Ta= ble of Contents

Table of Contents...................................................................= ...........................................................................= ................ 0

List of Figures.................................................................= ...........................................................................= ........................... 2

List of Tables.................................................................= ...........................................................................= ............................. 5

Abstract.......................................................................= ...........................................................................= ................................... 6

1. Introduction.................................................................= ...........................................................................= .......................... 6

1.1 The Lunar Environment.........................= ...........................................................................= ................................... 6

1.2 Other Considerations......................= ...........................................................................= .......................................... 8

2. Existing and Prop= osed Telescopes......................= ...........................................................................= ............... 10

2.1 Existing Major Space Telescope Designs...............................= ................................................................. 10

2.2 Proposed L= unar Surface Telescope Concepts..........= .......................................................................... = 13

2.3 Proposed Free-Space Telescope Concepts.......= ...........................................................................= ............ 16

3. Stakeholder Analysis..........................................= ...........................................................................= ......................... 17

3.1 Stakeholder Identification......................= ...........................................................................= ......................... 17

3.2 N^{2
Representation of Stakeholder Flows.=
...........................................................................=
.................}18

3.3 Estimates = of Resource Flows......................= ...........................................................................= ........................ 19

3.4 Stakeholder Value Delivery Network Model........= ......................................................................... <= /span>21

3.5 Important Loops in the Stakeholder Value Delivery Network.......................................... 22

4. Science Goals.................................................................= ...........................................................................= ....................... 24

4.1 Needs and Goals...............................= ...........................................................................= ............................................. 24

4.2 Candidate Scientific Programs.................= ...........................................................................= ....................... 24

4.3 Ranking of Science Objectives..................= ...........................................................................= ......................... 25

5. Broad System Requirement= s..........................................= ...........................................................................= .......... 31

6. Concept Development Methodology.....................= ...........................................................................= ......... 34

6.1 Initial Formulation of Concept Space........= ...........................................................................= ................. 34

6.2 Object-Pro= cess Methodology Diagram and Concept Space Matrix................................... 35

6.3 Existing Concept Investigations..............= ...........................................................................= ........................ 41

6.4 Concept Downselection Cycles................= ...........................................................................= ........................ 41

7. Lunar Interferome= tric Radio Array (LIRA)..............= ...........................................................................= .... 44

7.1 Approach a= nd Assumptions.........................= ...........................................................................= .......................... 44

7.2 Instrumentation and Radio Array.....= ...........................................................................= ............................ 52

7.3 Electronic= s Subsystem..........................................= ...........................................................................= ................. 57

7.4 Power Subsystem...........................= ...........................................................................= ............................................... 58

7.5 Cluster Structure Subsystem.................= ...........................................................................= .......................... 61

7.6 Communicat= ions Subsystem...........................= ...........................................................................= ..................... 63

7.7 Transporta= tion Subsystem...........................= ...........................................................................= ....................... 70

7.8 Deployment Subsystem...........................= ...........................................................................= ................................. 72

7.9 Trade Study and Optimization....................= ...........................................................................= ....................... 78

8. Lunar Infrared Mo= dular Interferometric Telescope (LIMIT)............................................... 82

8.1 Approach a= nd Assumptions.........................= ...........................................................................= .......................... 82

8.2 Instrumentation and Interferometric Array......................................................................= ........... 89

8.3 Electronics Subsystem...........................= ...........................................................................= ................................ 96

8.4 Power Subsystem...........................= ...........................................................................= ............................................... 97

8.5 Structure Subsystem...........................= ...........................................................................= .................................... 99

8.6 Thermal Control Subsystem...................= ...........................................................................= ......................... 102

8.7 Communicat= ions Subsystem...........................= ...........................................................................= ................... 111

8.8 Transportation, Deployment, and Servicing Subsystems...............................= ....................... 113

8.9 Dust Mitigation..........................................= ...........................................................................= ................................ 122

9. Cost Estimation and Spreading.......................= ...........................................................................= ..................... 126

9.1 Telescope = Cost Estimation..........................= ...........................................................................= ....................... 126

9.2 LIRA Cost Estimation....................................................................= ...................................................................... 126

9.3 LIMIT Cost Estimation..........................= ...........................................................................= .................................. 129

9.4 Software a= nd Ground Segment Development Cost.....= ................................................................. 133

9.5 Ares V Transportation Costs................= ...........................................................................= ............................ 133

9.6 Operating Costs...............................= ...........................................................................= ........................................... 134

9.7 Cost Sprea= ding..........................................= ...........................................................................= ................................... 134

9.8 Cumulative Cost Spreading......................= ...........................................................................= ......................... 137

10. Future Work.................................................................= ...........................................................................= .................... 139

10.1 Further Design Trades.......................= ...........................................................................= ................................. 139

10.2 Other Fut= ure Development.........................= ...........................................................................= .................... 141

11. Conclusion.................................................................= ...........................................................................= ........................ 142

Acknowledgments.................................................................= ...........................................................................= ............ 143

References...................................................................= ...........................................................................= ............................. 144

Appendices...................................................................= ...........................................................................= .............................. 149

Appendix A: Contributors of = new material by section.............= ...................................................... 149

Appendix B: An Analysis of T= eam Interactions..........................................= ............................................. 150

List of Figures

Figure 1. Earth as seen from the lunar surface..................................................................= .............. 7

Figure 2. Earth’s atmospheric opacity for different wavelengths.= ..........................................= ........ 9

Figure 3. The Hubble Space Telescope......................................................................= .................... 12

Figure 4. The James Webb Space Telescope..................................................................= ............... 13

Figure 5. The Spitzer Space Telescope.....................................................................= ..................... 13

Figure 6. The Herschel Space Telescope....................................................................= ................... 14

Figure 7. The SAFIR observatory= ...........................................................................= ...................... 14

Figure 8. The Terrestrial Planet Finder telescope.................................................................= ......... 15

Figure 9. Conceptual design for the Large Lunar Telescope..........................................= ............... 16

Figure 10. Artist’s rendition of a liquid mirror telescope on the Moon................................= ......... 17

Figure 11. A lunar interfer= ometer concept.............................= ....................................................... 17

Figure 12. A radio telescope on the Moon uses a crater to support its large primary dish............ 18

Figure 13. Major stakeholders in the design and development of a lunar telescope..................... 19

Figure 14. N² diagram indicating the types of flows between stakeholders........................= ......... 20

Figure 15. N² diagram indicating the importance of each flow between stakeholders................= . 21

Figure 16. Rate of publication of papers using Hubble data..........................................= ............... 22

Figure 17. Cost and speed of observation for instruments on the Hubble Space Telescope......... 23

Figure 18. Stakeholder value delivery network model...........................................= ....................... 24

Figure 19. The most important loop in the stakeholder value delivery network........................... <= /span>25

Figure 20. Public outreach flows. = PAGEREF _Toc167454378 \h = 25

Figure 21. Relative strength of six candidate science programs..........................................= ......... 31

Figure 22. Concept development process....................................................................= .................. 36

Figure 23. Object-Process Methodology description of telescope design.= ................................... 38

Figure 24. Concept tree = for segmented reflecting telescopes.....= .................................................. 44

Figure 25. Exemplar Pugh matrix for Far-IR telescopes...........................................= .................... 45

Figure 26. N² diagram of the major relationships between parameters..........................= ............... 46

Figure 27. All important technical parameters in the LIRA telescope design..............................= . 47

Figure 28. Lunar noise attenuation from the lunar far side.= ......................................................... = PAGEREF _Toc167454386 \h = 50

Figure 29. Lunar polar sunlight illumination fraction..........................................= .......................... 51

Figure 30. Noise attenuation utility......................................................................= ......................... 52

Figure 31. Illumination and utility versus angle..................................................................= .......... 52

Figure 32. Angular resolution utility.....................................................................= ........................ 52

Figure 33. Component masses....= ...........................................................................= ........................ 53

Figure 34. Utility versus angular resolution..................................................................= ................. 54

Figure 35. Folded LIRA cluster.= ...........................................................................= ........................ 64

Figure 36. Deployed LIRA cluster. = PAGEREF _Toc167454394 \h = 64

Figure 37. LIRA communications systems cost and size scaling...........................................= ....... 66

Figure 38. Interior communications system arrangement...........................................= ................... 68

Figure 39. Relay subsystem.....= ...........................................................................= ........................... 68

Figure 40. Total system view...= ...........................................................................= ........................... 69

Figure 41. Storable mode, front and top views..................................................................= ........... 70

Figure 42. Partially-deployed standing mode..................................................................= ............. 70

Figure 43. Fully-deployed relay...........................................................................= ......................... 71

Figure 44. Relay optical package. = PAGEREF _Toc167454402 \h = 71

Figure 45. Artist’s conception of the Ares V launch vehicle..........................................= .............. 72

Figure 46. Artist’s conception of NASA’s Lunar Surface Acc= ess Module..............................= .... 73

Figure 47. NASA’s unpressurized rover concept.................................................................= ......... 74

Figure 48. Notional view of array deployment..................................................................= ........... 76

Figure 49. Notional view of communications relay deployment..........................................= ......... 77

Figure 50: Scientific Figure Of Merit/Cost trade study surface...........................................= ......... 81

Figure 51. Sensitivity of LIRA.= ...........................................................................= ......................... 82

Figure 52. Angular resolution of LIRA.....................................................................= .................... 83

Figure 53: Hybrid IR telescope design.....................................................................= ..................... 84

Figure 54. Stars with exoplanets seen by Spitzer..................................................................= ........ 89

Figure 55. Star with an exoplanet.........................................................................= ......................... 89

Figure 56. Baseline configuration for LIMIT concept.................................................................= . 92

Figure 57: The final layout of the ARGOS optical train..........................................= ..................... 93

Figure 58: Beam combining layout for LIMIT beam combiner............................................= ........ 93

Figure 59: A sparse-aperture telescope implemented with twelve separate focal telescopes feeding a common beam combiner................................................................= ........................................................................ 94

Figure 60. Existing telescope comparison of angular resolution...........................................= ........ 94

Figure 61. Point Spread Function for a Golay-3 configuration...........................................= .......... 95

Figure 62. Point Spread Function for a Golay-9 configuration...........................................= .......... 96

Figure 63. Comparison of SNR to a single telescope of equivalent diame= ter............................... 96

Figure 64. Required increase in imaging time for a sparse array...........................................= ........ 97

Figure 65. Conceptual design of LIMIT unit telescope...........................................= ................... 101

Figure 66. Mount concept consisting of hollow aluminum honeycomb...................................... 102

Figure 67. Simplified mount structure for analysis..................................................................= ... 103

Figure 68. Finite element von Mises stress analysis.................................................................= ... 104

Figure 69. Surface temperature for lunar craters at three latitudes;..........................................= .. 107

Figure 70. Mirror temperature and longest observed wavelength..........................................= ..... 108

Figure 71. Radiation model for emissivity relationship to temperature.= ..................................... 109

Figure 72. Temperature variation with effective MLI.................................................................= 110

Figure 73. Model to determine the time required.........= ............................................................... 111

Figure 74. Transient results for radiative cooling = to sky............................................................. 111

Figure 75. Helium cooling concept for initial deployment of telescopes= .................................... 111

Figure 76. Transient temperature of He-cooled temperature and amount o= f He required.......... = PAGEREF _Toc167454434 \h = 112

Figure 77. Cost versus downlink data rate.................................................................= ................. 114

Figure 78. Cost versus distance from human base..................................................................= .... 114

Figure 79. Communications system overview.................................................................= ............ 115

Figure 80. Moon base at the lunar south pole= ..........= .................................................................... 116

Figure 81. Telescope location..........= ...........................................................................= ................. 117

Figure 82. Ares V (CaLV)..........= ...........................................................................= ...................... 117

Figure 83. Lunar Surface Access Module (LSAM= )..........= .......................................................... = PAGEREF _Toc167454441 \h = 118

Figure 84. Crew/rover-assisted deployment..........= ...................................................................... 118

Figure 85. ATHLETE rover..........= ...........................................................................= ................... 119

Figure 86. Deployment process..........= ...........................................................................= .............. 121

Figure 87. Repair process..........= ...........................................................................= ....................... 123

Figure 88. Lunar dust grain....= ...........................................................................= .......................... 124

Figure 89. Transient temperature of dust grain incident on a LIMIT telescope mirror............... 126

Figure 90. Smoothed surfa= ce of sintered lunar dust...........................................= ........................ 127

Figure 91. Concept for lunar lawn mower for microwa= ve regolith sintering.............................. 127

Figure 92. Effect of number of dipoles on total system cost..........................................= ............ 130

Figure 93. Effect of number of telescope elements on total system cost= .................................... 134

Figure 94. Spreading of the $1.987 billion development cost for LIRA.<= span style=3D'mso-tab-count:1 dotted'>................................... 137

Figure 95. Spreading of the $1.631 billion development cost for LIMIT<= span style=3D'mso-tab-count:1 dotted'>................................... 138

Figure 96. Cumulative cost spreading of $1.987 billion development cost for LIRA................ 139

Figure 97. Cumulative cost spreading of $1.631 billion development cost for LIMIT.............. 140

= List of Tables

Table 1. Estimated Vehicle Parameters for Telescope...........................................= .......................... 9

Table 2. Importance of each stakeholder...................................................................= .................... 19

Table 3. Example of stakeholder value metrics for NASA and the media.<= span style=3D'mso-tab-count:1 dotted'>.................................. = 27

Table 4. Derived stakeholder utility scores for each science objective= ......................................... <= /span>28

Table 5. Expected level of strength for each stakeholder value loop...........................................= . 29

Table 6. Expected strength of each stakeholder value loop for science objective AGN.............. <= /span>30

Table 7. Level 0 and Level 1 requirements.................................................................= ................... 32

Table 8. Detailed concept space matrix....................................................................= ..................... 37

Table 9. Requirements for LIRA.= ...........................................................................= ....................... 46

Table 10. Optimal value ranges..............................= ...................................................................... 53

Table 11. Command & data handling parameters for LIRA...........................................= .............. 59

Table 12. Power subsystem constants...........................= ............................................................... 60

Table 13. Final power subsystems design values (solar-powered)...........................................= ..... 62

Table 14. High-flow and low-flow data systems..................................................................= ........ 66

Table 15. Relay properties.....= ...........................................................................= ............................. 71

Table 16. Rover energy requirements and battery mass...........................................= ..................... 78

Table 17. Requirements for IR interferometer..................................................................= ............ 84

Table 18. Optical parameters of Optical Units..................................................................= ............ 90

Table 19. Metrics for LIMIT power system..................................................................= ................ 98

Table 20. Space IR telescope wavelengths and temperatures...........................................= .......... 107

Table 21. System components to be transported..................................................................= ....... 119

Table 22. Deployment time estimate........................................................................= ................... 121

Table 23. Typical human activities and maximum ranges..........................................= ................. 125

Table 24. Subsystem mass and cost breakdown for the LIRA concept...................................... 127

Table 25. Total transportation cost for the LIRA concept...........................................= ............... 128

Table 26. Subsystem mass and cost breakdown for the LIMIT...........................................= ....... 130

Table 27. Total transportation cost for the LIMIT concept..........................................= ............... 130

Table 28. Research and development cost multipliers for various LIMIT telescope subsystems. = 132

Abstract

The National Aeronautics= and Space Administration (NASA) has outlined plans to return humans to the Moon= by the year 2020. Because of the inherent advantages to performing astronomy from the lunar surface, the Moon has long been envisioned as a possible site for a space telescope. With the most recent lunar plans s= erving as a motivation and basis for re-consideration of the Moon as the location = of an astronomical observatory, this report provides a thorough investigation = into the design of a lunar telescope facility.

An overview of features = of the lunar surface relevant to a telescope is provided. A literature review gives the cont= ext in which a lunar telescope facility is considered. This context includes previous ide= as for telescopes on the Moon and concepts for other space telescopes (both existi= ng and planned).

Using the 2001 National = Research Council Astronomy and Astrophysics Decadal Survey as a principal reference,= the science goals for the next generation of space telescopes are enumerated and ranked based on an analysis of the relevant stakeholders. This methodology develops a value = delivery network model and ranks the relative importance of the key stakeholders and= key flows in the network. Feature= s of the network, such as the historical values of important flows and the role = of the media in key loops, are also noted.&nb= sp; The stakeholder value delivery network is then used to perform a uti= lity analysis of the six candidate broad science objectives. This analysis informs the subseque= nt telescope concept enumeration and downselection.

A methodology developed = for concept downselection consists of: 1) elucidating the full concept space via the use of a design space matrix, 2) narrowing the concepts down via a tree method of isolating attractive options from the design space matrix, and 3) selecting the best of these concepts using the quantitative ranking techniq= ues of Pugh analysis, with the results of the stakeholder analysis informing th= e downselection process. Through this methodo= logy, a comprehensive architecture space of 6048 possible concepts is narrowed to j= ust two, which are then developed in detail for use as reference designs.

Specific trades emerge a= s the two reference designs are matured, and detailed investigations lead to development of the subsystems. The subsystems analyzed include instrumentation, electronics, power, structures, thermal, communications, and transportation/deployment. Cost, mass, and power figures for = all these systems are calculated, as are subsystem and overall costs for each design. Recommendations are a= lso made to help identify the areas that should require further study and research.<= /p>

The results of this stud= y show how two potential space telescope concepts are uniquely enabled by returnin= g to the Moon, both of which would provide scientific output beyond anything that has before been possible. The= Lunar Interferometric Radio Array (LIRA), is a large array of radio-frequency dip= oles located on the far side of the Moon, where shielding from radio noise creat= ed by Earth would allow unsurpassed sensitivity to regions of the radio spectr= um never observed. The Lunar Inf= rared Modular Interferometric Telescope (LIMIT), is an interferometric array of 8= 5-cm infrared (IR) apertures located in the cold Shackleton Crater at the lunar south pole. The long and stab= le baselines of this array would achieve an angular resolution better than any existing or proposed IR telescopes. Both of these telescope designs would greatly benefit from, and prov= ide scientific motivation for, returning to the Moon, and they would serve to l= ook at our universe at wavelengths that until now have had only limited study.<= /p>

1. Introduction

This study into a lunar telescope facility was conducted by members of the Space Systems Engineering class (16.89/ESD.352) at the Massachusetts Institute of Technology in the spring of 2007. The challenge of the class was to design a lunar telescope facility = that would deliver the most scientific value, while leveraging the proposed crew= ed lunar transportation architecture and ensuring both technical and budgetary feasibility. The approach to = this challenge is outlined in this report, and two final design proposals are presented that meet these goals.

The initial specification for the proposed Lunar Telescope Facility was to crea= te a lunar telescope, with consideration of location including points on the sur= face of the Moon, as well as points in space near the Moon, or at a Lagrange poi= nt between the Earth and the Moon or the Earth and the Sun. Due to the need for new telescopes= to advance the state of the art beyond previous designs, telescopes in Low Ear= th Orbit (LEO) were initially discounted as possible design goals, although th= ey provide a useful context for later phases of the design.

= 1.1 The Lunar Enviro= nment

Although the Moon was on= e of the first objects at which Galileo pointed his early telescopes, it was not unt= il the middle of the 20^th century that the idea of putting a telesc= ope on the Moon was conceived. Wh= ile some of the earliest ideas of the time required people to build and run the observatory (even manually changing on the photographic plates and looking through the eyepiece), many advantages of the lunar surface remain the same= for more modern telescope concepts [1].

The results of a literat= ure search illustrate the major features of the lunar surface, and their potent= ial as arguments for and against the development and deployment of a lunar telescope. The discussion draws heavily upon a comprehensive discussi= on put forth by Lester et al. [2].

=

Figure 1. Earth as seen from the lunar surface.=

1.1.1 Advan= tages and disadvantages of a lunar surface location

The major features of th= e lunar surface are detailed here, with relevant information for telescopes given.<= span style=3D'mso-spacerun:yes'> Potential advantages and disadvant= ages are also noted.

· Feature: Low temperatures

Cold temperatures are = reached on the Moon, particularly the lunar poles where limited incident light arri= ves from the Earth and the Sun. Crater floors at the poles with no direct line-of-sight to either body could potentially create a naturally cold environment, with ambient temperatures around 40-50 K. This is optimal for IR telescopes, which otherwise must be actively cooled.

· Feature: Radio quiet

The far side of the lu= nar surface is shielded from terrestrial radio interference, both man-made and naturally occurring. On Earth= , the ionosphere also blocks much of the radiation coming in at radio frequencies= of interest. Modern radio interf= erence mitigation techniques, which can be implemented at lunar distances in free = space, deliver similar levels of shielding from interference effects, although the costs are higher.

· Feature: Lifetime

The lunar surface is a= stable location that carries no inherent cost for maintaining telescope position a= nd orientation once deployed. Th= is is opposed to free-space telescopes, which have finite levels of cryogens for active cooling and a limited amount of propellant for station-keeping.

· Feature: Solid surface

The lunar surface prov= ides a stable foundation for deploying interferometers with a range of baselines.<= span style=3D'mso-spacerun:yes'> Free-space interferometers have be= en conceived, but precise formation flying at large baseline distances has not= yet been demonstrated in space, and the truss structure required for formation flying at smaller baseline distances may be prohibitive. A possible drawback of the lunar s= urface is the presence of dust. Luna= r dust presents a contamination hazard for optics and could impede mechanical syst= em performance. See Section 8.9 = for a discussion of possible means for mitigation of lunar dust issues.

· Feature: Gravity

Lunar gravity enables = the design and deployment of liquid mirror telescopes, which offer huge collect= ing areas for zenith surveys (large liquid mirrors cannot be achieved on Earth = due to wind effects on the surface). A disadvantage of telescopes on the Moon is they would require a more substan= tial structure to withstand the gravitational forces. Working on a solid surface where p= arts do not float away, however, would be of benefit to astronauts doing deploym= ent or maintenance work.

· Feature: Slow sidereal rate

Slow motion of celesti= al sphere about lunar sky enables long-duration surveys with less precise guid= ing.

· Feature: Stable thermal environment

Slower motion of the S= un across the lunar sky creates longer periods of thermal equilibrium, which yields more consistent optical performance. Telescopes in low Earth orbit (LEO) undergo cycles of thermal expansion due to heating and cooling each orbital period, but free-space telescopes at long distances from Earth (i.e. Lagran= ge points) are not susceptible to these effects.

· Feature: Absence of substantial atmosphere, magnetic field, orbital debris

Like other free-space telescopes, viewing from outside the Earth’s atmosphere opens up regi= ons of the electromagnetic spectrum that are inaccessible from the ground. Absorption of incoming radiation or emission from the atmosphere prevents astronomical observations at certain wavelengths in the IR and RF bands (see Figure 2).

=

Figure 2. Earth’s atmospheric opacity for different wavelengths [3].<= /span>

1.1.2 Discu= ssion of a lunar surface location

Most of t= he features of the lunar surface offer equal performance or distinct performan= ce advantages over other possible locations, such as in free space, in Low Ear= th Orbit, or on the surface of the Earth.&nbs= p; However, some disadvantages are inherent in the lunar surface proper= ties already described in Section 1.1.1. Access to crater floors at the lu= nar poles and structural needs under gravity conditions present challenges for = system designers. In addition, lunar dust presents a challenge. Lunar dust issues are not importan= t for free-space locations, although similar issues exist (and have been largely mitigated) on Earth-surface locations.&nbs= p; There is also the impact on cost of needing to land mass on the Moon. This, in general, requi= res more expenditure of propellant than if a telescope remains in free space. Also, provisions would need to be = made to ensure the telescope could endure a soft landing on the Moon. A returned human presence on the M= oon, however, would supply further impetus and opportunity to capitalize on the advantages of the lunar surface environment.

1.2 Other Considerat= ions

1.2.1 Human spacecraft servicing

Human servicing of spacecraft has proven = tremendously successful when viewed in the context of the Hubble Space Telescope (HST) a= nd the International Space Station (ISS).

For the HST, the most important and visib= le servicing mission was to correct the optics, which were found to be manufactured incorrectly after the HST was initially put in orbit. The successful repair has been one= of the most notable achievements in the history of space telescopes. Completed extravehicular activity = (EVA) tasks have included installing new scientific instruments and replacing spacecraft components that have failed.&nb= sp; In addition to installing new instruments, astronauts have replaced,= or are planning to replace, solar panels, control moment gyros, and batteries, which degrade over continuous operations in the Low Earth Orbit environment. The net effect o= f this servicing has been to increase the on-orbit lifetime of the HST while continually upgrading its scientific capability [4].

While ISS astronauts have occasionally installed scientific experiments during EVA, the bulk of the spacewalks have been devoted to construction and maintenance of the ISS. During construction of the space station, astronauts installed fluid, electrical and structural connections between station elements during their activation. Automated features to perform these functions were ruled out due to envelope restrictions of the launch vehicle= and cost considerations [5].

These spacecraft servicing efforts have s= hown how beneficial human servicing can be for the success of a space project, especially one involving the construction, upgrade, and repair of complex s= pace systems. This should be consi= dered in terms of the proposed long-term presence of humans on the Moon.

1.2.2 Robotic spacecraft servicing

In the aftermath of the Columbia tragedy, the final shuttle ser= vicing mission to the HST was canceled and a number of teams performed studies on = the possibility of robotically performing the mission requirements. The University of Maryl= and developed a concept using mostly developed flight hardware. It utilized a rebuilt propulsion mo= dule designed for ISS station-keeping and a robotic servicing module largely bui= lt from existing hardware. The propulsion module was flown to perform propulsion, rendezvous, communicatio= ns power generation, and station-keeping during repair. To perform all the requirements of= the last servicing mission, the vehicle parameters shown in Ta= ble 1 were estimated [6].

Table 1<= span style=3D'mso-bookmark:_Toc161034266'>. Estimated Vehicle Parameters for Telescope.

Propulsion Module Dry Mass<= /span>	3000 kg
Robotic Module and Hubble Component Mass	4900 kg
Total Servicing Craft Wet Mass	8500 kg
Launch Cost	$150M
Total Mission Cost	$500M

<= span style=3D'mso-bookmark:_Toc161034223'>

It is important to note that the total co= st of the spacecraft does not include the cost of developing the propulsion module and that the estimate was not detailed.&nb= sp; Given that there has never been previous robotic servicing of a spac= ecraft, and given the rough nature of the estimate, the true cost of the mission wo= uld likely be significantly higher.

1.2.3 Constellation EVA architecture for zero-g and lunar surface missions=

According to NASA’s exploration architecture study [7], NASA plans a robust EVA presence on the lunar surfa= ce. The planned airlock design will be based in the Lunar Surface Access Module (LSAM) and may have accommodations for up to 3 or 4 astronauts simultaneously. This will ena= ble many lunar surface EVAs.

However, NASA plans a much more limited E= VA capability for zero-g beyond the ISS orbit. Current plans for the Crew Expl= oration Vehicle (CEV) do not include an airlock.&n= bsp; Any excursions from the crew capsule would require all crewmembers donning their suits, which have umbilicals for life support, and depressuri= zing the cabin. These suits are be= ing designed primarily for launch and entry requirements, so it is unlikely that EVA operations would be as easy as with purpose-designed spacesuits.

In the event that the lunar airlock were = used in zero-g along with lunar suits, this would require at minimum an Ares V launch to get the LSAM to the desired orbit, as well as some level of redes= ign to make the airlock functional in zero-g.

Potential EVA operations that could benef= it a lunar telescope might be connecting electrical infrastructure between parts= of an interferometer to enable beam combining, removing launch restraints from mechanical telescope assemblies, and installing new scientific instruments. The possibility = of EVA operations in zero-g from the CEV is negligible. Therefore, staging EVAs beyond the= ISS will only be cost-feasible from the lunar surface, unless consideration is given to the adaptation of the existing Constellation architecture.

2. Existing and Proposed Telescopes

&nbs= p;

A further result of the literature search was a large amount of information on existing telescopes and proposed concepts, both in free space and on the lu= nar surface, which provide a context for development of the proposed lunar telescope facility. This sect= ion presents some of the details of these existing and proposed concepts.

= 2.1 Existing Major Space Telescope Designs

2.1.1 Hubble Space Telescope

The Hubble Space Telescope, deployed into= Low Earth Orbit in 1990, has arguably been the most successful of the space telescopes launched as part of NASA’s Great Observatories program. Its 2.4-m diameter primary mirror observes over near-infrared, visual, and UV wavelengths. It was designed to be human-serviceable and has b= een serviced in orbit 4 times, with a 5th and final servicing mission planned f= or early 2008. The final servicing mission will extend its life until at least 2013. The HST has been a fantastic success, expanding our understanding of star birth, star death, and galaxy evolution, and helping = move black holes from scientific theory to fact. In addition, the HST has garnered a great deal of public support with the release of many captivating images th= at are immensely popular the world over. The HST required $2 billon in development costs and has an operations cost of $452 million per year [8].<= o:p>

3D"Hubble

Figure 3. The Hubble Space Telescope [8].=

2.1.2 James Webb Space Telescope

The James Webb Space Telescope (JWST), pl= anned to start operating around the time when the HST reaches the end of its life= , is NASA’s next major space telescope.&n= bsp; The JWST, operating at near- and mid-infrared wavelengths, will be deployed at the second Earth-Sun Lagrange point, 1.5 million km from Earth.=

With a primary mirror 6.5 m in diameter,<= span style=3D'mso-spacerun:yes'> JWST will have a collecting area seven times= that of Hubble, and will achieve four primary astronomical objectives: identification of the first bright objects that formed in the early univers= e, determination of how galaxies and dark matter evolved to the present day, s= tudy of the birth and early development of stars and solar systems, and understanding the physical and chemical properties of solar systems where building blocks of life may be present. Current cost estimates for t= he James Webb put it around $3.5 billion [9].

&nbs= p;

Figure 4. The James Webb Space Telescope [9].

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2.1.3 Spitzer Space Telescope

The Spitzer Space Telescope, formerly known as the Space Infrared Telescope Facility (SIRTF), is the element in NASA's suite of Great Observatories that operates in the mid- to far-IR wavelengths, where it serves to study astronomical targets including the brown dwarfs, the early universe, protop= lanetary and planetary debris disks, and active galactic nuclei. Located in a heliocentric, Earth-trailing orbit, the Spitzer Space Telescope can conduct both imaging = and spectroscopy, and its 85-cm aperture produces 5 x 5 arcminute exposures. This is the state = of the art facility for IR astronomy, and cost around $700 million to develop [10]= .

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3D"Spitzer

Figure 5. The Spitzer Space Telescope [10].

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2.1.4 Herschel Space Telescope

Slated for a July 2008 launch aboard an Ariane-5, the three-year mission for the Herschel Space Telescope at the Earth-Sun L2 point will conduct astronomical science into the far-IR spectrum. Jointly launched with the Planck science mission at an estimated cos= t of $2 billion, the 3.5-m primary mirror will enable the study of the formation= of galaxies in the early universe, the creation of stars, the chemical composi= tion of the atmospheres and surfaces of comets, planets, and satellites, and the molecular chemistry of the universe [11].

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3D"Fact

Figure 6. The Herschel Space Telescope [11].

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2.1.5 Single Aperture Far-IR Observat= ory

The Single Aperture Far-IR (SAFIR) observatory is planned as the next extension= of JWST. With a primary mirror diameter of 10 m, the telescope would be cooled to temperatures around 5 K, allowing currently unparalleled ability to observe the epoch of reionization, trace the formation and evolution of star formation and active galaxies, explore black holes, study planetary system formation, and search= for prebiotic molecules in the interstellar medium. The proposed 5-year mission is sch= eduled for development by around 2020 [12].

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3D"SAFIR

Figure 7. The SAFIR observatory [12].

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2.1.6 Terrestrial Planet Finder<= /o:p>

NASA’s Terrestrial Planet Finder (TPF) is a suite of two space observatories whose purpose is to study various aspects of planets outside our solar system. The coronograph and nulling interferometer observatories (TPF-C and TPF-I, respectively) would work in tandem to probe the disks of dust and gas around newly forming stars. Plans exist to launch TPF-C by 201= 6 and TPF-I by 2020, but the missions are currently in a state of indefinite hiat= us [13].

<= /span>

3D"Terrestrial

Figure 8. The Terrestrial Planet Finder telescope [13].

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2.1.7 Highly Advanced Laboratory for Communications and Astronomy

The Highly Advanced Laboratory for Communications and Astronomy (HALCA) is an orbital radio telescope, and is the first astronomical satellite dedicated = to the Very Long Baseline Interferometry Space Observatory Program, which enab= les imaging of astronomical radio sources with a significantly improved resolution over ground-only observations. Tar= gets observed by the system include active galactic nuclei and extragalactic rad= io sources such as quasars, radio galaxies and pulsars. Observations can be made in the wavelength ranges of 18 cm, 6 cm, and 1.3 cm. The maximum angular resolution ach= ieved by this telescope is 0.4 milliarcseconds.&= nbsp; Along with the ground radio telescopes, the effective aperture of th= is device is more than 30,000 km, which, at microwave frequencies, produces angular resolution more than a hundred times higher than the Hubble Space Telescope [14].

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2.1.8 Low Frequency Array =

Located in the Netherlands, the Low Frequency Array (LOFAR) is a radio-frequency array of antennas currently being implemented with funding primarily from the Dutch governmen= t. It is expected to achieve breakthr= ough sensitivity for astronomical observations at radio frequencies below 250 MHz. The large computational = power required to run the array is expected to improve as processing ability continues to advance rapidly [15].

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2.2 Proposed Lunar Surface Telescope Concepts

There have been numerous concepts published for telescopes based on the Moon. This section details some of the m= ost recent and most interesting ideas for lunar telescopes.

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2.2.1 Large Lunar Telescope

The Large Lunar Telescope (LLT) study conducted by the NASA Marshall Space Flig= ht Center in 1991 describes a 16-m segmented mirror telescope to be located at= an equatorial latitude, on the lunar limb (about 0° latitude, 85° west longitude), where the Earth would always be low on the horizon. Expec= ted to achieve nominal resolution performance of 10 milliarcseconds in the visi= ble spectrum, it would scan wavelengths between 0.1 and 100 μm. With= the lunar day-night cycle lasting approximately 28 Earth days, the LLT could passively reach temperatures as low as 70K, but would require shielding dur= ing the day to avoid the temperatures of up to 380K.

The optical design consists of a four-reflection system, with a Coudé fo= cus and imaging equipment buried beneath lunar regolith to protect sensitive photodetectors from cosmic rays and particles. The primary reflector = is made up of 1,098 hexagonal mirrors 0.5 m in diameter, which are clustered i= n 18 groups, each with a diameter of 4 m [16].&= nbsp; Figure 9 shows a concept for the LLT.

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Figure 9. Conceptual design = for the Large Lunar Telescope [16].

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2.2.2 Liquid Mirror Telescope

Another concept that has been proposed is= a Liquid Mirror Telescope (LMT). A LMT consists of a spinning reflective liquid, usually mercury, which forms a perfect parabola. At least two LMT’s are in use today: a 3-m version used by NASA in New Mexico, and = a 6-m version in Vancouver, Canada. A LMT on Earth = is limited in size because wind on the surface of the liquid distorts its ideal shape.

The presence of the Moon’s gravity (required for the parabola to form) in combination with no atmospheric disturbances provides the rationale behind a liquid mirror telescope. A 20-m LMT on the moon would have 3 times the resolution of the JWST, and with a y= ear of continuous viewing, could potentially observe an object 100 times fainter than the faintest object the JWST could observe.

Two challenges to the concept are finding= a reflective liquid that flows properly at extremely cold temperatures, yet s= till retains adequate reflective properties, and developing bearings to smoothly spin the liquid platform [17, 18].

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Figure 10. Artist’s rendition of a liquid mirror telescope on the Moon [17].

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2.2.3 Monolithic Primary Aperture

A study done for NASA in 2002 led by the Colorado School of Mines discusses a mid-infrared telescope located in a pe= rmanently dark crater at the Moon's south pole. This telescope would have a 25-m diameter primary mirror made up of hexagonal segments, each about 2.3 m in diameter. It would rotate on 2 axes and take advantage of the permanently dark and cold crater to keep the telescope at around 35K. In 2002, its cost= was estimated at $32 billion [19].

2.2.4 Interferometric Array (Lunar Surface)

A study done between NASA and JPL on a Lu= nar Interferometer Technology Experiment (LITE) in 1996 addresses the feasibili= ty of an array of 1-m class ultraviolet telescopes deployed with a 100-m baseline. The system could deliver observation capabilities not possi= ble on Earth [20].

Figure 11. A lunar interferometer concept [20].<= /p>

2.2.5 Radio telescopes on the far sid= e

The far side of the Moon provides a radio-quiet environment for a telescope in = the form of a giant dish situated in a crater, similar to the Arecibo Observato= ry in Puerto Rico, or a distributed series = of collectors spread across the surface, either of which would be of great val= ue in detecting astronomical signals at low frequencies [21].

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Figure 12. A radio telescope on the Moon uses a crater to support its large primary dish [21].

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2.3 Proposed Free-Space Telescope Concepts

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2.3.1 Cislunar space observatories

Along with observatories on the lunar surface, there also exist possibilities for putting a telescope in cislunar space. The most relevant locations are the Earth-Sun L2 Lagrange point, the Earth-Moon L1 Lagrange point, and in l= ow lunar orbit. Both Lagrange points have the advantage of semi-stable orbits relatively close to Earth. The JWST is an existing concept for= an observatory at the Earth-Sun L2 point. Low lunar orbit may pose probl= ems related to station-keeping, as the Moon’s gravitational field is non-uniform, but any observatory in space rather than on the Moon has the advantage of not requiring powered descent to the lunar surface.

2.3.2 Interferometric Array (space-based)

A study done by JPL on the Lunar Configur= able Array Telescope (LCAT) [22] details a lunar surface deployment with characteristics similar to those mentioned above, but also addresses deploy= ing this same system in lunar orbit. Due to the difficulty and time invol= ved in configuring a large array of telescopes, particularly in orbit, the study concludes that the expense to put a system in orbit for ten years would not adequately serve the greater astronomy community. The array wo= uld be less expensive than the Hubble Space Telescope, but the same array deplo= yed on the surface would provide greater benefit.

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2.3.3 Prototype microsatellite

A space-based telescope architecture is b= eing developed in conjunction with the European Space Agency (ESA). This concept is modeled after Dobsonian telescopes used by amateur astronomers. = The prototype unfolds from a suitcase-sized box to a space telescope with a 0.5= -m primary mirror capable of 30 cm resolution from orbit. The prototype would be considered a microsatellite, with dimensions smaller than 60 cm x = 60 cm x 80 cm, and a mass less than 100 kg. This concept could potential= ly be scaled up to provide significant cost savings [23].

3. Stakeholder Analysis

This section presents the stakeholder analysis, one of the first steps taken in the design process for the lunar telescope facility. The stakeholder analysis is developed as a springboard for further analysis of = the best means to deliver scientific value, leverage the planned crewed lunar transportation architecture, and ensure both technical and budgetary feasibility for the proposed lunar telescope facility.

3.1 Stakeholder Identification
For the proposed lunar telescope facility, all the relevant stakeholders in the program were identified using resource flow input/output diagrams. The major stakeholders are shown i= n Fig= ure 13.

=

Figure 13. Major stakeholders in the design and development of a lunar telescope.

In this analysis, it quickly becomes evident that certain stakeholders are more important than others, and that satisfying needs of the more important stakeholders is critical to the overall success of the program. For this reason, each stakeholder = was assigned a ranking from 1 (Helpful, but not particularly important) to 5 (E= ssential). These rankings were then combined = in a consensus-building discussion in which the overall rankings of the stakehol= ders were established. The resulti= ng rankings are shown in Table 2.

Table = 2. Importance of each stakeholder.

Importance

Stakeholders=

5

Scientists, NASA,

Congress

4

Executive Branch,

Telescope Operator

3

Contractors,

U.S. Public/Humanity

2

Media, Educators,

International Partners

1

The important stakeholde= rs (scoring 4 or 5) were identified as scientists, NASA, Congress, the Executi= ve branch, and the telescope operators. Note that no stakeholder scored 1; this is reflective of a natural b= ias to exclude stakeholders of lesser importance from the overall analysis.

3.2 N²= Representation of Stakeholder Flows

The process of identifying stakeholder flows involved building a consensus on the type and importance = of resource flows that occur between each pair of stakeholders. The results are displayed here in = an N² diagram describing these flows. In Fig= ure 14, cell m-n= contains the type of resource required by the stakeholder in row m from the stakeholder in column n. For example, cell j-f indicates that NASA requires a poli= cy directive from the president, and cell g-j indicates that the contractors require money and human resources (in this c= ase, jobs) from NASA.

Figure 14. N² diagram indicating the= types of flows between stakeholders. The meanings of the symbols are: $ = =3D Money; P =3D Policy directive; S =3D Political support; I =3D Instruments, = hardware; O =3D Observing time; D =3D Data; H =3D Human resources (e.g., jobs or stud= ents); and K =3D Knowledge, images, pictures. The meanings of the colors are

= =3D Essential;

= =3D Very important;

= =3D Important;

= =3D Somewhat important;

= =3D Helpful; and

= =3D Irrelevant.

Similarly, a correspondi= ng N² diagram, shown in Figure 15, presents the importance of these same resource f= lows (note that the importance scores are also indicated in Figure 14 by color). The numbers (and colors) indicate the importance of the given flow to the stakeholder receiving the resource, i.e. to the one in row m<= /i>. This is not necessarily the same a= s the importance of that flow to the provider of the resource or to the program a= s a whole. In addition, the level= of importance refers only to value delivery in the lunar telescope program. Therefore, the contributions of international partners to other scientific missions or to the International Space Station (ISS) are not reflected in the scores presented in these tabl= es.

Stakeholder Metrics	Science Objective
(1 =3D strong no; 5 =3D strong= yes)	EOR	AGN	XSP	GSF	DE	WGL
Congress & Executive
Will Congress & Executive gain public support for this objective?	3	3	4	3.5	3.5	2.7
Are concepts within this objective likely to stay within NASA’s budgetary limits?	4.7	4.5	2.3	2.7	2.3	2.3
Are concepts within this objective likely to be completed within= a timely schedule?

Ta= ble of Contents

List of Figures

= List of Tables

Abstract

1. Introduction

1.2 Other Considerat= ions

2. Existing and Proposed Telescopes

= 2.1 Existing Major Space Telescope Designs

2.2 Proposed Lunar Surface Telescope Concepts

2.3 Proposed Free-Space Telescope Concepts

3. Stakeholder Analysis

3.2 N²= Representation of Stakeholder Flows

3.3 = Estimates of Resource Flows<= /o:p>

3.4 Stakeholder Value Deli= very Network Model

3.5 = Important Loops in the Stakeholder Value Delivery Network

4. Science Goals

4.1 Needs and Goals

4.2 Candidate Scientific Programs

4.3 Ranking of Science Objectives

1. Introduction

= 2.1 Existing Major Space Telescope Designs

2.3 Proposed Free-Space Telescope Concepts

3.2 N2= Representation of Stakeholder Flows

3.3 = Estimates of Resource Flows<= /o:p>

3.2 N²= Representation of Stakeholder Flows