LEVITAS

LEVITAS: Levitodynamics for Accurate Individual Particle Sensing in Space

LEVITAS is a research programme developing an in-situ sensor for the rarefied media of the upper atmosphere, exosphere, and wider solar system. It grew out of an idea within LOTIS, with partners at Warwick and Strathclyde.

Concept

LEVITAS uses a single optically trapped nanoparticle, exposed to the space environment, as a sensor. Each gas particle from the surrounding medium that strikes it delivers a small momentum kick, and from the recoil the momentum of this impact is inferred.

Trapped nanoparticle struck by incoming neutral particles — A single optically trapped nanoparticle is struck by neutral particles from the surrounding medium.

The nanoparticle’s motion is continuously monitored with sufficient bandwidth and precision that these individual impact events are resolved.

Individual impacts resolved as momentum kicks in the tracked motion — Individual impacts (dashed lines) appear as momentum kicks in the tracked motion, and the momentum of each impact can be estimated.

From the record of impacts, the density, velocity, temperature, and composition of the surrounding medium can be estimated. LEVITAS works from low Earth orbit out to exospheric distances, and reaches into very different regions of momentum space, for example the high-velocity neutral gas from the interstellar medium that penetrates the heliosphere and flows through the solar system.

Recoil-momentum histogram of individual impacts, resolving atmospheric species — Recoil momenta of individual impacts in a simulated 600 km July orbit, resolving atmospheric species (H, He, N, O, and N₂ and O₂ in the inset). Grey is the simulated data; the dashed curve is the maximum-likelihood fit.

Studies

ESA funded the QSEO design study for its Quantum Sensors for Earth Observation (QSEO) initiative, which established the LEVITAS concept and led to the paper below.
A follow-on experimental study is in preparation.

Paper

R. Gajewski, R. T. Desai, J. Bateman, B. Eliasson, D. K. L. Oi, and A. Datta, LEVITAS: Levitodynamics for accurate individual particle sensing in space, Quantum Science and Technology 11, 045034 (2026); preprint at arXiv:2510.24524.

Related work

Closely related ideas explored elsewhere:

Y.-H. Tseng et al., Optomechanical Detection of Individual Gas Collisions, arXiv:2604.18371 (2026).
M. Perdriat et al., Single-atom detection with a quantum-controlled mechanical oscillator, arXiv:2608.17656 (2026).

LOTIS