Dr. David Spencer will present his talk, "Space Debris and its Effects on Space Operations," on Thursday, April 19, in 236 Katz, from 2:30 - 3:30 p.m.
About the Talk
Since the beginning of the space age, man has found useful purposes in exploring and exploiting space. However, history has shown us many times when man explores a new region, he leaves a residual presence. Space is no different. Since the launch of Sputnik 1 in 1957, there have been over 37,000 objects cataloged by the U.S. Space Surveillance Network (SSN). Currently, there are some 16,000 cataloged objects being actively tracked by the SSN. The catalog includes both active spacecraft and space debris.
Space debris is defined as any non-functioning man-made object orbiting the Earth. This definition distinguishes space debris from functioning operational payloads and natural meteoroids that pass through the Earth’s orbit. The key question raised by space debris is what is the likelihood that a given space asset will be damaged by a collision with another object? This question needs to be addressed for both current and possible future debris populations. Space debris is becoming of greater interest as the population of Earth orbiting objects continues to grow. As more objects orbit the Earth, the probability for collision will increase. Historically, the population of the largest objects has grown at a rate of 3-5% per year and an average of four fragment producing on-orbit breakups per year have occurred. Space debris would not be a problem if space assets could avoid or withstand a collision. Unfortunately, avoiding collisions would require both precise ground tracking and orbit determination and space vehicle maneuvering capabilities. Current measurement capabilities limit tracking to those objects in low Earth orbit (LEO) that are larger than approximately 10 cm in size. Most vehicles are not equipped for avoidance maneuvers. Current shielding technology is expensive to employ and at best can only protect an asset from objects smaller than about 1 cm in size. An impact with a piece of space debris can do a wide range of damage to spacecraft. The level of damage depends on debris size, impact velocity, and spacecraft design specifics such as component positioning and materials. In the worst case, an impact with a large piece of debris could destroy a space asset, potentially increasing the space debris population and thereby increasing the hazard to other systems. Less dramatic is damage from smaller debris that can result in pitting and surface erosion.
In this seminar, Dr. Spencer will provide a background in the problems associated with space debris and discuss the impact (no pun intended) debris has on space operations. He will also discuss current efforts to mitigate the growth of the debris environment and how spacecraft operators are working to maintain safe operations in this environment.
About Dr. David Spencer
Dr. David Spencer is a Professor in the Department of Aerospace Engineering at The Pennsylvania State University. His research areas include spacecraft dynamics and controls, trajectory optimization, space systems engineering, and theoretical and applied astrodynamics.
Prior to joining the faculty at Penn State in 1999, Dr. Spencer was a Member of the Technical Staff in the Astrodynamics Department at The Aerospace Corporation and held various positions at the Air Force Research Laboratory (and its predecessor, the Air Force Phillips Laboratory) in the Space Vehicles Directorate. He is a corresponding member of the International Academy of Astronautics and its Space Debris Committee, an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA), and a Fellow of the American Astronautical Society (AAS). He is also an Associate Editor for the AIAA Journal of Spacecraft and Rockets and is a member of the AIAA Astrodynamics Technical Committee. He is currently the Vice President for Publications for the AAS.
Dr. Spencer received a B.S. in Mechanical Engineering from the University of Kentucky, an M.S. in Aeronautics and Astronautics from Purdue University, an M.B.A. from Penn State, and a Ph.D. in Aerospace Engineering Sciences from the University of Colorado at Boulder.