Astronaut-Aided Construction of a Large Lunar Telescope

Background• Concepts for large astronomical facilities to follow the Next Generation Space Telescope are now being considered by NASA

• Current expectation is that such telescopes would be placed in the Sun-Earth L2 Lagrangian point

– Very large telescopes may require on-site human participation

– Maintaining humans at S-E L2 will be difficult

• The Moon may be an excellent location for such telescopes– Low gravity field, seismically very quiet; low ambient temperature in lunar polar craters for large IR telescope, reduced radiation and micrometeoroids due to shielding by the Moon, no naturally levitated dust

– Other activities on Moon could provide infrastructure that reduces operational costs for a large observatory

Objectives and Approach

• Consider requirements for and design of a large IR telescope/ observatory on the Moon– 25 m diameter IR telescope is ~10x NGST scale capable of operating to 25 m –

studies of early solar system, Jupiter-sized planets of nearby stars– Location in permanently shadowed terrain provides ambient temperature between

25 K and 70 K, with 30 K as operational target by shielding– By proper siting, telescope should be capable of viewing ~ 40% of sky, including

galactic center– Construction and operation avoids lunar dust by (1) proper construction sequence;

(2) local transportation system that does not allow elements to contact lunar regolith; (3) robotic construction using devices that never leave the structure.

– Infrastructure to support logistics

• Understand the potential role for humans and robots to construct and operate the facility– Construction robots of various types to emplace infrastructure, build and maintain

telescope– Humans are required at all phases for inspection and supervision of robotic

systems

4

Telescope construction Sequence

1 2

3 5

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2) First super-conductingmagnet ring

6) Secondary mirror supports

7) Placement of mirror segments and secondary mirror

4) Main axis and contra weight and instru- ment housing

1) Placement of foundation

3) Second ring and main supports 5) Main mirror

support structure

Status

• Overall architecture defined– Telescope in crater near Lunar South PoleConcept for telescope and

construction sequence developed; Infrastructure based on L1 Gateway

• Robotic systems identified– Rolling cable distributor – a device that allows cables to be deployed for a

local transportation system as well as for power and data lines– Construction robot builds telescope foundations and towers for tramway– Tramway provides local transportation system for moving materials and

humans without them directly contacting the lunar surface– Telescope construction robots remove individual pieces directly from local

transportation system (without leaving telescope) and climb on previously-built structure to emplace pieces

– Observation robots

• Human participation considered– Direct inspection using observation robots– Supervision of robotic systems (teleoperated and semi-autonomous systems)– Calibration, maintenance and repair

Remaining Work and Issues

• Complete analysis of robotic construction systems, defining their requirements and interfaces

• Complete preliminary analysis of human support requirements– Construction phase generally understood

– Commissioning phase (i.e., calibration, problem detection and correction) not yet well established

• Definition of human infrastructure and space transportation requirements• Preliminary characterization of construction and operations costs, based on an

analysis of the expected mass of the facility• Definition of growth phases from single telescope to interferometric

capability• Issues:

– A complete analysis of the thermal properties of the telescope is beyond the resources available and will require considerable work

– Evaluate effectiveness of lunar propellant production on cost of facility

– The current study provides only a start; more detail is required for all systems to evaluate the reasonability of the concept in comparison to space-based telescopes