|Subject:||OST STDT Bi-Weekly Telecon||Date:||10/6/2017|
|Purpose:||To discuss science activities for OST.||Facilitator:||Margaret Mexiner |
Telecon: WebEx Online
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|Note Taker:||Sydney Jones|
Mission Concept 1 Mission Design Lab (MDL) Results - Ruth Carter/Dave Leisawitz
- See PowerPoint presentation for Concept 1 study status.
- MEV acronym stands for Maximum Expected Volume (volume of contingency)
- Important Things
- Writing interim report and preparing for Concept 2 study
- October is dedicated to preparing for descope concepts for Concept 2.
- Slew and settle time question - Melnick added that configuration looks top heavy relative to space craft bus. What is the slew and settle time?
- See response below provided by David Leisawitz (including follow up message from Anel Flores (Unlicensed)) in follow up to Gary Melnick's question regarding slew and settle time:
- "In response to Gary’s question regarding slew and settle time, the “minute or so” David Leisawitz mentioned was in reference to the settle time. Thanks to a followup message from Anel Flores (Unlicensed), we know that the slew time is about 21 minutes for a 30-degree re-targeting slew, and the slew rate is about 60 arcsec/second in Survey Mode."
- Stoneking has analyzed this
- Leisawitz mentioned that it may be a minute or so
- Slew should be relatively as fast as James Webb Space Telescope (JWST)
- Florez added that the mass ratio is about 10% or .01
- Launch Readiness Review (LRR) date needs to be changed to another date.
- The sunshade layers are all parallel.
- Slide 13 includes the multi layer sun-shield.
- The structure was made off of aluminum and needs to be light weighted. Needed material that could meet thermal requirements and that was also less expensive.
- Mass breakdown for 29 kilos? (6th face-to-face (F2F) had 8K kilograms, this would be right for production).
- The point of the report is to do a concept design. Explain proof of principle in the report (David Leisawitz added that this applies to both interim and final reports. The idea is that we don’t have the study resources to develop optimized mission designs. They are, instead, “proof of concept” designs intended to show that something could be done, in principle)
- We have reached the end of the study for Concept 1.
- Cost is based on the MEL.
Mission Concept 2: Telescope Diameter Exercise Results and Discussion – Margaret Mexiner
- Question asked that given an instrument, look at what science can do with a 3.5 and 5 meter telescope and decide whether you can convince your team of this
- Still Waiting For
- Rise of metals write up will be sent in by next week (10/9/2017) and first dust.
- 5 meters is still interesting and 3.5 meters is marginal and not as interesting.
- Rise of metals and first dusts will use the same program, will be a blind case. ACTION: Need to determine luminosity functions/simulations and survey depth for telescope diameters.
- Should be able to calculate number of luminosity functions with each of the air bars. Rise of metal has five ten to the minus three, the pH functions are one ten to the minus two.
- Joaquin Vieira and Matt Bradford will discuss simulations for this off line.
- Rise of metals is different from first dusts.
- Water content was sent in. Think that water content case is a highly compelling case, 3.5 meters is interesting.
- Having 1000 hours for each one means that we need to put the 15000 hours together.
- Confusion for this arose when we moved into the theme based. This will fall out of the survey. First dust and H2 is red shift.
- Need to work through how many sources we will get from Alexandra Pope
- Can do a lot with a 5 meter, 3 meter may not allow for much. Cost at red shift with a 9 meter, but might be able to do one.
- There is a preference and there is something to think about (in terms of red shifts) should have a discussion on what we think is sellable vs. what is not sell able.
- May find that it is okay to go over $3B.
- Survey of smaller bodies... - Interesting
- Not probing smaller bodies (population telescopes is the advantage)
- Using smaller field of view
- Appropriately scaled for the instrument
- Water transport...- Not a huge difference in science return. Can do mapping in the same amount of time regardless of diameter
- There is still trans-formative science to do with lower water lines
- Trans-formative theory without regards to SPICA
- Important to understand the difference in what Herschel and SPICA can do
- Direct detection with MRSS can detect fewer sources
- Mapping of most applications is listed in the killer app
- Killer app was all things water and was divided, there are still some boundaries
- Should coordinate to see where things are different - Klaus Pontoppidan and Karin Sandstrom will discuss this off line.
- Kuiper Belt Analogues
- Incremental targets are not worth it especially if SPICA flys
- Ozone alone is not tracing life
- Verify that anything below 5 meters may not be compelling
- Compared to these features they are really weak, afraid that they are not possible
- Any detection of bio-signatures would be trans-formative (arguing for something like 12 which can be received with 5 meters)
- ACTION: Margaret Meixner to follow up with whomever is responsible for writing the bio-signatures proposal/case.
- It gets confusing when it gets to parts per million and wavelength bands. Can we sell the idea of observing transits?
- Need to engage the bio-signature group more, the number of targets relates to best estimate we have now. Think carefully about how we will incorporate the expectation for targets of the future mission
- How many objects to look at to get something interesting could possibly be ten target systems. They are not common, seeing one or two would be exciting. 10 seems adequate.
- If we don't find bio-signatures, anything that comes out of this becomes interesting
- It is important to add in the report and discuss different size apertures, we may not get signatures, can do other studies.
Science figures & Writing for interim report – Asantha Cooray
- Mexiner checked in with those assigned to writing sections for the interim report
- Have grafic figures for tracebility of habitaible figures (Pope submitted hers)
- Section has been broken up into a number of topics. Discussed a figure that is comparable to the water figure, still want to iterate on this. Will tag up with these folks in the next week or so.
- Could there be some figure with debree disks. Could show debree disks in the Far-Infra Red - ACTION: Kate Su will see if she can work on this
- Redundancy is one way to look at it
- Interim Report Concept 1
- Planet 9 may be found (by the time flagships fly). Cannot image it but may be able to characterize it
- Groups of people think it is still out there and some still think its skeptical
- If an object is found in the solar system like planet 9, we should be able to characterize it
- Interim Report Writing
- MISC instrument
- Europeans still working and hope to send their draft around for comments, FIP and HRSS are doing the same.
- Mexiner appreciates the time being spend on the report.
- Exoplanet group and biosignatures science figures
- Exoplanet case falls under the theme of habitability
- Make a comparison between JWST, MIRI and OST MISC.
- Galaxy Evolution
- Sent graphic like WMAP image, showing hubble
- Mexiner thought it was a great graphic
- ACTION: David Leisawitz sending email to Jay to follow up on this.
AAS Plans – Desika Narayan
- Abstract deadline of 10/3/2017 has passed
- Have a wiki page for this conisting of mostly notes thus far
- Currently Planned Activities
- Poster session
- Large number of posters submitted (12 or so)
- Special session on exoplanet charcterization throgh emission spectroscapy
- Special session on decadal studies
- Had conversation with team (tentative SIG scehdule)
- OST is not flagship for SIG session
- 25 minute OST Talk
- May contact these people to talk about science in the conext of OST
- Table at NASA booth for all decadal studies
- Hyperwall talks, one of the slots will be shared with the decadal program
- Could have three of our own plus the fourth one
- should we reuse these hypertalks or do new ones?
- They take a lot of time to make, should probably reuse these
- They are a lot of work to do, might see twelve to eighteen people just sitting around and not actually paying attention to hyperwall talks
- The location for last years was offset near the core table offset in a random location
- One way to potentially enhance this is to record the talks, talked a little bit with NASA, our time is better spent doing other things. We could be asked if they could give us unified slides, but it would take a significant amount of work.
- Suggested setting up a video camera and put these on the website. ACTION: Desika Narayanan to check with Kartik Sheth or Dave Freelander on this.
- Prospective time/date for AAS are Wenesday morning or Tuesday or Wednesday afternoon? What is the date?. Reuqest to them was that the FAR SIG was fine to meet tuesday or wednesday afternoon (whcihever one is chosen for SIG should be the oposite day). Plan is to be a half day to discuss issues that have arosen.
|No.||Action Item(s)||Owner||Target Due Date||Status (In progress/Completed)|
|1.||Follow up with whomever is responsible for writing the bio-signatures proposal/case on status.||10/19/2017|
|2.||Work on figure with debree disks, showing debree disks in the Far-Infra Red.||10/19/2017|
|3.||Send email to Jay to follow up on galaxy evolution graphic. ||David Leisawitz||10/19/2017|