The carbon carbon space radiator partnershop (CSRP), an informal partnership of Government and industrial personnel, was formed to promote the use of carbon carbon composite (C-C) as engineering materials for spacecraft thermal management applications as a part of this effort the partnership has built a structural radiator for the Earth Orbiter-1 (EO-1) spacecraft. This radiator, using C/C facesheets with an aluminum honeycomb core, will demonstrate both the thermal and structural properties of C/C under actual service conditions as well as provide performace data from space flight. This article will present results from the design of the radiator, the thermal/mechanical tests of the facesheet materials, and subcomponent test results on the C/C/Al honeycomb sandwich material.
The 29- by 28-inch radiator was designed to support two electronics boexes with a combined heat output of 60 watts maximum and a weight of 58 lbs. The analysis of the radiator design shows that the radiator constructed with 20-mil-thick facesheets of a P30-fiber-reinforced C/C from CFCCARBON is able to meet or exceed all the required thermal and mechanical requirements.
The carbon-carbon spacecraft radiator program was formed in August 1995. This informal partnershop was formed to demonstrate that carbon-carbon is now a viable engineering material for the spacecraft community because of its superb properties: lightweight, high tailorable thermal conductivity, chemical inertness and others. CSRP members believe that C/C should be considered in the engineering trade space of spacecraft manufacturers but realize that databars of operational hardware do not exist. The members of CSRP have selected a structural elecronics radiator as the demonstration article and plan a direct comparison to aluminum and organic composites under the same operational conditions. The radiators will be fabricated and will undergo extensive ground testing. A listing of the membership as well as two photographs. In addition to the demonstration articles, the partnership has also decided to take advantage of flight opportunities as they come available. The first flight opportunity the partnership has responded to was to build a structural radiator for the EO-1 spacecraft.
The EO-1 is the first of a series of earth orbiting missions for the NASA’s new nillennium program. This mission will validate a number of revolutionary technologies that will provide Landsat follow-on instruments with increased performance at lower cost. The primary payload is an advanced land imager instrument. Once on orbit, EO-1 will provide 100-200 paired scene comparisons between ALI and the landsat 7 imager, ETM+. Such a comparison will validatethe suitability of the multispectral capability of the ALI. EO-1 is scheduled to launch May 28, 1999.
Three equipment radiators were designed, built and tested. In addition, a spare carbon-carbon composite facesheet was characterized thermally and mechanically. The radiators were designed to meet the requirements of the bay-four radiator for the EO-1 spacecraft. The 29*28 inch radiator was designed to support two electronics boxes and a total maximum heatoutput of less thn 60 watts.The radiator was constructed using two approximately 0.020-inch thick C/C facesheets bonded to both sides of an aluminum honeycomb core for a total panel thickness of 1 inch.The properties used for the design of the radiator were estimated using a database developed from previous C/C programs encompassing a wide variety of C/C composites. The thermal and mechanical tests carried out in this study were used to verify the facesheet and sandwich property values used in the mechanical modelsof the radiator.