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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.

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At least 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Enhanced Stationkeeping Maneuver Control Technique for Delta-V Cost Reduction in the Korea Pathfinder Lunar Orbiter

Final document is attached. This paper proposes an enhanced control technique for stationkeeping maneuvers to reduce delta-v costs for the Korea Pathfinder Lunar Orbiter (KPLO). A scheduled circularization control technique exploits patterns in the evolution of the line of apsides and eccentricity to achieve a significant reduction in stationkeeping delta-v costs based on spacecraft requirements. The technique is compared against previous algorithms implemented for maneuver operations of the Lunar Prospector and Lunar Reconnaissance Orbiter (LRO) missions in the USA and KAGUYA in Japan. Through Monte Carlo analysis, the efficacy and robustness of the proposed method are verified, and the technique is shown to meet the operational requirements of KPLO.

Davis, Diane C.↗
NASA NTRS2014

Contingency Trajectory Design for a Lunar Orbit Insertion Maneuver Failure by the LADEE Spacecraft

A contingency trajectory analysis was performed for NASA Ames Research Center’s (ARC’s) Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft in case of a missed lunar orbit insertion (LOI) maneuver. Recovery trajectory options are shown to exist for all LADEE launch opportunities throughout a one year period. Recovery ΔV costs primarily depended on the spacecraft’s apogee location on or near the Sun-Earth weak stability boundary (WSB) and the time needed by the spacecraft to recover (e.g. to “wake up” from “safe” mode) to perform an escape prevention maneuver after the missed LOI.

Genova, A. L.↗
NASA NTRS2019

Maneuver design overview of the 2018 InSight Mars lander mission

Launched on May 5, 2018, the Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) spacecraft landed safely on Mars on November 26, 2018. To deliver the lander accurately to the landing site, six trajectory correction maneuvers (TCMs) were planned along the reference trajectory from Earth launch to Mars entry. For the last two TCMs, there were two corresponding contingency TCMs planned that could be executed in the event that the corresponding nominal one failed. There were also twenty pre-designed menu TCMs available for execution at the time of the last contingency TCM, about 8 hours before the Mars entry, descent, and landing. This navigation paper overviews the maneuver design of each TCM, as well as how each one actually performed during operations.

Wallace, Mark↗
NASA NTRS2017

Cassini Maneuver Experience Through the Final Targeted Titan Flyby and the Grand Finale

Amassing valuable scientific information about the Saturnian system for 13 years, the Cassini spacecraft is now in the last phase of its mission. The Grand Finale, a series of 22 orbits with Cassini passing through a gap between Saturn’s innermost ring and its upper atmosphere, began after the last targeted Titan flyby on April 22, 2017 and ends with the spacecraft plunging into Saturn on September 15, 2017. This paper reports on the maneuvers performed to achieve the final targeted Titan encounter and the maneuvers used to maintain the Grand Finale orbits.

Wong, Mau C.↗
NASA NTRS2017

Maneuver Operations During Juno’s Approach, Orbit Insertion, and Early Orbit Phase

The Juno spacecraft was launched on August 5, 2011 for a 1795-day journey to Jupiter, and arrived on July 5, 2016 with the successful Jupiter Orbit Insertion (JOI) maneuver. This paper will discuss the maneuver operations that took place starting from the Jupiter approach phase (specifically TCM11 on February 3, 2016) through JOI, and the first year of Juno orbital operations through OTM07.

Pavlak, Thomas A.↗
NASA NTRS2018

Numerical Challenges in Cassini Maneuver Operations

Launched in 1997 to observe Saturn and its system, Cassini successfully entered Saturn orbit in 2004 and impacted the planet on September 15, 2017 after 22 orbits each skimming over Saturn’s cloud tops. The Cassini mission represents the most complex gravity-assist trajectory ever flown. As such, the Flight Path Control team encountered many difficulties along the way, resulting in a continuously evolving maneuver process. In this paper, we focus on the challenges presented by the well-known singularities in the transfer problem and the unexpected numerical instabilities in state propagations through flybys, maneuver algorithm convergence issues, and orbital element targeting difficulties.

Hahn, Yungsun↗
NASA NTRSDate not supplied

Optimal Angle of Attack Control for Aerocapture Maneuvers

Recent investigations of aerocapture maneuvers have considered direct force control as a promising alternative to bank angle control. By modulating the angle of attack and sideslip angle independently, the longitudinal and lateral channels can be decoupled and thus solved separately. However, the optimal angle of attack profile for minimizing post-atmospheric propellant expenditure was previously unknown. This research applies principles of optimal control theory to numerically solve for the optimal angle of attack profile for control of the longitudinal channel. Direct methods are first employed to discretize the angle of attack profile and show that an optimal solution follows a nearly bang-bang (full lift up then full lift down) structure under a variety of conditions along the flight path angle corridor. To corroborate these results, indirect methods were also applied to scope the Optimal Control Problem (OCP) as a Two Point Boundary Value Problem (2P-BVP) which could then be solved numerically. The indirect optimization results aligned closely with the direct results, providing further evidence that a bang-bang structure provides a good approximation for the optimal angle of attack profile for aerocapture maneuvers using direct force control.

aerocapture↗
NASA NTRSDate not supplied

Debris Avoidance and Phase Change Maneuvers in Near Rectilinear Halo Orbits

Over the course of its lifetime, Ga teway may execute excursions from itsba seline NRHO that include short-lead maneuvers to avoid other spacecraft or debris objects or long-lea d rephasing within the NRHO to support rendezvous or other mission objectives. The dynamical cha racteristics of the NRHO a re distinct from those of low Ea rth a nd low luna r orbits due to the simulta neous gra vitational influences of the Ea rth a nd Moon. Thus, new a pproaches for executing debris a voidance ma neuvers a nd repha sing ma neuversa re necessary. The current investiga tion proposesmethods for designing low-cost DAMs with short-lead pla nning time a s well a s rephasing maneuvers with many months of advance notice.

Diane C Davis↗
NASA NTRSDate not supplied

Implementation of the Solar Exclusion Zone Burn Through Maneuvers for DSCOVR to Preserve Fuel for the Gyro-less Spacecraft in a Sun-Earth L1 Lissajous Orbit

DSCOVR (Deep Space Climate Observatory) is a National Oceanic and Atmos-pheric Administration (NOAA) space weather, space climate, and Earth obser-vation satellite operating in a Sun-Earth L1 Lissajous orbit. This report summa-rizes the two-burn maneuver campaign performed in Summer 2021 to transfer DSCOVR from the collapsing phase into the expansion phase of the Lissajous orbit to avoid the Solar Exclusion Zone (SEZ). The two-maneuver campaign performed in July and August 2021 was successful and resulted in saving the mission 31 kilograms of fuel and 100 m/s of delta-v reserved for SEZ maneu-vers which are no longer required until 2026 or 2027.

DSCOVR↗
NASA NTRSDate not supplied

Planning and Execution of the Three Mid-Course Correction Maneuvers for the James Webb Space Telescope

The James Webb Space Telescope (JWST) was successfully launched on December 25, 2021 12:20 UTC on an Ariane 5 rocket out of Kourou, French Guiana on a direct, lower energy manifold transfer out to the Sun Earth-Moon (SEM) L2 point. Three mid-course correction (MCC) maneuvers, designated MCC-1, MCC-1b, and MCC-2, were required to provide the energy necessary to reach L2 due to a purposeful biasing down of the launch vehicle. This paper will document the prelaunch preparation, nominal planning, contingency preparation, and successful execution of the three mid-course correction maneuvers.

Jeremy Peterson↗
NASA NTRS2021

Mars Reconnaissance Orbiter Maneuver Plan Following Mars 2020 Landing

The Mars Reconnaissance Orbiter spacecraft continues to perform valuable science observations at Mars, provide telecommunication relay for surface assets, and characterize landing sites for future missions. The spacecraft provided the primary relay support for the Mars 2020 mission during entry, descent, and landing on February 18, 2021. This paper discusses the propulsive maneuver plan following the Mars 2020 landing to return the spacecraft to its primary science orbit by November 2021 and maintain it through 2029. Alternate maneuver plans considered for supporting Mars 2020 surface operations and the entry, descent, and landing of the ExoMars 2022 mission are also described.

Menon, Premkumar R.↗
NASA NTRSDate not supplied

Assessment of Remote Pilot Maneuver Taskload under Multi-Vehicle Control

Multi-vehicle control schemes where a number of remote pilots (m) supervise a number of uncrewed vehicles (m:N) are desired to enable scalability of operations, such as air cargo delivery, in the face of pilot shortage and other constraints. We use queuing models derived from historical track data to assess the increased task load on a remote pilot due to maneuvering demands as the number of supervised vehicles increase. We quantify metrics such as the probability that the inter-maneuver time and inter-communication time.

Multi-Vehicle Control↗
NASA NTRSDate not supplied

Applicability of Fly Neighborly Noise Recommendations to UAM Quadrotors Undergoing Steady Maneuvers

This initial study examines whether the Helicopter Association International (HAI) Fly Neighborly operational recommendations that are based on single main rotor/tail rotor configurations will hold for non-conventional UAM rotorcraft with multiple rotors. The 6-occupant quadrotor concept vehicle designed under the NASA Revolutionary Vertical Lift Technology (RVLT) Project is studied. The tip speed is 550 ft/sec, with three blades per rotor (“550/3”). Predictions are made for three steady maneuvers: level turns, descending turns, and climbing turns. The RVLT Toolchain is exercised using CAMRAD II, pyaaron/AARON/ANOPP2 and a beta version of AMAT (ANOPP2 Mission Analysis Tool). AMAT provides functionality to acoustically model the curved flight paths associated with maneuvers. In addition to quadrotor trim and performance, this study includes analysis of azimuthal variations of the vertical blade loading and its derivative in the form of contour plots on a rotor plane and line plots at one radial location (r/R=0.765). Quadrotor noise trends are analyzed using maximum Overall Sound Pressure Level (OASPL) and Effective Perceived Noise Level (EPNL). The Fly Neighborly guideline that addresses descents (“Level turns are quieter than descending turns”) is predicted to hold for the RVLT Quadrotor as well.

UAM↗
DOE OSTI2021

Distributed Maneuver Planning With Connected and Automated Vehicles for Boosting Traffic Efficiency

Connected and automated vehicles (CAVs) have the potential to improve traffic throughput and achieve a more efficient utilization of the available roadway infrastructure. They also have the potential to reduce energy consumption through traffic motion harmonization, even when operating in mixed traffic with other human-driven vehicles. The key to realizing these potentials are coordinated control schemes that can be implemented in a distributed manner with the CAVs. In this paper, we propose a distributed predictive control framework that features a two-dimensional maneuver planner incorporating explicit coordination constraints between connected vehicles operating in mixed traffic at various penetration levels. Here, the framework includes a distributed implementation of a reference speed assigner that estimates local traffic speed from on-board measurements and communicated information. We present an extensive evaluation of the proposed framework in traffic micro-simulations at various CAV penetrations from traffic flow, energy use, and lane utilization points of view. Results are compared to a baseline scenario with no CAVs, as well as, a benchmark one-dimensional planner.

33 ADVANCED PROPULSION SYSTEMS↗