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Evaluation of Cyclo Olefin Polymer as Sabot Material for High-Density Projectiles
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A Framework for Scaling in Filtering and Linear Covariance Analysis
Get PDFScaling is used extensively for numerical optimization and trajectory optimization. Its use in the estimation community is almost nonexistent. This paper creates the framework for practical scaling in space navigation, in general, and linear covariance analysis, in particular
Advanced Colloids Experiment (Temperature Controlled) ACE-T10
No full textIncrement 59-60 Science Symposium presentation of Advanced Colloids Experiment (ACE-T10) (by GRC (Glenn Research Center) to the RPO-JSC (Research Planning Office-Johnson Space Center), via WebEx. The purpose of this event is for Principal Investigators to present their science objectives, testing approach, and measurement methods to agency scientists, managers, and other investigators
Modulated Exo-Brake Flight Testing - Modeling and Test Results - Successes with Exo-Brake Development and Targeting for Future Sample Return Capability: TES-6,7,8 Flight Experiments
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Development of Composite Bonded Joints for Space Launch Vehicle Structures
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High-Fidelity Multiple-Flyby Trajectory Optimization Using Multiple-Shooting
Get PDFRendering a complex spacecraft trajectory in high fidelity can be an expensive endeavor, both computationally and from a human time/cost standpoint. However, in many cases, a low-fidelity trajectory that reasonably approximates a high-fidelity counterpart is much easier to obtain. Thus, it is important to have an efficient process for converting a trajectory from lower-fidelity model to high fidelity. We present a method for converting low-fidelity trajectories into high fidelity that relies on multiple shooting, nonlinear programming, and numerical integration. The procedure converts any zero-radius sphere-of-influence gravity-assist events to fully integrated flyby events. Several numerical examples are presented that showcase the flexibility of the high-fidelity rendering process across multiple mission types and flight regimes
Ground Related Safety Issues Through the Eyes of Flight Crews
Get PDFThis presentation reviews voluntary safety reports received by NASA's Aviation Safety Reporting System pertaining to safety issues related to Ground Operations
Investigation of Transonic Truss-Braced Wing Aircraft Transonic Wing-Strut Interference Effects Using FUN3D
Get PDFThis paper presents a computational study of transonic wing-strut interference effects of Transonic Truss-Braced Wing (TTBW) aircraft using the high-fidelity CFD (Computational Fluid Dynamics) code FUN3D (Fully Unstructured Navier-Stokes Three Dimensional). The study is conducted for the wing-strut and the wing-alone configurations at different Mach numbers and Reynolds numbers. The interference effects are calculated by comparing the wing aerodynamics along the spanwise direction between the wing-strut and the wing-alone configurations. The presence of the strut underneath the wing induces a suction peak on the lower surface of the wing, which causes changes in aerodynamic forces and moments, as well as the aerodynamic center location. The interference effects become more pronounced as the Mach number increases. The Reynolds number has less impact on the interference effects. A transonic wing-strut interference aerodynamic correction method is developed for use in a lower-fidelity tool, VSPAERO [a vortex lattice flow solver], coupled to a finite-element model for rapid flutter analysis
Application of Delay Tolerant Networking on the International Space Station
Get PDFNetworking between ISS payloads and the ground presents challenges given the delays in communication and frequent satellite handovers that occur in orbit. Delay Tolerant Networking (DTN) provides a method to store and forward information when the link is available without intervention by the user. While DTN is helpful for the ISS in Low Earth Orbit (LEO), it will become much more important for deep space missions where round trip delays make use of most standard network protocols impossible. The lessons learned from ISS and other programs will help improve standards and ultimately support future NASA deep space missions
Orbital Debris Quarterly News
Get PDFThe Indian spacecraft Microsat-R (International Designator 2019-006A, U.S. Strategic Command [USSTRATCOM] Space Surveillance Network [SSN] catalog number 43947), launched on 24 January 2019, was intentionally destroyed in a test of a ground-based, direct-ascent Anti-Satellite (ASAT) weapon system at 0640 GMT on 27 March 2019. At the time of breakup the 740 kg spacecraft was in an approximately 294 x 265 km altitude, 96.63 orbit. A total of 101 debris have entered the public satellite catalog (through object 2019-006DF), of which 49 fragments remain on-orbit as of 15 July 2019. However, over 400 fragments were initially tracked by SSN sensors and cataloging is complicated by the low altitude of the event and the concomitant rapid orbital decay. A Gabbard plot of this debris cloud is presented in the figure on page 2. A Centaur V Single-Engine Centaur (SEC) rocket variant (International Designator 2018-079B, SSN number 43652) fragmented in early April 2019. At the time of the event the stage was in an approximately 35,092 x 8526 km altitude, 12.2 orbit. This Centaur V upper stage is associated with the launch of the USA 288, or Advanced Extremely High Frequency 4 (AEHF 4), spacecraft from the (U.S.) Air Force Eastern Test Range on 17 October 2018. The cause of the event is unknown. No debris have entered the catalog at this time, but the ODQN will provide updates should they become publicly available