sofia engineering meeting - 12may2011.ppt · – increased sensitivity of sis over heb really...

SOFIA ProposalEngineering Meeting 12-May-2011

CDLU d t i l t tiUpdates since last meeting

• Two science teleconferences held– Astronomers involved include Al Wooten, Todd Hunter, Yancy

Shirley, Tony Remijan, Ted Bergin, Gary Melnick, Bryan Butler, and Mark Gurwell

– Increased sensitivity of SIS over HEB really really wanted– Need to have at least order-of-magnitude improvement over GREAT

without sacrificing frequency agilityg q y g y• Since we can’t yet get this improvement in sensitivity, get it in

mapping speed with more pixels

2SOFIA Proposal Engineering Meeting 12-May-2011

CDLU d t i l t tiUpdates since last meeting

• Expanded science case– SOFIA is an observatory, not a mission– Given constraints of airplane, flight plans, etc., need to observe

multiple targets each flight to maximize relatively small observing time p g g y g(only 1000 hours per year in full opertations)

• Al working on sensitivity calculator for SOFIA with 1000K and 300K DSB noise temperaturep

• Met with Ed Tong from SAO who has been working with HEB mixers– 0.5 K/GHz is current state-of-the-art for HEB mixers

• Gives 700K for 1 4 THz plus allowances for optics etc 1000K is • Gives 700K for 1.4 THz, plus allowances for optics, etc., 1000K is reasonable spec for 1.2-1.5 THz


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CDLSOFIA Completes First Flight of GREAT p gApril 7, 2011

SOFIA Proposal Engineering Meeting 12-May-2011 7

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CDLCurrent Strawman Specs for NRAO pInstrument• Facility Instrument• 8 pixels balanced HEB• Single-polarization• 1218-1492 GHz1218-1492 GHz• 1.5-3.0 GHz 1st IF• 1000K DSB

S• Spectrometer– 1.5 GHz, 2048 channels (732 kHz resolution) with 187.5 MHz zoom

mode (92 kHz resolution)• At 1.4 THz, 300 km/s range with 18 m/s resolution in zoom mode

• SIS is an upgrade path


CDLSOFIA C ll f P lSOFIA Call for Proposals

• Scheduled to be released June 30• Final proposal then due Sept 30• $35M spread over FY12-FY18

– One investigation to begin mid-FY12 additional investigations to begin One investigation to begin mid-FY12, additional investigations to begin one year later

• One new instrument commissioned per year starting FY15


CDLS i I t t S tScience Instrument System

• SI assembly (cryostat, optics, electronics) mounted at the instrument flange of the Telescope Assembly

• “Counterweight Rack” mounted on Telescope Assembly which can be populated with SI equipment. 19-inch rack frame provided by NASA

• Up to three “PI Racks” of SI equipment installed over center wing section of main deck. Dual-bay, short, 19-inch rack frames provided by NASA

• Chopper interface electronics (optional) to drive Telescope Assembly pp ( p ) p ysecondary mirror chopper

• SI Installation Cart to transport the SI through ground facility, onto aircraft, and install on Telescope Assembly instrument flange, p y g

• Any lab stands or ground support equipment required for routine maintenance of instrument


CDLNASA F i h d E i tNASA Furnished Equipment

• PI rack(s)• PI rack installation dolly• Counterweight rack• Counterweight rack installation cartCounterweight rack installation cart• Lab space at DAOF for integration activities• Lab technicians and supplies to support integration


CDLT i t i i t i thi f SITopics pertaining to airworthiness of SI

• Anything that can cause injury to personnel• Anything that can cause a fire• Commands by one system to others that result in hazardous conditions• Systems that monitor provide warning of or prevent hazardous Systems that monitor, provide warning of, or prevent hazardous

conditions• Anything that affects the aircraft pressure boundaries• Foreign Object Damage and equipment security• Foreign Object Damage and equipment security• Pressure systems• Cryogens• Toxic substances• Radiation, both ionizing and non-ionizing


CDLI t t I t f O ti lInstrument Interfaces - Optical

• SOFIA telescope is a two mirror bent Cassegrain with single Nasmyth instrument mount fed by a flat tertiary

• Effective aperture is 2.5m and provides f/19.5 beam to instruments• Secondary mirror provides p-p chop amplitude of 10’ between 0-20 Hzy p p p p p

– Secondary mirror chopper triggered from TTL waveform from SI• Dichroic tertiary for optical imaging and guiding cameras• No window installed in optical path i e the SI is the pressure barrier to • No window installed in optical path, i.e. the SI is the pressure barrier to

the main cabin


CDLI t t I t f El t i lInstrument Interfaces - Electrical

• Connections to SI include power, LAN, GPS, and IRIG-B timing– Provided at PI patch panel near PI racks

• PI racks and telescope assembly separated by ~25 feet• SOFIA provides cables from PI patch panel to Telescope Assembly (TA) SOFIA provides cables from PI patch panel to Telescope Assembly (TA)

patch panel routed under the cabin deck• SI and counterweight rack connect to TA patch panel• Currently a total of 5 KVA available for SI use• Currently a total of 5 KVA available for SI use• Intent is to provide up to 15 KVA for new instruments


CDLI t t I t f S ftInstrument Interfaces - Software

• Observatory is controlled by the Mission Command and Control System (MCCS) which coordinates the aircraft, telescope, and science instrument (SI)

• SI issues commands to the observatory via the SOFIA Command Language (SCL), which are then executed by the MCCS

• MCCS provides housekeeping data to SI for reducing data and populating FITS headers

• SOFIA Data Cycle System (DCS) provides long-term archival and retrieval functions for raw and reduced SI data (data stored in FITS files)


CDLCommissioning and Guaranteed gObserving• Proposers shall estimate number of flight hours needed for commissioning• In addition, PI is granted 50 hours of guaranteed observing time


CDLProposal Requirementsp q• Scientific/Technical Investigation (20 page limit)

– Overview– Scientific Goals and Objectives– Investigation Requirements

• Must include “Traceability Matrix” describing required “objectives-Must include Traceability Matrix describing required objectivesto-measurement-to-mission traceability”

– Measurement Data and Other Investigation ProductsDescope Options– Descope Options


CDLP l R i tProposal Requirements

• Scientific/Technical Investigation continued…– Implementation: Instrumentation

• Preliminary description with a block diagram showing interfaces, along with description of estimated performanceg p p

• All enabling technologies required to be at TRL 6 or higher– TRL 6: “System/subsystem model or prototype demonstration

in a relevant environment”in a relevant environment• Data analysis and archiving• Science/Technology Team



• Investigation Implementation (20 page limit)– Heritage and maturity of mission elements– Reliability measures (use of redundancy, etc.)– Instrument assembly testing and calibrationInstrument assembly, testing, and calibration– Technology Development (discouraged)

• Plan for bringing identified items to TRL 6P d A– Product Assurance

– Risk Identification and Mitigation– Identification of instrument to aircraft interfaces



• Investigation Implementation continued…– Management and Schedule– Cost and Estimating Methodology

• Highly encouraged to provide the following (not counted against Highly encouraged to provide the following (not counted against page limit)

– MELWBS– WBS

– WBS Dictionary– WBS Cost Table– Basis of Estimate Details



• EPO Plan not needed (SOFIA provides)• Appendices

– Letter(s) of Commitment– SOWsSOWs– Resumes– Heritage

R f– References


CDLI t t D i O tiInstrument Design - Optics

• Need to couple 8 beams from feedhorn to Telescope Assembly optics• Baseline is waveguide balanced mixer, fallback is single-ended mixer with

LO beamsplitter• For proposal, want preliminary design with Inventor drawingsp p , p y g g


CDLI t t D i MiInstrument Design - Mixer

• HEB Mixers– NbN p-HEB fabricated at UVA– Edward Tong (SAO) is lead on this

• NTC shop to fabricate prototype mixer block of E Tong’s design this NTC shop to fabricate prototype mixer block of E. Tong s design this summer

• E. Tong already has some HEB mixer chips (quartz) • Will perform noise measurement at SAO this summer with results in • Will perform noise measurement at SAO this summer, with results in

time for proposal• HEB then will be redesigned on SOI, first single-ended then balanced

I d F dh /M /LNA• Integrated Feedhorn/Mixer/LNA• Integrate 4 or 8 pixels into single block?


CDLI t t D i L l O ill tInstrument Design – Local Oscillator

• ALMA Front End LO Design, using YIG-tuned oscillator with x3 AMC and PA

• MMICs in PA block will use GaN rather than GaAs– W-band GaN MMICs available from HRL or QuinstarQ– Trying for demonstration this summer

• Use VDI x2-x3-x3 frequency multipliers with 67.8-82.8 GHz driver (same as ALMA LO Band 4/8/9)as ALMA LO Band 4/8/9)

• >10 W over full band (enough for balanced SIS or single-ended HEB with coupler/beamsplitter)


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CDLI t t D i IFInstrument Design - IF

• 1.5-3.0 GHz IF• No isolator, use either SiGe HBT or balanced HFET cold LNA• Recently delivered HBTs from ST wafer give Tmin of 1K at 4 GHz

– Matt Morgan has 1 7-2 6 GHz LNA design using these devicesMatt Morgan has 1.7-2.6 GHz LNA design using these devices• Results from this LNA can be used in proposal


CDLInstrument Design – Digitization & g gSpectrometer• 1.5 GHz is current capability of CASPER hardware• Digitize in second Nyquist zone• Capitalize on GUPPI and new GBT spectrometer experience• Can also use “off-the-shelf” spectrometer from RPG or Omnisys as Can also use off-the-shelf spectrometer from RPG or Omnisys as

benchmark for costing and power consumption• Rich Lacasse working on this


CDLC i d M h i l D iCryogenics and Mechanical Design

• Current instruments (GREAT and CASIMIR) use liquid He filled Dewars• Increase from 5 KVA to 15 KVA allows use of Sumitomo refrigerator• “The design and operations of SOFIA Science Instruments shall permit

installation on the SOFIA aircraft, optical alignment, cryogenic servicing , p g , y g gand cold functional check-out of Science Instruments within an 8 hour period.”– Therefore, receiver must be cold before moving onto plane and , g p

installation• For proposal, need some initial drawings, calculations, and cost estimates

for design and airworthiness qualificationg q


CDLS ft & D t Pi liSoftware & Data Pipeline

• Help!• For proposal, need plan and cost estimates


CDLC lib tiCalibration

• Help!• “SOFIA Science Instrument astronomical data shall be flux calibratable to

within 20% RMS.”


CDLN t tNext steps

• Preliminary costing• Sensitivity calculator for next Science meeting• Awaiting release of “Science Instrument Developers Handbook”


sofia engineering meeting - 12may2011.ppt · – increased sensitivity of sis over heb really...

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