Cold Atoms in Space: Community Workshop Summary and Proposed Road-Map

Abstract

We summarize the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible roadmap for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with ESA and national space and research funding agencies. research areas. As anticipated for a Europe-based event, about 80% of the registrations are from European countries, as seen in the lower right panel of Fig. 1, but there is also significant North American and Asian participation.This community provides the backbone for long-term planning and the support needed to see the challenging cold atom missions foreseen in the road-map through to their successful completions. The participants display an excellent and diverse mix of expertise, building an outstanding basis for the success of the workshop and the development of the corresponding road-map, which defines possible interim and long-term scientific goals and outlines technological milestones. Section 2 is an introduction to our document, Sections 3 to 5 discuss our main science themes, namely atomic clocks, Earth Observation and fundamental physics, Section 6 discusses the technology developments required before quantum sensors can be deployed in space, Section 7 summarises the discussions during the Workshop, and in Section 8 we outline the corresponding Community road-map.

MICROSCOPE’s view at gravitation

“…As mentioned above, cold atom interferometers are highly accurate over the entire frequency range and do not need any external calibration, they thus have the capability to surpass electrostatic accelerometers. Following this report, the cold atom community set out a roadmap, where the main milestones are presented with the objective to test gravity with cold atoms in space in the middle of the century [364].…”

Some Warnings About Quantum Space Gravimetry Enhance Earth Observations Project

“…A recent survey on quantum physics in space, including some of the above issues, different modern achievements, open problems, perspectives, existing different approaches and results can be found in the very recent and more detailed review [26,27].…”

Using a Multiobjective Genetic Algorithm to Design Satellite Constellations for Recovering Earth System Mass Change

“…This is a critical path to pursue, as the implementation of new gravity-sensing technologies (atom interferometry, etc.) are still some years away [22]. A constellation composed of small satellites could allow for higher spatial and temporal resolution as well as multiple decades of observations since it lacks single-point failures that are present in single pair satellite constellations.…”