Article

LPSU12/LOJHS04 Launch Ahoy                                                               June 8, 2009

How could I get you to read this? This launch was perfect! This launch was a disaster!
•    Cloudy, but not raining.
•    H2-filled 3000g latex balloon with 3 redundant tracking methods, a camera, and thoughtful experiments by the LO JHS students with ground data for comparison: creative, well-planned, and well-built. Included another cockroach—a big one. Teacher Greg Mylet's LOJHS story is attached below.
•    A handpicked student released the experiment to a countdown and cheers from the school student body. The balloon took off straight up for 20,000ft, then ultimately went 12.5miles SSW bursting at just over 110,000ft before screaming to earth, reaching a maximum speed of 463mph before decelerating to terminal velocity of ~44mph where it crash landed on a hangar roof at Aurora State Airport. All the luck! (see images for flight path)
•    But we didn’t find the payloads right away because they were retrieved within 15minutes after impact by one of the airport personnel—who witnessed the fall. We were there too—we just didn’t have access/clearance to the exact spot and missed it coming down from the east. ‘They’ returned our stuff, but the LO JHS boxes were not there. Yep, they must have fallen out during the flight, or something else. More on this later.
•    The parachute only partially deployed…thus, antenna broken, gps and camera shut off upon impact, battery of radio popped off, and multi-use Styrofoam box shattered. Oh, well. Just about every one of Ben’s photos turned out well and we include several here—973 RAW images were taken, 15GB.
The missing LO JHS boxes are a concern, but someday they will probably be returned since they fell over a populated area. Here’s a theory of where they went…See the attached figures that show rise rate data for two launches—this launch and the previous launch. The rise rate is pretty steady in general, but this launch had a bump in the rise rate just after 15:36 zulu time. The total payload was about 8 lbs, and the LO payloads were about 3 lbs. It can be shown that the decrease in weight should increase the rise rate of the balloon by about 20%. This is approximately the change in slope seen in the altitude graph for the LPSU12 graph. So, the point where the slope changes could be the point where the packages fell out. This point is identified on one of the figures and the region where they would have fallen is also identified. So if you get a wild hair and buy any of this argument, that would be a place to try looking. Without the parachute, those packages probably hit the ground at about 70mph, so the biodegradable boxes may not have fared well. But someday, search or not, they may return to the school.
Here are the stats…

LPSU…3000g latex balloon, Hydrogen filled, ~3.5lb free lift
Total payload 3.53kg (7.76lb),
Old tracker box (radio, antenna, gps, heater): 858g
New tracker box (camera and SX1 gps transmitter): 1101g
Dog tracker: 110g
Parachute: 129g
Total payload mass (incl. tape): 3.527kg

L.O. payload: 1336kg (2.94lb)
Experiments: great, involved… antifreeze, compass, UV experiments (skin cells, plant cells, etc., cockroach, …)

Launch time: 8:20:16 PST, 6/08/2009
Ave. rise rate: 1229ft/min
Max. elevation recorded: 110,522ft (10:04:14 PST)
Final descent rate: Approx 5,500ft/min (impact at about 44mph)
Max descent velocity: 463mph
Landing time: 10:26:17 PST
Total flight time: 126min
Ground distance: 12.5 miles SSW

People…
LPSU: Launch: Yongkang Chen, Ben Semerjian, Donald Bell, Jenna Faulkner, Max Gibson, MMW, and LPSU Alumns: Guy Lewis, Pete Levno, Brian Frasnelly
LPSU: Recovery: Ben Semerjian, Max Gibson, MMW, Alumns: Guy Lewis, Pete Levno, Brian Frasnelly
LPSU on the web: Donovan Finnestad (man in the air)