Autonomous Large Distributed CubeSat Space Telescope (ALDCST)

ASTE 527: Space Exploration Architectures Concepts Synthesis Studio Midterm Presentation October 16, 2012 Professor: Madhu Thangavelu

Concept Presentation: Jesus Isarraras

BACKGROUND / HISTORY

• • • •

NASA

– – Hubble Space Telescope; ~570km LEO orbit; 2.4m mirror aperture James Webb Space Telescope scheduled for launch in 2018; 1.5M km (Earth-Sun Lagrangian L2) orbit; 6.5m mirror aperture – Studying next generation UVOIR space observatory through the Advanced Technology Large-Aperture Space Telescope (ATLAST)

California Polytechnic State University & Stanford

– Developed CubeSat Standard

Cal Tech & University of Surrey

– Autonomous Assembly of a Reconfigurable Space Telescope (AAReST) Technology Development – Surrey Training Research and Nanosatellite Demonstrator (STRaND) payload development for AAReST

Naval Post Graduate School

– Pseudospectral Estimation for optimal controls problems 2

RATIONALE

• Develop key technologies and architectures for large space apertures to improve the capability of future imaging and sensing using CubeSat innovations http://www.jwst.nasa.gov/comparison.html

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TIMELINE OF TECHONOLOGIES FOR ADVANCED TELESCOPES

2012 2013 2014 2015 2016 2017 2018 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q 2020’s Direct Tech Insert JWTS Direct Tech Insert ARReST STRaND-1 STRaND-2 S-Android Logo Payload contains Google Nexus Smartphone; Nexus will fully control nanosat Kinect S-Android Logo Kinect Tech for 3D modeling spacial awareness ATLAST-8m ATLAST-9.2m

ATLAST-16m 4

ASSUMPTIONS / GROUNDRULES

• • • • • • • Time frame: 10 years Successful STRaND – 1 mission in 2012 Successful STRaND – 2 mission in 2014 Successful ARReST mission in 2015 Successful JWTS launch and mission in 2018 Adaptive Optics Gap size between sub-mirrors is < 0.01D; aberration is minimized 5

CONCEPT - PROPOSAL

• Provide an alternative architecture for large primary mirror (D>20m) for space telescopes – Alternative for next generation UVOIR telescopes (e.g ATLAST) – CubeSat cluster with segmented mirrors – Autonomous formation and control • Potential Benefits – Potential lower cost and mass – Mirror segment replacement – Removes human activity for fielding – Faster production/manufacturing http://www.jwst.nasa.gov/comparison.html

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CONCEPT - LOCATION

• Direct extrasolar planetary observations become possible with large (D>20m) apertures – Earth-Sun Lagrangian point L2 – Opportunity to study early universe phenomena, monitor extremely faint and distant galaxies, dark matter and dark energy http://www.jwst.nasa.gov/comparison.html

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CHALLENGES

 Deployable mirror segment alignment  Achieving high surface accuracy of a large segmented mirror (optical figuring)  Surface and structure control stabilization • Vibration isolation and potential jitter control • Control of adaptable/flexible mirrors  Wavefront sensing and correction (sensors)  Thermal management/distortion mitigation  Power management of segmented architecture 8

COMPLEX SUBSYSTEMS

Architecture - Structure Launcher

• • • • Launcher to hold multiple layers Layers deployed in sequence Each layer contains 6 segments Each segment contains N mirrors 9

COMPLEX SUBSYSTEMS

Architecture - Structure Nth CubeSat Layer of Mirror

Hex-Frame: provides stability and links Pod’s together

Top view of Nth Layer

Flexible joints connecting sat’s

Top view of Nth Layer

Expands to create Hexagon Shape 10

COMPLEX SUBSYSTEMS

Architecture - Structure Autonomous formation

• Control − ADC • − Advanced algorithms (e.g PS) Sensing • • − Lasers, optical, IR Actuation − Cold Gas, PPT, Hall Comm − Short range wireless − LOS Wireless − Laser 11

COMPLEX SUBSYSTEMS

Architecture – Structure Layers Layer

1 2 3 4 5 20 50 75 100

# of Mirrors per Layer

6 12 18 24 30 120 300 450 600

Diameter

0.3

0.5

0.7

0.9

1.1

4.1

10.1

15.1

20.1

Total Mirrors: Total CubeSats: Total Layers: Total Segments: 30,300 30,300 5,050 600

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CONCEPT - COMPLEX SUBSYSTEMS

Architecture – Deformable Mirror

• Thin deformable mirrors with integrated actuators – >200 independent actuators – Wavefront correction for each mirror (algorithms) – Improved light gathering power – Improved resolution – Thermal management through shape/curvature correction Primary material: Polyvinylidene flouride (PVDF) 370μm http://www.kiss.caltech.edu/study/largestructure/technology.html

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CONCEPT - COMPLEX SUBSYSTEMS

Architecture – Advanced GN&C

• Pseudo-spectral estimation – GN&C stability of complete cluster structure – Optimal motion planning for autonomous vehicles in obstacle rich environments – Constraint Non-Linear Problems The Zero Propellant Maneuver demonstrated on the ISS. November 5, 2006 rotated 90 deg and March 3, 2007 rotated 180 degrees Autonomous Reentry and Decent of Reusable Launch Vehicles 14

CONCEPT - EVOLUTION

• • • • • • • Mirror packaging Mirror wavefront sensors Flight formation sensors Adaptive optics systems Mirror actuators CubeSat P-POD and dimension growth Instrumentation (cameras, sensors, etc) 15

CONCLUSIONS

• • • Large apertures can be created through CubeSat Cluster design Segmented and adaptable mirrors future of telescope design Complex CubeSat architectures affordable options of the future 16

FUTURE QUANTITATIVE STUDY

• • • • • • • • Secondary Mirror Deployment Aberration and Mirror stabilization Orbit definition Thermal management of cubesat’s and system architecture (e.g Passive – radiate heat to space vs active – refrigerator system) Sun shield technology Radiation hardening requirements Power Management Communication architecture 17

REFERENCES

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Patterson, K., Yamamoto, N., Pellegrino, S. (2012). Thin deformable mirrors for a reconfigurable space telescope. Retrieved from http://pellegrino.caltech.edu/PUBLICATIONS/AIAA_SDM2012_1220023%20(2).pdf

Postman, M. (2009). Advanced Technology Large Aperture Space Telescope Study NASA. Retrieved from http://www.stsci.edu/institute/atlast/documents/ATLAST_NASA_ASMCS_Public_Report.pdf

Keck Institute for Space Studies. (2012) http://www.kiss.caltech.edu/lectures/index.html

Steeves, J., Patterson, K., Yamamoto, N., Kobilarov, M., Johnson, G., Pellegrino, S. (2012). AAReST Technology Development. Retrieved from http://kiss.caltech.edu/workshops/smallsat2012/presentations/steeves.pdf

Patterson, K., Pellegrino, S., Breckinridge, J. (TBD) Shape correction of thin mirrors in a reconfigurable modular space telescope. Retrieved from: http://www.kiss.caltech.edu/study/largestructure/papers/patterson-pellegrino breckinridge.pdf

McClellan, J. (TBD). Aurora Flight Sciences CubeSat Cluster. Retrieved from: http://icubesat.files.wordpress.com/2012/06/icubesat-org-2012-c-3-3 _presentation_mccellan_201205251247.pdf

Padin, S. (2003). Design Considerations for a Highly Segmented Mirror. Retrieved from: http://authors.library.caltech.edu/5664/1/PADao03b.pdf

Postman, M. (2007). Advanced Technology Large-Aperture Space (ATLAS) Telescope: A Technology Roadmap for the Next Decade. Retrieved from: http://www.stsci.edu/institute/atlast/documents/Submitted_proposal_TEAM_DISTN.pdf

Fundamental Optics. Retrieved from: http://cvimellesgriot.com/Products/Documents/TechnicalGuide/Fundamental-Optics.pdf

Naval Post Graduate School. (2012). Conference Papers. Retrieved from: http://www.nps.edu/academics/gnclab/Conference.html

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Thank you for your time!

Jesus Isarraras [email protected]

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BACKUP CHARTS

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CONCEPT - COMPLEX SUBSYSTEMS

Large Space Aperture Architecture Comparison Type of Mirror Primary Aperture (m) Mirror Mass (kg) Wavelength ( μm) ALDCST

Segmented 20 635 (mirrors, actuators)

HST

Monolithic 2.4 / 0.3

828 0.8 – 2.5 (IR) 0.1 – 0.8 (UV, visible)

JWST

Segmented 6.5

705 0.6 to 28 (IR)

Herschel Space Observatory

Monolithic 3.5

300 (full telescope) 60 to 500 (IR)

Orbit

.11 - 2 (UV,IR) Earth-Sun L2 Lagrange point; 1.5 million km 10 μm in IR LEO; 570km Earth-Sun L2 Lagrange point; 1.5 million km

Resolution

0.1 arcsec in red light; Main camera; 16M pixels 13.2 x 4.2

Earth-Sun L2 Lagrange point; 1.5 million km 2 μm in IR Main camera: 32M pixels 22 x 12 5 – 50 arcsec

Size (L x W) (m) Mission Length Total Dev Cost ($M)

TBD 10 yr?

<$1B

15

$1.5B

5-10 yr

$1B

9 x 4.5

>3

€1.1

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Preliminary Mass Calculations

• From Patterson, K., Pellegrino, S., Breckinridge, J. Shape correction of thin mirrors in a reconfigurable modular space telescope Complete mirror structure w/ areal density ~2kg/m^2:

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COMPLEX SUBSYSTEMS

Architecture - Structure

• • • • Hex-Frame Contains ADC Comm Link Enhancement Layer Stabilization Network Communication 24

CONCEPT - COMPLEX SUBSYSTEMS

Architecture – Secondary Mirror & Instruments

6U CubeSat Secondary Mirror Deployer Focal Plane Detector Instruments (Camera, Optical/IR Sensors, etc) 25

Formation Flying Control Challenges

• • • • Complexity – Systems of systems (interconnection/coupling) Communication and Sensing – Limited bandwidth, connectivity, and range – What? When? To whom?

– Data Dropouts, Robust degradation Arbitration – Team vs. Individual goals Resources – Always limited, especially on a CubeSat 26

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Hubble Space Telescope

• Payload: Optics: The telescope is an f/24 Ritchey-Chretien Cassegrainian system with a 2.4 m diameter primary mirror and a 0.3 m Zerodur secondary. The effective focal length is 57.6m. The Corrective Optics Space Telescope Axial Replacement (COSTAR) package is a corrective optics package designed to optically correct the effects of the primary mirror's aberration on the Faint Object Camera (FOC), Faint Object Spectrograph (FOS), and the Goddard High Resolution Spectrograph (GHRS). COSTAR displaced the High Speed Photometer during the first servicing mission to HST.

Hubble Space Telescope

• Instruments: The Wide Field Planetary Camera (JPL) consists of four cameras that are used for general astronomical observations from far-UV to near-IR. The Faint Object Camera (ESA) uses cumulative exposures to study faint objects. The Faint Object Spectrograph (FOS) is used to analyze the properties of celestial objects such as chemical composition and abundances, temperature, radial velocity, rotational velocity, and magnetic fields. The FOS is sensitive from 1150 Angstroms (UV) through 8000 Angstroms (near-IR). The Goddard High Resolution Spectrometer (GHRS) separates incoming light into its spectral components so that the composition, temperature, motion, and other chemical and physical properties of objects can be analyzed. The HRS is sensitive between 1050 and 3200 Angstroms.