1. Background The Apollo program sent 12 Americans to the lunar surface between 1969 and 1972, but humans have not set foot on the moon since then. In January 2004, President Bush announced a new focus for US space policy. The goal is to return humans to the moon by 2020, and eventually create a permanent base to use as a jumping-point for further exploration of the solar system. See attached Main Objectives: Design a system capable of transporting materials needed for a lunar colony from the earth to the moon. Keeping in mind the economical and practical aspects of such an undertaking, compare and contrast this design with NASA’s proposed Constellation program and two alternative systems. Our Design The cargo supply mission begins with the launch of an Ares V rocket. The rocket carries an expendable Earth Departure Stage (EDS) which propels the Lunar Surface Access Module (LSAM) from LEO toward the moon, and is discarded during transit. The LSAM, containing the moon-bound cargo, then enters LLO and lands on the lunar surface, where its cargo is unloaded either autonomously or by crew stationed on the moon. In a cargo supply mission, only the Ares V’s solid rocket boosters are reusable. Because the Constellation vehicles are propelled by chemical fuel (LOX and hydrogen), only 3.9% of the Ares V’s gross liftoff weight is payload. While the combustion used by rockets is the only propulsion method able to break the atmosphere, once in space the chemical rocket is not very fuel-efficient. Therefore, the cost per unit of mass for Constellation is very expensive. The Lunar Outpost The lunar outpost will be located at the moon’s south pole, near the rim of the Shackleton Crater. This location has been chosen because it receives nearly constant sunlight, which can be harnessed to generate electrical power. Temperature fluctuation is relatively minor at the pole, generally remaining at -50 ±10°C, making internal structural temperature easier to control. In addition, the Shackleton Crater itself lies in constant darkness, so there may be water ice available which the outpost could exploit. The south pole location also provides for easy communication with ground control, since it is continuously visible from the earth. Pictured above right is a rendering of a design for a permanent lunar habitat. In this design, initial size will be 4 spokes, each with a different function, and more can be added as needed. This type of design could also be used as an entrance to future habitats in lunar lava tubes, or it could be buried beneath lunar soil for added radiation protection. The crew will be rotated every 6 months, and periodic resupply and expansion missions will be made as needed. Sponsors: National Aeronautics and Space Administration (NASA) NASA Goddard Space Flight Center (GSFC) NASA Goddard Institute for Space Studies (GISS) NASA New York City Research Initiative (NYCRI) Stevens Institute of Technology (SIT) Contributors: Dr. Siva Thangam, PI Prof. Joseph Miles, PI William Carroll, HST Alyssa Barlis, HSS Michael Creech, HSS Marina Dawoud, HSS The Ad Astra Rocket Company is developing a lunar cargo transport system based on VASIMR (Variable Specific Impulse Magnetoplasma Rockets) propulsion technology. Their system uses Solar Electric Power (SEP) to ionize argon as a propellant, which is cheaper than traditionally- used xenon. Because SEP cannot produce the thrust necessary to reach escape velocity, Ad Astra’s system is only intended for the transport of cargo from Low-Earth Orbit (LEO) to moon. Pictured left is a rendering of their vehicle in transit from LEO to the moon. The outpost will have an initial capacity of 4 crewmembers, and will be expandable to a total of 50 people. Pictured left is a NASA prototype for a temporary lunar shelter for use during assembly of the permanent structure. Earth- Moon Transportation System From the Earth to the Moon II Works Cited: NASA’s Exploration Systems Architecture Study Final Report completed November 2005. Ad Astra Rocket Company. Lunar Transportation Systems. LTS Mission Architecture Note: ELV=Expendable Launch Vehicle Pictured right is Ad Astra’s mission architecture for a lunar cargo mission. The system is launched into orbit by chemical rockets, then has rendezvous points in LEO and Low-Lunar Orbit (LLO). The Orbital Transfer Vehicle (OTV) is reusable, but a new Cargo Delivery Vehicle (CDV) must be launched for each mission. Transit time for the system is related to power usage, so one example of a practical mission is a 10- month mission which has a cargo capacity of 37.6 mT (I sp = 5000s, 2010 kW). Because the system can deliver up to 39% of its mass in LEO to the lunar surface, it has a lower cost per unit of payload mass than an all-chemical system. Lunar Transportation Systems, Inc. (LTS) is a private company currently developing a system to transport cargo from the Earth to the Moon. The mission architecture and types of vehicles used differ from NASA’s Constellation and Ad Astra’s VASIMR system. LTS uses modern Delta II Heavy-class Launch Vehicles to lift all of their vehicles into orbit. The Lunar Lander and the Propellant Transporter are the only two reusable vehicles in this system, and all LTS vehicles are powered by chemical fuels. In terms of cost, the biggest cost is the delivery of spacecraft to LEO, 70% of which goes towards fuel. The expendable vehicles used are expensive. If either propellants are made on the Moon or if reusable heavy lift vehicles are implemented, the costs would drop 60%. Since the technology used is either in existence or emerging, the development costs will be low but the implementation costs will be high. The system’s two most expensive craft are reusable, so even though the short term cost will be similar to current systems, the long term cost will be lower on the whole, and the reusability makes the system easier to scale up for human transport. Chemically-powered rockets are the only present-day practical method which can reach the velocities necessary to escape the earth’s orbit. Our system will use NASA’s Ares V rockets to reach LEO. Our design incorporates a reusable, autonomously-operated Lunar Cargo Transport Vehicle (LCTV). In emergencies, it could be operated remotely from the earth. The LCTV uses Solar Electric Propulsion (SEP). Once in LEO, the LCTV and the cargo will rendezvous, then the LCTV’s SEP system will propel the craft to the moon. Comparative Analysis Conceptual Design of a Lunar Colony NASA is currently developing a transportation system known as Constellation, which will replace the space shuttle, transport crew and cargo to the moon, and support future missions to Mars. Lunar mission architecture involves launches of both the manned Ares I rocket and the unmanned Ares V rocket. Emerging Technologies which would dramatically alter the design are: Use of SCRamjet propulsion within Earth’s atmosphere Nuclear Electric Propulsion Systems for interplanetary travel Nuclear fusion as a practical energy source Antimatter-fueled rockets Nanosolar film for more efficient solar panels Fly-by-optics flight controls