped functioning at the beginning of this month, is still there in Yorke's lab at Dartmouth. Yorke will likely send it to Meade to get it repaired (on Chris Stubbs' kindly proffered tab, as he is the owner) right after xmas. First, though, Yorke might conceivably try another attempt at uploading new firmware to it from a different computer, as the Meade firmware bootloader would not work on the computer that Yorke first tried to do the updated firmware upload from, a few weeks ago.
Karun has a copy of the diffusive light source which Yorke sent up from Hanover -- Karun is leading the development at UVic of tripod-mounted devices to, in the field immediately before launch, and right after recovery, cross-check both photometry information, and yaw-pitch-roll information, from the ALTAIR gondola -- and having a copy of the diffusive light source is needed for the former. He is working with the machine shop (and the electronics shop) at UVic to develop and construct those devices, which will be accurate & precise to 1% or so (note that photometry checks which will be more precise than that will be done in the lab, most precisely at NRC, and/or NIST -- however we want to have the ability to do quick cross-checks in the field immediately before and after flight). Karun is also now working with a sample microcontroller board (with Microchip PIC18F87J50 microcontroller -- circuit diagram attached) from the electronic shop, to use for testing motor control for an ALTAIR motor and propulsion control microcontroller board we will be designing this term. He has now gotten the pulse width modulation code for it up and running -- video at https://particle.phys.uvic.ca/~jalbert/MotorAndPropTests/IMG_2136.MOV and now Karun has also solved the problem of simultaneous control of two propulsion motors, and of controlling a servo as well as propulsion motors. He's now working on monitoring the input from the on-chip A/D converters (which will be monitoring temperatures, motor RPM rates, and current flow). We just purchased a second little PIC microcontroller board: http://www.digikey.ca/product-search/en/programmers-development-systems/accessories/2621524?k=PIC18F97J94 with a more advanced version of the PIC18F87J50 -- the PIC18F97J94 -- so that we can test out that new one as well before we make our custom board with it. We also have the beginnings of a little mechanical test rig, the internals and externals of which can be found in the four attached photos, and in the following movie showing the lightweight but strong servo gearbox for rotation of the propulsion support axle: https://particle.phys.uvic.ca/~jalbert/MotorAndPropTests/IMG_2145.MOV When within ALTAIR, the motor and propulsion control microcontroller board will logic interface with Yorke's main board (in a similar way to how the present cutdown-motor control board interfaces with the main board. A separate propulsion battery will of course be carried.)
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.
We sent in our CSA FAST 2015 application in October, and the next one will be a NATO "Science for Peace and Security" application which will be due at the end of _January_.
*** CONGRATULATIONS *** to ALTAIR alumnus, and literal hero, Max Fagin, who just graduated this month with his Master's in Aerospace Engineering from Purdue!!!!! Max is continuing on to a critical role with a major space flight company here in the U.S. (name withheld upon request), in which he will be working very closely with NASA on our planet's next couple decades' goal of getting a few of our fellow human beings, alive and kicking, to Mars.
That's all I remember, please send things that I forgot. Next telecon in two weeks, on Thursday, Jan. 7, at 4 pm Eastern time.
cheers, thanks all, and have very happy holidays!!!!! justin
On Thu, 17 Dec 2015 02:49:56 GMT, Justin Albert wrote:
> Hi! > > Telecon tomorrow (Dec. 17) at the usual time: 4:00 pm Eastern (1:00 pm > Pacific, 10:00 am Hawaii, 22.00 European). Discussion items include: > flights in NH (including planned flight of semi-"bare" SPOT Trace); > Meade telescope(s) status and tests -- tracking, alignment, calibration, > and observation; light sources and light source modelling; goniometric > and pre- and post-flight calibration; propulsion work; nanosat bus and > payload solid models; computing/website; 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 (4 pm Eastern, 1 pm Pacific). > 4) If there is any trouble, or if you don't get a Skype-call for some reason and would like to join, just send me an e-mail (firstname.lastname@example.org). > > Here's the tentative agenda: > > I) Flight status and planning (including of the "bare" SPOT Trace) > II) Telescope tests, and current status -- tracking, alignment, calibration, and observation > III) Diffused light source, and its modelling, pre- and post-flight calibration, and goniometric calibrations > IV) Propulsion & motor control work > V) Nanosat solid models & Houman's thesis > VI) Computing/website > VII) Grant applications > VIII)AOB > > Talk to you all tomorrow, thanks! > justin
Attachments: http://projectaltair.org/HyperNews/get/AUX/2015/11/02/17.58-64210-asseminternal.jpg http://projectaltair.org/HyperNews/get/AUX/2015/11/02/17.58-182-assemexternal.jpg http://projectaltair.org/HyperNews/get/AUX/2012/11/12/18.02-43361-Schedule-20120702_hqp.pdf http://projectaltair.org/HyperNews/get/AUX/2015/10/04/14.03-62663-GPBoard.pdf http://projectaltair.org/HyperNews/get/AUX/2015/08/18/08.29-60788-ionDeadlines_Fall2015.pdf