News Archive

Dr. Andreas Mogensen selected as Astronaut

May 2009

Congratulations to Andy Mogensen, one of our very own alumni, who has been selected as an astronaut by the European Space Agency.  Andy was picked as one of only six new European astronauts from thousands of applications.  Andy is a citizen of Denmark and the first Danish Astronaut.  As a new astronaut, Andy may have the opportunity to work on the International Space Station by 2013.

 

Andy received his Ph.D. from UT-Austin in 2007 on the topic "Real-Time Navigation for Mars Final Approach using the Mars Network." His research focused on two-way Doppler measurements using radio transceivers between spacecraft as a means to provide precise navigation during a satellite's final approach to Mars.  While at Austin, he was also a member of the Austin Mars Society, and an avid rugby player.

Since his graduation from UT-Austin, Andy has held engineering positions at Astrium (Germany) and Surrey Space Centre (UK). 

We are very proud of Andy's achievement as our newest Longhorn Astronaut!  Congratulations to Andy and Hook'em Horns!

For more information on Andy's Bio at UT-Austin, click here.  For a press release discussing Andy's astronaut selection, click here.

 

 

Getting Kids Interested in Space, Science, and Robotics

April 2009

Since the spring semester began, the Lightsey Research Group has been developing and testing curriculum for after-school robotics clubs at local middle schools.  These lessons aim to teach kids about robotics and space exploration in an effort to garner more interest in math, science, and engineering.  Currently, two middle schools and 1 high school from the greater-Austin area are participating in this pilot program. And to help the teachers give the lessons, a few undergraduate students from UT-Austin go to each class to help students with their robots.

Each lesson is based on using Lego Mindstorms robotics kits to teach kids how to build, program, and operate their very own robot!  By using Legos and the Mindstorms’ user-friendly design, kids’ imaginations are able to run wild!  Students are able to build various mechanisms with the provided gears, lego blocks, and wheels.  Additionally, the kits also come with a light sensor, touch sensor, ultrasonic sensor, motors, main computer, and software for easy programming.  With all these elements, students can build complex robots in a class period and learn how to program them.

Lessons teach the basics of programming such as loops, switching statements, and user-defined functions--but in a manner understandable to the average middle school student. Real world applications of robotics and programming are also discussed to illustrate the cool things kids can do with math and science. Students learn to program their robots to collect objects just like the Mars Rovers. Or they program their robot to find a light source, track it, and then point towards it just like a solar panel.

 

Texas 2-STEP at FCR

February 2009

The Texas 2-STEP team had a wild ride at the UNP-5 Flight Competition Review (FCR) held in Albuquerque, NM on Tuesday, January 20, 2009. The day-long competition went very well. The team did an exceptional job preparing for and during the competition. I would like to take this time to congratulate each and every person who worked on Texas 2-STEP! Thank you.

Unfortunately, events following the review were not so pleasant. The Chaser satellite and electrical ground support equipment (EGSE) were stolen from our rental vans at ~1:00am Wednesday morning. As the team was preparing to leave Albuquerque at 6:00am, a team member noticed that the van containing the hardware had two smashed windows and, subsequently, that the satellite and hardware were stolen. After consulting the police and acquiring a new rental van, the team left Albuquerque in despair as two+ years of hard work was simply gone.

Thankfully, around 1:00pm the police called to report they recovered the both the satellite and hardware! The team graciously thanks the Albuquerque police for recovering the stolen hardware! The police also arrested the three men responsible for the theft and AFRL shipped the satellite and EGSE back to UT. Texas 2-STEP actually made the Albuquerque evening news: http://www.krqe.com/dpp/news/crime/crime_krqe_albuquerque_burglars_boost_satellite_before_launch_200901230105 When the equipment arrived, surprisingly, everything worked!

 Thanks again to everyone who was apart of this happy ending!

 

Texas 2-STEP Ready for Proto-Flight Integration

December 2008

Texas 2-STEP is ready for full flight integration of the Chaser satellite. During the next two weeks the team will be verifying their responsive-space mission objective to fully integrate and test the satellites within a short period of time. After which the satellite will be heading to Johnson Space Center (JSC) for a thermal vacuum test December 17 – 19th. The thermal-vacuum test will qualify the satellite for the space environment. Thus the test will verify the functionality of our components and overall design as they are intended to work during the mission.

Texas 2-STEP is part of the University Nanosat Program - 5 (UNP-5) hosted by the Air Force Research Lab. The program is a two-year competition of multiple universities across the country competing for a chance to launch their satellites into space. January 20th, 2009 is the Flight Competition Review (FCR) and the end of the two-year cycle. Thus, our satellite and all of our work for the past two years on Texas 2-STEP is currently being prepared for the review. At the review, we will showcase the satellite and with hope convince the judges our satellite deserves a flight into space. Wish us luck!

 

Test Launch Succesful for PARADIGM

November 2008

 The BEVO-1 and AggieSat-2 teams succesfully tested the launch deployment of their 5-inch CubeSats. The satellites are manifested to launch inside the Space Shuttle Picosatellite Launcher (SSPL) on STS-127 Endeavor. On the ground, the dynamics were simulated using a SSPL mock-up created by a Texas A&M student. The SSPL mock-up has the same dimensions as the SSPL, only the bottom is cut out to allow the satellites to rest on air bearing pucks. The two air bearing pucks have light air source tubes attached that travel with the pucks along a set of dry erase boards lined up along a smooth surface. The result is a high fidelity 2-dimensional experiment.

The satellites seperate in a similar manner as MAST. The quarter-wave monopole antennas of BEVO-1 is partially embedded in AggieSat-2 inside the SSPL. During seperation, the antenna pushes on the AggieSat-2 with a spring force that is balanced by the AggieSat-2's antenna on the opposite corner. The actuation powers on the satellites and connects the antenna to the radio.

With this test a success, the obstacles facing the BEVO-1 team are reduced even further. Delivery is slated for February 2009.

 

Satellite Program Updates

October 2008

This has been a very exciting semester for the satellite design programs at UT. 

FASTRAC: After schedule delays, the new AFRL built battery boxes for the FASTRAC Satellites finally arrived in Austin in mid October.  The satellites are now undergoing final integration before they are delivered to AFRL in mid November for a complete array of environmental testing.

PARADIGM:  The paradigm team has been able to complete their engineering design unit and are now gearing to start building the flight satellite.  They have recently completed their Phase 0, 1, & 2 Safety Review succesfully. Congratulations to the paradigm team for this accomplishment.

TEXAS 2-STEP:   The Texas 2-Step team has been working very hard in the SDL getting ready for the Flight Competition Review in January for the University Nanosat Program.  

 

Autonomous Cislunar Navigation Research for Orion Spacecraft Begins its Second Year

October 2008

The Lightsey Research Group is not entering its second year of work on autonomous cislunar navigation for NASA's Orion vehicle. Over the last year, work has focused on identifying promising measurement types and technologies. Many of the results from our first year of work were presented at the AIAA Guidance, Navigation, and Control Conference in August 2008. A copy of the paper may be found here.

The intensity of research effort is expected to increase significantly as we move into our second year of work in this area. Much of the increased work will be enabled by the recent addition Sebastian Munoz, a PhD student in the Lightsey Research Group, to the team working on this task. As we move forward we plan to address the following topics:

1. What sensors are best suited for autonomous cislunar navigation
2. Development of measurement models for the selected sensors
3. Performance assessment of an on-board navigation algorith
4. Determining the resulting trajectory dispersions associated with the navigation errors during lunar return
5. Assessment of the impact of all the above considerations on the entry and landing requirements for an autonomous return

Significant results and findings will be posted on the Lightsey Research Group webpage as they become available - so remember to visit our site to keep up to date on our latest results and activities.

 

Bevo-1 Satellite Begins Flight Build

September 2008

With delivery scheduled for February of 2009, the UT-Austin PARADIGM satellite design team started to build their flight hardware. The satellite dubbed "Bevo-1" is a 5-inch cube to be launched into orbit on STS-127 out of the Space Shuttle Pico-satellite Launcher (SSPL).

The satellite is being built at the flight assembly facility of the Center for Space Research. The students are currently in preparation for the Phase 0/1 Safety briefing at the Johnson Space Center. Bevo-1 will fly and characterize a NASA built Dragon GPS receiver. The receiver will be utilized in future LONESTAR missions to perform an autonomous rendezvous and docking.

 

August 2008 Small Satellite and AIAA GNC Conference Participation

September 2008

Several members of the Lightsey Research group attended the 22^nd Annual Small Satellite Conference in Logan, Utah in August 2008. The FASTRAC (Formation Autonomy Spacecraft with Thrust Relnav Attitude and Crosslink) project manager, Sebastian Muñoz, presented the paper "The FASTRAC Satellites: Software Implementation and Testing". FASTRAC is enthusiastically preparing to launch in December 2009. Cinnamon Wright’s paper, “Bridging the Gap: Collaboration Using Nanosat and CubeSat Platforms Through the Texas 2 STEP (2 Satellite Targeting Experimental Platform) Mission” was also included in the proceedings. The Texas 2 STEP nanosatellite team participated in the University Nanosat 5 Proto-Qualifying Review. The team received valuable feedback from the Air Force Research Laboratory reviewers as well as other aerospace industry participants. This information will be used as the team pushes forward toward the Final Competition Review in January 2009.

 

Two papers were also presented at the AIAA Guidance, Navigation, and Control Conference and Exhibit held in Hawaii in August 2008. “A Review of Options for Autonomous Cislunar Navigation” was presented by John Christian. “Optimal Impulsive Maneuvering Within a Confined Hover Region” by Jessica Williams and E. Glenn Lightsey was also presented. These papers and presentations are now posted on the Lightsey Research Group website.

 

More information about FASTRAC can be found at http://fastrac.ae.utexas.edu.

 

More information Texas 2 STEP can be found at http://texas2step.ae.utexas.edu.

 

Seminar Series Schedule Fall 2008

September 2008

The Fall 2008 Research Seminar schedule is as follows:

 

Date, Speaker, News Article

• Sept. 11, Dr. Lightsey, Dr. Lightsey
• Sept. 25, John Christian, Cinnamon Wright
• Oct. 9, Sebastian Munoz, John Christian
• Oct. 23, Cinnamon Wright, Sebastian Munoz
• Nov. 6, Kjellberg & Maglothin, Kjellberg & Maglothin
• Nov. 20, Dax Garner, Eric Hagen
• Dec. 4, Eric Hagen, Dax Garner

All seminars are held on Tuesday from 4-5 pm in WRW 410.  Attendance is strongly encouraged for all research group participants.

 

Links to presentations given in the seminar series will be listed in a project labeled 08-09 Research Group Seminar Series (and will usually be cross-referenced with another on-going research project).

 

Thanks, we hope to see you there!

 

FASTRAC Satellites to Set Up and Ship Out!

March 2008

It is an exciting time for the FASTRAC satellite team and community.  The FASTRAC satellites have been officially manifested for launch and have returned to Austin for the first time since 2006! During the next few months the satellite team will be working on the satellites in the newly developed Flight Integration Lab at the Center for Space Research.  This new lab, set up in what was previously the CSR library, facilitates the FASTRAC flight build and will soon accomodate other student-built satellite projects from the University of Texas.  (The FASTRAC team would like to sincerely thank CSR for its gracious accommodations for our project.) 

During the next few months, FASTRAC will be undergoing maintenance before final delivery to the Air Force Research Laboratories in Albuquerque, New Mexico. Before April 1^st, the FASTRAC team will have completely disassembled the satellite, fixed issues including replacing fuses and installing new memory cards, and completely reassembled the satellite. In addition to working on the satellite hardware, several members of the FASTRAC team are also working on satellite software. In order to ensure a completely reliable mission, the software is being fine-tuned to make sure that all known problems are removed from the flight code. While satellite flight hardware and software is being completed, the FASTRAC ground station at the University of Texas W.R. Woolrich Laboratories is also undergoing testing and advancement. The ground station has already performed excellently in simulated satellite passes and the new, student-developed ground station software is extremely exciting.

 

On April 1^st, the satellites will be packaged in their container and shipped off to New Mexico for environmental and pre-launch testing. During this test phase, the satellites will be subjected to conditions that approximate those found during launch and in a space environment. After completing this final phase of testing, the satellites will be launched from Kodiak Island, Alaska in the fall of 2009 on a Minotaur IV rocket. After launch, the FASTRAC crew will be manning the ground station waiting to make first contact with the satellites and begin the mission!

 

 

Once again, the FASTRAC team would like to thank the many people involved in helping in this final push. Without the hard work from the team and the community as a whole, the project would never be as close to success as it is today. With a few more months of hard work, the satellites will be ready for their launch into space on the University of Texas' inaugural student-satellite spaceflight.

 

 

 

 

Absolute and Relative Estimation for Satellite Formations

December 2007

Introduction

As part of a grant from the General Dynamics corporation, I am exploring methods of implementing an estimation algorithm in the form of a SIMULINK model that will take measurement data and return an estimate of a chaser satellite relative to a host satellite. This project provides the input to a control system that can be used to generate specific relative orbits of the chaser about the host that may be necessary for a variety of missions.

Absolute Estimators

Currently there are two de-coupled estimators working to provide a position for the chaser satellite. The first estimator accepts a measurement, in the current configuration this is a range from a ground station, and uses that measurement in conjunction with an initial condition and a dynamic model to return an estimated current state. The estimator itself uses an extended form of the Kalman filter algorithm which updates state and covariance at each time step. The model was built to be flexible and can accept any rate of measurement data and an update to the dynamic model requires the editing of only a single block.

Relative Estimator

The relative estimator has nearly the same form as the absolute estimator. Instead of a ground station range, the relative estimator utilizes a range measurement between the two satellites to perform state updates. Also, since the relative estimator is based on the Clohessy-Wiltshire equations, which are linear and do not require integration of a state transition matrix, there is no integrator block in this model. The two estimations generated by the measurements can be combined to provide an absolute estimate for the chaser satellite which is required for performing course adjustments in a control algorithm. Currently only the absolute estimator includes perturbation effects, such as drag and J2, in its dynamic model. Future work will include re-deriving the CW equations with drag and J2 accounted for and merging the estimation algorithm with the control algorithm.

The full story with results and images can be found here.

 

The Impact of Multipath on BOC Modulated GNSS Signals

November 2007

by Ben Harris

 Introduction

My dissertation topic explores how M-Code can be used to perform orbit determination. As part of that investigation I've looked at how M-Code and a similar class of signals called BOC modulated codes will reject multipath. These are the results of that investigation which I completed from August to October 2007.

Basics of BOC Modulation

M-Code belongs to a new class of GNSS signals that are based on Binary Offset Carrier or BOC modulation. BOC modulation is conceptually similar to the common amplitude modulation associated with consumer radio, and with the Binary Phase Shift Key or BPSK modulation used to encode the standard GPS signals, however there is a twist. The BOC modulated signal is modulated with an additional square wave that overlays the pseudorandom code. BOC signals are denoted BOC(α,β), where α is the period of the square wave in multiple of the chipping rate of C/A, and β is the chipping rate of the pseudorandom part of the code. The following image depicts standard BOC and BPSK modulations

Note that M-Code will be modulated using BOC(10,5).

Signal Multipath

Because GNSS receivers are omnidirectional (generally speaking), each GNSS signal is subject to interference from its own reflections. The following image depicts this phenomenon which is called multipath.

Two modes of multipath are shown: specular and diffuse. Diffuse multipath spreads the reflected energy in many directions, creating essentially noise. Specular multipath redirects the energy in a uniform direction to create a consistent signal similar to the LOS signal. This is also known as coherent reflection. Though the reflections are always delayed with respect to the line of sight or LOS signal, the induced error in tracking can be positive or negative. It is possible to model the value of that error, when the reflector is coherent and if the additional distance traveled by the multipath signal is known.

At the point of reflection two affects occur. First the multipath signal is shifted in phase relative to the LOS signal. Second the amplitude is reduced. The distance added to the signal due to the reflection also provide an opportunity for the signal to continue changing in phase relative to the LOS signal.

Additional affects change the multipath signal compared to the LOS. The multipath signal pierces the antenna from a different direction, and is therefore received with a different gain. This is because GNSS antennas do not uniformly pickup signals from all directions. There are other affects that cause the signal to distort in phase as it is received at the antenna.

In the end, the error introduced by the reflected signal can be productively modeled as a function of three variables:

1. the delay caused by the reflection,
   
2. relative phase, and
   
3. relative amplitude.
   

Multipath Error Envelope for BOC Modulated Codes

The impact of a single, specular reflector on any BOC modulated code can be solved. The solution requires tracing the influence of the reflected signal through the chain of processes that occur inside a GPS receiver. These processes include correlation and discrimination. Often the error is presented in the form of an error envelope. In the envelope, the amplitude of the multipath reflection is fixed, and the error is plotted as a function of distance for two different phases, 0° and 180°. Here is the multipath error associated with BOC(10,5) signal, with an amplitude of 0.5.

The red lines correspond to multipath error associated with a relative phase of 180°. Blue is for 0° relative phase. These values were generated from a numerical simulation written for my dissertation. The green values are generated by the analytical model I have solved. More detail about the model will of course be presented in my dissertation. Also we have submitted an abstract to the IEEE/PLANS 2008 conference on this topic.

 

Research Begins on Cislunar Navigation

October 2007

In the Fall 2007 Semester, the Lightsey Research Group began work on cislunar navigation for the Orion/CEV Program. As NASA prepares to send humans to the Moon, the need arises for precise orbit determination – this is especially true during the return trip from the Moon. Due to entry, descent, and landing (EDL) constraints, precise knowledge (and control) of the spacecraft’s position and attitude is required at entry interface.

During operations in Low Earth Orbit (LEO), the data required for navigation may be obtained through an onboard Global Positioning System (GPS) receiver or through other traditional navigation methods used for crewed spacecraft. As the distance between the spacecraft and Earth increases, these methods become problematic due to design (e.g. GPS signals are designed to transmit towards the Earth) and/or poor geometry. To address this difficulty, past spacecraft operating in cislunar space have employed a combination of inertial measurements (e.g. data from accelerometers and gyros) and inertial state updates from ground tracking. The current lunar architecture and concept of operations, however, makes it desirable for the Orion vehicle to be capable of on-board inertial navigation updates.

The Lightsey Research Group is currently investigating a number of potential solutions that would allow for on-board inertial navigation updates. At the present time, research is focused on solutions that rely primarily on optical measurements. In such a scenario, the Orion vehicle would detect satellites for which precise position data is available (e.g. GPS satellites, many geostationary satellites, etc). Then, by coupling accurate angular measurements with precise satellite position information, the resulting data may be used to produce an estimate of the Orion’s inertial position.  Concerns regarding satellite geometry and satellite visibility (i.e. how easy is it to detect the satellite with the camera and at what distance can this reliably be done) are also being addressed.

 

Supported GPS Receiver Launched into Space

June 2007

 

Sensors and Actuators Laboratory Offered To Students

June 2007

There has been a new addition to The University of Texas Aerospace Engineering department to enable students to receive further hands-on training.  The Sensors and Actuators Laboratory has been developed and is now being offered as a course to graduate students.  The students are experimenting with instruments ranging from gyroscopes to sun sensors and even robots.  There are experiments involving visualization, remote actuation, and attitude determination. The idea was originally proposed by Dr. Glenn Lightsey and Department Chairman, Dr. Robert Bishop and was approved in the spring of 2006.  National Instruments (NI) decided to get involved by providing financial support, donating some of its CompactRio and PCI data acquisition equipment.  NI also provided software to aid the students in studying many different types of sensors and actuators with a large range of input/output interfaces.

 

The course was offered for the first time in spring of 2007.  The students got the chance to be creative and get hands on experience with real hardware.  For part of the semester the students formed their own experiments in groups, then they got the chance to perform the other’s experiments.  This provided for a lot of work, but a different type of learning experience. “Getting off the tracks every once in a while is a welcome change from the barrage of cookie-cutter assignments subjected to students” said former student, Eric Rogstad. The students encountered real world problems and were able to apply their education to actual space applications.

 

Development will be continued through the summer and the laboratory will be available to students for research during semesters when a class is not being offered.  The Sensors and Actuators Laboratory will be a continually growing and changing project that will  provide exciting and useful opportunities for numerous students. 

 

Consortium for Autonomous Space Systems

December 2006

 

 

This fall semester The University of Texas at Austin and Texas A & M University have started a very interesting collaboration sponsored by the Air Force Research Laboratories in the form of the new Consortium for Autonomous Space Systems. CASS will be focused in five major areas which are:

1. 1. Novel Spacecraft Designs
2. 2. Smart Sensors
3. 3. Autonomous Spacecraft Control Systems
4. 4. Cooperative Control of Satellite Formations
5. 5. Enhanced Education, University, Industry and Government Teaming, and Technology Transfer

Each of the universities has been chosen to explore key technology in these five areas which will be very helpful for the Air Force in future DoD missions. UT will be involved in the following major tasks,

1. 1. Orbit Determination for Microsatellite Clusters
2. 2. Small Satellite Propulsion System
3. 3. Autonomous Rendezvous Maneuvers
4. 4. New Methods in Satellite Design
• Autonomous Formation Conops Design
• New Testing Methods for Rapid Response Satellite Design
5. 5. Satellite Proximity Sensors

The research for CASS will be conducted by professors, staff, and students at each university. It has to be noted that apart from CASS both universities are also involved in other programs for satellite developement such as the Nanosat program.

 

 

Application of conceptual docking technology to university satellite programs

November 2006

How can two spacecraft dock and separate in orbit? Conventional methods incorporate a mechanical linkage system, but the PARADIGM (Platform for Autonomous Rendezvous and Docking with Innovative GN&C Maneuvers) satellite design team at UT-Austin is investigating a different type of separation mechanism: electromagnetic docking.

An electromagnetic dock research investigation was originally proposed and explored by the EGADS (Electromagnetically Guided Autonomous Docking and Separation in Zero-Gravity) Microgravity University team and flown onboard the C-9 experimental aircraft in March 2006. The concept proved relevant to PARADIGM, a pico-scale satellite program, in cooperation with Texas A&M University and sponsored by NASA JSC, that aims to separate and dock two 5-inch cube satellites. An electromagnetic dock would allow the two picosatellites to perform both maneuvers without complicated mechanical equipment or precise alignment requirements.

The EGADS experiment hopes to fly onboard the C-9 again in 2007 to test additional docking and separation capabilities that could potentially apply to PARADIGM. Students interested in participating in either project can contact Jessica Williams (jessica-williams@mail.utexas.edu) for additional information.

 

Fall Presentation Schedule Posted

September 2006

The Research Group is meeting in WRW 410 every other Wednesday from 4-5 pm. The format of the meeting is usually brief announcements followed by a presentation from a student or staff member. The schedule for Fall 2006 is posted here for future reference.

9/6/2006 Mariela Gunn, Web Site Intro
9/20/2006 Benjamin Harris, GPS Research
10/4/2006 Andreas Mogensen, Mars Approach Navigation
10/18/2006, Dr. Key-Rok Choi, topic TBD
11/1/2006 Tena Wang, Sensor Fusion
11/15/2006 Thomas Campbell, Beyond FASTRAC: Communications
11/29/2006 Jamin Greenbaum, FASTRAC@AFRL & Conops

Additionally the following members will contribute news articles to the web site in the following months:

September, Daero Lee
October, Jessica Williams
November, Sebastian Munoz
November, Jack Goetz
December, Eric Rogstad
January, Cinnamon Wright

 

GPS Sensor Featured in Ready To Commercialize Workshop

September 2006

A single antenna GPS attitude sensor developed by the Lightsey Research
Group is being featured in a University of Texas Ready to Commercialize
Workshop on October 12. The workshop brings investors to The University
of Texas to learn about products that could be licensed and
commercialized. The Single Antenna GPS Attitude (SAGA) sensor was
developed for the Formation Autonomy Satellite with Thrust Relnav
Attitude and Crosslink (FASTRAC) spacecraft, which is expected to launch
in 2007. Although the device was originally designed for operation on a
satellite, it can work with other kinds of vehicles and platforms as
well. SAGA's potential for miniaturization makes it very promising for
applications where the sensor size must be very small.

For more information about the UT Ready to Commercialize Workshop, see:
http://www.otc.utexas.edu/Events/Oct2006/index.jsp

For more information about the FASTRAC mission, see:
http://fastrac.ae.utexas.edu

 

Greg Holt finishes Ph.D.

August 2006

Dr. Greg Holt successfully defended his Ph.D. thesis on August 8, titled "Generalized Approach to Navigation of Spacecraft Formations Using Multiple Sensors." Greg has successfully completed all of his Ph.D. degree requirements and graduated in Summer 2006. Congratulations, Greg!

During his time as a student at The University of Texas at Austin, Greg was part of the pulse of the Aerospace Department. A partial list of his accomplishments includes: leading the Formation Autonomy Satellite with Thrust Relnav Attitude and Crosslink (FASTRAC) as the first student manager (he was also the GPS lead and delivered the software for the Orion GPS receivers that are on the satellite), and teaching his fellow students officially as an Assistant Instructor for ASE 167M Flight Dynamics Lab and unofficially as a volunteer Indiana Jones on many GPS Scavenger Hunts for K-12 students. Greg also received a National Science Foundation scholarship during the years from 2001-2004.

Greg has accepted a job at NASA Johnson Space Center and has moved to the Houston area with his wife Amanda. We will miss Greg, but we are very proud of him wish him all the best in his new job! Hook'em!

 

GPS Flight Software Delivered to TerraSAR-X Satellite

July 2006

Jacob Williams and Key-Rok Choi recently delivered their build of GPS receiver flight software to a German radar satellite mission known as TerraSAR-X in July 2006.

The mission, which is scheduled to be launched in late 2006, will make radar maps of the Earth surface from space. The commercial data product is made possible with highly accurate knowledge of the satellite's position from space using a dual frequency BlackJack receiver manufactured by Broad Reach Engineering. UT-Austin was contracted to make software modifications to the receiver to perform precise orbit determination and occultation measurements of the Earth's ionosphere. For more information, see information about our TerraSAR-X project.

 

Williams Wins NASA Fellowship

March 2006

Jacob Williams has been awarded a NASA Earth System Science (ESS) Fellowship award for his Ph.D. proposal "Extending the Capabilities of the BlackJack GPS Receiver for Earth Science Applications." The fellowship is one out of 55 selected from more than 200 proposals. Good job, Jacob!

More information on Jacob Williams

 

Balloon Payload Sets SDL Altitude Record

March 2006

Greg Holt, Shaun Stewart, Tom Campbell, and Michael Linford designed and flew a camera payload (pictured left) to more than 100,000 feet on a high altitude balloon in Summer 2003. The camera took the image shown above right. The workshop, held in Boulder Colorado, was part of the University Nanosatellite program. The team was noted for their enthusiasm about the great state of Texas!

More information on the Satellite Design Lab

More information on our Nanosatellite Project, FASTRAC

 

Madsen, Monda Graduate In Spring 2003

February 2006

Congratulations to Jared Madsen (pictured) and Eric Monda for receiving their graduate degrees in 2003!

Jared Madsen successfully defended his Ph.D. dissertation, "Robust Spacecraft Attitude Determination Using Global Positioning System Receivers." Dr. Madsen has accepted a position with Sandia Laboratories and moved to Albuquerque, NM. More information on Dr. Jared Madsen

Eric Monda completed his Masters thesis, "Investigation of Real-Time GPS Pseudolite Relative Navigation." Eric is continuing on at UT in pursuit of a Ph.D.

 

Navigating with Satellites at Explore UT

February 2006

Students from the research group recently participated in the University-wide open house, ExploreUT. As part of the College of Engineering section, the group gave a series of talks and demonstrations on the subject "Navigating With Satellites". Participants were treated to a hands-on demonstration of Global Positioning System technology and research. The talk was geared toward high school students interested in pursuing engineering fields in college.

Go to UT College of Engineering Page
Go to ExploreUT page

 

Demo Introduces High School Students to GPS

January 2006

Group members recently put on a hands-on demonstration of the Global Positioning System for visiting high school students. As representatives of the MITE (Minorities Introduction To Engineering) and NexTech (Young Technology Leaders) programs, these students were given the opportunity to hear an explanation of GPS from grad students Tifanie Smart and Greg Holt. Then, they were taken on a GPS archaeological hunt led by Greg as Indiana Jones!



Hands-on experience using the GPS receivers during the archaeological hunt

A brief talk before heading out


The 1-minute history of navigation...

Live GPS data right in the conference room!

You're almost there, keep looking!

The intrepid team poses for a shot