TBEx Launched, Deployed, and Operational

by Andrew Stephenson and MXL

The two TBEx satellites launched in June 2019 will give scientists detailed insight into the effects of plasma bubbles in the upper atmosphere and how this space weather impacts space communication.
A SpaceX Falcon Heavy rocket carrying 24 satellites as part of the Department of Defense's Space Test Program-2 (STP-2) mission launches from Launch Complex 39A, Tuesday, June 25, 2019 at NASA's Kennedy Space Center in Florida. Four NASA technology and science payloads which will study non-toxic spacecraft fuel, deep space navigation, "bubbles" in the electrically-charged layers of Earth's upper atmosphere, and radiation protection for satellites are among the two dozen satellites that will be put into orbit. Photo Credit: (NASA/Joel Kowsky)
A SpaceX Falcon Heavy rocket carrying 24 satellites as part of the Department of Defense’s Space Test Program-2 (STP-2) mission launches from Launch Complex 39A, Tuesday, June 25, 2019 at NASA’s Kennedy Space Center in Florida. Four NASA technology and science payloads which will study non-toxic spacecraft fuel, deep space navigation, “bubbles” in the electrically-charged layers of Earth’s upper atmosphere, and radiation protection for satellites are among the two dozen satellites that will be put into orbit. Photo Credit: (NASA/Joel Kowsky)

On June 25, 2019, two CubeSats developed by the Michigan Exploration Laboratory (MXL) were deployed in low Earth orbit by a SpaceX Falcon Heavy rocket. These satellites, called the Tandem Beacon Experiment (TBEx), are part of a NASA project to understand unpredictable plasma bubbles that form in the upper atmosphere and how they impact communications. The launch was funded by the US Space Test Program.

During their year long mission, the TBEx satellites will send radio signals to ground stations and the world, which will measure the distortions caused by the plasma bubbles. Signals such as GPS transmissions are distorted unpredictably when they pass through the ionospheric plasma bubbles.

MXL worked with SRI International to develop the TBEx mission for NASA. MXL developed the satellite system and the payload was developed by SRI International. Graduate students Prince Kuevor who works at MXL, and Paul Knudsen who runs the TBEx operations from MXL’s control center, spoke about the design challenges they faced. Both cited the complex antennas, which are packed for the launch and deploy when the satellite is in orbit, as the biggest challenge. The satellites were also equipped with an advanced attitude control system built in house, a first for MXL.

MXL is run by Associate Professor James Cutler who led graduate and undergraduate students to design, build, test and fly the TBEx satellites. As students graduate and take their experience and expertise with them, new engineers must be trained to carry on the work. “Test regularly and write things down” is the philosophy of Kuevor, who joined MXL as a sophomore and is now working on his PhD. Kuevor sees MXL as a good source of experience and inspiration for these students: “[The Laboratory] is a great way to get young, interested, and innovative minds involved in this field.”

Over the next year, the MXL team will coordinate TBEx flight experiments with additional satellites developed by NOAA, six COSMIC-2 satellites. Together, as a constellation of small satellites, they will explore plasma bubble evolution and development over time. The use of CubeSats as large scale constellations is at the forefront of space research, and these MXL students are leaders in this global CubeSat effort.

More details on the TBEx mission are found online here.

TBEx Launch: T-minus 4 Days

MXL’s first pair of coordinated satellites are scheduled to launch in 4 days.  This will be the first part of a constellation that we hope grows with additional nodes for space weather monitoring and technology demonstrations.  The Enhanced Tandem Beacon Explorers (E-TBEx) will map the Earth’s upper atmosphere to characterize how plasma bubbles develop in both space and time.  The satellites will broadcast phased locked radio signals that ground receivers will receive and process for ionospheric measurements.   Both E-TBExes were integrated at CalPoly with their PPOD launchers earlier this year in April, 2019.

The TBEx mission is a collaboration between SRI, the science leads and instrument builders, and MXL which contributed the bus.  The mission was funded by the heliophysics division of NASA and will be launched by the USAF. The two photos below show the E-TBEx satellites integrated in the Falcon Heavy and an E-TBEx integrated in its PPOD. The launch is targeted for no earlier than (NET) June 24 at 11:30 PM EST.

The two TBEx satellites are  scheduled to launch on 24 June 2019 23:30 EDT / 25 June 2019 03:30 UTC.  The countdown has commenced.

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More information is found here.

PPod stack in preparation for integration.
PPod stack in preparation for integration.
Location of the PPods inside the fairing.
Location of the PPods inside the fairing.

 

Thanks to our friends at Calpoly for integration!
Thanks to our friends at Calpoly for integration!

Strato night flight of LITE

LITE system
The LITE payload near the wave field for testing.

The thirty-first flight of MXL’s Strato high-altitude ballooning project launched from a skatepark in Marshall, MI at 10:47 pm local time on May 10, 2018. The mission, called Strato LITE (LED Initial Testing Experiment), carried two prototype LED panels for MXL’s next CubeSat candidate, PHAROS (Phased-Array Optical Satellite). The LED boards, blinking in a distinct pattern, were carried by a CubeSat-like structure that included a Raspberry Pi microcontroller, accelerometers, rotation rate gyros, a GPS receiver, an APRS transmitter, a magnetometer and two GoPro cameras, all attached to a baseplate with four large booms to help dynamically stabilize the platform.

As the balloon ascended to its maximum altitude of 100,200 feet, telescopes in the Angel Hall observatory at the University of Michigan’s Central Campus tracked the balloon and took 80 GB of image data that will be used to determine if the chosen LEDs are suitable for use on a CubeSat mission, and to verify mathematical models of how the optical signals from the LEDs change as they pass through the atmosphere.

Strato LITE Launch
The team prepares for the night launch.

The team successfully recovered the payload near Dundee, MI at 1:56 AM local time with moderate structural damage but minimal damage to the electronics. After repairs and improvements, the team hopes to fly the mission a second time in the fall of 2018 to verify their results and collect better data.

Some members of the team will be traveling to Los Angeles, CA to present their findings at the 42nd COSPAR Scientific Assembly this summer and to look for funding partners to help enable  a more advanced version of the payload on PHAROS.

By Matthew Szczerba.

PHAROS Lights Up

The Michigan eXploration Laboratory has begun research and development on its tenth mission, PHAROS (PHased ARray Optical Satellite), which is an optical orbit determination experiment utilizing light emitting diodes (LEDs). The name of the mission comes from the Lighthouse of Alexandria, named Pharos, which served as the tallest lightsource in the world for many centuries and shared guidance and awareness to nighttime travellers. It is also one of the Seven Wonders of the Ancient World. PHAROS is a combined ground station and CubeSat mission that will use LEDs on-board a CubeSat and remote optical observatories from around the globe to track the satellite and use a machine learning algorithm to accurately predict its orbital characteristics—eventually without the use of radio transmitted GPS “truth” data. 

Adolfo Apolloni helping out with LED characterization tests in MXL.
Adolfo Apolloni helping out with LED characterization tests in MXL.

In November 2017, the team presented a mission concept poster at the MCubed 2.0 Symposium at the University of Michigan, which earned the mission its initial funding. Since then, the team has developed a high level plan encapsulating what it will take to complete the mission from cradle to grave. Progress has included developing an optical link budget defining the feasibility of our LED communications architecture, collaborations with the U-M Astronomy Department on orbital tracking science, and collaborations with the S5 Laboratory in Rome, Italy on optical orbit determination systems. We plan to eventually become externally funded in the future.

The next step for the mission is to demonstrate our technology on a high-altitude balloon (HAB) flight with our Strato team—we are dubbing the flight Strato LITE (LED Initial Testing Experiment). It will test our link budget and determine if we have accounted for all the light power losses our system might encounter in the LED payload, the atmosphere and the telescope configuration. If we determine we succeeded with the flight(s) we will then start scaling up to a spacecraft design. We plan to test our ground station network schema by using U-M’s Angell Hall Observatory and various amateur astronomy devices such as an All-Sky camera and amateur telescopes. Our testing concept has been submitted to the 2018 COSPAR Conference in Pasadena, California at CalTech, where if accepted we will get to present our concept to academic and industry leaders from around the world.

Stay tuned for more updates in the near future as our team tests preliminary payload designs and telescope testing procedures!

 

To find out more or to get involved please contact us!

Justin Schachter (Project Manager) jschach@umich.edu  

James Cutler (MXL Director)jwcutler@umich.edu

TBEx flight build

The TBEx flight build is underway. Led by Nathanael England, the MXL team is building the two TBEx satellites and preparing them for final environmental testing. TBEx is scheduled to launch in mid 2018 as part of the STP-2 mission onboard a Falcon Heavy.

TBEX, the Tandem Beacon Experiment (TBEx), consists of a tandem pair of CubeSats, each carrying tri-frequency radio beacons, in near identical, low inclination orbits and a cluster of diagnostic sensors on five islands in the Central Pacific sector. The science objectives and goals of TBEx are to study how the dynamics and processes in the troposphere can act to cause variability in the behavior of the upper atmosphere and ionosphere. TBEx being developed by SRI International and MXL with funding from NASA.

TBEx M and B (maize and blue)  during integration in the clean room.
TBEx M and B (maize and blue) during integration in the clean room.
Dan Gu works on TBEx integration and testing.
Dan Gu works on TBEx integration and testing.