Lunar Farside Observatory - Abstract
Lunar Farside Observatory
Brent Harding, et. all
December 13, 1989
This report presents the final design of a man-tendable Lunar Farside Observatory and Science Base by the OUTLOOK Design Team. A farside observatory will allow high accuracy astronomical observations, as well as the opportunity to perform geological and low gravity studies on the Moon. The requirements of the observatory and its support facilities will be determined, and a preliminary timeline for the project development will be presented.
The primary areas of investigation in the design of a Lunar Farside Observatory (LFO) included observatory equipment, communications, habitation, and support operations. Each area was investigated to determine the available options, and each option was evaluated to determine its advantages and disadvantages. This document discusses the options deemed most suitable based upon current information.
Several assumptions were made before the design of the LFO could proceed. These assumptions were that
The above assumptions were used in conjunction with the mission groundrules to guide the design of the observatory. Some of the groundrules were: that the maximum set -up time for the observatory would be three (3) years, that two launches from the LEO transportation node were permitted per year, and that after construction was complete, one piloted mission per year from Earth would be scheduled to conduct maintenance of the observatory. Periodic maintenance of the observatory would also be supported by crews stationed at the nearside base.
- a lunar nearside base was in place and has the capability to process lunar materials for the production of fuel and oxygen,
- an advanced launch system (ALS) consisting of a heavy lift launch vehicle (HLLV) existed to transport materials to low earth orbit (LEO),
- the use of nuclear power in space is reliable and accepted, and
- semi-autonomous robotic capabilities exist to facilitate teleoperated and fully automated robotic construction of the observatory.
The science equipment necessary for the successful operation of a farside observatory includes a mixture of optical telescopes, radio interferometers, x-ray and gamma ray telescopes, and selenographic experimental packages. This equipment must be shielded from the harsh thermal environment which exists on the moon; the equipment must also be protected from the lunar dust, radiation, and micrometeorites. To provide power for the observatory, an SP-100 nuclear reactor will be used at the observatory. A schematic of the base layout is shown in Figure 1.1.
To provide constant communication with the lunar nearside base as well as Earth, a communication system was devised where the relaying point is a satellite in a halo orbit about the L2 unstable libration point. This would permit full coverage of the lunar farside and the constant monitoring of the construction activities being conducted. Since L2 is an unstable libration point, stationkeeping burns totaling 93.3 fps/yr and period control burns totaling 240 fps/yr will have to be conducted in order to maintain the orbit. After three years, the satellite at L2 will be refueled and moved to the stable libration point L5, where it will remain throughout the lifetime of the observatory.
To transport the materials and equipment of the LFO to the observatory site, a lunar cargo lander designed by students at the Department of Mechanical Engineering at the University of Texas at Austin will be used. This lander will transport the habitation module, robots, and observation equipment to the observatory site. Two unpressurized lunar rovers were included in the design for transportation around the base.
For the habitation module of the astronauts, OUTLOOK chose the Space Station common module. The module will be covered by a layer of lunar regolith supported by the lunar cargo lander platform. This covering will shield the module from the radiation of outer space, as well as provide some degree of thermal and micrometeorite protection for the module. Figure 5.4 shows the final habitation configuration.
A completely closed atmospheric regeneration system was chosen for life support since it reduces the need for resupply and waste removal. To replenish the water used at the observatory, the Super Critical Wet Oxidation (SCWO) system was selected. For the thermal control of the observatory systems, an active thermal control system (ATCS) will be used. This system uses redundant two-phase outer loops with two-phase inner loops to perform the heat acquisition and transport phase of the ATCS. The system will utilize two-phase fluid flow to allow for higher heat transfer coefficients. Surface radiators will be used to reject heat.
Two areas were considered in surface operations: extravehicular activity (EVA) and robotics. A zero pre-breathe suit (ZPS) will be used for astronaut EVA. Furthermore, the astronauts will not conduct more than two EVA shifts in one day. The robotics used at the LFO will consist of a foreman robot and worker robots. The foreman robot is programmed to the level of artificial intelligence and assigns jobs to the worker robots. The worker robots are lunar construction utility vehicles (LCUV) designed by students at the Department of Mechanical Engineering at Old Dominion University. These workers use a manipulator arm to lift objects. Also, lunar telerobotic servicers (LTS) will be used to perform high risk tasks at the farside observatory. To perform heavy lifting tasks, a lunar crane developed by the students at the Department of Mechanical Engineering at the University of Texas at Austin will be used.
The OUTLOOK management structure is shown in Figure 8.1. The design team was led by a project manager and four technical managers. The job of the technical managers was to oversee the completion of tasks which the engineers were assigned. The project manager ensured that all groups interacted with one another so that the project development proceeded smoothly.
The costs for the design project consisted of manpower costs and materials costs. Based upon current salary information, the total manpower cost of the project was $36,313.20. The total materials cost, which included photocopies, personal computer usage, and model construction was $1787.50. Therefore, the total cost for OUTLOOK's design of a lunar farside observatory was $38,100.70.
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