While traveling to Venus, electronics and instruments go through enormous pressure, temperature, and atmospheric environment changes. In the past, this has caused problems with the life expectancy of electronics and instruments. Cornerstone Research Group, CRG, proposes to develop a Sialyte(TM)-based composite pressure vessel to perform in such extreme environments. Sialyte(TM) is an inorganic resin that can operate at high temperatures and pressures and can prevent buckling when used as a sandwich structure core (good compressive strengths). Sialyte(TM) has thermal properties similar to a ceramic material, yet processing characteristics like an organic polymer. Sialyte(TM) is also resistant to many chemicals. CRG previously developed this material and is currently using it for structural and protective applications. By using Sialyte(TM) in combination with Nextel(TM) ceramic fabric, CRG can fabricate a filament wound structure using conventional composite manufacturing processes that will perform in extreme environments. The use of filament winding for fabrication will allow for many possible design options in an affordable manner. A Sialyte(TM)-based composite pressure vessel tank will not only meet but exceed NASA's requirements for a pressure vessel for extreme environments.