School Seminar Program

Inter-spacecraft Laser Interferometry for Gravity Sensing

Dr Kirk McKenzie
ANU Centre for Gravitational Astrophysics (CGA)

Tracking the relative motion of spacecraft for gravity-sensing enables incredible array of science; monitoring the effects of climate change on a global scale, probing internal structure of planets and moons, and in future: space based gravitational-wave detection.

Until recently, all Doppler-tracking missions have relied on inter-spacecraft microwave-sensing; with precision as good as 1 micrometre. Inter-spacecraft laser interferometry is the future with orders of magnitude better precision.

The first inter-spacecraft laser interferometer, the Laser Ranging Interferometer (LRI), begun operation in 2018 on the Gravity Recovery and Climate Experiment (GRACE) Follow-On mission.
The LRI is a joint NASA/German instrument and was able to achieve all goals as a technology demonstrator including an improvement in precision of more than 100 over the microwave instrument on the same mission. The instrument is still continuously operating 3 years after turning on and looks to improve the science return of the mission.

This talk will introduce the technique of inter-spacecraft laser interferometry, the success of the LRI, and look to opportunities for Australian contributions to future missions, particularly for space-based gravitational wave detectors like the Laser Interferometer Space Antenna (LISA) and future GRACE missions.

Dr. Kirk McKenzie is a Senior Research Fellow at the ANU Centre for Gravitational Astrophysics (CGA) and leads the CGA Space Interferometry Theme. He is a Chief Investigator and Space Theme leader for the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) and a Chief Investigator and Node Manager for the ARC Centre of Excellence for Engineered Quantum Systems (EQUS). McKenzie joined the ANU CGA in 2019 after working at NASA/Jet Propulsion Laboratory from 2008-2019. He received the NASA Exceptional Public Achievement Medal for his work on the GRACE Follow-On mission.

Zoom details : 
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