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The proposed presentation will give an overview of a mechanically deployable entry system concept development with a comprehensive summary of the ground tests and design development completed to-date, and current plans for a small-scale flight test in the near future.
The Adaptable Deployable Entry and Placement Technology Sounding Rocket One flight test is a demonstration experiment for deployable atmospheric decelerator technologies. The suborbital flight test occurred on 12 September 2018, at the White Sands Missile Range. Data from on-board and ground-based sensors were collected, from which the as-flown trajectory was reconstructed using an iterative extended Kalman filter-smoother. This paper describes the methodology, test vehicle instrumentation, and data analysis results from the flight test trajectory reconstruction.
This paper summarizes some of the future civil missions requiring large space systems technologies. Antenna, collector, and reflector missions are generalized to define a similar set of system requirements and characteristics. Although many concepts exist for both deployable and space assemblable large structures, four technically mature deployable concepts are reviewed. Two of these concepts are probably applicable to only antenna/collector missions, whereas the other two employ continuous trusses which can be configured for a broad range of planar, linear, or curved structures. Finally, technology problems or needs associated with large deployable systems are reviewed to highlight additional research and development, both analytical and experimental, required to reduce mission risk.
The Large Deployable Reflector (LDR), a proposed 20 m diameter telescope designed for infrared and submillimeter astronomical measurements from space, is discussed in terms of scientific purposes, capabilities, current status, and history of development. The LDR systems goals and functional/telescope requirements are enumerated.
The Adaptable, Deployable Entry and Placement Technology (ADEPT) is a mechanically deployable low-ballistic coefficient aeroshell entry system which performs entry, descent, and landing (EDL) functions for a broad range of planetary destinations including Mars, Venus, Titan and Earth. The deployable system allows mission planners to develop an aeroshell design that is stowed like a folded umbrella, and yet prior to the EDL mission segment, transforms into a deployed, near-rigid low ballistic coefficient configuration. The ADEPT architecture is scalable from a sub-1m class to 6m diameter entry vehicles for Venus and and it has been studied at up to 15m – 20m scale for human exploration class missions. There has been growing interest in performing interplanetary missions with small spacecraft as secondary payloads and ADEPT offers small satellite mission designers the ability to consider Aeroassist technologies to expand mission applications. The ADEPT architecture introduces a new approach for entry vehicle design. It deploys a flexible 3D woven carbon fabric as the primary drag surface. It is capable of surviving high aerothermal heating during entry, while maintaining a robust impermeable membrane that provides high drag for vehicle deceleration. The ADEPT project team has advanced this decelerator technology via systems-level testing at the one meter diameter (nano-ADEPT) scale. A subsonic aeroloads test (May 2015) and a pathfinder arc-jet aeroheating test (Sept 2015) and a successful sounding rocket flight (SR-1) launch of a 0.7 meter deployed diameter ADEPT (September 2018). The SR-1 flight experiment demonstrated most of the primary end-to-end mission stages including: launch in a stowed configuration, separation and deployment in zero-g, exo-atmospheric conditions, and passive ballistic re-entry of a 70 degree half-angle cone geometry. The ADEPT SR-1 sounding rocket flight experiment had to address challenges such as stowing within the constrained payload envelope, fabric folding, and packaging concerns.
The scientific rationale for the large deployable reflector (LDR) and the overall technological requirements are discussed. The main scientific objectives include studies of the origins of planets, stars and galaxies, and of the ultimate fate of the universe. The envisioned studies require a telescope with a diameter of at least 20 m, diffraction-limited to wavelengths as short as 30-50 micron. In addition, light-bucket operation with 1 arcsec spatial resolution in the 2-4 microns wavelength region would be useful in studies of high-redshifted galaxies. Such a telescope would provide a large increase in spectroscopic sensitivity and spatial resolving power compared with existing or planned infrared telescopes.
The concept of a mechanically deploy- able hypersonic decelerator, developed initially for high mass (40 MT) human Mars missions, is currently funded by OCT for technology maturation. The ADEPT (Adaptive, Deployable Entry and Placement Technology) project has broad, game-changing applicability to in situ science missions to Venus, Mars, and the Outer Planets.
Ultra-low mass deployable and erectable truss structure designs for spacecraft are identified using computerized structural sizing techniques. Extremely slender strut proportions are shown to characterize minimum mass spacecraft which are designed for shuttle transport to orbit. Discrete element effects using a recently developed buckling theory for periodic lattice type structures are presented. An analysis of fabrication imperfection effects on the surface accuracy of four different antenna reflector structures is summarized. The tetrahedral truss has the greatest potential of the structures examined for application to accurate or large reflectors. A deployable module which can be efficiently transported is identified and shown to have significant potential for application to future antenna requirements. Investigations of erectable structure assembly are reviewed.
Ultra-low mass deployable and erectable truss structure designs for spacecraft are identified using computerized structural sizing techniques. Extremely slender strut proportions are shown to characterize minimum mass spacecraft which are designed for Shuttle transport to orbit. Analytical results are presented which demonstrate discrete element effects using a recently developed buckling theory for periodic lattice type structures. An analysis of fabrication imperfection effects on the surface accuracy of four different antenna reflector structures is summarized. This study shows the tetrahedral truss to have the greatest potential of the structures examined for application to accurate or large reflectors. A deployable module which can be efficiently transported is identified and shown to have significant potential for application to future antenna requirements. Recent investigations of erectable structure assembly are reviewed. Initial experiments simulating astronaut assembly by extra-vehicular activity (EVA) show that a pair of astronauts can achieve assembly times of 2-5 min/strut. Studies indicate that an automated assembler can achieve times of less than 1 min/strut on an around-the-clock basis.
This paper describes an automated decision support system designed to facilitate the management of a continuously changing portfolio of technologies as new technologies are deployed and older technologies are decommissioned.
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Increased airspace density from Advanced Air Mobility (AAM) will result in more potential for radio-frequency interference. NASA is developing phased array antenna technologies that can mitigate communication interference to enable safe and efficient aviation operations and more reliable and secure communications.
The current NASA-sponsored Antenna Technology Development Program of the offset wrap-rib antenna concept is based on a ground test program of 'proof of concept' hardware whose potential on-orbit performance is based on analytical estimates. The ground demonstration hardware represents a partial 55-meter diameter reflector and feed support structure. Testing will include automated deployment, reflector surface quality evaluation and validation of analytical performance models. Test results and hardware fabrication costs will be used to refine the models that will be the basis for the preliminary design of a 100-meter diameter wrap-rib antenna system. Additionally, the design, processes, tooling, fabrication techniques, fixturing and assembly approaches used for the 'proof of concept' hardware are directly applicable to building flight systems up to 100 meters in diameter.
This paper discusses recent developments in rapid technology assessment resulting from an active collaboration between researchers at the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base (WPAFB) and the NASA Langley Research Center (LaRC). This program targets the unified development and deployment of global measurement technologies coupled with a virtual diagnostic interface to enable the comparative evaluation of experimental and computational results. Continuing efforts focus on the development of seamless data translation methods to enable integration of data sets of disparate file format in a common platform. Results from a successful low-speed wind tunnel test at WPAFB in which global surface pressure distributions were acquired simultaneously with model deformation and geometry measurements are discussed and comparatively evaluated with numerical simulations. Intensity- and lifetime-based pressure-sensitive paint (PSP) and projection moire interferometry (PMI) results are presented within the context of rapid technology assessment to enable simulation-based R&D.
The physical parameters of the Large Deployable Reflector (LDR) required to achieve the anticipated astronomical objectives are reviewed briefly. System parameters and performance requirements for the LDR are enumerated. The LDR was compared with the Cosmic Background Experiment (COBE), the Infrared Astronomical Satellite (IRAS), and the Space Infrared Telescope Facility (SIRTF). Angular resolution and high resolution spectroscopy requirements for LDR were considered.