Search NASA⌕ Search

SEARCH · Search NASA

Results for “Navigatio”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

Flight Avionics Sequencing Telemetry (FAST) DIV Latching Display

The NASA Engineering (NE) Directorate at Kennedy Space Center provides engineering services to major programs such as: Space Shuttle, Inter national Space Station, and the Launch Services Program (LSP). The Av ionics Division within NE, provides avionics and flight control syste ms engineering support to LSP. The Launch Services Program is respons ible for procuring safe and reliable services for transporting critical, one of a kind, NASA payloads into orbit. As a result, engineers mu st monitor critical flight events during countdown and launch to asse ss anomalous behavior or any unexpected occurrence. The goal of this project is to take a tailored Systems Engineering approach to design, develop, and test Iris telemetry displays. The Flight Avionics Sequen cing Telemetry Delta-IV (FAST-D4) displays will provide NASA with an improved flight event monitoring tool to evaluate launch vehicle heal th and performance during system-level ground testing and flight. Flight events monitored will include data from the Redundant Inertial Fli ght Control Assembly (RIFCA) flight computer and launch vehicle comma nd feedback data. When a flight event occurs, the flight event is ill uminated on the display. This will enable NASA Engineers to monitor c ritical flight events on the day of launch. Completion of this project requires rudimentary knowledge of launch vehicle Guidance, Navigatio n, and Control (GN&C) systems, telemetry, and console operation. Work locations for the project include the engineering office, NASA telem etry laboratory, and Delta launch sites.

Moore, Charlotte↗

Parametric Covariance Model for Horizon-Based Optical Navigation

This Note presents an entirely parametric version of the covariance for horizon-based optical navigation measurements. The covariance can be written as a function of only the spacecraft position, two sensor design parameters, the illumination direction, the size of the observed planet, the size of the lit arc to be used, and the total number of observed horizon points. As a result, one may now more clearly understand the sensitivity of horizon-based optical navigation performance as a function of these key design parameters, which is insight that was obscured in previous (and nonparametric) versions of the covariance. Finally, the new parametric covariance is shown to agree with both the nonparametric analytic covariance and results from a Monte Carlo analysis.

Optical Navigatio↗

Sextant X-Ray Pulsar Navigation Demonstration: Initial On-Orbit Results

The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a technology demonstration enhancement to the Neutron-star Interior Composition Explorer (NICER) mission. SEXTANT will be a first demonstration of in-space, autonomous, X-ray pulsar navigation (XNAV). Navigating using millisecond X-ray pulsars which could provide a GPS-like navigation capability available throughout our Solar System and beyond. NICER is a NASA Astrophysics Explorer Mission of Opportunity to the International Space Station that was launched and installed in June of 2017. During NICER's nominal 18-month base mission, SEXTANT will perform a number of experiments to demonstrate XNAV and advance the technology on a number of fronts. In this work, we review the SEXTANT, its goals, and present early results from SEXTANT experiments conducted in the first six months of operation. With these results, SEXTANT has made significant progress toward meeting its primary and secondary mission goals. We also describe the SEXTANT flight operations, calibration activities, and initial results.

Navigatio↗

SEXTANT X-Ray Pulsar Navigation Demonstration: Initial On-Orbit Results

Millisecond pulsars (MSPs) are rapidly rotating neutron stars that appear to pulsate across the electromagnetic spectrum. Some MSPs have long-term timing stability that rivals that of atomic clocks. Pulse arrival phase can be predicted with great accuracy at any reference point in the Solar System through use of a pulsar timing model on a spacecraft. Comparing observed phase to predictions gives information that may be used in a navigation process. Why X-rays? Some stable MSPs have conveniently detectable X-ray emissions. X-rays are immune to interstellar dispersion effects thought to limit radio pulsar timing models. Highly directional compact detectors possible.

Navigatio↗