Opening Remarks Tammy Brown Feb 13, 2012

1. X-Ray Calorimeter ~ Concept Presentation ~ Opening Remarks Tammy Brown Feb 13, 2012

2. Presentation Agenda

3. General Reminders • The concept presentations presented on Friday, Feb 17 were still a work in progress • Mass results werepreliminary, and are expected to grow as the model is finalized • We have identified small discrepancies and worked to correct them or note them in the final report • Cost results will be available NET Friday, March 9 • Costing starts when the mass model is complete, and are available approximately 10-12 business days following the study • The final report is provided following the cost presentation

4. IDL Products List • Systems summary of changes implemented, trades considered, and future recommendations • Notional instrument block diagram • Point Design Summary (PDS) spreadsheet to summarize final instrument configuration • Detector assessment • Cryo design • ADR design • Mechanism definition • Mechanical model • Thermal model • Electrical architecture & flight software approach • Reliability assessment • Micrometeorite assessment • Mass model (a.k.a. master equipment list (MEL)) • Parametric cost product We have produced a single baseline configuration for costing Alternative recommendations have been documented in subsystem presentations Instrument-Specific Conceptual DesignConsistently Represented Across All Subsystems

5. Scope of Work (1 of 7) • Updated the 2008 IDL design for a 3 year lifetime at L2 • We presented an approach to meet a healthy mission level reliability by setting a goal of 90% reliability for the instrument, and used that to establish the instrument redundancy we implemented in our baseline • Our baseline design considers redundancy in the cryocooler electronics, redundant releases on the vent doors, redundant motor windings and electronic drivers, as well as some power supplies, and recognizes the inherent redundancy in the FPA and FEE electronics • We have produced a reliability assessment for multiple reliability cases, and made a recommendation for the best use of selective redundancy for a 3 year mission • We have revised the instrument description of operational modes, although at a lower fidelity than what has been done in the past, and we have confirmed that there are relatively few operational impacts to the instrument in an L2 orbit • Revamped the 2008 IDL design for a single instrument • We actually started with the mechanical model of the ASTRO-H ADR and built outwards, so we didn’t need to take specific action to modify the 2008 model • We built our electrical architecture from scratch, so it also didn’t consider the translation platform functions that were in the 2008 design • We also started with a fresh MEL to ensure that we had authentic 2012 input

6. Scope of Work (2 of 7) • Repackaged the dewar for a smaller ADR, fewer detectors, and 4.5k operation of SQUID amplifiers • We actually started with the mechanical model of the ASTRO-H 3-stage ADR • The 3-stage ADR built in-house for ASTRO-H will need to be slightly modified for this instrument, but we’re notionally showing the same mass and volume • We referred to the Athena proposal’s dimensions for the Focal Plane Assembly, and we incorporated ASTRO-H’s mechanical design of the aperture cylinder • We redesigned the dewar to make it as short and narrow as possible to save mass and cost • What we have shown needs to be evaluated for ease of assembly (can it physically be assembled with these size gaps between the shells) as well as for thermal performance (a cryo-specific thermal model will be necessary to confirm the parasite heat losses with this mechanical design) • Again, we referred to the Athena proposal for the FPA power dissipation estimates to assess the feasibility of the 3-stage ADR in cooling the FPA and associated SQUID electronics at the 50mk and 4-4.5k stages • We scaled the mass of the dewar internal support structures from the ASTRO-H design • We have generated a more accurate hierarchy of the cryostat that reflects the intended integration philosophy

7. Scope of Work (3 of 7) • Updated the mechanical layout of the dewar • We notionally represented the filter wheel assembly that was provided by SRON for ASTRO-H as that specific heritage design cannot be proposed for this version • While the filter wheel has likely heritage references at Goddard that can be readily modified for this application, the housing holds the x-ray calibration sources that we did not find commercial or parametric references for yet • The x-ray sources require close proximity high voltage power supplies, which we also haven’t found costable references for yet • We are currently able to parametrically cost the electro-mechanical assembly • We considered the relative placement of the dewar and the filter wheel assembly to the instrument mounting deck for the smallest size filters and filter wheel • We referred to the mechanical profile of the SRON filter wheel, which appeared to be as high as 12” above the x-ray calibration source assembly where the 2 x-ray sources seem to be integrated • The combination of the 7” clearance to open up the top door and the 12” profile height of the filter wheel assembly would have required moving the dewar further way from the instrument deck and subsequently enlarging the filters in the filter wheel and the ones in the aperture assembly within the dewar • We mounted the filter wheel on the other side of the instrument deck (flipping the orientation) • We scaled the external mounting struts to the dewar

8. Scope of Work (4 of 7) • Updated the mechanical layout of the dewar (continued) • We included 2 doors to the dewar, as was implemented on ASTRO-H (the primary one on the top, and a contingency one on the side), notionally representing them from the Japanese design on ASTRO-H • The combination of the 7” clearance to open up the top door and the 12” profile height of the filter wheel assembly would have required moving the dewar further way from the instrument deck and subsequently enlarging the filters in the filter wheel and the ones in the aperture assembly within the dewar • Notionally represented a generic American design for the cyrocooler and electronics • We have shown a reasonable volume for the cryryocooler and control electronics in our mechanical model • Our mass model captures the mass estimate from the averaged RFI responses • We are somewhat concerned that the RFI did not describe sufficient details about the temperate stability requirements, and that the responders did not show margin in their performance curves – there is a concern that the cost doesn’t reflect the performance and margin that would be required for flight

9. Scope of Work (5 of 7) • Considered a more cost effective electrical architecture • We combined into a single Main Electronics Box (MEB) all the electrical functions we thought could be commercially purchased from vendors experienced at delivering flight qualified electronics to minimize cost, schedule and risk • These vendors are experienced at delivering entire integrated electrical boxes including the chassis and internal harnesses between the boards • There is modest software control of the instrument in the MEB single board computer (SBC) that we will cost parametrically • We assumed that the stepper motor filter wheel control could be realized in this way, but we kept the high voltage power supply for the x-ray calibration sources on the top of the filter wheel structure, as they need to be in close proximity to the sources • We reviewed the customer’s references for the electrical architectures for the custom Front End Electronics (FEE), Digital Electronics (DE), and Event Processing (EP) functions • We have proposed a specific hardware approach for the FEE/DE/EP that we can parametrically cost for the hardware and software, and we have a grassroots scheme for costing the FPGA firmware • These vendors are experienced at delivering entire integrated electrical boxes including the chassis and internal harnesses between the boards • Updated the detector readout scheme for fewer pixels, but with the addition of a central Point Source Array (PSA)

10. Scope of Work (6 of 7) • We developed an in-house grassroots cost estimate for the focal plane assembly (FPA), but we used the more conservative, detailed estimate derived by S. Bandler/662 and J. Chervenak/553 in the instrument-level cost estimate • The in-house grassroots estimate is documented in the detectors presentation, and only speaks to case #1 that was requested • The more conservative estimate assumes GSFC and NIST labor, and a schedule that varies slightly from the proposed schedule developed by S. Seipel/158 (XMS_Schedule Feb2_2012.pdf) for the milestones following CDR • This might impact the labor rate estimate, as a longer instrument development schedule was assumed • Requested FPA estimates: • Bandler estimate • IDL estimate (Kotecki/Chervenak) • IDL • B • For baseline design, estimate the cost to fabricate the detectors as shown with1060 total TESs and integrate into focal plane assembly (FPA) assuming all components are ≥TRL-6 • This is the preferred architecture for science, but it presents an integration challenge • Provide an estimate to mature the current state of technology to TRL-6 • This estimate may only be related to the integration of the detectors from two different wafers, and not the fabrication of the individual detectors themselves if that is already at TRL-6 • This estimate is not related to the readout chain, which will be estimated parametrically • Provide an estimate to integrate the FPA for a different option that does not include the PSA • This option is only for the integration effort of 200 outer Hydra TESs & 800 TESs in a central row • IDL • B • IDL • B

11. Scope of Work (7 of 7) • Reviewed the function of the filter wheel mechanism to include an aperture function as well as a diffuser element • Estimated the probability of orbital debris at L2 • We will provide a mass model that considers all hardware components at TRL 6 or higher, but documents required advancements in current state of the art • The outcome of this study will be a written report by the customer team t to recommend a future x-ray mission capability for 2015 where the required technology development is assumed to be covered elsewhere • However, in each subsystem report we are expected to document recommended approaches and concerns about maturing the current state of the technology to TRL -6 levels, or where TRL can’t be assumed at the assembly level even if all the components are ≥TRL-6 (e.g. cryostat)

12. Time Permitting: Add’l Actions We were not able to address any of these actions during the study close-out process • Discuss the possibility of using ASICs to readout the detector • Consider an electrical architecture where the instrument control unit (ICU) is a S/C provided function • The electrical architecture we’ve proposed includes very modest flight software control within a very modest commercial single board computer, and may present the least costly approach to keeping this control within the instrument • Provide an estimate of the relationship between cost and the number of read-out columns in the FPA • Consider feasibility of incorporating a FET-based anti-coincident detector instead of TES

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14. IDL Team • Cryo – Peter Shirron, Paul Whitehouse, & Mike Dipirro • Detectors – Carl Kotecki & Jay Chervenak (remote) • Electrical – Terry Smith & Paul Earle • Flight Software – Kequan Luu • Mechanical Designer – Dave Palace • Mechanical Systems – Dave Robinson • Mechanisms – Pat Jordan • Micrometeorite Assessment – Ivonne Rodriguez • Optical Systems – Peter Hill • Parametric Costing* - Sharon Seipel & Sanjay Verma • Reliability – Aron Brall • Structural Analysis* - Ryan Simmons • Systems – Brian Ottens & Martha Chu • Team Lead – Tammy Brown • Thermal – Mike Choi • Facilitators & IT Support – Carlos Dutan, Dawn Cathers & Henry Cao • Spacecube Consultant: Tom Flatley/587 • Calibration Source Consultant: TimoSaha/551 New to the IDL *these results will be presented at a later date as this analysis does not begin until the week following your study