Meeting Minutes - OST STDT Bi-Weekly Telecon - January 26, 2018


Origins Space Telescope (OST)

Science Technology and Definition Team (STDT) Telecon


Purpose: To discuss science activities for OST.Facilitator/Host:Margaret Mexiner/Spitzer Science Center

Telecon: WebEx Online

Click here to join the meeting!

Meeting Number:

1-855-749-4750 (Toll Free)


Access Code: 194 170 917

Scribe:Sydney Jones

Discussion Topics 

1:30-1:45 PM OST Advocacy: Cara Battersby/Tiffany Kataria

  • Conferences 
    • Landscape of Space Astrophysics in the 2020 and 2030s, shooting for March 2019
    • Communications training would serve as a forum to discuss talking points, and provide an overview of communication strategies to improve communication.
    • List on wiki for upcoming conferences -  STDT members should add any conferences to this list 
    • Possibility of OST at Co-Star, Pasadena, CA, July 2018 or August 2018
  • White Papers
    • One or two papers per discipline? Submit it on a special issue? Timelines?
    • The National Academy of Sciences has put out a call for white papers to help develop an exoplanet science strategy.  Dave Charbonneau is co-chairing the committee, along with Scott Gaudi.  You can get more info at the following links:

    • Recent call for exoplanet science strategy white papers from National Academies of Science, very time critical. Will discuss coordinating white paper assignments at the next exoplanet call on Thursday,  See link to Exoplanets Working Group for exoplanet meeting minutes, and more information on white papers. 
    • STDT members are welcome to attend. 
    • Committee members haven't been announced yet. 
    • Kevin Stevenson will send out Google link for white paper committee information. 
    • STDT members should start thinking about details for white paper. 
  • Public news articles  
    • Spoke with forums and science magazine at AAS.
    • Focusing on major science article. 
    • Working with National Geographic Magazine 
    • Suggested spreading this out and aiming for Fall 2018 timeframe. 
    • Send suggestions for advocacy to Cara Battersby
  • Communications Training
    • Making people more knowledgeable of communication skills with giving advocacy talks and improving general STDT communication
    • Tiffany Kataria spoke with Alex Lockwood at StScI regarding communications training 

1:45-2:10 PM Science discussion - top level extragalactic theme and question (Alex Pope/Lee Armus) - Presentations for this discussion topic can be found here:

  • Feedback from reviewers found that science cases needed improvement, not focused enough on central themes and questions. 
  • Suggested using three questions only
  • Alexandra Pope and Lee Armus put together a brief document that has three questions (from NASA road map) (Margaret Meixner to send Sydney Jones document that includes three questions and answers). Discussed how to frame main science areas under three questions. Some people thought we shouldn't use NASAs questions. 
    • Are we alone? - Exoplanet biosignatures case 
    • How did we get here? - Trail of water mainly of disks 
    • How does the universe work? - How did our galaxy get here (black holes)
  • Alexandra Pope and Lee Armus feel that they should stick to questions and understand how OST can answer all these questions 
  • Road map failed in connection of questions to surveyor missions. 
    • Asantha Cooray added that STDT was putting too much info into the science questions and need to further define key drivers for mission design and requirements
    • David Leisawitz  the conversation of rule of three is being conflated with NASAs three sciences themes for astrophysics. Can have three key ideas for mission. These don't have to map to NASAs three science themes. Added that the rule of three is not necessarily NASAs three science themes, its OSTs questions
    • Alexandra Pope questions are out there. OST addresses all three questions, and should use these. Emphasized that we have broad science reach, but needed to sell it better.
    • Asantha Cooray added that we should think about extra-galactic case in mapping to observations.
    • Lee Armus have to map observations back to themes. 
    • Margaret Meixner need to write the report so things flow through. 
    • Margaret Meixner will share the link with everyone to the document for STDT to review and provide comments. Where will this be posted?
    • David Leisawitz it is more than document flow. The other part is defining main talking points to communicate the what OST can do. Need a better way of packaging what can be sold. David Leisawitz thinking this is overemphasizing NASAs science themes and not OSTs areas including . 

2:10-2:40 PM High-resolution spectroscopy ­ science requirements and instrument options (Klaus Pontoppidan/Matt Bradford) - Presentations for this discussion topic can be found here: Spectral_Resolution_H2O.pdf  and OSS_etalon_Jan2018.pdf

  • Slide three shows what the spectrum looks like. It shows a broad spectrum of where notches are removed due to ground water. 
    • The red curve shows sloth spectrum smooth to resolution of 11 km/second.
  • One case is looking at protostars of the interstellar medium and one looking at protoplanetary disks. 
  • What is it that drives resolving power of 140 thousands microns? 
    • The reference PP disk model @125 pc - water + HD shows all the water lines 
    • With MRSS you just barely get the width of the lines with no other information
  • Gary Melnick at 5 km per second the heterodyne is not emitted 
    • The point is anticipating modifications to the MRSS instrument
    • At 3 km/second the heterodyne is on the cusp of being useful
  • There is a another dimension to the problem that Maryvonne Gerin mentioned. Specifically regarding ability to resolve intrinsic line profile for three sets of continuum. (See slides for this)
    • In spectra where there is continuum...we see? 
    • Concept 1, letting HRS detect the water lines. These detections would alow us to see what heterodynes. 
    • Concept 2, if we marry capabilties of MRSS with HERO, we would count on the MRSS to tell us which disks have emissions to help us detect line profiles. 
      • If we have HERO then we wouldnt need a high-resolution spectrometer
  • Matt Bradford 
    • New name....Origins Survey Spectrometers (OSS) 
    • Presented interfrometer halves 
    • Increasing the R - Can try to bump up capability of FTS or expand it. Can get about a factor of 2 if we wanted. 
    • HRS proposed to use add a etalon in collimated beam at a position like this. (15-20 cm). Stll need FTS. 
      • Typically use mesh for etalon mirrors.
      • Achieving at a wide bandwidth is another issue. 
      • Can do HD and 179 micron 
    • What is our experience with TRL? ISO did have a fibre pero. Vibration isolation will occur anyways.
    • Fundamental limitations 
      • Ultimate divergence limit for Bcm beam 
      • Practical limit...
    • Conservative Sensitivity Comparison 
      • Should baseline the existing instantaneous sensitivity 

2:40-2:45 PM Spring face-to-face meeting - location and dates (Asantha Cooray)

  • Detector workshop at caltech in March 2018 
  • Lee Armus will organize this 
  • Asantha Cooray will talk to IPAAC about organizing this 
  • OST is invited to Lockheed Martin in Palo Alto

2:45-2:55 PM Study Center update (Dave Leisawitz/Ruth Carter)

  • Need one face-to-face meeting to resolve instrument suite May 30, 2018
  • Instrument suite decision must also be made by May 30, 2018
  • Detector road map is a white paper that will go in the report (Due by May 30)
  • Need to know what detectors will be used 

2:45-2:55 PM Study Center update (Dave Leisawitz/Ruth Carter)

  • Concept 2, heritage with greatly reduced complexity 
  • Same collecting areas as JWST
  • Minimize number of deployments necessary 
  • Taking advantage of existense of launch vehicles with larger faring
  • Launch vehicles have demonstrable lift capacity than we need
  • Concept 1 cost? Will not be doing this and will not put in the interim report. Lot of effort that went into this and would like to have some follow through, to understand trades for Conept 2. 

Action Items

#Action ItemOwner Due Date
1Type up calculations for white paper.AudreyTBD
2Look at sensitivity and ask questions and reasess Johannes Staguhn's question.Klaus PontoppidanTBD
3Sending out doodle poll for when to hold detector road map meeting.

Johannes Staguhn

Margaret Meixner

4Send the slides with three science questions to Sydney Jones for others to access.Margaret MeixnerTBD