IMPROVING SPACE OPERATIONS 2013
Track 2: Satellite Co-location and Collision Avoidance
Joint Sessions
Day 1: April 30
11:15 – 11:45
Steve Smith, SES
The Space Data Association Framework for Informed and Actionable SSA
Bio:
Mr. Steven Smith is a Senior Manager in Operations Support at SES, and is
representing the Space Data Association (SDA), SES being one of the Executive
Members of the SDA.
In his current role with SES, he holds the position of Senior Manager, Operations
Support, and is responsible for developing requirements for operational systems and
provision of technical support to operational teams. He also represents SES on
various industry groups, including the SDA and Satellite Interference Reduction
Group (sIRG).
Prior to this position, Mr. Smith was VP of Technical Operations at ProtoStar,
responsible for the satellite ground infrastructure and payload operations, and prior
to that, Director of Commercial Satellite Services at Intelsat.
Mr. Smith has over 25 years’ experience in satellite ground system engineering and
operations, communications operations, and project management, with satellite
operators, the European Space Agency, and UK Ministry of Defence.
Abstract:
An overview of the Space Data Association (SDA) will be presented, including its
goals, objectives, philosophy and future plans. The SDA’s focus on data fusion of the
most authoritative data and further SSA direction in the area of RFI mitigation will
also be presented.
11:15 – 11:45
Dan Oltrogge, Analytical Graphics
Debris Mitigation Strategies, Standards and Best Practices With Sample
Application to CubeSats
Bio:
Daniel Oltrogge is a Senior Research Astrodynamicist with AGI's Center for Space
Standards and Innovation and CEO of 1Earth Research. Dan is also Project
Manager of the Space Data Center, providing space situational awareness and
analysis support to government, civil and commercial space operators. Dan’s
specialties include launch and early orbit operations, nanosatellites, collision
avoidance, RF interference mitigation, international space operations and debris
mitigation standards development, space situational awareness and astrodynamics.
Abstract:
Debris mitigation is of concern for small satellites, since they have the capability to
be mass-produced, launched and deployed. We will examine some of the pertinent
debris mitigation standards that are either published or in work, and examine how
those standards, when coupled with space operations best practices, permit the
development of suitable deployment and flight concepts-of-operation for a sample
CubeSat mission thus demonstrating these standards and concepts for a relatively
recent and popular class of satellite.
Day 1: April 30
13:30 – 14:00
Rich Burns, NASA/GSFC
Recent NASA/GSFC Collision Avoidance Events
Bio:
Rich Burns currently serves as Project Manager for Space Science Mission
Operations at NASA Goddard Space Flight Center. In that capacity, he is
responsible for mission operations on eleven NASA missions on orbit, six of which
are operated at GSFC. Previously, Rich served in various systems and GN&C
engineering positions at GSFC since arriving in 2001. Prior to that, he worked as an
astrodynamics engineer for ten years at AFRL at Kirtland AFB.
Abstract:
For two recent collision avoidance events encountered by NASA/GSFC each
presented unique and difficult decisions for flight engineers and management. On
the first, an SDO maneuver was waived when the no-maneuver was shown to be on
one side of the secondary and the post-maneuver ephemeris was on the other. In the
second event, NASA/GSFC executed a collision avoidance maneuver on Fermi,
which was an atypically difficult decision because there was a strong desire to fly the
entire mission without using the prop system as it had been added only to carry out
the required deorbit.
14:00 – 14:30
Justin McNeill, The Aerospace Corporation
Space Situation Monitoring Laboratory: An Integrated Web-Based Environment for
Space Environment Information and Analysis
Bio:
Justin F. McNeill, Jr. is a Senior Project Engineer and has been with The Aerospace
Corporation for about ten years. Since the fall of 2010, he has supported the NASA
Programs Division at Aerospace. Mr. McNeill has led various studies for the benefit
of the NASA program offices at the Marshall Space Flight Center and Kennedy
Space Center. Prior to supporting this division, he managed a team of software
engineers in the Engineering Technology Group of Aerospace, providing specialized
engineering software to both internal and external customers. Also, Mr. McNeill led
an Aerospace team supporting operations and sustainment of science planning
software at Caltech for the Galaxy Evolution Explorer mission (GALEX). This
support was provided to GALEX mission for six and a half years. Prior to
Aerospace, Mr. McNeill worked over six years on the ground system development
for Northrop Grumman. Mr. McNeill started his career at the Jet Propulsion
Laboratory (JPL) in 1989, supporting the Multi-mission Image Processing
Laboratory in the Observational Systems Division (Division 38). Mr. McNeill holds
a B.S. in Electrical Engineering from the University of Delaware and an M.S. in
Electrical Engineering from Stanford University.
Abstract:
The Space Situation Monitoring Laboratory (SSML) is a web-based system designed
to detect, display, monitor, and archive anomalous events and provide automated
notifications to researchers and engineers. The system employs new algorithms and
tools for the monitoring, analysis, and study of the space environment. SSML
includes information on satellite ephemeris, predicted satellite closest
approaches, space weather, and satellite orbital changes that are indicative of
maneuvers, collisions, explosions, or even atmospheric effects. The system uses
displays and visualizations with web services
infrastructure to present information in an intuitive fashion that lead to a broader
understanding of the current satellite environment.
14:30 – 15:00
Joshua Wysack, Space-Nav
Collision Probability Forecasting using a Monte Carlo Simulation
Bio:
Josh Wysack is a senior aerospace engineer at SpaceNav working on the topics of
collision risk management and Space Situational Awareness. He began his career
as an orbit analyst working launch operations for the MilStar communications
satellites. His work on the topic of collision avoidance includes several years spent
working for the NASA Goddard CA effort. CA operations and analysis support was
also provided for NOAA and DMSP satellites. Josh has a B.S. degree in Aerospace
Engineering and a M.S. degree in Applied Mathematics. He has been with
SpaceNav for two years.
Abstract:
Satellite operations collision risk assessment processes use the probability of
collision to quantify the collision risk for a given close approach event. The collision
probability value is an assessment of the risk using the latest available state and
covariance data. Often times the collision probability is computed days prior to the
conjunction event. Thus the probability value changes as the time to the
conjunction event is reduced. This presentation describes a method for statistically
estimating how the collision probability evolves as the time to closest approach is
reduced. Our approach utilizes a Monte Carlo simulation to forecast the risk
evolution. The method will take into account future changes in the state of both
objects as well as the changes in the covariance. The utility of the method will be
illustrated by demonstrating the performance for historical close approach events.
The Missile Defense Space Development Center is currently using this method at
Schriever AFB.
Sample Output
The Pc bins shown below represent the likelihood that the Pc value at the forecast
time will be within the lower and upper limits of the bin. Probability of occurrence
is the ratio of the number of Pc values in a bin to the number of Monte Carlo trials,
expressed as a percentage.
15:15 – 15:45
Joe Chan, Intelsat
Conjunction Assessment Activities at Intelsat
Bio:
Joe Chan is the Director of Flight Dynamics at Intelsat, where he manages
operations for a fleet of over 75 geostationary communication satellites. Joe has
also worked in the satellite geodesy branch at Goddard Space Flight Center, NASA.
Involved in different science missions including the Topex/Poseidon mission, Mars
Observer and the high resolution EGM geopotential models
Abstract:
A brief description and overview of Intelsat’s activities in conjunction assessment
will be presented. Some examples of recent close approaches and mitigation
strategies will be discussed. Paths to improved conjunction assessment processes
are proposed.
15:45 – 16:15
Dave Desrocher, JHU/APL
Situational Awareness for Conjunction Trending – The Forest AND the Trees
Bio:
Dave Desrocher is a retired AF officer who has been working in the national defense
arena for 37 years. While his academic background is physics, his primary pursuit
has been to simplify hard problems in multiple domains, to include global nuclear
treaty monitoring, missile defense, space operations and space control, national
strategy for cyber situational awareness, border security and more. Dave was the
lead advisor to HQ AFSPC on the Commercial and Foreign Entities (CFE) pilot
program that was enabled by Congress in the 2004 Defense Authorization Act. The
work was based on pathfinder capabilities principally created by this Session Chair
while at The Aerospace Corporation. While that vision was not fully embraced in
what became the current Space-Track.org activity, Dave has continued to work with
the National Security Space domain to improve Space Situational Awareness
capabilities. Dave is currently employed by the Johns Hopkins University Applied
Physics Lab, though he is here today to present some personal work that he has
done leveraging T.S. Kelso’s SOCRATES data to provide additional trending
methods and insight for debris mitigation planning and space operations.
Abstract:
Conjunction assessment (CA) in operations is predominantly focused on detection
and mitigation of near term collision risks. Processing limitations have typically
constrained routine Situational Awareness (SA) activity to focus on select objects in
the Resident Space Object (RSO) catalog (“The Trees”). Additional insight into the
CA problem space can be gained through trend analysis of all predicted
conjunctions (“The Forest”) across the RSO catalog for given parameters. Moreover,
continuous CA trending can identify changes in the overall collision risk
environment, to include periodic and evolving threats. This presentation will
demonstrate one simple way to approach continuous trending for SA into the forest
to find the trees. The approach employs script-based automated processing of
SOCRATES conjunction forecast files from 2006 to present and a web-based
interface to generate various plot views of the data. Other datasets could equally be
used, as the method simply aims to plot views of the data to render SA. Potential
use includes identification of worst offenders, which could be targeted for
removal/mitigation when such capabilities become possible. Other potential uses
will be explored.
16:15 – 16:45
Debi Rose and Tiffany Finley, Southwest Research Institute
CYGNSS MISSION – Deployment and Management of a Constellation of MicroSats
Abstract:
Hurricane track forecasts have improved in accuracy by ~50% since 1990, while in
that same period there has been essentially no improvement in the accuracy of
intensity prediction. One of the main problems in addressing intensity occurs
because the rapidly evolving stages of the tropical cyclone (TC) life cycle are poorly
sampled in time by conventional polar-orbiting, wide-swath surface wind imagers.
NASA’s most recently awarded Earth science mission, the NASA EV-2 Cyclone
Global Navigation Satellite System (CYGNSS) has been designed to address this
deficiency by using a constellation of micro-satellite-class observatories designed to
provide improved sampling of the TC during its life cycle.
Deploying and managing a constellation of micro-satellites requires a focus on
ensuring the microsats do not collide with each other during the deployment and
mission life-time as well as avoiding conjunctions with other objects in the same
orbit during lifetime operations. In addition, it is necessary to ensure the
communications strategies employed in both the commissioning and operations
phases occur with no interference between microsats. The CYGNSS microsat has a
simple attitude control system with no propulsion capability on-board, thus the
movement of the microsats will be effected using pitch maneuvers to increase the
drag profile of a microsat in relation to the other microsats in the constellation or
other objects in the orbit.
This presentation provides an overview of the CYGNSS mission and operations
concept as well as a look at the current status of the on-going studies and trades
that are occurring to address deployment, maneuvering and communication with
the microsats within the CYGNSS constellation
Day 2: May 1
10:00 – 10:30
Larry Bryant, NASA
Juno Collision Avoidance Maneuver Strategy
Abstract:
The Juno spacecraft launched in August of 2011 and is scheduled to perform an
Earth flyby on October 9, 2013. To achieve the gravity assist required to put Juno
on a trajectory to Jupiter, the planned Earth flyby altitude is fairly low, at 560 km.
This low altitude flyby, along with the large Juno cross area due to the large solar
arrays, have driven us to have a strategy in place for conjunction assessment and
the possible need to perform a collision avoidance maneuver quickly, just prior to
Earth closest approach. This talk will focus on the plans the Juno project has to
design and build the potential collision avoidance maneuvers in advance, prior to
Earth approach, and give the rationale for the collision avoidance maneuver
characteristics. We will also discuss the plans in place to work with the CARA
(Conjunction Assessment Risk Analysis) group at Goddard to help identify the
possible need to perform one of the collision avoidance maneuvers.
10:30 – 11:00
Dan Oltrogge, Analytical Graphics
Order-of-Magnitude SSA Actionability and Error Source Characterization
Bio:
Daniel Oltrogge is a Senior Research Astrodynamicist with AGI's Center for Space
Standards and Innovation and CEO of 1Earth Research. Dan is also Project
Manager of the Space Data Center, providing space situational awareness and
analysis support to government, civil and commercial space operators. Dan’s
specialties include launch and early orbit operations, nanosatellites, collision
avoidance, RF interference mitigation, international space operations and debris
mitigation standards development, space situational awareness and astrodynamics.
Abstract:
SSA analyses have been performed for decades and are the foundation of operator
collision avoidance and RFI mitigation processes. Yet the data that feed such
analyses are typically not designed or intended to be used for this purpose, and
when we use them without examining their suitability, we often run into
unintended consequences. We will investigate, at a top level, the suitability of
different data sources and types for SSA analysis.
11:00 – 11:30
Joshua Wysack, Space-Nav
Optimal Collision Avoidance
Bio:
Josh Wysack is a senior aerospace engineer at SpaceNav working on the topics of
collision risk management and Space Situational Awareness. He began his career
as an orbit analyst working launch operations for the Milstar communications
satellites. His work on the topic of collision avoidance includes several years spent
working for the NASA Goddard CA effort. CA operations and analysis support was
also provided for NOAA and DMSP satellites. Josh has a B.S. degree in Aerospace
Engineering and a M.S. degree in Applied Mathematics. He has been with
SpaceNav for two years.
Abstract:
Operational collision threat characterization is now an essential component of space
mission operations. Most spacecraft operators have some semblance of a process to
evaluate and mitigate high-risk conjunction events. As the size of the space object
catalog increases, satellite operators will be faced with more conjunction events to
evaluate. Thus more sophisticated collision threat characterization and collision
avoidance strategies must be implemented. This presentation describes an optimal
collision avoidance maneuver planning strategy. Our approach reduces the collision
risk for one or more high-risk conjunction events; accounting for mission unique
constraints and requirements. The approach utilizes a derivative-free optimization
(DFO) algorithm.
Sample Output
Iterations of the DFO algorithm are shown for maneuver time and magnitude. The
algorithm converges at the minimum maneuver magnitude that will achieve the
desired collision probability.