(James) Ira Thorpe was born and raised in Santa Fe, New Mexico and spent his childhood exploring the mountains by foot, bicylce, and ski. He graduated from the Santa Fe Preparatory School in 1997 and enrolled at Bucknell University in Mechancial Engineering. Ira graduated from Bucknell in 2001 with degrees in Mechanical Engineering and Physics and moved to the Maryland suburbs of Washington, DC to study Physics at the University of Maryland. While at UMD, Ira was selected for a fellowship at NASA where he began research with the nascent Laser Interferometer Space Antenna (LISA) project in the area of laser frequency stabilization. That experience was enough to catch the LISA and gravitational wave fever and Ira decided to transfer to the University of Florida to pursue a Ph.D. developing technologies for LISA metrology. Ira arrived in Gainesville after a brief hiatus in Patagonia with the National Outdoor Leadership School where he spent three months backpacking and kayaking in the Chilean wilderness. Ira completed his Ph.D. at UF in 2006 and returned to NASA as a postdoctoral fellow to work on LISA. In 2009, Ira converted to a civil servant, and he has been working on LISA and gravitational waves ever since. He lives in the Maryland suburbs with his wife and three children.
Laser Interferometer Space Antenna: Space-based Gravitational Wave observatory
Gravitational Waves are an exciting new tool for astronomy which can be used to study extreme astrophysical systems involving objects like black holes and neutron stars moving at velocities near the speed of light. Predicted by Einstein in 1918, Gravitational Waves were first observed by the ground-based Laser Interferometer Gravitational-wave Observatory (LIGO) in September 2015 after deacdes of effort in developing instrumentation. The scientific impact of LIGO's first few detections has been immense including suggestions of a new population of black holes, confirmation of the mechanisim behind short gamma-ray bursts, tight constraints on alternative theories of gravity, and, in concert with a suite of electromagnetic insturments, the discovery of the origin of heavy elements in the universe.
I'm interested in extending this new window on the universe to longer-wavelength gravitational waves, which requires placing the detector in space. The Laser Interferometer Space Antenna (LISA) mission has been studied for nearly 20 years and has recently been selected by the European Space Agency as a flagship mission for the early 2030s. NASA is collaborating with ESA to contribute to this mission and I am the lead scientist at NASA for this effort. LISA will use optical interferometry to monitor the separations between three spacecraft in a triangular constellation billions of meters on a side. The interferometric system will be sensitive enough to detect fluctuations in the spacecraft separation at the tens of picometer level that are produced by passing gravitational waves.
The science potential for a space-based gravitational wave observatory is particularly strong due to the high density of sources in the milliHertz frequency band, a band that is only accessible from space. I'm interested in the details of how to realize such a detector including the instrument technologies, mission design, data analysis, and science interpretation.
Previously, I worked on the LISA Pathfinder (LPF) mission, a technology demonstrator for gravitational wave missions that was also led by ESA and had signifcant contributions from NASA and a number of European National agencies. The primary goal of LPF was to demonstrate a low-disturbance test mass via the technique of drag free control. On LISA, these test masses will serve as the fiducial point for measuring the gravitational wave signal. Ideally, these test masses would be inertial particles but in practice their trajectories can be disturbed by non-gravitational forces. The single LPF spacecraft was be sensitive to gravitational waves, but was be sensitive to many of the same noise sources. LPF was a fantastic success, demonstrating that the test masses could be isolated more than well enough to meet the LISA requirements.
Interferometric Optical Metrology
Optical interferometry is a measurement technique that takes advantage of the wave-nature of light. By using light with a wavelength around 1 micron, it is possible to measure distance changes at the level of nanometers, picometers, or even femtometers. My particluar focus has been on building ultra-stable platforms for metrology and the related applicaiton of stabilizing laser frequencies.
Laser Interferometer Space Antenna
The Laser Interferometer Space Antenna (LISA) is a space-based observatory for gravitational waves under development through a collaboration of the European Space Agency, NASA, and a collection of European National Agencies. LISA will extend our windown into the gravitational wave universe to lower frequencies, a regime where astrophysicists expect to find a large number of sources of varying types. LISA is in the early stages of formulation and expects to launch in the 2030s. I am currently the NASA Study Scientist for LISA, meaning that I help to organize NASA's effort to contribute technical, engineering, and scientific expertise to the ESA-led LISA mission.
LISA Pathfinder was an ESA-led technology demonstrator for future space-based gravitational wave mission such as LISA. LPF launched on December 3rd, 2015 and operated until July of 2017. I was a member of the LPF Science Working Team and participated in operations, analysis, and interpretation of the data.
NASA Goddard Space Flight Center - Greenbelt, MD
March 2009 - Present
Civil servant position in gravitational wave astrophysics. Emphasis on mission concept development, instrument prototyping, and data analysis. US lead for data analysis on LISA Pathfinder mission.
NASA Postdoctoral Fellow
Oak Ridge Associated Universities - Greenbelt, MD
February 2007 - February 2009
Research in gravitational wave detection, laser ranging, and optical communication. Led laboratory effort to develop frequency-stabilized lasers for applications in space-based gravitational wave detectors. Participated in studies of LISA's astrophysical measurement capabilities (i.e. source parameter estimation).
Thesis: Laboratory Studies of Arm-Locking using the Laser Interferometer Space Antenna Simulator at the University of Florida
M.S. in Physics - University of Maryland - College Park, MD (2003)
NASA Laboratory for High-Energy Astrophysics Fellow
B.S. in Mechanical Engineering / B.A. in Physics - Bucknell University - Lewisburg, PA (2001)
Graduated summa cum laude with Bucknell University Prize for Men
American Physical Society
2001 - Present
American Astronomical Society
2007 - Present
American Association for the Advancement of Science (AAAS)
2016 - Present
International Astronomical Union
2018 - Present
GSFC Special Act - Individual Award (2023)
For support of the Gravitational Astrophysics Laboratory
GSFC Special Act - Individual Award (2021)
For ongoing leadership of NASA's LISA Study Office
Robert H. Goddard Award (2017)
For leadership of NASA's participation in the LISA Pathfinder mission
NASA Group Achievement Award (2017)
For the successful operations of the Space Technology 7 (ST7) mission, meeting all mission success criteria
ESA Corporate Team Achievement Award (2016)
In recognition of your valuable contribution to the success of the LISA Pathfinder mission
GSFC Astrophysics Division Peer Award (2015)
For ongoing work as a central and active member of the gravitational astrophysics laboratory and your work on the LISA Pathfinder mission.
GSFC Special Act - Individual Award (2015)
For ongoing work as a central and active member of the Gravitational Astrophysics Laboratory
GSFC Special Act - Team Award (2012)
For insightful contributions to the Gravitational Wave Mission Concept Study
NASA Group Achievement Award (2011)
For outstanding planning, design, and delivery of a high-quality and fun middle school Summer of Innovation educational experience for 800 students.
Jennrich, O., N. Luetzgendorf, J. I. Thorpe, J. Slutsky, and C. Cutler. 2021. Sensitivity limits of space-based interferometric gravitational wave observatories from the solar wind Physical Review D 104 (6): 062003 [10.1103/physrevd.104.062003]
Bailes, M., B. K. Berger, P. R. Brady, et al. M. Branchesi, K. Danzmann, M. Evans, K. Holley-Bockelmann, B. R. Iyer, T. Kajita, S. Katsanevas, M. Kramer, A. Lazzarini, L. Lehner, G. Losurdo, H. Lück, D. E. McClelland, M. A. McLaughlin, M. Punturo, S. Ransom, S. Raychaudhury, D. H. Reitze, F. Ricci, S. Rowan, Y. Saito, G. H. Sanders, B. S. Sathyaprakash, B. F. Schutz, A. Sesana, H. Shinkai, X. Siemens, D. H. Shoemaker, J. Thorpe, J. F. van den Brand, and S. Vitale. 2021. Gravitational-wave physics and astronomy in the 2020s and 2030s Nature Reviews Physics [10.1038/s42254-021-00303-8]
Baghi, Q., J. I. Thorpe, J. Slutsky, and J. Baker. 2021. Statistical inference approach to time-delay interferometry for gravitational-wave detection Physical Review D 103 (4): 042006 [10.1103/physrevd.103.042006]
Thorpe, J. I., J. Slutsky, J. G. Baker, et al. T. B. Littenberg, S. Hourihane, N. Pagane, P. Pokorny, D. Janches, M. Armano, H. Audley, G. Auger, J. Baird, M. Bassan, P. Binetruy, M. Born, D. Bortoluzzi, N. Brandt, M. Caleno, A. Cavalleri, A. Cesarini, A. M. Cruise, K. Danzmann, M. de Deus Silva, R. De Rosa, L. Di Fiore, I. Diepholz, G. Dixon, R. Dolesi, N. Dunbar, L. Ferraioli, V. Ferroni, E. D. Fitzsimons, R. Flatscher, M. Freschi, C. García Marirrodriga, R. Gerndt, L. Gesa, F. Gibert, D. Giardini, R. Giusteri, A. Grado, C. Grimani, J. Grzymisch, I. Harrison, G. Heinzel, M. Hewitson, D. Hollington, D. Hoyland, M. Hueller, H. Inchauspé, O. Jennrich, P. Jetzer, B. Johlander, N. Karnesis, B. Kaune, N. Korsakova, C. J. Killow, J. A. Lobo, I. Lloro, L. Liu, J. P. López-Zaragoza, R. Maarschalkerweerd, D. Mance, V. Martín, L. Martin-Polo, J. Martino, F. Martin-Porqueras, S. Madden, I. Mateos, P. W. McNamara, J. Mendes, L. Mendes, M. Nofrarias, S. Paczkowski, M. Perreur-Lloyd, A. Petiteau, P. Pivato, E. Plagnol, P. Prat, U. Ragnit, J. Ramos-Castro, J. Reiche, D. I. Robertson, H. Rozemeijer, F. Rivas, G. Russano, P. Sarra, A. Schleicher, D. Shaul, C. F. Sopuerta, R. Stanga, T. Sumner, D. Texier, C. Trenkel, M. Tröbs, D. Vetrugno, S. Vitale, G. Wanner, H. Ward, P. Wass, D. Wealthy, W. J. Weber, L. Wissel, A. Wittchen, A. Zambotti, C. Zanoni, T. Ziegler, P. Zweifel, P. Barela, C. Cutler, N. Demmons, C. Dunn, M. Girard, O. Hsu, S. Javidnia, I. Li, P. Maghami, C. Marrese-Reading, J. Mehta, J. O’Donnell, A. Romero-Wolf, and J. Ziemer. 2019. Micrometeoroid Events in LISA Pathfinder The Astrophysical Journal 883 (1): 53 [10.3847/1538-4357/ab3649]
Fulda, P., R. T. DeRosa, E. DeMarco, et al. M. Aitken, J. Livas, and J. I. Thorpe. 2019. Multi-axis heterodyne interferometry at MHz frequencies: a short-arm measurement demonstration for LISA with off-the-shelf hardware Applied Optics 58 (23): 6346 [10.1364/ao.58.006346]
Baghi, Q., J. I. Thorpe, J. Slutsky, et al. J. Baker, T. D. Canton, N. Korsakova, and N. Karnesis. 2019. Gravitational-wave parameter estimation with gaps in LISA: A Bayesian data augmentation method Physical Review D 100 (2): 022003 [10.1103/physrevd.100.022003]
Armano, M., H. Audley, J. Baird, et al. P. Binetruy, M. Born, D. Bortoluzzi, E. Castelli, A. Cavalleri, A. Cesarini, A. Cruise, K. Danzmann, M. de Deus Silva, I. Diepholz, G. Dixon, R. Dolesi, L. Ferraioli, V. Ferroni, E. Fitzsimons, M. Freschi, L. Gesa, F. Gibert, D. Giardini, R. Giusteri, C. Grimani, J. Grzymisch, I. Harrison, G. Heinzel, M. Hewitson, D. Hollington, D. Hoyland, M. Hueller, H. Inchausp'e, O. Jennrich, P. Jetzer, N. Karnesis, B. Kaune, N. Korsakova, C. Killow, J. Lobo, I. Lloro, L. Liu, J. L'opez-Zaragoza, R. Maarschalkerweerd, D. Mance, N. Meshksar, V. Mart'in, L. Martin-Polo, J. Martino, F. Martin-Porqueras, I. Mateos, P. McNamara, J. Mendes, L. Mendes, M. Nofrarias, S. Paczkowski, M. Perreur-Lloyd, A. Petiteau, P. Pivato, E. Plagnol, J. Ramos-Castro, J. Reiche, D. Robertson, F. Rivas, G. Russano, J. Slutsky, C. Sopuerta, T. Sumner, D. Texier, J. Thorpe, D. Vetrugno, S. Vitale, G. Wanner, H. Ward, P. Wass, W. Weber, L. Wissel, A. Wittchen, and P. Zweifel. 2018. Beyond the Required LISA Free-Fall Performance: New LISA Pathfinder Results down to 20 ensuremathmu Hz prl 120 061101 [10.1103/PhysRevLett.120.061101]
Armano, M., H. Audley, G. Auger, et al. J. Baird, M. Bassan, P. Binetruy, M. Born, D. Bortoluzzi, N. Brandt, M. Caleno, L. Carbone, A. Cavalleri, A. Cesarini, G. Ciani, G. Congedo, A. Cruise, K. Danzmann, M. de Deus Silva, R. De Rosa, M. Diaz-Aguiló, L. Di Fiore, I. Diepholz, G. Dixon, R. Dolesi, N. Dunbar, L. Ferraioli, V. Ferroni, W. Fichter, E. Fitzsimons, R. Flatscher, M. Freschi, A. García Marín, C. García Marirrodriga, R. Gerndt, L. Gesa, F. Gibert, D. Giardini, R. Giusteri, F. Guzmán, A. Grado, C. Grimani, A. Grynagier, J. Grzymisch, I. Harrison, G. Heinzel, M. Hewitson, D. Hollington, D. Hoyland, M. Hueller, H. Inchauspé, O. Jennrich, P. Jetzer, U. Johann, B. Johlander, N. Karnesis, B. Kaune, N. Korsakova, C. Killow, J. Lobo, I. Lloro, L. Liu, J. López-Zaragoza, R. Maarschalkerweerd, D. Mance, V. Martín, L. Martin-Polo, J. Martino, F. Martin-Porqueras, S. Madden, I. Mateos, P. McNamara, J. Mendes, L. Mendes, A. Monsky, D. Nicolodi, M. Nofrarias, S. Paczkowski, M. Perreur-Lloyd, A. Petiteau, P. Pivato, E. Plagnol, P. Prat, U. Ragnit, B. Raïs, J. Ramos-Castro, J. Reiche, D. Robertson, H. Rozemeijer, F. Rivas, G. Russano, J. Sanjuán, P. Sarra, A. Schleicher, D. Shaul, J. Slutsky, C. Sopuerta, R. Stanga, F. Steier, T. Sumner, D. Texier, J. Thorpe, C. Trenkel, M. Tröbs, H. Tu, D. Vetrugno, S. Vitale, V. Wand, G. Wanner, H. Ward, C. Warren, P. Wass, D. Wealthy, W. Weber, L. Wissel, A. Wittchen, A. Zambotti, C. Zanoni, T. Ziegler, and P. Zweifel. 2016. Sub-Femto-gFree Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results Physical Review Letters 116 (23): 231101 [10.1103/physrevlett.116.231101]
Preston, A. M., J. I. Thorpe, and L. Miner. 2012. Quasi-Monolithic Structures for Spaceflight Using Hydroxide-Catalysis Bonding 2012 IEEE Aerospace Conference
McWilliams, S. T., (. I. Thorpe, J. G. Baker, and B. J. Kelly. 2010. Impact of mergers on LISA parameter estimation for nonspinning black hole binaries Physical Review D 81 064014 [10.1103/PhysRevD.81.064014]
Wand, V., Y. Yu, S. Mitryk, et al. D. Sweeney, A. M. Preston, D. Tanner, G. Mueller, J. I. Thorpe, and J. C. Livas. 2009. Implementation of armlocking with a delay of 1 second in the presence of Doppler shifts Journal of Physics: Conference Series 154
Livas, J. C., J. I. Thorpe, K. Numata, et al. S. Mitryk, G. Mueller, and V. Wand. 2009. Frequency-tunable pre-stabilized lasers for LISA via sideband locking Classical and Quantum Gravity 26 4016 [10.1088/0264-9381/26/9/094016]
Thorpe, J. I., S. T. McWilliams, B. J. Kelly, et al. R. P. Fahey, K. A. Arnaud, and J. G. Baker. 2009. LISA parameter estimation using numerical merger waveforms Classical and Quantum Gravity 26 094026 [10.1088/0264-9381/26/9/094026]
Preston, A. M., R. Cruz, J. I. Thorpe, G. Mueller, and R. Delgadillo. 2006. Dimensional stability of Hexoloy SA® silicon carbide and Zerodur™ glass-ceramic using hydroxide-catalysis bonding for optical systems in space Proceedings of the SPIE 6273
Cruz, R., J. I. Thorpe, A. M. Preston, et al. R. Delgadillo, M. Hartman, S. Mitryk, A. Worley, G. Boothe, S. Guntaka, and S. Klimenko. 2006. The LISA benchtop simulator at the University of Florida Classical and Quantum Gravity 23 S751-S760