Upcoming Seminars:

Coronagraph Design Survey

May 20, 2024 10:00 PDT

Speakers: Rus Belikov (NASA/ARC), Chris Stark (NASA/GSFC)

In January 2023, the Exoplanet Exploration Program (ExEP) kicked off the Coronagraph Design Survey, chartered to collect and document a broad range of coronagraph designs that may be applicable for NASA’s Habitable Worlds Observatory (HWO). The working group that conducted the Survey, led by Rus Belikov (ARC) and Chris Stark (GSFC), cast a very wide net capturing known and never-heard-of-before novel coronagraph designs. They have completed their 17-month study and will be delivering a final report to the HWO Technical Assessment Group (TAG). Come hear their public briefing of what they learned, and how the results of their survey help point the way to future direct imaging of Earth-like planets.

please email the colloquium organizer for connection information

Deformable Mirror Technology Roadmap Study

June 7, 2024 9:30 am PDT

Speakers: Duncan Liu (NASA/JPL), Tyler Groff (NASA/GSFC)

In February 2023, the ExEP kicked off the Deformable Mirror Technology Roadmap study chartered to create a roadmap for deformable mirror (DM) technologies to reach TRL 5 for a Habitable Worlds Observatory (HWO) concept. Their work was to also inform NASA on prioritized vendors, manufacturing needs, and test facilities to ensure DM technology readiness. The working group that conducted the study, led by Tyler Groff (GSFC) and Duncan Liu (JPL), cast a very wide net capturing known and not so known DM technologies. They have completed their 16-month study and will be delivering a final report to the HWO Technical Assessment Group. Come hear their public briefing of what they learned and their recommended path forward to one day directly imaging Earth-sized planets.

please email the colloquium organizer for connection information

Coronagraphy Technology Roadmap Study

June 11, 2024 10:00 PDT

Speakers: Pin Chen (NASA/JPL), Laurent Pueyo (STScI)

In January 2023, the ExEP kicked off the Coronagraph Technology Roadmap study chartered to create a roadmap for maturing coronagraph technologies to TRL 5 for a Habitable Worlds Observatory (HWO) concept. Their work was to also inform NASA on prioritized investments in architectures, hardware, modeling, manufacturing capabilities, and test facilities to ensure coronagraph technology readiness. The working group that conducted the study, led by Pin Chen (JPL) and Laurent Pueyo (STScI), covered a broad range of wavelengths from the UV to the NIR and included 30+ experts. They have completed their 17-month study and will be delivering a final report to the HWO Technical Assessment Group. Come hear their public briefing of what they learned and their recommended path forward to one day helping NASA directly image Earth-sized planets.

please email the colloquium organizer for connection information

Past Seminars

Starshades 101

August 4, 2023

Speakers: Professor Jeremy Kasdin (Princeton), Stuart Shaklan (JPL)
Seminar Recording
Presentation Slides

In the leadup to the ExEP Starlight Suppression Workshop August 8-10, we will offer introductory (“101”) talks that may be useful for new members of the field as well as engineers and scientists who aim to support NASA’s future Habitable Worlds Observatory (HWO).

To directly image Earth-like exoplanets, NASA has invested in two approaches to high-contrast imaging. Perhaps lesser known than a coronagraph instrument is an external occulter, or starshade. The starshade is a spacecraft that flies in formation with a space telescope to block light from a star, allowing orbiting exoplanets to be seen and characterized. There are numerous advantages to suppressing the starlight before it reaches the space telescope, including large bandwidth, deep contrast, high-throughput, and access to planets appearing very close to their parent star, all without imposing any stringent requirements on the telescope. The key technical challenges are to build the starshade to the required tolerances, limit solar glint, and fly it in tight formation with the telescope. Unlike a coronagraph, which can be pointed from target to target on a daily basis, the starshade can be positioned to observe new targets with a cadence of a week or two. We have scheduled a special ExEP Technology Colloquium by Jeremy Kasdin (Princeton) and Stuart Shaklan (JPL) to describe fundamentals of starshades: how they work, some of the key design features and considerations, some point designs based on past studies, as well as how far this technology has matured.

Please register here for the Starlight Suppression Workshop taking place August 8-10.

Coronagraphy 101

August 1, 2023

Speaker: Professor Jeremy Kasdin, Princeton
Presentation Slides
Seminar Recording

In the leadup to the ExEP Starlight Suppression Workshop in August, we will be offering a few 101 courses that might be helpful for new members in the field as well as future engineers and scientists supporting NASA’s Habitable Worlds Observatory. Our first will be on the “science of coronagraphy”. Coronagraphy, first demonstrated in the 1930s, has a come a long way since being used to create artificial eclipses and enable the study of the Sun’s corona. Coronagraph technology has enabled high-contrast imaging of exoplanets, including from space with Hubble and James Webb. In the 2020s, the first high-contrast coronagraph instrument with wavefront control will be launched with the Roman Space Telescope and will pave the way for the even more technically demanding capability to directly image and spectrally characterize terrestrial exoplanets with the Habitable Worlds Observatory.

The path to achieve contrast performance at the extreme levels required for this new mission is not an easy one. Developing space coronagraph technology remains a specialized field with many subtleties that are often not well understood.

We are pleased to present a special Exoplanet Exploration Technology Colloquium from Professor Jeremy Kasdin who will demystify the coronagraph by covering its basics. His talk will cover general physics and operations of coronagraphy, the key components of a coronagraph, observing in space, and will identify areas of difficulty.

Please register here for the Starlight Suppression Workshop taking place August 8-10.

Terrestrial Exoplanets 101

July 25, 2023

Speaker: Giada Arney, NASA/GSFC
Seminar Recording

In the leadup to the ExEP Starlight Suppression Workshop August 8-10, we will offer introductory (“101”) talks that may be useful for new members of the field as well as engineers and scientists who aim to support NASA’s future Habitable Worlds Observatory (HWO).

The Astro2020 decadal survey highly prioritized the study of Earth-like exoplanets and the search for life in the universe, recommending a future large mission (HWO) to address this science. The capability to spectrally characterize these planets will drive the architecture of HWO, as shown by the recent LUVOIR and HabEx mission concept studies, particularly in the areas of starlight suppression, wavelength coverage, and sensitivity to these dim planets.

We are delighted to present a special ExEP Technology Colloquium by Dr. Giada Arney (NASA GSFC), who will describe science goals for the study of Earth-like exoplanets in detail, including the evolution of biosignatures and habitability indicators throughout a planet’s history. This deep dive into the science will shed light on necessary measurement capabilities which in turn has implications for future HWO architecture choices and measurement goals.

Please register here for the Starlight Suppression Workshop taking place August 8-10.

Towards Institutional Diversity: One Company’s Journey

May 24, 2023

Speakers: Sarah Lipscy and Stephen Rock, Ball Aerospace

Seminar Recording

The 2020 Decadal Survey in Astronomy and Astrophysics (Astro2020) recommended that NASA develop a program to enable a new series of Great Observatories, the first of which will be the Habitable Worlds Observatory. Realizing these ambitious missions will require a large, talented, and diverse workforce, institutions need to be intentional in efforts that attract and retain talent. These strategies are critical to the success of these multi-decadal efforts. In recognition of the need to build and sustain this workforce, Astro2020 also placed the state of the profession front and center in its report. The report recognized that diversity is a driver of innovation and recommended that barriers to participation be removed. In synergy with the report, many technical institutions have recently also recognized the essential need for diversity, equity, inclusion (DEI), and many have attempted major changes to support this need. For example, NASA has adopted inclusion as a core value and has developed a policy statement to support it, further adding the importance of “accessibility” to DEI.

Ball Aerospace is another institution that is committed to diversity & inclusion and has shown that intentionality can indeed create progress. They have set out on a corporate journey to recruit, inspire, and retain a more diverse workforce. One example of their successes lies in their focus in increasing female representation in technical leadership roles.

We are pleased to depart from our normally technical topics to announce a colloquium with a talk by Ball Aerospace Director of Civil Space Business Development, Sarah Lipscy, and Ball Aerospace Diversity & Inclusion Manager, Stephen Rock, that will describe strategies they have undertaken to implement DEI within their organization. Come learn ideas for best practices and lessons that we can potentially implement at our own institutions.

November 16, 2022

Update on Starshade Technology: Prospects for a Future Great Observatory

Speaker: Case Bradford (JPL)

Seminar Recording


Is the starshade still a relevant technology for the IR/O/UV Future Great Observatory recommended by Astro2020? It certainly didn’t appear to feature prominently. Concerns about low yields, fuel limitations, a second spacecraft, and violation of NASA’s “test as you fly” guideline make this starlight suppression approach challenging. However, numerous benefits with respect to coronagraphs demand that it stays in the trade discussion – higher throughput, lower inner working angle, operability in the UV, no active optics, and no ultra-stability requirements levied on the telescope.

NASA’s Starshade Technology Activity (also known as S5) has been maturing the technology over the past 6 years, including a subscale lab demonstration of contrast deeper than 1e-10 over a 10% band. In this technology colloquium, Case Bradford, S5 Technology Manager, will give us an update on how far they’ve come (you may be surprised). He’ll also describe what is left to do and challenges in having a starshade ready for a future great observatory.

September 27, 2022

Wavefront Control for Coronagraphs on Segmented Space Telescopes

Seminar Recording


Laurent Pueyo (STScI)

presentation slides

Axel Potier (JPL)

presentation slides

The 2021 Decadal Survey recommended that NASA launch an ambitious Future Great Observatory with a roughly 6 meter diameter primary mirror capable of searching for biosignatures on ~25 Earth-like exoplanets in the IR/Vis/UV. Within months of this recommendation, the James Webb Space Telescope mission demonstrated that a telescope with a 6.5 meter segmented primary mirror can be successfully deployed on orbit and achieve tens of nanometers of wavefront stability. However, the coronagraph instrument necessary for the Future Great Observatory may require wavefront stability at the level of tens of picometers - a challenging jump of a factor of 1000 in required performance. Can a telescope ever be built that achieves this stability?

Fortunately, wavefront sensing and control on timescales relevant to coronagraph observations is a possible way to relieve stringent telescope stability requirements. Join us for a doubleheader of talks by Laurent Pueyo (STScI) and Axel Potier (JPL) who have each separately explored wavefront control schemes for coronagraphs on segmented space telescopes, using the LUVOIR architectures as references, including realistic models of telescope stability.

February 28, 2022

Choosing the Future: The Kepner-Tregoe Matrix for Complex Trades

Seminar Recording


Speaker: Dr. Gary Blackwood (ExEP/JPL)

Regardless if you’re trying to pick between home options, a new car, a new position/job, or down-selecting between different technical approaches, a good decision-making technique is indispensable. With the release of the 2020 Decadal Survey, NASA’s Astrophysics Division, along with the community, will need to make some important and challenging decisions over the next decade. Come hear Dr. Gary Blackwood (ExEP/JPL) talk about a technique that he has been using for over two decades called the Kepner-Tregoe Matrix (KTM). It was originally developed by Kepner and Tregoe from the Rand Corporation as a tool used to support organizational decision making. The technique is transparent, inclusive, quantitative, and captures risks. Gary has led a number of astrophysics teams through this process recently to make decisions between architectures, including the Lynx mission concept study, the Starshade working group, and the Roman Space Telescope Coronagraph Instrument pre-project. Please join us to hear Gary give a tutorial on the KTM that will certainly be used in the years to come.

August 19, 2021

A Worldwide Survey of Deformable Mirror Technologies

seminar recording

Presentation slides

Speaker: Eduardo Bendek (JPL/Caltech)

Deformable Mirrors (DMs) are an essential technology for high contrast imaging from space using a coronagraph. For future observations of Earth-like exoplanets from space, NASA will need DMs with very precise actuator control, low wavefront error, high actuator count, and suitability for the space environment.

The Exoplanet Exploration Program (ExEP) carried out a worldwide survey, which concluded earlier in 2021, to assess the maturity and suitability of available DM options. The two leading architectures include devices constructed with electrostrictive materials (such as those DMs selected for Roman Space Telescope’s coronagraph instrument) and MEMS devices, but are there better options for future flagship space missons? What new materials and approaches are under development for deformable mirrors that may emerge as contenders in the future?

June 17, 2021

The Power of Coronagraphy plus High-Resolution Spectroscopy

seminar recording


Nem Jovanovic (Caltech)

presentation slides

Arthur Vigan (LAM)

presentation slides

Reflected light spectroscopy in the visible and near infrared bands of terrestrial exoplanets in the habitable zones of Solar-type stars will represent a huge leap forward in the search for life in the Galaxy. NASA's long term technology goals include developing these capabilities while ground-based observatories are keenly targeting terrestrial planets around M dwarfs. However, to date, ground-based direct imaging has been limited to the study of giant planets in young systems at large stellar separations.

But due to recent advances in ground-based technology, instrumentation and observing techniques for exoplanet direct imaging are pushing the envelope of what was thought possible from the ground. This trend will continue as the ELT's come online in the coming years.

Please join us to hear two presentations describing the Keck Planet Imager and Characterizer (KPIC) instrument and the High-Resolution Imaging and Spectroscopy of Exoplanets (HiRISE) project, both based on the technique of combining high resolution spectroscopy and coronagraphy. This concept represents the cutting edge of exoplanet spectroscopy from the ground at mid-infrared and near-infrared wavelengths. We will hear what scientists and engineers working towards future space missions can learn from this advance in ground-based technology, and get insight into how technology demonstrations and new measurement capabilities from the ground will help to advance NASA's long term goals for the study of exoplanets and the search for life.

April 15, 2021

Title: The Past, Present, and Future of Nulling Interferometry

Speaker: Gene Serabyn (JPL)

Presentation Slides

Seminar Recording

Confirmation of future exoplanet biosignature detection through spectroscopy in the Vis/NIR will likely require observations in the mid-infrared. High angular resolution measurements at longer wavelengths call for interferometry, a capability that is not currently on the Exoplanet Exploration Program (ExEP)’s Technology Gap List.

As we await the recommendations of the Astro2021 Decadal Survey, we anticipate that mid-infrared interferometry might be mentioned in some form. ExEP has begun a small study of the current state of the technology needs for such a mission, ultimately contingent on the recommendations of the Decadal Survey. The study is being carried out by JPL’s Bertrand Mennesson, Gene Serabyn, Stefan Martin, and GSFC’s Bill Danchi and Chris Stark.

The team recently completed their first milestone, which was to identify lessons learned from recent advances in ground-based nulling interferometry from Keck, Palomar, LBT, and the VLT. Come join us to hear Gene Serabyn from JPL present the lessons learned over the last decade and how they may impact future missions.

September 18, 2020

Title: MEMS Deformable Mirror developments in HCIT

Speakers: Garreth Ruane, Eduardo Bendek (JPL)

Presentation Slides

Garreth Ruane and Eduardo Bendek (JPL/Caltech) on behalf of the team at ExEP’s High Contrast Imaging Testbed (HCIT) present recent results and lessons learned on MEMS Deformable Mirrors and their drive electronics collected over the last few months as the team has been conducting coronagraph experiments aimed at the 1e-9 to 1e-10 contrast level in the vacuum testbed. This includes characterizing DM surfaces with a Zernike wavefront sensor, as well as coronagraph contrast demonstrations.

August 12, 2020

Title: The Coronagraph Instrument (CGI) on the Roman Space Telescope : A Status Update

Speaker: Feng Zhao, Deputy Instrument Manager for Roman/CGI (JPL)

Presentation Slides

The Coronagraph Instrument (CGI) on the Roman Space Telescope will make the first demonstration of a high-contrast coronagraph technology (capable of wavefront control) on a space telescope for direct imaging of exoplanets when it launches in the mid-2020s. In developing the instrument, the CGI team has matured a number of key technologies: low-order wavefront sensing and control, deformable mirrors, electron-multiplying CCD detectors, coronagraph masks for a highly obscured pupil. The instrument is now in the final design and fabrication phase and CGI’s upcoming mission will greatly reduce risk for future NASA missions capable of imaging and characterizing Earth-like exoplanets in the habitable zone of their star, such as LUVOIR or HabEx.

May 26, 2020

Title: Update on S5's Starshade Technology Activities: Advancements in Starlight Suppresion and Deployment Accuracy and Stability

Speaker: Phil Willems (NASA ExEP, S5 Manager)

Presentation Slides

Advanced Wavefront Sensing Workshop May 1, 2020

March 31, 2020

Title: Method for deriving optical telescope stability specifications for Earth-detecting coronagraphs

Speaker: Bijan Nemati (UAH) Presentation Slides

We present an approach to arrive at wavefront stability requirements for high contrast direct imaging applications. The method begins by setting requirements on the flux ratio noise based on the science objectives (target flux ratio and desired SNR). Next we use a diffraction model to arrive at a coronagraph’s basic performance parameters such as core throughput and contrast. Using these parameters and an analytical model of photometric errors, we propose a method for deriving a basic top level error budget, including allocations for wavefront instability. Next, we use the diffraction model to derive the sensitivity of the given telescope/coronagraph combination to the expected wavefront error instabilities that might be encountered. We describe a simple weighting algorithm that can be the basis of a first-cut set of allocations to each instability mode in a system engineering process. Using this algorithm and the computed sensitivities, we arrive at requirements for stability in each mode. We end by demonstrating the utility of this method for comparing the ability of several monolithic and segmented telescope and coronagraph combinations to detect an exo-Earth at 10 pc.

Title: Exoplanet detection with the LUVOIR coronagraph instrument - Performance evaluation and aberration sensitivity requirements

Speaker: Roser Juanola-Parramon (NASA/GSFC) Presentation Slides

Future space missions such as the Large UV-Optical-Infrared Surveyor (LUVOIR) and the Habitable Exoplanet Observatory (HabEx) require large apertures and coronagraphs with active wavefront control to suppress starlight so that faint planets can be detected and characterized adjacent to their parent star. The Extreme Coronagraph for Living Planet Systems (ECLIPS) is the coronagraph instrument on the LUVOIR Surveyor mission concept, an 8-15-meter segmented telescope. ECLIPS is split into three wavelength channels: UV (200 to 400 nm), optical (400 nm to 850 nm), and NIR (850 nm to 2.0 microns), each equipped with two deformable mirrors for wavefront control, a suite of coronagraph masks, a low-order/out-of-band wavefront sensor, and dedicated imaging cameras and spectrographs.

The Apodized Pupil Lyot Coronagraph (APLC) and the Vector Vortex Coronagraph (VVC) are the baselined mask technologies for ECLIPS. Both mask types enable 10-10 contrast observations in the habitable zones of nearby stars. Their performance depends on active wavefront sensing and control, as well as metrology subsystems to compensate for static and dynamic aberrations. We have simulated the effect of static aberrations induced by segment errors (piston and tip/tilt, among others), secondary mirror misalignment, global low-order wavefront errors, as well as the effects of dynamic aberrations due to segment jitter and segment drift.

Here we present the latest results of the simulation of these effects for the two mask technologies and discuss the achieved contrast for exoplanet detection and characterization after closed-loop wavefront estimation and control algorithms have been applied. With respect to dynamic wavefront aberrations, both designs maintain their target contrast of 1e−10 with segment jitter and drift wavefront error levels of around 32pm and 12pm, respectively. For a 3-sigma detection, the segment jitter and drift required is of the order of 20pm and 7pm, respectively. Finally, we show simulated observations using high-fidelity spatial and spectral input models of complete planetary systems generated with the Haystacks scene framework.

December 16, 2019 Presentation Slides

Title: The Standard Definitions and Evaluation Team Final Report: A common comparison of exoplanet yield

Speaker: Rhonda Morgan (JPL/Caltech)

The Exoplanet Standard Definition and Evaluation Team (ExSDET) has performed an unbiased exo-earth yield analysis of the LUVOIR and HabEx large mission concepts using a transparent and documented set of common inputs, assumptions and methodologies. The Standards Team established science metrics for yield to allow for a common comparison of the point-designs presented in the final reports: LUVOIR A (15 m on-axis), LUVOIR B (8 m off-axis), HabEx 4H (4 m with coronagraph and starshade), HabEx 4C (4 m with coronagraph only), and HabEx 3.2S (3.2m with starshade only). Yield analysis shows that these concepts can directly image and spectrally characterize earth-like planets in the habitable zone and that each architecture has complementary strengths and provides different quality of science products.

This talk presents an overview of the astrophysical assumptions and inputs, including recent developments such as the results of the LBTI HOSTS survey of exozodical dust brightness and the incorporation of radial velocity occurrence rates and application of theoretical constraints to the SAG-13 exoplanet occurrence rates. The approaches for the two different design reference mission simulation codes is described: Altruistic Yield Optimization (AYO) by Chris Stark and the Exoplanet Open-Source Imaging Mission Simulator (EXOSIMS) by Dmitry Savransky et al. The individual observing scenarios of each concept is delineated and the subsequent yield metrics descripted. The common comparison of LUVOIR to HabEx to the various metrics is presented, including the impact of observation scheduling. The talk concludes with a brief look at the potential impact of precursor knowledge from a potential extreme precision radial velocity instrument.

November 12, 2019 Presentation Slides

Title: Results from the NASA-Chartered In-Space Assembled Telescope (iSAT) Study: Implications for Future Space Observatories

Speaker: Nick Siegler (NASA ExEP, Jet Propulsion Laboratory/California Institute of Technology)

The recent top recommendation of the National Academies’ Exoplanets Science Strategy Report for NASA to commission a telescope capable of directly imaging exoplanets and conducting reflection spectroscopy opens up the possibility that a large aperture telescope may also be recommended by the 2020 Decadal Survey. While large apertures offer the possibility of greater exoplanets yield the current paradigm of folding large telescope into smaller fairings and deploying them from single launch vehicles also pose the risk of great cost and risk. An alternative to the current paradigm is a combination deployment and assembly in space where key elements of the telescope, its sunshade, and its instruments are architected as individual modules capable of being robotically assembled. Multiple, currently existing, medium-lift commercial launch vehicles would then be used to transport the modules to a space platform and orbit where the assembly and checkout would occur. This talk will present final report findings and recommendations of a NASA Astrophysics Division chartered study whose objective was to assess the cost and risk benefits, if any, of this new paradigm.

May 20, 2019

Title: Segmented Space Telescopes for the Search for Life: Key Findings from System-Level Segmented Space Telescope Studies

Speaker: Larry Dewell (Lockheed Martin Space) Presentation Slides

Achieving ultra-stability of large segmented optical systems with integrated coronagraphs, such as envisioned on NASA’s generation-after-next great space-based observatories, involves the integration of high-performance subsystems, including isolation, reaction-cancelling fast steering mirrors, wavefront sensing and control and segment relative position control, to name a few. This presents significant systems engineering and integrated design challenges, and a rigorous approach to system-level modeling is necessary to quantify the performance and assess compliance. In this talk, a comprehensive integrated model of a segmented optical space telescope is described, using the LUVOIR 15-meter architecture as a specific example, including optical sensitivities realistic disturbance sources. Predicted dynamic line-of-sight and wavefront errors during steady-state coronagraph science operations are presented, and preliminary results on the settling time of such errors after a repositioning slew maneuver is examined. With this modeling approach, the technical viability of this LUVOIR architecture is established versus the coronagraph instrument requirements, and important system design implications that were observed are enumerated that have application to other large telescope architectures under the Astro2020 purview.

Speaker: Laura Coyle (Ball Aerospace and Technologies Corp.) Presentation Slides

This presentation documents the key findings from the Ultra-Stable Large Telescope Research and Analysis (ULTRA) study. The contract was awarded to our industry team (Ball Aerospace, Harris Corp., Northrop Grumman Corp. Aerospace Systems, Northrop Grumman Corp. Innovation Systems, SGT and the Space Telescope Science Institute) through the NASA ROSES-17 solicitation, element D.15 – which calls for a one-year system-level engineering design and modeling study for a >10-m class UV/optical/IR segmented-aperture telescope with sub-nanometer wavefront stability.

This challenging stability requirement is driven by the science goal to directly image and characterize exo-Earths with a high contrast coronagraph. Two mission concepts requiring sub-nanometer stability are the Large UV/Optical/Infrared Surveyor (LUVOIR) and the Habitable Exoplanet Observatory (HabEx), both of which are under consideration by the 2020 Astrophysics Decadal Survey. This study augments the work completed by the LUVOIR and HabEx Science and Technology Definition Teams (STDTs) and their NASA center engineering teams by identifying and prioritizing key technologies for near-term development that will result in credible system architectures. While this study uses these mission concepts (especially LUVOIR) to perform specific assessments, the findings are applicable to similar architectures with comparable stability needs.

Our approach is a holistic systems architecture study treating the observatory, telescope and coronagraph as a complete system and considering the impacts of instability in both the temporal and spatial domains. It is guided via the formalism of error budgets, where sub-system allocations are compared to current capabilities, often including trade studies of potential technologies or approaches. Technology gaps are identified where current capabilities will not meet allocations and roadmaps are provided to prioritize and propose a path forward for development of the most urgent technologies.

April 11, 2019

Title: SISTER: Starshade Imaging Simulation Toolkit for Exoplanet Reconnaissance Presentation Slides

Speaker: Sergi Hildebrandt (JPL)

SISTER (Starshade Imaging Simulation Toolkit for Exoplanet Reconnaissance) is a versatile tool aimed at quantifying mission designs with starshade. SISTER allows one to control: (1) the starshade design in use, (2) the exoplanetary system, (3) the optical system (telescope) and (4) the detector characteristics (camera). The simulations may be stored on disk for data analysis, or plotted with its own plotting interface. SISTER is a live, open source project that will continue to grow and support current and future starshade studies

March 13, 2019

Title: S5: The Starshade Technology Development Activity

Speaker(s): Phil Willems (NASA ExEP; S5 Deputy Manager) Presentation Slides

In 2016, NASA decided to reorganize its starshade technology development from competitively funded grants into a centralized directed activity, with the goal of closing all starshade technology gaps by driving their core technologies to TRL5. In 2018 NASA’s Astrophysics Division approved the plan for this activity, which is called ‘S5’. We will present a summary of starshade technology, the plan to close the technology gaps, and recent results.

October 29, 2018

Title: Architecture for space-based exoplanet spectroscopy in the mid-infrared

Speaker: Joe Green (JPL) presentation slides

Characterizing exo-Earths at wavelength about 10 micron offers many benefits over visible coronagraphy. Apart from providing direct access to a number of significant bio-signatures, direct-imaging in the mid-infrared can provide 1000 times or more relaxation to contrast requirements while greatly shortening the time-scales over which the system must be stable. This in turn enables tremendous relief to optical manufacturing, control and stability tolerances bringing them in-line with current technology state of the art. In this talk, we explore a reference design that co-optimizes a large, segmented, linearized aperture telescope using one-dimensional phase-induced aperture apodization to provide high-contrast imaging for spectroscopic analysis. By rotating about a parent star, the chemical signatures of its planets are characterized while affording additional means for background suppression.

October 5, 2018

Title: Terrestrial exoplanet characterization enabled by quasi-random structured-pupil

Speaker: James Breckinridge (Caltech/University of Arizona) Slides

Here we introduce the concept of the structured telescope pupils whose unique diffraction pattern significantly reduces the non-uniform distribution of background radiation. Diffraction patterns from these pupils are compared to the monolithic filled aperture, the classical Cassegrain, the 60-degree symmetry of the hexagonal segments (JWST, E-ELT, etc.). Diffraction “spikes” are reduced by at least 105 . We discuss advantages to spectroscopy, image processing, and observatory operations. We assert that, segment fabrication, alignment and mounting of curved-sided mirrors is not more difficult than fabrication of the classic hexagonal mirror segments.

May 30, 2018

Title: Cost Drivers for Traditional Space Telescope Missions

Speakers: Keith Warfield (NASA/JPL) Slides and Phil Stahl (NASA/MSFC)

March 1, 2018

Title: Stability of Mid-Infrared Detectors for Future Space-based Transit Spectroscopy Measurements

Speaker: Craig McMurtry (Rochester) Presentation Slides

The future space missions that are designed to observe exo-planets using transit spectroscopy, e.g. OST (Origins Space Telescope), will require the detector arrays and their controllers to be stable to < 5 ppm. OST’s MISC (Mid-IR Imager, Spectrometer, Coronagraph) covers the mid-IR range 5 – 38 um. The current baseline includes Si:As and Si:Sb BIB detector arrays to cover the 5-38 um wavelength range. We suggest that long wave HgCdTe, which we have developed, is an attractive alternative for 5-15 um, while Si:As BIB detector arrays would cover out to 27um, and Si:Sb BIB detector arrays are the only alternative that works out to 38 um. We will discuss those three detector technologies and some development that may be needed to reach the required stability. Further, both the Read-Out Integrated Circuit (ROIC) and any associated data acquisition controllers may need to be redesigned for several reasons.

October 24, 2017

Title: Multi-Star Wavefront Control: A Method for Exoplanet Imaging in Multi-Star Systems​

Speaker: Ruslan Belikov (NASA/Ames) Presentation Slides

The technology to directly image exoplanets has been steadily advancing for more than a decade. It enables future space missions such as WFIRST, LUVOIR, and HabEx to directly image planets by reflected light and possibly find evidence of life on them. However, many prime multi-star systems are reluctantly omitted from the target lists of missions because mature starlight suppression technology for multi-star systems does not yet exist. Enabling the study of multi-star systems is very important because more than half of Sun-like stars belong to multi-star systems. This includes Alpha Centauri A and B, which would probably be the best target for any direct imaging mission (by a large margin), if it was not a binary.

This talk will cover the science motivation as well as the progress in technology development of Multi-Star Wavefront Control (MSWC), a method to directly image planets and disks in multi-star systems. This method works with almost any coronagraph (or external occulter with a DM) and requires little or no change to existing and mature hardware. Because of the ubiquity of multistar systems, this method potentially broadens the science yield of many missions and concepts such as WFIRST, Exo-C/S, HabEx, LUVOIR, and potentially enables the detection of Earth-like planets (if they exist) around our nearest neighbor star, Alpha Centauri, with a small and low-cost space telescope such as ACESat or Project Blue, in addition to the larger missions.

September 28, 2017

Title: GAIA design considerations and lessons learned

Speaker: Alessandro Atzei (ESA/ESTEC) Presentation Slides

This presentation will focus on the considerations that led to the GAIA design as well as the key lessons learned from the mission. The presentation will focus on the (system) engineering aspects.

Title: Flight Operations Experience on the GAIA mission

Speaker: David Milligan (ESA/ESOC) Presentation Slides

This presentation will focus on the mission operations experience gained in flying Gaia through the first years of the mission (covering the launch, LEOP, commissioning and Routine Ops phases).

September 5, 2017

Bendek TDEM pupil image
Title: High-Precision Imaging Astrometry: TDEM-13 milestone report and its application for future missions

Speaker: Eduardo Bendek (NASA/Ames) Presentation Slides

Measuring masses of long-period planets around F, G, K or brighter stars is necessary to characterize exoplanets and assess their habitability. Imaging stellar astrometry offers a unique opportunity to measure exoplanet masses. However, its accuracy is limited by the non-systematic dynamic distortions that arise from perturbations in the optical train. We have tested a novel approach to measure and calibrate field distortion potentially enabling better than 1µas imaging astrometry accuracy. In this talk, we will review the architecture, milestones, and performance of the simultaneous astrometry and high-contrast imaging laboratory built at NASA Ames Research Center as part of a TDEM program. We will also discuss the impact and benefits of applying this technology to future flagship exoplanet missions, such as HABEX, STEP, and Theia.

Title: Detector Metrology for Ultra Precise Astrometry on LUVOIR

Speaker: Mike Shao (JPL) Presentation Slides

Astrometry at the sub-micro-arcsec level can detect and Earth mass planets in the habitable zone around a large number of nearby FGK stars. Reducing and/or calibrating instrumental systematic errors is the key to achieving very high astrometric accuracy. There are two major sources of systematic error for astrometry with a large focal plane detector, one optical distortion the optics and the second is imperfections in the focal plane. This talk discusses the imperfections in the focal plane, how they can be calibrated both on the ground and in orbit. The metrology system is part of the LUVOIR high definition imager instrument concept and we'll summarize what the capabilities of such an instrument would be for exo-Earth detection.

May 11, 2017

Title: MEMS Deformable Mirrors for Astronomical Adaptive Optics

Speaker: Paul Bierden, Boston Micromachines Corporation

As the astronomical community continues its excitement about the progress being made toward the building of the high contrast imaging telescopes, technical development is ongoing for the components needed for these instruments. This presentation will show the progress that has been made by Boston Micromachines on the design and fabrication of micro-electromechanical (MEMS) deformable mirrors that will be needed for future scientific progress. Large actuator count, high yield, and stable deformable mirrors are being made for on-sky planet finding instruments as well as test beds where the next generation instruments are being developed. The challenges addressed in this design and fabrication and the results achieved will be presented as well as how this will translate to meet future needs. Also, presented will be the results from current instruments and test beds. Finally, future plans for mirror development will be presented.


April 11, 2017

Title: Colloidal Micro-Newton Thrusters for Precision Attitude Control

Colloid micronewton thrusters offer a precise, low-mass, low-vibration (0.1 µN thrust precision with ≤0.1 µN/rtHz thrust noise) solution for fine pointing of space observatories. These electric thrusters can meet pointing requirements of <0.1 milliarcseconds for Hubble-class telescopes, exceeding the state-of-the art for reaction wheels while using less mass and similar power levels. Vibrations induced by the thrusters have been shown to produce less than 4nm displacements for a 500 kg spacecraft. This technology has been advanced to a high level of readiness (TRL 7) through the Space Technology 7 Disturbance Reduction System (ST7-DRS) technology demonstration payload, which was part of LISA Pathfinder's test of precision, drag-free control for the future LISA gravitational wave observatory. Continuing technology development now focuses on validating thruster lifetime and improving reliability for a flagship class science mission.

Speaker: John Ziemer (JPL)


January 23, 2017

Title: Edge Sensors for Segmented Mirrors

Future astronomical telescopes in space will have architectures that must meet complex and demanding requirements in order to meet science goals. The missions now under consideration by NASA for imaging exoplanets and characterizing their atmospheres have technical challenges that are near or beyond the state of the art of telescope stability. This colloquium describes segment edge sensing and control technologies developed for ground based telescopes, and shows how they might be used to stabilize space telescopes to picometer-class wavefront errors.

Speakers: Scott Knight (Ball Aerospace) Presentation, Chris Shelton (JPL) Presentation

November 29, 2016

Title: Segmented Coronagraph Design and Analysis (SCDA) Study

Reaching high contrast ratios at close angular proximity to a star is an extremely challenging undertaking for a coronagraph with a filled-aperture telescope and is even more challenging with segmented, partially obscured apertures proposed for a large space-borne observatory. The primary goal of the ExEP-funded SCDA study is to identify coronagraph designs that maximize exo-Earth detectability with a variety of segmented apertures including hexagonal-segment and pie-wedge segment architectures. Both on-axis and off-axis designs are considered. The SCDA study is funding the design of pupil-plane, image-plane, and hybrid coronagraph designs. In this presentation, we discuss the progress in coronagraph designs and science yield performance since the study began in January 2016

Speakers: Stuart Shaklan (NASA-JPL) Presentation, Neil Zimmerman (STScI) Presentation, Garreth Ruane (CIT) Presentation, Olivier Guyon (UA) & Rus Belikov (NASA-ARC) Presentation