MIL-STD-1809

Abstract

The purpose and scope of this document is to state the parameters of the earth's natural environment, above 100 kilometers, for use in space vehicle and space system design. The natural environment includes neutral atmosphere, plasma, energetic charged particles, meteoroids, geomagnetic field, electromagnetic radiation, gravitational field, cosmic rays, and solar energetic particles. The geosynchronous environment and the ionosphere are treated in detail. The trapped radiation belts, drag due to the neutral density, atomic oxygen, and particle impacts are treated as well. <br>This standard is intended for use in acquisition contracts for selected space vehicles and upper stage vehicles. The standard should be cited in the technical requirements (program-peculiar specifications) as may be appropriate to specify the natural space environment parameters that are applicable for the space system acquisition. <br>THIS PAGE INTENTIONALLY LEFT BLANK <b><u>Intended Use:</u></b> This standard is intended for use in acquisition contracts for selected space vehicles, upper stage vehicles, payloads, and space experiments. The standard would be cited in the system specifications or other technical requirement documents to specify the natural space environment parameters as applicable to the acquisition. Note that this standard does not address effects of human operations in space such as orbiting space debris, transmitter radiations, fluid discharges from space vehicles, outgassing, or surface contamination. Neither does it address the interaction between the environment and an orbiting space vehicle, such as atomic oxygen burning of surface materials, surface glow, plasma waves generated by the presence of the space vehicle, space vehicle charging, or orbital dynamics. Nor, finally, does it address the effects of the environment on the space vehicle and subsystems, such as ionizing radiation damage, single event upsets in electronics, or backgrounds such as luminescence and Cerenkov radiation in optical materials. It does, however, provide the necessary environmental parameter data for calculations of space system performance as modified by the presence of these environmental elements. Although this standard does not address the effects of human operations or the induced environment that is due to the interaction between the environment and a body in space, this should not be interpreted as indicating that these areas are not important. Their effects on a space system may be greater than that due to the natural environment. These areas vary with human activities, tend to be program peculiar, and, therefore, are simply not appropriate for inclusion in this standard. However, these areas should also be included in the analyses of the effects of the total environment on space systems, to the extent they are applicable. Note that this standard would not normally be used in the acquisition of other types of equipment, such as ground equipment. <br>