AAE450 Spring 2009

Caitlyn McKay

Structures and Thermal

AAE450 Spring 2009

Passive Thermal Control Barbeque mode

– .1 deg/sec Space blanket

– Kapton: .005” thick, $15.50 per ft^2– Teflon: .031” thick, $21.47 per ft^2

Heat Pipe– .25” to 1” outside diameter carries 100W to 1000W– >10 kg for 1 m of pipe

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009

Active Thermal Control cryogenic cooler

– turbo-Brayton cryocoolers• very small mass and size• 4 to 10 Kelvin range

– Sunpower M77• $40,000• lift 4W at 77K for 100W input• large mass

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009

Barbeque Mode Used in Apollo Initial attitude that would place the

spacecraft side-on to the Sun while avoiding gimbal lock

Rotation of axis can begin to rotate causing coning

Tracking programs used to carefully control overall attitude as rotation progressed

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009

Space Blanket Hubble has 16 thin layers of dimpled

aluminized Kapton material covered by outer aluminized Teflon shell

less than one tenth of an inch thick Allows rovers to use smaller solar panels

and batteries

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009

Space Blanket Teflon

– withstand 260 ° C

Kapton– withstand -268 ° C to 400 ° C– .005” thick = 27 ft^2/lb

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009 [Name] [Group]

Heat PipeFigure based on M&M Metals website

AAE450 Spring 2009

Cryogenic Cooler Reverse-Brayton Cryocooler

– centrifugal compressor, recuperative heat exchanger, expansion turbine and thermal interfaces to the load and heat rejection devices

– radiator used to reject heat from the compressor space

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009 [Name] [Group]

Reverse-Braton CryocoolerFigure based on Creare website

AAE450 Spring 2009

turbo-Brayton Cryocooler Creare, Inc compressor, counterflow heat exchanger

and tuboalternator (expander) 1 million RPM used on NIMCOS

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009

References Barbeque Mode

– How Apollo Flew to the Moon by W. David Woods

Space Blanket– nasa.gov– kapton.dupont.com– professionalplastics.com

Caitlyn McKayStructures and Thermal

AAE450 Spring 2009

References Heat Pipe

– mmmetals.com– energytransferinc.com

Cryogenic Cooler– creare.com– cryo.gsfc.nasa.gov

Caitlyn McKayStructures and Thermal