{"project":{"acronym":"","projectId":91565,"title":"High Contrast Imaging of Extrasolar Planets with a Vector Vortex Coronagraph","primaryTaxonomyNodes":[{"taxonomyNodeId":10743,"taxonomyRootId":8816,"parentNodeId":10740,"level":3,"code":"TX08.1.3","title":"Optical Components","definition":"Optical component technologies are ultimately aimed at finding breakthrough technologies that can enable entirely new instrument or observatory architectures. Optical component technologies are grouped in the following categories: ultraviolet imaging, wide field of view imaging for near-Earth asteroids, and instruments for quantum interferometry. These improvements in optical components must complement improvements in associated detectors.","exampleTechnologies":"Mirrors, lenses, interferometers, gratings, prisms, fibers, dynamic pointing components (e.g. field steering mirrors), active optical elements, advanced surface technologies (e.g. frequency selective surfaces and composites), ground metrology and systems","hasChildren":false,"hasInteriorContent":true}],"startTrl":2,"currentTrl":3,"endTrl":3,"benefits":"The discovery of rocky planets orbiting their parent stars in the habitable zone,the area where the temperature is such that water is able to exist in liquid form, is one of the most compelling goals in astrophysics and a top priority of NASA's Science Mission Directorate. This project aims to develop novel devices and methods to calibrate, test, and improve the performance of ultra-high precision Doppler velocimeters. This project aims to use these devices to help achieve the design goals of two instruments: Minerva and LAEDI. If they reach their design precision, both of these instruments will be able to detect rocky, habitable-zone planets around nearby stars.","description":"The discovery of rocky planets orbiting their parent stars in the habitable zone,the area where the temperature is such that water is able to exist in liquid form, is one of the most compelling goals in astrophysics and a top priority of NASA’s Science Mission Directorate. Rocky, habitable-zone planets around the stars nearest to the sun would be the most important discoveries, as they would be most amenable to study from powerful space-based instruments like the James Webb Space Telescope. None have yet been found, even though studies have convincingly demonstrated that they should be extremely common. The most promising method of finding these planets is through Doppler velocimetry, where a star’s radial velocity is analyzed for the characteristic back-and-forth motion caused by an orbiting planet. State-of-the art instruments are able to detect stellar velocities just under 1 meter/second, the speed of a human walking. Despite this achievement, this level of precision is about a factor of ten larger than the signal of an Earth-like planet orbiting a Sun-like star. The precision of the best instruments is generally limited by the inability to compensate for tiny changes in temperature, pressure, and illumination of the optics, all of which can masquerade as velocity shifts and swamp the low signals of orbiting planets. For the next generation of instruments, whose design precisions approach or exceed the ~10 cm/s necessary to detect small, rocky planets, these noise sources will be extremely important to characterize and control. I propose to develop novel devices and methods to calibrate, test, and improve the performance of ultra-high precision Doppler velocimeters. These devices will simulate velocity shifts on real light, whether calibration light or starlight, using optomechanical and acousto-optical techniques. I propose to use these devices to help achieve the design goals of two instruments I am working on: Minerva, an automated, distributed-aperture robotic observatory dedicated to precision Doppler velocimetry every night; and LAEDI, a novel combination of an interferometer and spectrograph. If they reach their design precision, both of these instruments will be able to detect rocky, habitable-zone planets around nearby stars.","startYear":2013,"startMonth":8,"endYear":2016,"endMonth":6,"statusDescription":"Completed","principalInvestigators":[{"contactId":437319,"canUserEdit":false,"firstName":"Shrinivas","lastName":"Kularni","fullName":"Shrinivas Kularni","fullNameInverted":"Kularni, Shrinivas","publicEmail":false,"nacontact":false}],"programDirectors":[{"contactId":84634,"canUserEdit":false,"firstName":"Claudia","lastName":"Meyer","fullName":"Claudia M Meyer","fullNameInverted":"Meyer, Claudia M","middleInitial":"M","primaryEmail":"claudia.m.meyer@nasa.gov","publicEmail":true,"nacontact":false}],"programExecutives":[{"contactId":84634,"canUserEdit":false,"firstName":"Claudia","lastName":"Meyer","fullName":"Claudia M Meyer","fullNameInverted":"Meyer, Claudia M","middleInitial":"M","primaryEmail":"claudia.m.meyer@nasa.gov","publicEmail":true,"nacontact":false}],"programManagers":[{"contactId":183514,"canUserEdit":false,"firstName":"Hung","lastName":"Nguyen","fullName":"Hung D Nguyen","fullNameInverted":"Nguyen, Hung D","middleInitial":"D","primaryEmail":"hung.d.nguyen@nasa.gov","publicEmail":true,"nacontact":false}],"projectManagers":[{"contactId":147846,"canUserEdit":false,"firstName":"Eugene","lastName":"Serabyn","fullName":"Eugene Serabyn","fullNameInverted":"Serabyn, Eugene","primaryEmail":"eugene.serabyn@jpl.nasa.gov","publicEmail":true,"nacontact":false}],"coInvestigators":[{"contactId":330055,"canUserEdit":false,"firstName":"Michael","lastName":"Bottom","fullName":"Michael Bottom","fullNameInverted":"Bottom, Michael","primaryEmail":"mbottom@hawaii.edu","publicEmail":false,"nacontact":false}],"website":"https://www.nasa.gov/directorates/spacetech/home/index.html","libraryItems":[],"transitions":[{"transitionId":75650,"projectId":91565,"transitionDate":"2016-06-01","path":"Closed Out","details":"The goal of this work was to develop the technology for high-contrast imaging of extrasolar planets, primarily through the construction of an advanced vector-vortex coronagraph. This instrument, called the “Stellar Double Coronagraph,” is a flexible platform for experimentation and scientific research. It is currently operational at Palomar observatory and is still being used by ourselves and other groups. The instrument had a number of technical and scientific accomplishments, summarized below a) Multistage vortex coronagraphy One promising technique to improve coronagraphic performance on telescopes is using multiple vortex coronagraphs in tandem. The technical motivation behind this is that obscured apertures (such as a telescope with a secondary mirror) diffract some light into the pupil of the telescope, ruining the ability to achieve high contrast and low inner working angles. Multiple vortices in tandem can significantly improve contrast, especially very close to the star. We successfully implemented multistage vortex coronagraphy in the instrument, having two coronagraphs in series as our default observation mode. Using this setup, we demonstrated improved contrast both in the lab and on-sky, gaining up to factors of five in raw contrast, and more when using wavefront control techniques. We used this mode to resolve a previously unseen companion around a nearby star, and other scientific investigations. b) Ring apodized vortex coronagraphy A separate way to deal with the secondary obscuration is to use an upstream focal plane mask. By precisely configuring the mask to a particular transmissivity, it is theoretically possible to completely null the starlight in a particular region of the pupil. A second mask can transmit only this area of the pupil, which results in a complete null in the focal plane. This promising technique, known as the “Ring-apodized vortex coronagraph”, is relatively recent, having only been proposed in the last two years. It has never been implemented in an instrument, or even tested in a lab. We implemented a ring-apodized vortex coronagraph in SDC, tested it in the lab and observed with it on-sky. We achieved excellent raw suppression (factor of 10 better) using the ring-apodized coronagraph, demonstrating the design was sound and performed as expected. Variations of this design are now being considered for other telescopes like Keck and TMT. c) Focal plane wavefront control with speckle nulling Optical aberrations after the wavefront sensor of the adaptive optics system can lead to scattered light in the focal plane of the instrument that is many times brighter than any planetary companions at the same locations in the image. These “speckles” are the most serious barrier to imaging extrasolar planets. As part of the work with the SDC, we developed a speckle control code that uses the science camera and the deformable mirror to iteratively correct the focal plane, improving contrast by nearly an order of magnitude. We ported this code to the Keck observatory, where it was used with the new vortex coronagraph installed there. Tests at Keck achieved what is likely the highest contrast (in terms of planet sensitivity) ever demonstrated; we were able to probe down to subJupiter mass planets at Jupiter-like separations from the host star. This work will be published soon. d) Coronagraphic phase-shifting interferometry Another way of dealing with speckles is to exploit the fact that they are composed of starlight, and so will interfere with it. We installed a common path interferometer in SDC to interfere a portion of (usually blocked) starlight with the speckles in the focal plane. Since speckles will change brightness depending on the interferometer position, while planets will not, this is a way of actively discriminating between the two based on optical coherence. Interferometer readings can also be used to measure the phases of speckles in the focal plane, and then remove them using the deformable mirror. We successfully developed and demonstrated this technique both as a focal plane wavefront sensor and as a method of discovering substellar companions in imaging data on-sky. This is, to our knowledge, the first time optical coherence has been demonstrated to distinguish between a substellar companion and a speckle. This work was just accepted pending minor reviesions to Monthly Notices of the Royal Astronomical Society.","infoText":"Closed out","infoTextExtra":"","dateText":"June 2016"}],"responsibleMd":{"acronym":"STMD","canUserEdit":false,"city":"","external":false,"linkCount":0,"organizationId":4875,"organizationName":"Space Technology Mission Directorate","organizationType":"NASA_Mission_Directorate","naorganization":false,"organizationTypePretty":"NASA Mission Directorate"},"program":{"acronym":"STRG","active":true,"description":"
\tThe Space Technology Research Grants Program will accelerate the development of "push" technologies to support the future space science and exploration needs of NASA, other government agencies and the commercial space sector. Innovative efforts with high risk and high payoff will be encouraged. The program is composed of two competitively awarded components.
","programId":69,"responsibleMd":{"acronym":"STMD","canUserEdit":false,"city":"","external":false,"linkCount":0,"organizationId":4875,"organizationName":"Space Technology Mission Directorate","organizationType":"NASA_Mission_Directorate","naorganization":false,"organizationTypePretty":"NASA Mission Directorate"},"responsibleMdId":4875,"stockImageFileId":36658,"title":"Space Technology Research Grants"},"leadOrganization":{"acronym":"CalTech","canUserEdit":false,"city":"Pasadena","country":{"abbreviation":"US","countryId":236,"name":"United States"},"countryId":236,"external":true,"linkCount":0,"organizationId":3115,"organizationName":"California Institute of Technology","organizationType":"Academia","stateTerritory":{"abbreviation":"CA","country":{"abbreviation":"US","countryId":236,"name":"United States"},"countryId":236,"name":"California","stateTerritoryId":59},"stateTerritoryId":59,"murepUnitId":110404,"naorganization":false,"organizationTypePretty":"Academia"},"supportingOrganizations":[{"acronym":"JPL","canUserEdit":false,"city":"Pasadena","country":{"abbreviation":"US","countryId":236,"name":"United States"},"countryId":236,"external":true,"linkCount":0,"organizationId":4946,"organizationName":"Jet Propulsion Laboratory","organizationType":"FFRDC_2fUARC","stateTerritory":{"abbreviation":"CA","country":{"abbreviation":"US","countryId":236,"name":"United States"},"countryId":236,"name":"California","stateTerritoryId":59},"stateTerritoryId":59,"naorganization":false,"organizationTypePretty":"FFRDC/UARC"}],"statesWithWork":[{"abbreviation":"CA","country":{"abbreviation":"US","countryId":236,"name":"United States"},"countryId":236,"name":"California","stateTerritoryId":59}],"lastUpdated":"2024-2-6","releaseStatusString":"Released","viewCount":518,"endDateString":"Jun 2016","startDateString":"Aug 2013"}}