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Lau, Eunice

Publications and source records attributed to Lau, Eunice.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

2018 Mars Insight Trajectory Reconstruction and Performance from Launch Through Landing

The InSight mission successfully launched to Mars on an Atlas V 401 launch vehicle from the Western Test Range (WTR) at Vandenberg Air Force Base (VAFB) at 04:05:00 PDT on May 5th, 2018 and landed in the Elysium Planitia Region on November 26th, 2018. Data confirming nominal touchdown was received at 11:52:59 AM PST. This paper summarizes in detail the actual vs. predicted performance of the InSight spacecraft and all associated assets in terms of launch vehicle events, injection performance, DSN performance, cruise performance, and Entry, Descent, and Landing events.

Abilleira, Fernando↗
NASA NTRS2019

Charting a course to the sun: flight path control for Parker Solar Probe

The successful launch of the Parker Solar Probe (PSP) on August 12, 2018 with a Delta IV rocket and Star-48BV third stage has placed the spacecraft on a 7-year trajectory to study the Sun. The goals of PSP are to better characterize our solar environment and advance our understanding of the Sun at 9.86 Rs. A total of 42 trajectory correction maneuvers are planned. This paper documents trajectory correction maneuver analysis performed just prior to launch until just past the first solar encounter. The pre-launch analysis culminated in two final design cycles which analyzed 24 reference trajectories.

Ryne, Mark↗
NASA NTRS2019

Enabling repeat-pass interferometry from low Venus orbit

Repeat-pass interferometry is a powerful technique for determining changes in topography by flying a radar over the terrain two or more times. These overflights must be very close to each other in space. To design and maintain a low Venus orbit that enables this requires the consideration of drag, non-spherical gravity effects, and solar tides. Once the orbit is designed, the spacecraft must be navigated. To do so requires the use of radar-based terrain-relative navigation in addition to the traditional radiometric datatypes. The mission design and navigation to enable repeat-pass interferometry at Venus are described.

Hensley, Scott↗
NASA NTRS2019

InSight orbit determination

The InSight mission relied on accurate deep-space navigation for a successful Mars landing on November 26, 2018. In this paper, we discuss the role of the cruise Orbit Determination team, whose responsibilities included determining the spacecraft state, predicting the future trajectory, and quantifying the uncertainty associated with those estimates. In particular, we will focus on spacecraft dynamic modeling, small forces due to attitude control, radiometric tracking data, filter strategies, uncertainty quantification, and responses to unexpected flight situations. We will also provide analysis of reconstructed maneuvers, small forces, and delivery accuracy at Mars arrival.

Seubert, Jill↗
NASA NTRS2019

Navigation performance of the 2018 InSight Mars Lander mission

The NASA InSight spacecraft was launched successfully from Vandenberg Air Force Base on an Atlas V 401 launch vehicle on May 5, 2018 and landed on November 26, 2018. Accurate targeting to the atmospheric entry point by the Navigation team achieved by carefully controlling the final entry flight path angle to -12.0 degrees with a tolerance of +/- 0.21 degrees. This paper will describe how the InSight Navigation team met this difficult task in the presence of frequent unbalanced thrusting for attitude control. The continuous correction for this unplanned ∆V far exceeded pre-launch expectations and proved a challenge to predict accurately.

Wallace, Mark↗
NASA NTRS2019

Enabling repeat-pass interferomtetry from low Venus orbit

Repeat-pass interferometry is a powerful technique for determining changes in topography by flying a radar over the terrain two or more times. These overflights must be very close to each other in space. To design and maintain a low Venus orbit that enables this requires the consideration of drag, non-spherical gravity effects, and solar tides. Once the orbit is designed, the spacecraft must be navigated. To do so requires the use of radar-based terrain-relative navigation in addition to the traditional radiometric datatypes. The mission design and navigation to enable repeat-pass interferometry at Venus are described.

Hensley, Scott↗
NASA NTRS2017

Orbit Determination Covariance Analyses for the Parker Solar Probe Mission

This paper details pre-launch navigation covariance analyses for the Parker Solar Probe mission. Baseline models and error assumptions are outlined. The results demonstrate how navigation will satisfy requirements and are used to define operational plans. A few sensitivities are identified and the accompanying investigations are described. Predicted state uncertainty results show that most requirements are met with substantial margin. Moreover, navigation sensitivities may be accommodated operationally and this has been incorporated into project planning. Detailed results are presented only for select launch dates, however twenty unique trajectories (one per launch opportunity) have been assessed.

Jones, Drew Ryan↗
NASA NTRS2017

Parker Solar Probe Navigation: one year from launch

Parker Solar Probe (PSP) will be the first spacecraft designed to fly deep within the Sun’s lower corona and also becoming the fastest spacecraft flown. Launch is scheduled for next year, with a 20-day launch period beginning on 31 July 2018. PSP will be on a ballistic trajectory, requiring seven Venus flybys to progressively lower the perihelion over the seven-year mission. This near-solar environment can be particularly challenging from a spacecraft design as well as a navigation perspective. We discuss an overview of the mission along with some of the particular challenges in navigating PSP.

Valerino, Powtawche↗
NASA NTRS2017

JPL Navigation Support for the JAXA Akatsuki (Planet-C) Return to Venus

This paper details the orbit determination activities undertaken at JPL in support of the Akatsuki (a.k.a. Planet-C) mission’s return to Venus. The JPL navigation team’s role was to provide independent navigation support as a point of comparison with the JAXA generated orbit determination solutions. Topics covered will include a mission and spacecraft overview; small forces modeling; cruise, approach, and Venus phase orbit determination results; and the international teaming arrangement. A discussion of the preparations for the Venus orbit insertion maneuver, which was successfully executed on December 7, 2015, is also covered in detail in the paper.

Young, Brian↗
NASA NTRS2016

Final Mission and Navigation Design for the 2016 Mars InSight Mission

NASA’s Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport (InSight) mission was scheduled to launch the next lander to Mars in March 2016 arriving to the Red Planet in the fall. Derived from the Phoenix mission which successfully landed on Mars in May 2008, the InSight Entry, Descent, and Landing system will place a lander in the Elysium Planitia region. This paper specifies the mission and navigation requirements set by the Project and how the final mission and navigation design satisfies those requirements. Background information affecting navigation including spacecraft modeling and the physical environment which influences the spacecraft motion are included. (Note from the author: The InSight launch in 2016 was suspended due to critical issues with the Seismic Experiment for Interior Structure (SEIS) instrument that could not be fixed prior to the planned launch period. This paper represents the state of the design for the 2016 mission. No attempt has been made to reflect the latest developments).

Abilleira, Fernando↗
NASA NTRS2015

A Journey with MOM

In late 2013, the Indian Space Research Organization (ISRO) launched its "Mars Orbiter Mission" (MOM). ISRO engaged NASA's Jet Propulsion Laboratory (JPL) for navigation services to support ISRO's objectives of MOM achieving and maintaining Mars orbit. The navigation support included planning, documentation, testing, orbit determination, maneuver design /analysis, and tracking data analysis. Several of MOM's attributes had an impact on navigation processes, e.g., S -band telecommunications, Earth Orbit Phase maneuvers, and frequent angular momentum desaturation s (AMDs). The primary source of tracking data was NASA/ JPL's Deep Space Network (DSN); JPL also conducted a performance assessment of Indian Deep Space Network (IDSN) tracking data. Planning for the Mars Orbit Insertion (MOI) was complicated by a pressure regulator failure that created uncertainty regarding MOM's main engine and raised potential planetary protection issues. A successful main engine test late on approach resolved these issues; it was quickly followed by a successful MOI on 24-September - 2014 at 02:00 UTC. Less than a month later, Comet Siding Spring's Mars flyby necessitated plans to minimize potential spacecraft damage. At the time of this writing, MOM's orbital operations continue, and plans to extend JPL 's support are in progress. This paper covers the JPL 's support of MOM through the Comet Siding Spring event.

Mars orbiter↗
NASA NTRS2013

GRAIL Orbit Determination for the Science Phase and Extended Mission

The Gravity Recovery and Interior Laboratory Mission (GRAIL) is the 11th mission of the NASA Discovery Program. Its objective is to help answer funda-mental questions about the Moon's internal structure, thermal evolution, and collisional history. GRAIL employs twin spacecraft, which fly in formation in low altitude polar orbits around the Moon. An improved global lunar gravity field is derived from high-precision range-rate measurements of the distance between the two spacecraft. The purpose of this paper is to describe the strategies used by the GRAIL Orbit Determination Team to overcome challenges posed during on-orbit operations.

near-coplanar orbits↗
NASA NTRS2012

Gravity Recovery and Interior Laboratory Mission (GRAIL) Orbit Determination

Launched on 10 September 2011 from the Cape Canaveral Air Force Station, Florida, the twin-spacecraft Gravity Recovery and Interior Laboratory (GRAIL) has the primary mission objective of generating a lunar gravity map with an unprecedented resolution via the Ka-band Lunar Gravity Ranging System (LGRS). After successfully executing nearly 30 maneuvers on their six-month journey, Ebb and Flow (aka GRAIL-A and GRAIL-B) established the most stringent planetary formation orbit on 1 March 2012 of approximately 30 km x 90 km in orbit size. This paper describes the orbit determination (OD) filter configurations, analyses, and results during the Trans-Lunar Cruise, Orbit Period Reduction, and Transition to Science Formation phases. The maneuver reconstruction strategies and their performance will also be discussed, as well as the navigation requirements, major dynamic models, and navigation challenges. GRAIL is the first mission to generate a full high-resolution gravity field of the only natural satellite of the Earth. It not only enables scientists to understand the detailed structure of the Moon but also further extends their knowledge of the evolutionary histories of the rocky inner planets. Robust and successful navigation was the key to making this a reality.

Orbit Period Reduction (OPR)↗