Far Side Lunar Observatory - Abstract
Far Side Lunar Observatory

Dawn M. Hannula, et. all

December 6, 1991

Executive Overview

This document outlines the design completed by members of Lone Star Aerospace, Inc. (L.S.A.) of a lunar observatory on the far side of the Moon. Such a base would not only establish a long term human presence on the Moon, but would also allow more accurate astronomical data to be obtained.

A lunar observatory is more desirable than an Earth based observatory for the following reasons:

All the conditions listed above are favorable for astronomical data recording.

The technical aspects investigated in the completion of this project included site selection, mission scenario, scientific instruments, communication and power systems, habitation and transportation, cargo spacecraft design, thermal systems, robotic systems, and trajectory analysis.

The site selection group focused its efforts on finding a suitable location for the observatory. Hertzsprung, a large equatorial crater on the eastern limb, was chosen as the base site.

Primary and Secondary Base Designs:

Two possible base designs were developed. After analyzing these two designs, a primary base design and a secondary base design were selected. These two designs differ in the positioning of the larger instrument packages that will be placed on the lunar surface as well as in the type of habitat module that will be utilized. The primary base design consists of a main base with a Space Station Common Module (SSCM) type habitat and three large independent instrumentation fields - one separate field for the Very Low Frequency Array (VLFA), one for the Optical Interferometer (OI), and one for the Submillimeter Interferometer (SI). The secondary base, on the other hand, consists of a main base with an inflatable habitat and one large instrument field in which the fields for the VLFA, OI, and SI overlap each other.

The advantages of the primary base were analyzed. The main advantages of this base were as follows:

The advantages of the secondary base were as follows:

After analyzing these advantages and considering the fact that the main purpose of constructing the base is to obtain the most accurate astronomical data possible, the base with the SSCM and three independent instrumentation fields was chosen as the primary base. A sketch of the primary base is shown in Figure 1.

Overview of Subsystems:

The design of the far side lunar observatory involved investigation into seven subsystems. These subsystems included instrumentation, habitation and transportation, power and communications, robotics, thermal systems, cargo spacecraft design, and trajectory analysis. The following sections give a brief overview of each of these subsystems.

Figure 1. Primary Base Configuration.

Instrumentation. Astronomical, geological, and environmental instrumentation packages will be emplaced on the lunar surface. The following is a list of the major instruments to be utilized:

The mass of the total instruments package has been calculated to be 91 metric tons.

Habitation and Transportation. Two SSCM modules connected end to end will provide for habitation on the lunar base. Two airlocks at either end of this arrangement will provide adequate ingress and egress. A partially-closed environmental control and life support system will be utilized. MOSAP and LOTRAN vehicles will provide lunar transportation.

Communication and Power. During the construction phase, a satellite in an L2 halo orbit will relay data from the lunar surface to a geostationary satellite in Earth orbit to the Earth's surface. When the base becomes fully operational, however, a radio-free sky is desired to take accurate astronomical readings. Therefore, a fiber optic cable will be used as a communication link from the base to a transmitter/receiver station on the near side of the Moon. It will be laid out by a robotic rover from the base to the limb of the Moon. From there, the signal can be broadcasted directly to Earth without interfering with astronomical observations.

The base will be powered by four clusters of four Soviet manufactured Topaz reactors. These will supply the base with approximately 160 kWe of energy. Use of this cluster arrangement will prevent the total loss of power to the base in the event of a failure. If an emergency occurs and a cluster must be shut down, the other reactors can still produce 120 kWe for the base.

Robotics. Four robotic elements will set up the far side lunar base. They include a crane, an excavator/digger, and two assembly robots. They will dig holes, bury the habitation modules and reactors, lay power and communications cable, and set up the instruments. These robotic elements will use a combination of artificial intelligence and tele-robotics to successfully navigate and construct the base.

Thermal Systems. The lunar base will be thermally controlled with the use of both radiators and heat exchangers. Radiators will be used to cool the reactors and heat exchangers will be used to cool the habitat and some of the smaller astronomical instrument packages. Manufactured shades will be used if passive cooling of the larger instrument packages is necessary.

Cargo Spacecraft Design. A cargo spacecraft designed by Eagle Engineering will be used to carry the 180 metric tons of materials from Low Earth Orbit to Low Lunar Orbit. A Lunar Operations Vehicle will then transport these materials to the lunar surface.

Trajectory Analysis. Cargo spacecraft trajectories will consist of "spiral-in" type trajectory with a time of flight of approximately 130 days. Any manned missions to the base will use hybrid free-return trajectories.

Management and Cost:

Lone Star Aerospace is composed of a project leader, integration leader, chief technical engineer, administrative leader, and seven technical departments (each with its own department leader). This type of management structure has worked quite efficiently. No major problems have arisen in the design of the far side lunar observatory.

A cost analysis on the design of the lunar base has been performed based on the hardware costs incurred over the past fifteen weeks as well as the number of man-hours utilized. These figures were then compared to the estimated cost for the project as presented in the proposal. The total cost for the design of this base has been calculated to be $51,853., well under the budget agreed upon in the proposal.