DACC is an OCT Game Changing Division project which contains two distinct project elements; 1) Adaptable Deployment Entry and Placement Technology (ADEPT) and Conformal Ablative TPS (CA250). DACC is a 2 year base project started in FY12 with a possible 3rd year option in FY14. One element of DACC is the development of a conformal ablative TPS technology to TRL 5 targeting missions requiring peak heat-flux around 250 W/cm2 (CA250). A conformal TPS over a rigid aeroshell has the potential to solve a number of challenges faced by traditional rigid (low strain-to-failure) TPS materials. The compliant (high strain to failure) nature of the conformal ablative materials will allow easier integration of the TPS with the underlying aeroshell structure and enable monolithic-like configuration and larger segments (or parts) to be used.
By reducing the overall part count, the cost of installation (based on cost comparisons between blanket and tile materials on the Space Shuttle) should be significantly reduced. The conformal ablator design will include a simplified design of seams between gore panels, which should eliminate the need for gap filler design.The second DACC element, ADEPT is a mechanically deployable semi-rigid aeroshell entry system to achieve low ballistic coefficient during entry. The concept is akin to an umbrella with a flexible and deployable carbon fabric integrated to the underlying deployable mechanical system. For the ADEPT concept, the woven carbon fabric, which covers large portion of the frontal surface and supported by rigid ribs, is the primary drag-producing surface. Its flexibility allows it to be stowable and deployable.
The 3-D carbon fabric will encounter high heating during entry and with its high thermal conductivity allows re-radiation from both the windward and leeward side of the fabric. As a result, this concept is a mass efficient drag device and has been shown to be mass competitive with all other concepts studied by NASA for heavy mass Mars applications. The combination of low ballistic coefficient, high thermal protection capability allows for lower entry flight path angle and as a result, ADEPT concept has been shown to be capable of achieving very low entry g-loads for mission such as robotic Venus, Mars, and Saturn.