Copyright, 1996 © Dale Carnegie & Associates, Inc. Design and Development of Small Balloon Payloads Prepared for Chris Koehler’s Gateway to Space Class Feb 2001 by Mike Manes,

Syllabus EOSS experiment proposal and review process Launch, flight and recovery environment Mechanical, thermal and EMC considerations Integration and testing Preflight and launch operations EOSS Shuttle command and telemetry interfacing Postflight analysis and reports

EOSS Proposals and review Initial proposal to EOSS membership for OK and scheduling Preliminary design review (PDR) – –Feasible, light, reliable, safe? Integration and testing – –As required for all but simplest payloads – –EOSS project lead available to assist if needed Critical design review (CDR) – –Ready to fly? Postflight report – –What did we learn?

Launch, flight and recovery environment Flight string prep at rural, open launch site Launch stresses: jerk and possible ground impact – –Windy launches can kill payload outright ~ 1000 fpm ROA to 100 k ft (10 mbar) in 90 min. Tropopause air temp ~ -80C Post-burst trauma: rapid accel to near Mach 1, line snap, unusual attitudes Cold, humid air infiltration on descent Landing impact ~ 2000 fpm Parachute drag at near surface wind speed Recovery virtually guaranteed by EOSS – –Provide T&R team with power-down, disarm instructions

Mechanical, thermal and EMC considerations FAR 101 limits: 6 lb, 3 oz/sq in - lighter is better Foamcore & hotmelt construction is flightworthy – –See Proceedings paper Tie down internal components, use stranded wire Don’t rely on convective cooling at 10 mbar 0.25” foamcore with tight seams -> -25C typical If in doubt, cold soak using dry ice in beer cooler Telemetry and ATV transmitters WILL get into analog circuitry! – –short harnesses; ground, shield and bypass! – –Integration testing is essential for sensitive payloads

Integration and testing Ensures that the experiment is compatible with EOSS hardware and flight environment Effort depends on complexity and extent of Shuttle support Simplest payloads need but a preflight show & tell Debugging complex payloads has run past finals K.I.S.S! Especially with early flights, tight schedules

Preflight and launch operations Typical setup at launch site at for launch to avoid winds and dark recovery. Minimize launch morning payload prep and test Never give Murphy and even break! At least one payload handler on the launch team At least one monitor / controller at ground station for payload checkout and assist in-flight operations Accompany Tracking and Recovery teams?

EOSS Shuttle Command & Telemetry interfacing Standalone conforms to K.IS.S. Shuttle II once had 6-ch 10-bit analog tlm and digital ground commanding, but is now old, tired and brain damaged. Low-res live TV imaging is available Shuttle III work is underway with PnP experiment interface and better ATV - plan for 2Q ‘01 Hobo data loggers are flight proven and best bet for near future - avail at RadioShack.com - cheap.

Postflight Analysis and Reports Usually presented at the EOSS membership meeting following the flight - valuable interchange of ideas and observations from the various teams Good professional experience for both industry and academic careers. Most important part of the entire project is compiling & disseminating what was learned. Even dismal failures can teach a lot - (this is why EOSS is so knowledgeable!) But success is a LOT more fun - s o o o... K.I.S.S!

Cubesat / EOSS Flight line Interface Specification 1200 gm latex balloon 1.8 m diam parachute EOSS Cutdown / CW Beacon EOSS GPS & telemetry 4x CU Cubesats spaced 12” 2.4mm braided Dacron line Anti-abrasion bushings, 3.6~5.5 mm ID, top and bottom. Figure-8 knots, top & bottom. Eyebolts >5mm ID Preferred Alternate Cubesat, <10 cm, <500 gm