Solar Ultraviolet and Space Radiation Effects on Inflatable Materials
Abstract
Inflatable structures are being developed for use in space to take advantage of the potential for lower packaging volumes and lighter weights. These structures may consist of thin polymer membranes as well as more robust inflatable, then rigidizable, structural elements. For space applications, it must be shown that the materials can tolerate the orbital environment. This includes the effects of solar radiation and electron/proton radiation on the optical properties and mechanical response of the materials, as well as atomic oxygen effects for possible LEO applications. The highest radiation concern is with the thin-film materials, e.g., the canopy and reflector of an antenna or components of a sun shade or solar sail. All materials used in an inflatable structure need to be capable of tolerating the orbital environment and maintaining properties within the mission requirements. The approach to assessing the effects of space environment on materials begins with consideration of the orbital environment. The solar radiation spectrum is not orbital dependent, but the radiation from electrons and protons varies by orders of magnitude, depending on the particular orbit. The atomic oxygen environment is strongly dependent on altitude and solar activity. Once an orbit has been defined, the atmospheric models are available to calculate the flux and energy of the particle radiation. The orbital lifetime then is used to calculate dose levels and solar exposures that the materials must tolerate. With the environment specified, the expected dose in the materials can then be calculated. If damage thresholds are available for the particular materials involved, possible degradation can be predicted; if not, a ground or orbital test is needed. For a ground test to assess the durability of a material in orbit, the methodology is to predict the dose levels in the materials, which then drive the test parameters.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 20, 2000
- Accession Number
- ADA384429
Entities
People
- M. J. Meshishnek
- W. K. Stuckey
Organizations
- The Aerospace Corporation