The CANDEL Project

CAN

Sat

DEL

ivery Project Laura Lewis Jens Ramrath Cecil Strickland

Background • • • Idea originated at the 1998 University Space Systems Symposium Expected Launch Date - Fall 1999 Participating Universities Include: Stanford Univ. of Tokyo Univ. of Hawaii Tokyo Inst. Of Tech.

Objectives • • • Design a carrier to house 12 CanSats Eject 12 CanSats from carrier Use onboard camera to view activity during deployment • • • Transmit pictures to specified location on Earth Reenter the Earth’s atmosphere Burn up on reentry

Initial Designs •Brainstorm concept at conference Our first design•

Final Deployment Design • • Use rotational velocity,  , as primary means of deployment Assist deployment by light springs 30° 

CanSat 2-D Design 70mm 142mm 382mm

Carrier Design • • Cylindrical case with a 382mm diameter Cylindrical burrows slightly larger than a “coke” can opening radially outward • Cylindrical area in middle for housing of camera, power, and tracking device • Thin wire covering CanSat openings

Can Attachment • Attached to: – Carrier – Adjacent Cans • Tether Joint

Subsystems Placement  Pressurized canister in the center of the carrier  Provides protection from the space environment  Reduces costs of subsystems

Satellite Subsystems • • • • Camera Suggestions Tracking Device Suggestions – GPS – NORAD Tracking Picture Transmittal Requirements

Camera CMOS Active Pixel Sensor • • • • • • • A single +3.3 V supply 11  pixel size - 512 x 512 pixel array Digital I/O Low noise Timing and control implemented in chip Low power (10mW at 1M pixels/sec) Radiation resistant compared to CCD’s

CMOS Active Pixel Sensor http://csmt.jpl.nasa.gov/APS/features

Dycam Modular Digital Camera • • • • • • Camera consumes 5V-9V at peak current Image organization 496 x 288 pixels Transmits picture to host computer upon request Camera has its own processor and memory (1 or 4 Megabyte) In sleep mode camera draws 3.5mA, awake mode 125mA, image capture 650 mA for 15ms Operated with Dycam’s Picture Viewer Software

Dycam Digital Modular Camera Camera Size: 63 x 24 x 197 mm Weight = 495 grams

Tracking Devices • GPS Options – Simple receiver • Contained in pressurized canister • Determines when pictures will be transmitted to receiver on Earth – Space-hardened • Expensive • NORAD tracking Picture from:www.sni.net

Transmittal Process – GPS • Transmit signal from satellite to receivers on Earth • Transmitter on Earth sends command to send pictures at appropriate time – NORAD tracking • Orbital Elements from NORAD will determine carrier location • Transmitter from Earth sends signal to receiver

Transmittal • Amateur band radio transmitter located on satellite • Device will be used to determine best transmit time to Earth • Various receivers will be placed all over the world to receive pictures

Requirements • • • • Camera Power – CMOS requires 10mW – Dycam requires 5-9 V at 500 mA peak current Ground Clock for picture transmittal GPS Power Power requirements will determine number of batteries needed

CanSat Deployment • CanSats move to final circular position using angular momentum and are restrained by tethers

CanSat Deployment • • • Carrier is ejected from primary payload Wire is heated and allows CanSats to eject CanSats will receive initial acceleration from springs

Manufacturing of Dispenser Three proposed materials: • • • Carbon-Epoxy composites Aluminum Foam

Advantages of Foam • • • • • Very light Easy to build satellite ourselves Can withstand vacuum Possible Temperature and radiation problems Several different kinds of foam available

Foam • • Expanded polystyrene – regular styrofoam – is permanently deformed by impacts • Extruded polystyrene – hard foam Expanded polypropylene – rubber-like foam – can withstand impacts

Tether • • There are several possible materials vectran – UV radiation resistant – zero creep parachute chord – cheap

Testing the dispenser • • Test model in 1-g environment Test in zero-g onboard NASA KC-135A aircraft (Vomit Comet)

Questions ?