Tag Archives: featured

Lecture 1 – Orbit Determination Concepts

If you wish to receive class updates and announcements please submit your email here!

[contact-form][contact-field label=”Email” type=”email” required=”1″ /][/contact-form]

Lecture

The inherent characteristics of an orbit determination (OD) problem are introduced. Dynamic state estimation, observations, linearization, and the state transition matrix are discussed. At the end, I have left a practice problem that we will review on Friday, 8 June. We throw a satellite up and watch it come down while introducing some important concepts.

[youtube https://www.youtube.com/watch?v=0g0QzppL1Ow]

Resources

Lecture 1 – Orbit Determination Concepts (slides)

AppendixA-ProbabilityAndStatistics

Statistical Orbit Determination

If you wish to receive class updates and announcements please submit your email here!

[contact-form][contact-field label=”Email” type=”email” required=”1″ /][/contact-form]

Class time/Preliminary Notes

I will be teaching a statistical orbit determination course this summer. This will be on my own time. All lectures will be posted to YouTube. I will be teaching the course out of Bob Schutz’s, Byron Tapley’s, and George H. Born’s, Statistical Orbit Determination. Feel free to use any textbook you desire but the problems and solutions will be assigned from this text. I have included some precursor notes in question and answer format on statistics and probability below.

AppendixA-ProbabilityAndStatistics

Syllabus

AEM_StatisticalOrbitDetermination_Syllabus_CRS

STATISTICAL ORBIT DETERMINATION

EXECUTIVE SUMMARY:

Orbit Determination (OD) is the problem of determining the best estimate of the state of a spacecraft whose initial state is unknown, from observations influenced by random and systematic errors, using a mathematical model that is not exact. Mordern OD is used to support all space missions from JSpOC’s observations of artificial Earth satellites to the International Space Station’s trajectory planning incorporating elements of probability, statistics, and matrix theory. A special projects class is needed to cover this vital part of the space curriculum that arguably makes the backbone of any space program.

DISCUSSION:

Modern OD approaches have been developed by the NASA Jet Propulsion Laboratory (JPL) to fulfill Earth and planetary navigation requirements and at the NASA Goddard Space Flight Center (GSFC) and the Department of Defense Naval Surface Weapons Center in applications of satellite tracking to problems in geodesy, geodynamics, and oceanography. The Joint Space Operations Center (JSpOC) at Vandenberg Air Force Base, the Conjunction Assessment Risk Analysis (CARA) at GSFC, and Trajectory Operation Officers (TOPO) at Johnson Space Center (JSC) use modern OD techniques in applications of satellite tracking, conjunction assessment, and protecting vital assets from the International Space Station to the National Reconnaissance Office (NRO) spy satellites.

Clearly, OD is an important part of any space mission. The proposed class will use the classical text, Statistical Orbit Determination, by Drs. Byron Tapley, Bob Schutz, and George Born. This basic OD course will cover:

  • Introduction to OD problem
    • Dynamic system and associated state
    • Observations are non-linear functions of state variables
    • Classical well-determined approach
    • Modern over-determined approach
  • Observations to measure satellite motion
    • Ground-based systems: laser, radiometric, etc.
    • Space-based systems: GPS, etc.
    • Error sources and media corrections
  • Non-linear OD reduced to linear state estimation
    • Application of linear system theory
    • Incorporation of algorithms to computational environment
    • Sequential processing of observations
    • Control of real-time processes

This will be supported by background and supplemental information in:

  • Probability and Statistics
  • Review of Matrix Concepts
  • Examples of State Noise and Dynamic Model Compensation
  • Solution of the Linearized Equations of Motion

Students can expect to incorporate their classroom knowledge into real-life by building optical and radiometric sensors supporting The University of Alabama’s new satellite ground station.

LECTURES:

Lecture 1 – Orbit Determination Concepts

Lecture 2 – Orbital Mechanics Review

Space Operations and Support Technical Committee

Today I received official notice: I am a member of the AIAA Space Operations and Support Technical Committee (SOSTC). The SOSTC Charter:

The Space Operations and Support Technical Committee (SOSTC) is concerned with all aspects of civil, military, and commercial space operations and support, including direct and supporting operations, the systems and software affecting operations, and space operations and operational risk management. The SOSTC addresses all types of space operations, including manned and unmanned space operations from low Earth-orbiting to deep-space systems. It is involved with all phases of mission operations, including pre-launch and launch activities, early mission commissioning activities, on-orbit activities, cruise and encounter activities, post-landing activities, and end-of-life operations. The SOSTC likewise addresses space related operational support activities, including training, servicing, mission planning, flight dynamics, telemetry transmission, command and control, and data handling, processing, analysis, and storage.

I’m very thankful for this opportunity.

Post-Flight Analysis Report (PFAR) of RX1

 

SUMMARY:

Christopher R. Simpson built a rocket to pass his Level 1 (L1) certification from the National Association of Rocketry (NAR). The rocket was a kit from Madcow Rocketry; the “Frenzy,” [1]. The RX1 used an Aerotech H550ST-14A, “Super Thunder,” motor with a total impulse of 71.9 lb-sec and a burn time of 0.57 sec. Construction of the rocket, flight, and recovery are reviewed to analyze and critique operations.

Post-Flight Analysis Report (PFAR) attached here: PFAR-RX1 (26 Feb 2018)

YouTube link to flight: https://www.youtube.com/watch?v=Xqff5scf-00

ACKNOWLEDGEMENTS:

A big thank you to Karson Holmes for certifying/critiquing me and William Ledbetter for making the trip to watch the fun take off! Also, a special thanks to Alabama Rocketry for allowing me to use their adapter.

RESOURCES:

Rocket Used: https://www.madcowrocketry.com/4-frenzy/

Motor/Supplier Used: https://csrocketry.com/rocket-motors/aerotech-rocketry/motors/38mm/dms-rocket-motors/aerotech-h550-14a-super-thunder-dms-rocket-motor.html

Alabama Rocketry Facebook Page: https://www.facebook.com/alabamarocketry/

Pheonix Missile Works Facebook Page: https://www.facebook.com/groups/58541022592/

 

 

 

FreeFlyer Demonstration: 2:00pm Sep. 28, 2017 for UA faculty and students

I will be giving a demonstration of FreeFlyer on Thursday, September 28 at 2:00 pm in SERC 3070. Faculty and Students feel free to drop on by! I have attached the flyer, here: FreeFlyerWithAttitude

Christopher Simpson will present a FreeFlyer demonstration, “FreeFlyer with Attitude,” on Thursday, September 28, 2017 at 2:00 pm in SERC 3070. FreeFlyer with Attitude will showcase the high-fidelity flight dynamics software with a Earth imaging satellite mission plan with specific pointing requirements. FreeFlyer is currently used on several NASA missions, including the Magnetosphere Multiscale (MMS) mission which set the record for closest flying formation at 7.2 km in September of 2016. Mr. Simpson recently interned with a.i. solutions, Inc. over the summer and worked with the FreeFlyer Tech Support team. He recently graduated with his B.S. in Aerospace Engineering and Mechanics from The University of Alabama in May 2016. He was recently awarded a SMART scholarship from the Naval Air Warfare Center – Weapons Division, China Lake. He is pursuing his Ph.D. at The University of Alabama under Dr. Charles O’Neill.

DemonstrationPhotos

WHAT WHO WHERE WHEN
Showcase of FreeFlyer Students & Faculty SERC 3070 2:00 PM

September 28, 2017

 A high fidelity flight dynamics software comparable to STK used on multiple NASA missions, including the ISS, MMS, OSIRIS-Rex, and for the SLS All with an interest in spacecraft and astrodynamics are welcome

 

2017 ESPRMC Graduate Research Symposium – The University of Alabama

I will be presenting “Benefits of Tracking Aids on a 1U CubeSat,” on Thursday, April 13 at the 2017 ESPRMC Graduate Research Symposium. Dr. O’Neill was my co-author. I hope to see you there.

Abstract:

Incoporating active/passive tracking aids into the design of a university/high school CubeSat mission promotes good space stewardship. Tracking aids are necessary for improved tracking covariance of CubeSats. Tracking aid support and design-space cost are covered. Reflectarrays, patch array(s), and deployable antennas show the potential benefit of transmitting data over S-band frequencies and tracking aids that enhance the mission capabilities. Passive and active tracking aids with low impact on the mission provide reduced covariance of CubeSats orbit tracks shown through use of modeling tools.

STK Certified

stk_certification

I’m now STK Certified Level 1. This means that I can use the GUI and some snippets of code to develop and analyze a scenario. The testing scenario involved the ability to analyze the access of sensors on a small UAV to ground sites and compare that access with satellites and other vehicles given certain restrictions.

The video of the scenario I developed is available here: Video of Test Scenario

Cesium Demo Using STK Scenario/TLE Data

Coming Soon: Orbital Mechanics/Astrodynamic Problem Solutions

While in the midst of preparing for a journal paper I decided that I wanted to showcase my abilities. I will solve all the problems from Vladimir Chobotov’s Orbital Mechanics, Third Edition, and Richard Battin’s An Introduction to the Mathematics and Methods of Astrodynamics, Revised Edition and post the solutions online. I hope to have this done by January 2.

Not only will this be a good review for myself but it will showcase my abilities to solve problems relating to the field I want to enter. Hopefully, it will prove to be a valuable tool in the future.

As for the featured picture: I am in the process of getting myself certified Level 1 with STK. I dropped this scenario into Cesium while I was practicing and exploring STK before the exam. My exam is due December 22. I will let you know the results soon!

Lessons from Gene Kranz's "Failure Is Not An Option"

FAILURE IS NOT AN OPTION is an overview of Gene Kranz’s time as a controller with the newly formed Mecury Program to the last Apollo mission. He describes the growth of a burgeoning new space program, the success and the failures, and the men and women that took America to the moon.

The dedication of Gene’s team and his resolve to be TOUGH and COMPETENT following the Apollo 1 disaster that claimed the lives of Ed White, Roger Chaffee, and Gus Grissom are exemplary of a leader. His resolve to forge his team from mere engineers to operators is incredible. His resolve paid off when he and his team helped bring home Apollo 13 alive and safe. Time and time again Gene makes critical decisions based on his extensive preparation, the implicit trust he has for his fellow controllers, and his gut. A new group of young controllers seems to join the old with each mission. With each mission the young become old with their experience in the trenches.

Several lessons that can be gained:

  • Preparation: “Failing to prepare is preparing to fail.”-John Wooden. Gene’s team was more than a group of engineers. They were operators. They knew the system and their spacecraft extensively inside and out.
  • Trust: If you don’t trust your team to make the right decisions then why do they work for you? There was an implicit bond of trust between Gene, his underlings, and his peers.
  • Mentorship: One day you will be replaced. If the system is to run smoothly  you have to encourage individual growth while showing them the ropes.

What does this mean for me?

In Dr. O’Neill’s laboratory we often face critical, time-constrained decisions. My ability to answer them is a reflection of my capabilities. In my current down-time I am focused on improving my CAD, Orbit Analysis, and Coding knowledge.

 

 

 

Lessons from Gene Kranz’s “Failure Is Not An Option”

FAILURE IS NOT AN OPTION is an overview of Gene Kranz’s time as a controller with the newly formed Mecury Program to the last Apollo mission. He describes the growth of a burgeoning new space program, the success and the failures, and the men and women that took America to the moon.

The dedication of Gene’s team and his resolve to be TOUGH and COMPETENT following the Apollo 1 disaster that claimed the lives of Ed White, Roger Chaffee, and Gus Grissom are exemplary of a leader. His resolve to forge his team from mere engineers to operators is incredible. His resolve paid off when he and his team helped bring home Apollo 13 alive and safe. Time and time again Gene makes critical decisions based on his extensive preparation, the implicit trust he has for his fellow controllers, and his gut. A new group of young controllers seems to join the old with each mission. With each mission the young become old with their experience in the trenches.

Several lessons that can be gained:

  • Preparation: “Failing to prepare is preparing to fail.”-John Wooden. Gene’s team was more than a group of engineers. They were operators. They knew the system and their spacecraft extensively inside and out.
  • Trust: If you don’t trust your team to make the right decisions then why do they work for you? There was an implicit bond of trust between Gene, his underlings, and his peers.
  • Mentorship: One day you will be replaced. If the system is to run smoothly  you have to encourage individual growth while showing them the ropes.

What does this mean for me?

In Dr. O’Neill’s laboratory we often face critical, time-constrained decisions. My ability to answer them is a reflection of my capabilities. In my current down-time I am focused on improving my CAD, Orbit Analysis, and Coding knowledge.