Edward E. Montgomery

Status of Solar Sail Propulsion: Moving Toward an Interstellar Probe

NASA’s In‐Space Propulsion Technology Program has developed the first‐generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first‐generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an areal density of less than 13 grams‐per‐square meter. A rigorous, multiyear technology development effort culminated last year in the testing of two different 20‐meter solar sail systems under thermal vacuum conditions. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In a separate effort, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long‐term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging envi...

Rapid Development of Gossamer Propulsion for NASA Inner Solar System Science Missions

Over a two and one-half year period dating from 2003 through 2005, NASA’s In-Space Propulsion Program matured solar sail technology from laboratory components to full systems, demonstrated in as relevant a space environment as could feasibly be simulated on the ground. This paper describes the challenges identified; as well as the approaches taken toward solving a broad set of issues spanning material science, manufacturing technology, and interplanetary trajectory optimization. Revolutionary advances in system structural predictive analysis and characterization testing occurred. Also addressed are the remaining technology challenges that might be resolved with further ground technology research, geared toward reducing technical risks associated with future space validation and science missions.

The Energy Tanker Concept

The energy tanker concept is based on the observation that solar flux increases as the square of the close distance to the sun. Such flux‐rich environs will provide both a more plentiful supply of radiant energy and photon momentum. Robotic mission concepts to deliver an energy collection facility in the inner solar system, then transport energy from that facility to LEO and other destinations benefiting Human and Robotic Exploration and Space Science is proposed. Potential destinations are discussed. A list of alternative energy transport technologies is compared. The sensitivity of the performance of these systems as a function of proximity to the sun is discussed. Basing strategies are developed, taking advantage of non‐keplerian orbit capabilities of solar sails. A primary trade‐off is beam transmission of energy versus physical transport of energy storage containers. The impact on science and exploration in LEO/GEO space, interplanetary missions, and finally interstellar missions is addressed.