by Amara Graps
Atom Interferometry on the European Continent, in Space
ESA was never shy about its interest in Quantum Sensors in Space.
In 2006, with France’s national research institutes, ESA, embraced Quantum Sensors in Space. In 2016, ESA inaugurated its first Quantum Technology – Implementations for Space workshop. By 2017, ESA was public with its intensions:
Quantum physics and space travel are two of the greatest scientific achievements of the last century. We now see huge great promise in bringing them together: many quantum experiments can be performed much more precisely in space, away from terrestrial perturbations. In addition, the new generation of quantum devices offer huge improvements to space-related technology.
Atom Interferometry, moreover, has a long history of implementation by Space Agencies on the European continent, I’ve discovered. After appreciating the intuitive nature of the physics principles underlying Atom Interferometry in Part One, and enjoying the direct connection to measurements of physical constants, in Part Two, I am astonished at Figure 1 of Abend et al., 2023’s article: Technology roadmap for cold-atoms based quantum inertial sensor in space.
The authors show a timeline of space experiments that were using Atom Interferometry beginning in approximately the year 2000. The first space mission listed on their timeline was the PHARAO Atomic Clock. That’s at least 24 years of Space experience in this quantum sensors subfield.
The Gravity Measurements and the Outreach Budgets are Comparatively Small
Why are these Atom Interferometry experiments not more famous? One reason might be the Outreach budget *size* and *which* space agency.
Assuming a comparable proportion and using 2024 budget figures, backwards in time, ESA’s budget is roughly thirty-two percent of NASA’s budget. Furthermore, with ESAs’ geo-return concept for its members, its obligations to those members become more complex. Your National Space Offices are more likely to bring you news about the Space achievements of your EU nation. To help you grasp how far Space Agencies can go with their budgets to communicate to the public on quantum technology, I have included a brief explanation below (**).
To put this collection of Quantum Sensors into context, it is a -large- subfield. Take a peek at some of the topics I plan to cover in the coming months. Gravity measurements are linked to Modality in the next Figure, which is part of GQI’s Quantum Sensors Stack.
The Cold Atom Based Space Experiments
Twenty years of experience is a long time for space-based atomic interferometry. According to Abend et al.’s publication from 2023, the field has concentrated on two strategies that make advantage of comparable technology designs:
- Space Geodesy using differential gravimetry, where two distinct atomic species are used at two different locations, and
- Testing the Universality of Free-fall (UFF) using a differential gravimeter and Einstein’s Equivalence Principle (EEP), specifically the Weak Equivalency Principle (WEP).
Abend et al., 2023’s, Table 1 is a useful chart to track the Space Experiments.
An update to this Chart on the Chinese Space Station (CSS), Atom Interferometry project. On November 12, 2022, the TianZhou-5 spacecraft (TZ-5) launched the payload onto the CSS. On December 10, 2022, it was then successfully powered on and deployed within the microgravity scientific laboratory cabinet (MSLC) that same day. It is anticipated that the cargo would remain in orbit for two years.
I recommend Abend’s full article for catching up in this field. After adding more fun labels (“EEP”, “UFF”, and “WEP”) to your collection so far (see Part Two), the Abend et al., article also provides useful references for microgravity facilities to test your gravity experiment.
For Professors of Undergraduate Physics Courses
After I wrote Part Two’s article, where I suggested to professors to include Atom Interferometry in upper undergraduate physics lessons, I found Chad Orzel’s very nice science blog series to explain the Cold Atom physics. Check it out here: Tools of the Cold-Atom Trade
Some Outreach Budget Numbers
(**) Surprised? Some numbers: NASA’s total 2024 budget (807-pg pdf, 30Mb) indicates $27B (pg. 770), with outreach (keyword ‘STEM’) as $143.5M (pg. 641), which means about 0.05% of NASA’s budget is devoted to communication (i.e. ‘Outreach’).
A comparison with ESA’s total 2024 budget shows $8.6B (7.8BEuro). Since ESA is an engineering-oriented organization for 22 ESA Member states, with varied budgets, even IF ESA had a generous outreach budget matching NASA’s proportion, only ~$46M is available for today’s ESA space projects to appropriately split amongst 22 ESA member states. That’s *why* space press (i.e., ‘Outreach’) is more often managed by the ESA member states themselves.
GQI’s Vast Quantum Technology Sensor Information
(*) GQI has a variety of resources to analyze the Quantum Technology Sensor sector, which is well-advanced across the Quantum Sensing Stack. The GQI Sensing Stack is a Framework designed by GQI to support analyses of the Stack’s components.
It is further described in the Sensing Report: GQI’s Quantum Sensing Outlook Report, which is a 114 page analysis, up and down the quantum sensing stack: the physics package, control package, control logic and framework required to access different sensing modalities (time, magnetic field, electric field, gravity & acceleration and others) for advanced applications. In GQI’s Quantum Sensing Outlook Report, the Report walks you through the operation principles of Atom Interferometry.
GQI’s Quantum Sensors State of Play presentation is a 33-slide, introduction, and walk-through, to bring you up to date on current trends. If you are interested to learn more, please don’t hesitate to contact [email protected]
October 2, 2024
