Title: A Study on a Quantum Gravity Gradiometer Pathfinder Mission
Presenting Author: Sheng-wey Chiow
Organization: NASA Jet Propulsion Laboratory
Co-Author(s): Nan Yu, David Aveline, Javier Bosch-Lluis, Robert Thompson, Siamak Forouhar, Clayton Okino, Norman Lay, Jason Hyon, Peter Brereton, Holly Leopardi, Anand Mylapore, Scott Luthcke, Bryant Loomis, Parminder Ghuman, Srinivas Bettadpur

Abstract:
Atom-based quantum gravity gradiometry (QGG) is a promising technology to achieve the mass change observable goals in the 2017 Decadal Survey. In this technique, laser-cooled atoms are placed into superposition via optical manipulation and subject to free fall in the Earth’s gravity field. The resulting atomic interference phase is a function of the local gravitational- and non-inertial accelerations and the interaction time of the atoms in these fields. Using two atom-interferometric sensor heads separated by a baseline and utilizing a common interferometry laser eliminates most common-mode noise and is highly sensitive to relative differences in the gravitational acceleration between the two sensor heads. The exquisite sensitivity and long-term stability of laser-cooled atoms to Doppler shifts from inertial and rotational accelerations could enable single-satellite orbital sensors to achieve an order of magnitude improvement over that achieved by the GRACE and GRACE Follow-On missions. In this talk, we will report the status of a study on a QGG pathfinder mission. The QGG pathfinder mission is a technology demonstration of using QGG for Earth gravity mapping, as a stepping stone for a science grade instrument that will provide data of sufficient precision to benefit Earth science. Targeting a host platform operating in the low Earth orbit, the payload is designed to measure the gravity gradient in the cross-track direction, with a sensitivity target of 100 mE/sqrt(Hz), a cycle time of 14 seconds per measurement, and a stability up to about 90 minutes. The mission design aims at two primary objectives: an end-to-end system demonstration and validation of atom-interferometric gravity remote sensing, and the advancement of ultracold atom interferometry technology and methods. This research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004).