====== Telecon Notes 20171011 ====== Attendance: Shaul, Dave Chuss, Amy, Laura Fissel, Al, Julian, Lloyd, Nick Battaglia, Charles, Jamie\\ Notes by: Karl Young (UMN) === Agenda === * {{:private:forbudgetdiscussion.xlsx|budget for discussion}} * {{:private:ec_slides_20171011.pdf|Slides from Imager Group }} * {{:private:extragalactic_update_20171011.pdf|Slides from the Extragalactic Group}} * {{:private:galacticgroup_20170920.pdf|Slides from Galactic Group}} * {{:private:theory3.pdf|Fundamental Physics WG update}} (Raphael) === Notes === Budget update (Amy) * Line 7, E,F phase * includes cost + reserves * primary cost is science analysis manpower, during and post mission * other costs: mission ops, DSN tracking, navigation, data management, etc. * Current number is scaled from $40M in EPIC. Jamie suggests recalculate this. * 3 minute estimate by Shaul of $25M. Assuming 30 postdocs, ~5 yrs. Needs refining. * Balance of post-docs, senior scientists, NASA scientists greatly affects cost * Charles: 30 post-docs, 5 yrs is right idea. * Charles, Jamie: take examples from Planck and WMAP. final science costs were large. somewhat driven by organization framework in Planck's case. Could use US Planck contribution as a guide. * long time-frame drives large cost. * **A/I** Shaul to make effort estimate * Charles will give opinions and input. * current thoughts of 30 post-docs, 5-6 yrs, some senior folks, e.g. Julian, as well. * Al: can we break line 7 into science, ops, DSN, etc.? * Amy: majority in line 7 is science, ops < 20%. * Line 9 clarification. Reserves are 30% * Amy: can change to 25% as stated in NASA slides. 25% is aggressive. * Also, may want to aim for < $1B to give buffer for independent costing. * Shaul: do 25% as we've been told to. Leave decision of a buffer below $1B for NASA. They can tell all probe-classes to do this. * Line 14, Spacecraft $200M * currently modelling. Scaling from previous satellites. * typical that spacecraft is more than instrument * nothing is technically risky, but requirements drive costs. * power (1 kW instrument, ~2.5 kW total), data rates and telecom, spinning * CL: Planck was 1.8 kW total. 1 kw instrument. less margin in panels since no angle to sun. * CL: Planck spacecraft + ancillary (don't remember what besides launch ops) was $250M. Majority was spacecraft. * Line 17, thermal * being refined with thermal models * estimate of $70M from CORE with 50 cm focal plane. significantly large focal plane would raise this. * CL: 50 cm isn't enough focal plane to get to low frequency, 20GHz. * Jamie: 100 mK may be primary cost, more or less mass at 100 mK may make a smaller difference. * Amy: True, cost not linear with focal plane size, but does increase with increasing focal plane size. Smaller imager? (Shaul) * if imager + Spectrometer then smaller imager. Cost limited. * Not limited by mass, volume, power, data rate. (except that these add cost) * 50 cm design to evaluate cost and science trade-offs more clearly. * Amy: detailed costing of a point-design is more Team X task. Beyond scope of her group. * but confident that a CORE + PIXIE design is over budget. * CL: both imager and spectrometer are difficult, complicated science. Doing both in 1 limits the science in both. Would rather do 2 separate satellites. * Jamie: Can spacecraft costs drop? MidEx are proposing L2. * Amy: No. This system is bigger and class B. * Jamie: Can we assume future savings? Concerned about a marginal science case due to cost limits. * Shaul: Set a baseline for now. * Sensitivities for 50cm sent to science groups. They'll report in 1 week. * Assuming a 4 K 50 cm system. * Big, 3x, hit to resolution. * Jamie: Does this kill the science? (wait for WG inputs) * CL: S4 simulated complex synchrotron foregrounds. 15' beams at 20 GHz gave 5x improvement at l = few hundred. * 30' beams at 20, 30, 40 GHz did similar. * more parameter space to be explored. * Dave and Nick to present science trade-offs next week. Laura gone.