QubeSat Experiment Gets Green Light for Launch

Tuesday, April 28, 2020

Most graduating seniors expect to write a final thesis, or perhaps co-author a paper or present a poster or talk at an academic conference.

By the time Paul Köttering graduates from the University of California, Berkeley, in 2021, he and his team hope to have launched a satellite.

Despite the shelter-in-place mandate during the coronavirus epidemic — Köttering is spending the remainder of the semester at his parents’ home in London — he and a team of UC Berkeley undergraduates are huddling weekly via Zoom in preparation for the launch next year of a shoebox-sized experiment to test new satellite navigation technology that is based on campus research.

This past February, the National Aeronautics and Space Administration announced that it would cover the costs of the launch — up to $300,000 — through the CubeSat Launch Initiative, which focuses on flying small experiments as auxiliary rocket payloads.

To actually build the satellite, the UC Berkeley team is raising about $15,000 dollars through crowdfunding and the campus’s Big Give campaign, and seeking donations of equipment from numerous manufacturers. They’ve already received a $4,950 grant from the UC Berkeley Student Technology Fund.

“The NASA grant is just for the launch, so we have still got to supply and manufacture the satellite ourselves,” said Kӧttering, a junior majoring in applied mathematics and physics. “Luckily, the cost of CubeSats has dropped significantly over the past three to four years. The communications systems, power systems, control systems — a lot of those are just off-the-shelf, commercial parts, so they are quite cheap. The payload itself is the more expensive item, but again, a lot of that comes from in-kind donations from companies.”

Called QubeSat, or quantum CubeSat, the group’s satellite will test a new type of gyroscope based on quantum mechanical interactions in imperfect diamonds. The diamond gyroscope was invented in the UC Berkeley laboratory of physicist Dmitry Budker, a Professor of the Graduate School who is now also at the Helmholtz Institute at Johannes Gutenberg University in Mainz, Germany.

The student team is part of an undergraduate aerospace club called Space Technologies at Cal (STAC) that has already flown experiments aboard balloons and the International Space Station — an impressive record for a group that started only four years ago. Some of the group’s graduates have gone on to work for SpaceX, Boeing and other aerospace companies.

Boasting about 65 members from a range of majors, including physics, math, engineering, chemistry and environmental sciences, they’re currently working on four projects they hope will push innovative new space technologies.

“UC Berkeley doesn’t have an aerospace program, and it is great that there are students that are that motivated,” said David Sundkvist, a researcher at UC Berkeley’s Space Sciences Laboratory (SSL) who is one of the group’s mentors. “Their project definitely was a winner because it is interesting, and it also has synergy with the whole campus in that it comes from Berkeley research. I think that made it possible for them to win this slot on the launch manifest, definitely.”

The QubeSat team plans to use some of the unique facilities available at SSL, including the vacuum chambers needed to test the spaceworthiness of the satellite.

Sundkvist is leading his own CubeSat project, the CubeSat Radio Interferometry Experiment (CURIE), which also received good news in February: It, too, is guaranteed a launch slot in the next few years, with similar funding from NASA. The CURIE — with a budget of $3.2 million, in addition to the launch subsidy — involves two identical satellites that will try for the first time to do radio interferometry in space. Interferometry, which integrates data from two separate radio antennas — for CURIE, the satellite receivers will be a couple of kilometers apart in Earth’s orbit — should more precisely pinpoint and track radio emissions from huge solar eruptions, called coronal mass ejections, that hurtle toward Earth and can disrupt communications satellites or even endanger astronauts in space.

Diamonds are for navigation

Kӧttering got involved in the CubeSat project after hearing about the great experiences of other STAC members, including sophomore Vidish Gupta, who, as a freshman, worked alongside seniors to design an experiment that flew a year ago on the Blue Origin rocket to the edge of space and back. During the trip, the automated experiment recorded roundworms — C. elegans, commonly found in biology labs — as they revived under little to no gravity, or microgravity. The team is still analyzing those results.

Before applying for the NASA funds, that 15-member CubeSat team explored various possible experiments — it was looking for something small, cheap, but innovative — before settling a year ago on its final proposal: to test a quantum gyroscope.

“The small-satellite community is becoming very, very large and keeps CubeSats very popular,” said Gupta, the project lead who is majoring in electrical engineering and computer sciences and will be building electronics for QubeSat. “We saw there were a couple of different technologies that are still kind of holding this back, and one of the big ones was a gyroscope technology for controlling the satellite, since you need to know where you are and the direction you’re going.”

To make the sensors, synthetic diamonds are blasted with nitrogen, some of which kick out carbon atoms and take their places, creating nitrogen-vacancy (NV) centers that have weird properties. One of these properties, studied by Budker’s group for more than 10 years, is that the NV centers’ atomic spins are very sensitive to magnetic fields. Magnetometers based on NV diamonds have already been launched to measure small changes in Earth’s magnetic field.

The QubeSat team plans to employ another quantum characteristic of NV centers: The spins of the nitrogen atoms precess or wobble in a magnetic field, like the wobble of a spinning top, and the frequency of that precession changes with the atoms’ orientation. The team’s experiment will incorporate a tiny, solid-state laser to excite the NV centers, a radio frequency generator to ping the atoms and a photodiode to detect the light they emit. The intensity of the emitted light provides a measure of the 3D orientation of the spacecraft.

“In comparison to more traditional onboard micromechanical gyroscopes, quantum gyroscopes provide improved resolution, improved drift stability and increased temperature operational range,” Kӧttering said. “QubeSat’s upcoming mission will allow us to evaluate the effect of the harsh space environment — including extreme temperatures, radiation and magnetic field variation — that could affect the gyroscopes’ performance in small-scale spaceflight.”

One of Budker’s former postdoctoral fellows, Andrey Jarmola, who is advising the QubeSat team, points out that the team’s attempt to demonstrate the diamond gyroscope in a satellite is ambitious. He and his colleagues are only now showing that the diamond gyroscope — what he called a nuclear magnetic resonance gyroscope — works in the lab.

But the stability and sensitivity of diamond gyroscopes promise to be better than those of the standard MEMS (microelectromechanical systems) gyroscopes in our cellphones, automobile airbag sensors and image stabilizers in cameras. And unlike other sensitive gyroscopes, diamond gyroscopes can be miniaturized and use less power.

“The number of applications of gyroscopes is just enormous. They are used in all mobile devices and for navigation for both the military and industry. It is a huge market,” Jarmola said, noting that he has invited some of the team members to work on the project in the lab in UC Berkeley’s physics department. “The students are very enthusiastic, and I really like consulting them and the idea of working with them in the future.”

Enthusiasm, dedication and ambition are hallmarks of the QubeSat team and the other STAC teams, which are working on high altitude balloon, microgravity and artificial intelligence lunar rover experiments.

“The reason why STAC exists is because there is no aerospace department on campus,” said Kӧttering, who is among many students and faculty lobbying UC Berkeley to create such a department. “There is no major or minor, so we try and act as a community in a place where all the students interested in aerospace can come, get involved, actually get hands on project experience, get their project hopefully flown or launched and also really develop those skills.”

And this group on campus is passionate about making space accessible to all — it’s the goal of the growing NewSpace movement — including future undergraduates in fields such as science, technology, math and engineering (STEM).

“QubeSat’s secondary goal is to increase the accessibility of space and to inspire STEM education. The QubeSat team and the larger STAC community hope to introduce high school and college students to our work though community outreach in the East Bay, giving them the support and inspiration to pursue microsatellite projects and careers in the burgeoning NewSpace era,” Kӧttering said.

Robert Sanders