The CANDEL Project

CANSat DELivery Project

Laura LewisJens Ramrath

Cecil Strickland

Background

• Idea originated at the 1998 University Space Systems Symposium

• Expected Launch Date - Fall 1999 • Participating Universities Include:

Stanford Univ. of HawaiiUniv. of Tokyo 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

382mm

200m

m142mm

70mm

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

CameraCMOS 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 usingangular angular momentum and momentum and are restrained are restrained by tethersby 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 ?