Aerogel in the NASA Stardust Mission Capture of dust from Comet - - PowerPoint PPT Presentation

Introduction NASA Stardust Summary

Aerogel in the NASA Stardust Mission

Capture of dust from Comet Wild-2 Edward Lilley

Hills Road Sixth Form College

January 2009

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Outline

1 Introduction

Properties Manufacture

2 NASA Stardust

Overview Particle Tracks

3 Summary

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

What is an aerogel?

Invented by Samuel Stephens Kistler in 1931 A dry, opencelled foam[1] (amorphous) Formed from a gel A colloidal structure with solid continuous medium and gaseous dispersed phase

Peter Tsou, Stardust PI, NASA Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

What is an aerogel?

Invented by Samuel Stephens Kistler in 1931 A dry, opencelled foam[1] (amorphous) Formed from a gel A colloidal structure with solid continuous medium and gaseous dispersed phase

Peter Tsou, Stardust PI, NASA Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

What is an aerogel?

Invented by Samuel Stephens Kistler in 1931 A dry, opencelled foam[1] (amorphous) Formed from a gel A colloidal structure with solid continuous medium and gaseous dispersed phase

Peter Tsou, Stardust PI, NASA Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Constituents

Silica – same as glass, sand & silica gel SiO2 Other Possibilities:

Aluminium oxide Sulphur oxide Selenium oxide Carbon Agar (organic) Various transition metal oxides In theory anything that forms a gel

Different aerogels have different properties Silica aerogel is most well-known & used

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Constituents

Silica – same as glass, sand & silica gel SiO2 Other Possibilities:

Aluminium oxide Sulphur oxide Selenium oxide Carbon Agar (organic) Various transition metal oxides In theory anything that forms a gel

Different aerogels have different properties Silica aerogel is most well-known & used

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Constituents

Silica – same as glass, sand & silica gel SiO2 Other Possibilities:

Aluminium oxide Sulphur oxide Selenium oxide Carbon Agar (organic) Various transition metal oxides In theory anything that forms a gel

Different aerogels have different properties Silica aerogel is most well-known & used

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Constituents

Silica – same as glass, sand & silica gel SiO2 Other Possibilities:

Aluminium oxide Sulphur oxide Selenium oxide Carbon Agar (organic) Various transition metal oxides In theory anything that forms a gel

Different aerogels have different properties Silica aerogel is most well-known & used

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Structure

Micropores around µm to nm scale Average particle size is 3 nm[4] “String of pearls”

Image: [3] Image: [2] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Density & Surface Area

95% to 99.8% porosity[1] Varies from 0.5 g cm−3 to 1.1 × 10−3 g cm−3 Lightest silica aerogel is least dense known substance Evacuated aerogel can be lighter than air Average surface area is 800 m2 g−1 – similar to ordinary silica gel Absorbs water very easily

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Density & Surface Area

95% to 99.8% porosity[1] Varies from 0.5 g cm−3 to 1.1 × 10−3 g cm−3 Lightest silica aerogel is least dense known substance Evacuated aerogel can be lighter than air Average surface area is 800 m2 g−1 – similar to ordinary silica gel Absorbs water very easily

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Density & Surface Area

95% to 99.8% porosity[1] Varies from 0.5 g cm−3 to 1.1 × 10−3 g cm−3 Lightest silica aerogel is least dense known substance Evacuated aerogel can be lighter than air Average surface area is 800 m2 g−1 – similar to ordinary silica gel Absorbs water very easily

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Density & Surface Area

95% to 99.8% porosity[1] Varies from 0.5 g cm−3 to 1.1 × 10−3 g cm−3 Lightest silica aerogel is least dense known substance Evacuated aerogel can be lighter than air Average surface area is 800 m2 g−1 – similar to ordinary silica gel Absorbs water very easily

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Density & Surface Area

95% to 99.8% porosity[1] Varies from 0.5 g cm−3 to 1.1 × 10−3 g cm−3 Lightest silica aerogel is least dense known substance Evacuated aerogel can be lighter than air Average surface area is 800 m2 g−1 – similar to ordinary silica gel Absorbs water very easily

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Density & Surface Area

95% to 99.8% porosity[1] Varies from 0.5 g cm−3 to 1.1 × 10−3 g cm−3 Lightest silica aerogel is least dense known substance Evacuated aerogel can be lighter than air Average surface area is 800 m2 g−1 – similar to ordinary silica gel Absorbs water very easily

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Thermal Conductivity

Most insulating substance known In air: k = 0.016 W/(m · K) (Air is 0.025)

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Thermal Conductivity

Most insulating substance known In air: k = 0.016 W/(m · K) (Air is 0.025)

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Thermal Conductivity

Most insulating substance known In air: k = 0.016 W/(m · K) (Air is 0.025)

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Toughness & Strength

Hardness is similar to glass Collapse occurs very gradually Rebound is eliminated High compression possible – possibly highest compressive strength to mass ratio[1] A typical silica aerogel can support 2000 times its own mass Young’s modulus E is 1–10 MPa

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Toughness & Strength

Hardness is similar to glass Collapse occurs very gradually Rebound is eliminated High compression possible – possibly highest compressive strength to mass ratio[1] A typical silica aerogel can support 2000 times its own mass Young’s modulus E is 1–10 MPa

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Toughness & Strength

Hardness is similar to glass Collapse occurs very gradually Rebound is eliminated High compression possible – possibly highest compressive strength to mass ratio[1] A typical silica aerogel can support 2000 times its own mass Young’s modulus E is 1–10 MPa

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Toughness & Strength

Hardness is similar to glass Collapse occurs very gradually Rebound is eliminated High compression possible – possibly highest compressive strength to mass ratio[1] A typical silica aerogel can support 2000 times its own mass Young’s modulus E is 1–10 MPa

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Toughness & Strength

Hardness is similar to glass Collapse occurs very gradually Rebound is eliminated High compression possible – possibly highest compressive strength to mass ratio[1] A typical silica aerogel can support 2000 times its own mass Young’s modulus E is 1–10 MPa

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Toughness & Strength

Hardness is similar to glass Collapse occurs very gradually Rebound is eliminated High compression possible – possibly highest compressive strength to mass ratio[1] A typical silica aerogel can support 2000 times its own mass Young’s modulus E is 1–10 MPa

Image: [8] Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Other Properties

Silica aerogels are cloudy blue Can be made transparent in zero gravity Only as toxic as its ingredients Low speed of sound[4] caerogel = 100 m s−1 cair = 343 m s−1 Highest known dielectric constant in a solid

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Other Properties

Silica aerogels are cloudy blue Can be made transparent in zero gravity Only as toxic as its ingredients Low speed of sound[4] caerogel = 100 m s−1 cair = 343 m s−1 Highest known dielectric constant in a solid

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Other Properties

Silica aerogels are cloudy blue Can be made transparent in zero gravity Only as toxic as its ingredients Low speed of sound[4] caerogel = 100 m s−1 cair = 343 m s−1 Highest known dielectric constant in a solid

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Other Properties

Silica aerogels are cloudy blue Can be made transparent in zero gravity Only as toxic as its ingredients Low speed of sound[4] caerogel = 100 m s−1 cair = 343 m s−1 Highest known dielectric constant in a solid

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Other Properties

Silica aerogels are cloudy blue Can be made transparent in zero gravity Only as toxic as its ingredients Low speed of sound[4] caerogel = 100 m s−1 cair = 343 m s−1 Highest known dielectric constant in a solid

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Other Properties

Silica aerogels are cloudy blue Can be made transparent in zero gravity Only as toxic as its ingredients Low speed of sound[4] caerogel = 100 m s−1 cair = 343 m s−1 Highest known dielectric constant in a solid

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Ingredients

Prepare gel – Tetraethoxysilane Si(OC2H5)4 Capillary structure prevents liquid flowing out Purified with ethanol repeatedly

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Ingredients

Prepare gel – Tetraethoxysilane Si(OC2H5)4 Capillary structure prevents liquid flowing out Purified with ethanol repeatedly

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Ingredients

Prepare gel – Tetraethoxysilane Si(OC2H5)4 Capillary structure prevents liquid flowing out Purified with ethanol repeatedly

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Ingredients

Prepare gel – Tetraethoxysilane Si(OC2H5)4 Capillary structure prevents liquid flowing out Purified with ethanol repeatedly

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Ingredients

Prepare gel – Tetraethoxysilane Si(OC2H5)4 Capillary structure prevents liquid flowing out Purified with ethanol repeatedly

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Supercritical Drying

Normal drying destroys structure (Xerogel) Solvent must evaporate out as a supercritical fluid Ethanol is dangerous at required temperature and pressure Must be replaced with CO2 High pressure increases expense

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Supercritical Drying

Normal drying destroys structure (Xerogel) Solvent must evaporate out as a supercritical fluid Ethanol is dangerous at required temperature and pressure Must be replaced with CO2 High pressure increases expense

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Supercritical Drying

Normal drying destroys structure (Xerogel) Solvent must evaporate out as a supercritical fluid Ethanol is dangerous at required temperature and pressure Must be replaced with CO2 High pressure increases expense

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Supercritical Drying

Normal drying destroys structure (Xerogel) Solvent must evaporate out as a supercritical fluid Ethanol is dangerous at required temperature and pressure Must be replaced with CO2 High pressure increases expense

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Supercritical Drying

Normal drying destroys structure (Xerogel) Solvent must evaporate out as a supercritical fluid Ethanol is dangerous at required temperature and pressure Must be replaced with CO2 High pressure increases expense

Edward Lilley Aerogel

Introduction NASA Stardust Summary Properties Manufacture

Uses

Insulation Capacitors Chemical adsorption High-velocity particle capture

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

The Stardust Mission

A mission to collect comet dust (‘stardust’) Information about formation of early Solar System Implications for astrobiology Launched on February 7, 1999

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

The Dust Collectors

132 blocks of aerogel[5] Graded density 1 m wide

Image: [7] Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

The Dust Collectors

132 blocks of aerogel[5] Graded density 1 m wide

Image: [7] Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Why Aerogel?

Light enough to fly Near-transparent Non-destructive obstruction of particles

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Why Aerogel?

Light enough to fly Near-transparent Non-destructive obstruction of particles

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Why Aerogel?

Light enough to fly Near-transparent Non-destructive obstruction of particles

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Characteristics

Two main types of track:

Type A—long, drawn out ‘champagne glass’[5], with widest point close to top; single, hard particle; 65% of tracks Type B—fragmented, subtracks, bits of particle lining track wall; 33% of tracks

Track lengths < 100 µm approach limit of resolution, so given as Type A Occasional split particle in Type A

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Characteristics

Two main types of track:

Type A—long, drawn out ‘champagne glass’[5], with widest point close to top; single, hard particle; 65% of tracks Type B—fragmented, subtracks, bits of particle lining track wall; 33% of tracks

Track lengths < 100 µm approach limit of resolution, so given as Type A Occasional split particle in Type A

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Characteristics

Two main types of track:

Type A—long, drawn out ‘champagne glass’[5], with widest point close to top; single, hard particle; 65% of tracks Type B—fragmented, subtracks, bits of particle lining track wall; 33% of tracks

Track lengths < 100 µm approach limit of resolution, so given as Type A Occasional split particle in Type A

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Characteristics

Two main types of track:

Type A—long, drawn out ‘champagne glass’[5], with widest point close to top; single, hard particle; 65% of tracks Type B—fragmented, subtracks, bits of particle lining track wall; 33% of tracks

Track lengths < 100 µm approach limit of resolution, so given as Type A Occasional split particle in Type A

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Characteristics

Two main types of track:

Type A—long, drawn out ‘champagne glass’[5], with widest point close to top; single, hard particle; 65% of tracks Type B—fragmented, subtracks, bits of particle lining track wall; 33% of tracks

Track lengths < 100 µm approach limit of resolution, so given as Type A Occasional split particle in Type A

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Calculation

Particles are normally too small to identify Relationship between particle diameter and entrance hole diameter established with pre-launch calibration Van der Graff dust accelerator used to fire glass beads at aerogel – 6 km s−1 Modeled with polynomial (quadratic) equation[5]: EHD = (60 ± 71) + 1.38 × OPD + 0.057 × OPD2 Mass of volume of aerogel enclosed by track is comparable to mass of particle[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Calculation

Particles are normally too small to identify Relationship between particle diameter and entrance hole diameter established with pre-launch calibration Van der Graff dust accelerator used to fire glass beads at aerogel – 6 km s−1 Modeled with polynomial (quadratic) equation[5]: EHD = (60 ± 71) + 1.38 × OPD + 0.057 × OPD2 Mass of volume of aerogel enclosed by track is comparable to mass of particle[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Calculation

Particles are normally too small to identify Relationship between particle diameter and entrance hole diameter established with pre-launch calibration Van der Graff dust accelerator used to fire glass beads at aerogel – 6 km s−1 Modeled with polynomial (quadratic) equation[5]: EHD = (60 ± 71) + 1.38 × OPD + 0.057 × OPD2 Mass of volume of aerogel enclosed by track is comparable to mass of particle[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Calculation

Particles are normally too small to identify Relationship between particle diameter and entrance hole diameter established with pre-launch calibration Van der Graff dust accelerator used to fire glass beads at aerogel – 6 km s−1 Modeled with polynomial (quadratic) equation[5]: EHD = (60 ± 71) + 1.38 × OPD + 0.057 × OPD2 Mass of volume of aerogel enclosed by track is comparable to mass of particle[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Calculation

Particles are normally too small to identify Relationship between particle diameter and entrance hole diameter established with pre-launch calibration Van der Graff dust accelerator used to fire glass beads at aerogel – 6 km s−1 Modeled with polynomial (quadratic) equation[5]: EHD = (60 ± 71) + 1.38 × OPD + 0.057 × OPD2 Mass of volume of aerogel enclosed by track is comparable to mass of particle[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Example

Track length of 320 µm Solve quadratic: OPD = −1.38 ±

• 1.904 − 0.228 × (60 − 320)

0.114 Particle size is 56 µm

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Example

Track length of 320 µm Solve quadratic: OPD = −1.38 ±

• 1.904 − 0.228 × (60 − 320)

0.114 Particle size is 56 µm

Edward Lilley Aerogel

Introduction NASA Stardust Summary Overview Particle Tracks

Images

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Results from Stardust

Return capsule parachuted onto the Utah desert on January 15, 2006 First successful return of cosmic dust to Earth Particles much larger than expected Actual ‘stardust’ is minor component ‘Spectacular’ silicate crystals found[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Results from Stardust

Return capsule parachuted onto the Utah desert on January 15, 2006 First successful return of cosmic dust to Earth Particles much larger than expected Actual ‘stardust’ is minor component ‘Spectacular’ silicate crystals found[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Results from Stardust

Return capsule parachuted onto the Utah desert on January 15, 2006 First successful return of cosmic dust to Earth Particles much larger than expected Actual ‘stardust’ is minor component ‘Spectacular’ silicate crystals found[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Results from Stardust

Return capsule parachuted onto the Utah desert on January 15, 2006 First successful return of cosmic dust to Earth Particles much larger than expected Actual ‘stardust’ is minor component ‘Spectacular’ silicate crystals found[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Results from Stardust

Return capsule parachuted onto the Utah desert on January 15, 2006 First successful return of cosmic dust to Earth Particles much larger than expected Actual ‘stardust’ is minor component ‘Spectacular’ silicate crystals found[8]

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Future Study

Only 20 out of 132 aerogel blocks have been studied in detail[5] Further techniques of analysis will be developed High resolution digital images of all blocks have been taken Looking for tracks takes a long time Outsourcing to the public via Stardust@home

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Future Study

Only 20 out of 132 aerogel blocks have been studied in detail[5] Further techniques of analysis will be developed High resolution digital images of all blocks have been taken Looking for tracks takes a long time Outsourcing to the public via Stardust@home

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Future Study

Only 20 out of 132 aerogel blocks have been studied in detail[5] Further techniques of analysis will be developed High resolution digital images of all blocks have been taken Looking for tracks takes a long time Outsourcing to the public via Stardust@home

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Future Study

Only 20 out of 132 aerogel blocks have been studied in detail[5] Further techniques of analysis will be developed High resolution digital images of all blocks have been taken Looking for tracks takes a long time Outsourcing to the public via Stardust@home

Edward Lilley Aerogel

Introduction NASA Stardust Summary

Future Study

Only 20 out of 132 aerogel blocks have been studied in detail[5] Further techniques of analysis will be developed High resolution digital images of all blocks have been taken Looking for tracks takes a long time Outsourcing to the public via Stardust@home

Edward Lilley Aerogel

Appendix Bibliography

Bibliography I

Stephen Steiner What is Aerogel? http://www.aerogel.org/?p=3 Subhash H. Risbud Department of Chemical Engineering and Materials Science, University of California Imaging and Structure of Quantum Dots, Nanoparticles and Aerogels, 2007 ObservatoryNANO Institute of Nanotechnology, UK Report on Scientific and Technological Trends, 2009

Edward Lilley Aerogel

Appendix Bibliography

Bibliography II

Marketech International Aerogel Specifications http://www.mkt-intl.com/aerogels/pages/silica.html

• M. J. Burchell et al.

Characteristics of cometary dust tracks in Stardust aerogel and laborartory calibrations Meteoritics & Planetary Science 43, No. 1/2, 23–40, 2008 Andrew Westphal & Stardust@home project members Stardust@home project http://stardustathome.ssl.berkeley.edu/

Edward Lilley Aerogel

Appendix Bibliography

Bibliography III

Amir Alexander Aerogel: The “Frozen Smoke” that Made Stardust Possible – The Planetary Society http://www.planetary.org/programs/projects/ stardustathome/aerogel.html

• P. Tsou & Stardust mission members

NASA Jet Propulsion Laboratory, Stardust mission http://stardust.jpl.nasa.gov/

Edward Lilley Aerogel