BARREL FUNCTIONAL / PERFORMANCE REQUIREMENTS DOCUMENT

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1 BARREL Functional / Performance Requirements Document BARREL FPRD-101-A BALLOON ARRAY FOR RBSP RELATIVISTIC ELECTRON LOSSES (BARREL) BARREL FUNCTIONAL / PERFORMANCE REQUIREMENTS DOCUMENT Revision: A Effective Date: March 10, 2011 National Aeronautics and Space Administration PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

2 BARREL Functional / Performance Requirements Document BARREL FPRD-101A Page 2 of 34 Prepared By: BARREL FUNCTIONAL / PERFORMANCE REQUIREMENTS March 7, 2011 David McGaw, BARREL Systems Engineer Date Approval: March 9, 2011 Robyn Millan, Dartmouth College, Principal Investigator Date Concurrence: March 10, 2011 Michael McCarthy, University of Washington, Co-Investigator Date March 7, 2011 David Smith, U. C. Santa Cruz, Co-Investigator Date March 9, 2011 John Sample, U. C. Berkeley, Power PDL Date PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

3 BARREL Functional / Performance Requirements Document BARREL FPRD-101A Page 3 of 34 CHANGE HISTORY LOG Revision Change Description / Pages Effected Date Approval - Draft RMM 9/2008 NA A Removed the following requirements SYS-38: a 2 minute real-time data storage capability for the DPU (hardware) SYS-39: ability to play back stored data (software) MIS-19: Changed 100,000 ft to 90,000 ft SYS-41: Changed wording 3/2011 PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

4 BARREL Functional / Performance Requirements Document BARREL FPRD-101A Page 4 of 34 Table of Contents 1. INTRODUCTION PURPOSE SCIENCE DEFINITION BASELINE SCIENCE OBJECTIVES APPLICABLE DOCUMENTS DEFINITIONS ACRONYMS REQUIREMENTS FLOWDOWN PROJECT REQUIREMENTS SCIENCE REQUIREMENTS (SCI-#) PROGRAMMATIC REQUIREMENTS (PRO-#) FUNCTIONAL REQUIREMENTS MISSION REQUIREMENTS (M-#) MISSION DESIGN PLATFORM OPERATIONS INSTRUMENT REQUIREMENTS (INS-#) X-RAY INSTRUMENT MAGNETOMETER SYSTEM REQUIREMENTS (SYS-#) MECHANICAL SENSORS DATA PROCESSING TELEMETRY POWER THERMAL CONTROL ELECTRICAL AND DATA HARNESSING INTEGRATION AND TEST GROUND SEGMENT REQUIREMENTS (GND-#) MISSION CONTROL SCIENCE OPERATIONS AND DATA ARCHIVING PERFORMANCE REQUIREMENTS PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

5 BARREL Functional / Performance Requirements Document BARREL FPRD-101A Page 5 of MISSION REQUIREMENTS MISSION DESIGN PLATFORM OPERATIONS INSTRUMENT REQUIREMENTS X-RAY INSTRUMENT MAGNETOMETER SYSTEM REQUIREMENTS MECHANICAL SENSORS DATA PROCESSING TELEMETRY POWER THERMAL CONTROL ELECTRICAL AND DATA HARNESSING INTEGRATION AND TEST GROUND SEGMENT REQUIREMENTS (GND-#) MISSION CONTROL SCIENCE OPERATIONS AND DATA ARCHIVING PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

6 BARREL Functional / Performance Requirements Document BARREL FPRD-101 Page 6 of INTRODUCTION 1.1 Purpose This document establishes the BARREL functional and performance requirements to ensure that the BARREL project achieves its scientific objectives. The purpose of this document is to Address functional, performance, and operational requirements Ensure that all requirements necessary for the success of the mission(s) are identified early in the project life cycle Provide a systematic basis for tracking flow-down requirements Provide an authoritative and controlled repository of the project s requirements The requirements table lists all the BARREL Project Requirements, Functional Requirements and Performance Requirements. Project Requirements are the drivers for the Functional Requirements. Functional Requirements include functions that must occur throughout the life cycle of the mission and what must be done to achieve the next-higher-goals. The system(s) developed are valid only if they satisfactorily perform these functions. Performance Requirements collate each requirement identified in the functional section to the subsystem(s) to which it applies. They are the quantitative description of how well the functional requirements perform. Beginning with the project-level requirements in this document, it is the responsibility of the System Engineer with the support of the PDL to continue the refinement of these requirements to be comprehensive enough to ensure that no essential item is overlooked; it is to be carried to a sufficient level to identify quantitative parameters by which the performance of the system can be tested. The requirements so derived will become the basis of the system verification plan and shall be documented and controlled by the Deputy Project Manager. A requirements tree is also shown in this document to illustrate requirement flow-down and traceability from Science Requirements to Functional Requirements. 2. SCIENCE DEFINITION 2.1 Baseline Science Objectives The BARREL investigation provides an essential tool for global monitoring of relativistic electron precipitation, and addresses one of the highest priority objectives identified by the Geospace Mission Definition Team (GMDT) for understanding radiation belt dynamics, differentiating among competing processes affecting precipitation and loss of radiation belt particles. BARREL will achieve the following science objectives: Determine the total electron loss rate during specific relativistic electron events by simultaneously measuring the precipitating flux of relativistic electrons over a wide range of local times. The loss rate will be compared with changes in the trapped flux for specific relativistic electron events to determine the importance of precipitation losses for radiation belt dynamics. Directly test models of wave-particle interactions in order to differentiate among different loss processes by combining precipitation measurements with simultaneous PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

7 BARREL Functional / Performance Requirements Document BARREL FPRD-101 Page 7 of 34 measurements of plasma waves and energetic particles. Determine the relative importance of two types of precipitation that have been previously observed: duskside MeV precipitation and microburst precipitation. BARREL will determine the importance of their associated precipitation mechanisms for different magnetic activity levels. Characterize the spatial extent and spatial structure of precipitation, which has been addressed previously only in a statistical sense. The region over which waves scatter electrons is a critical parameter for modeling electron loss timescales. BARREL will separate spatial and temporal variations and provide insight into the nature of temporal modulation of precipitation that has been observed. 3. APPLICABLE DOCUMENTS NASA Documents BARREL-SC PP-101 BARREL Project Plan BARREL CMP-101 BARREL Configuration Management Plan BARREL-SC CVP-101 BARREL Component Verification Plan Other Documents BARREL Flight Application BARREL Concept Study Report 4. DEFINITIONS Payload: The payload consists of the instrument package and its support systems. This includes all hardware below the attachment point to the balloon. This hardware is an integrated assembly of the instruments and any support systems, mounted within a support structure, and are designed to perform a specified mission in the upper atmosphere. Balloon Vehicle: A zero pressure balloon made with a non-extensible material which is a vented system to allow gas release. Data Processing Unit (DPU): This system performs the control and monitoring of the payload instruments, power system, and communications through a flight computer subsystem. It also controls and monitors the health and safety of the overall balloon system and collects and forwards data including positional data. Flight Control Systems: Those systems performing payload control and termination functions of the flight. These systems may include the parachute, micro-instrument package (MIP) and cabling. Housekeeping Data: Engineering data received from the payload that ascertains the health and operational status of the payload. The data include temperature, voltage and current monitors, on/off status, software status, subsystem status, etc. PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

8 BARREL Functional / Performance Requirements Document BARREL FPRD-101 Page 8 of 34 Instrument: A device consisting of sensors and associated hardware for making scientific measurements/observations in the upper atmosphere. The BARREL instruments are a Scintillator and a Magnetometer. 5. ACRONYMS bps bits per second Bps bytes per second BARREL Balloon Array for RBSP Relativistic Electron Losses CFR Code of Federal Regulations CSBF Columbia Scientific Balloon Facility DC Dartmouth College DPU Data Processing Unit EDI Engineering Data Interface EMI Electromagnetic Interference GPS Global Positioning System GSE Ground Support Equipment GSFC Goddard Space Flight Center I&T Integration and Test ICD Interface Control Document kbps Kilobit Per Second LOS Line-of-Sight MIP Micro-Instrumentation Package MOC Mission Operation Center NASA National Aeronautics and Space Administration NSF National Science Foundation OTH Over-the-Horizon PDL Product Design Lead PI Principal Investigator RFI Radio Frequency Interference SANAE South African National Antarctic Expedition SOC Science Operations Center UCB University of California at Berkeley PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

9 BARREL Functional / Performance Requirements Document BARREL FPRD-101 Page 9 of 34 UCSC UW WFF University of California at Santa Cruz University of Washington Wallops Flight Facility PRIOR TO USE, PLEASE CHECK THE BARREL MASTER DOCUMENT LIST AT TO VERIFY THIS IS THE

10 Page 10 of REQUIREMENTS FLOWDOWN

11 Page 11 of 34 SECTION ONE PROJECT REQUIREMENTS 1. SCIENCE REQUIREMENTS (SCI-#) Determine the loss rate of relativistic electrons Quantify the importance of due to duskside MeV events or dawnside SCI-1 Science Loss Rate precipitation losses on the microburst precipitation during specific trapped radiation belt flux. relativistic electron events. SCI-2 Science Energy Spectrum SCI-3 SCI-4 Science Science Relation to plasma waves Relative Importance SCI-5 Science Spatial Extent SCI-6 SCI-7 Science Science Variation with Activity Temporal Variations Determine the energy spectrum of precipitating electrons to distinguish relativistic precipitation from lower energy ( kev) precipitation. Relate precipitation losses to plasma waves and trapped particle distributions. Determine the relative importance of two dominant types of precipitation: relativistic electron microbursts and duskside MeV precipitation. Determine the spatial extent of the precipitation region for duskside MeV events and microburst precipitation. Determine how precipitation varies with geomagnetic conditions. Characterize temporal variations of precipitation and relate to temporal variations of other magnetospheric phenomena (e.g. ULF waves). Identify precipitation of radiation belt electrons and investigate the energy dependence of scattering. Understand and test models of precipitation mechanisms. Resolve the question of which type of precipitation is dominant. Necessary for quantifying loss rate and for constraining input parameters in models. Parameterize loss rate for use in radbelt models. Understand observed temporal modulation of electron precipitation. N /A

12 Page 12 of PROGRAMMATIC REQUIREMENTS (PRO-#) The BARREL project shall meet all safety PRO-1 Programmatic Safety requirements as described in the BARREL Project Plan. PRO-2 Programmatic IT Security An IT Security Plan shall be developed and documented PRO-3 Programmatic Risk A Risk Management Plan shall be developed Management and documented. PRO-4 Programmatic A Configuration Management Plan covering Configuration both hardware and software shall be developed Management and documented. PRO-5 Programmatic Cost The total cost shall be within 10% of the estimate As documented in Project Plan PRO-6 Programmatic Agreements Inter-agency agreements shall be in place for logistics, facilities, and support of launch and/or recovery operations. PRO-7 PRO-8 PRO-9 PRO-10 PRO-11 PRO-12 Programmatic Programmatic Agreement negotiation Data Management Programmatic Data Delivery Programmatic Reviews Programmatic Documentation Programmatic I&T Inter-agency agreements and/or memorandum of understanding shall be negotiated by the Balloon Program Office. A Data Management Plan shall be developed and documented A copy of all BARREL data shall be delivered to NASA The BARREL project shall support reviews as described in the BARREL Project Plan Documentation shall be in accordance with standard practice An integration and test plan shall be developed.

13 Page 13 of 34 Programmatic Safety and Mission Assurance PRO-14 Performance Documentation BARREL shall observe and be cognizant of preventive measures and improvement policies that will result in protecting the general public, assets, resources, and environment by mitigating or eliminating risk of injury or damage to personnel or systems. A Mission Operations plan shall be developed and documented.

14 Page 14 of 34 SECTION TWO FUNCTIONAL REQUIREMENTS 1. MISSION REQUIREMENTS (M-#) 1.2 Mission Design MIS-1 Functional Over the duration of a campaign, BARREL Local time coverage necessary shall obtain measurements from each SCI-3, Magnetic Local for detecting precipitation due to magnetic local time sector, in the latitudinal SCI-4, Time Coverage different mechanisms (expected to region corresponding to the outer radiation SCI-5 act at different locations) belt (L=3-7) MIS-2 Functional Conjunctions MIS-3 Functional Multi-point Measurements BARREL shall obtain measurements of precipitation magnetically mapping to within 3 deg latitude and 1 hour MLT of instruments that measure plasma waves, cold plasma density, and trapped particle distributions. BARREL shall obtain simultaneous multipoint measurements at three or more locations with typical separations of 1-2 hours of MLT. To directly correlate the occurrence of specific plasma waves and precipitation and to quantitatively test models of wave-particle interactions. To separate spatial and temporal variations and to measure the spatial extent of precipitation. 1.3 Platform The platform shall be nearly-stationary with MIS-4 Functional respect to the rotating Earth and provide the Necessary to separate temporal Nearly-stationary observing time to separate temporal-spatial and spatial variations in observed platform variations on timescales from 200 ms to precipitation. tens of minutes. SCI-7 SCI-3 SCI-1, SCI-5

15 Page 15 of 34 MIS-5 Functional Observing time MIS-6 Functional Altitude BARREL shall obtain a minimum of 1200 hours of science observations. The platform shall hold the payload aloft at sufficient altitude to meet the scientific objectives. Rough factor of ten more than each of prior balloon campaigns studying relativistic precipitation. 1.4 Operations There shall be well understood and MIS-7 Functional Launch documented launch procedures appropriate Procedures for rapid turn-around (~1 day) between MIS-3 successive launches. Near real-time communications between the MIS-8 Functional Communications MOC and the field teams shall be available during launch procedures and the ascent PRO-1 MIS-9 Functional Facilities and Equipment MIS-10 Functional Personnel MIS-11 Functional Flight Termination phase of each balloon launch All necessary facilities and equipment shall be available for vehicle pre-flight preparations and verifications, applicable CSBF flight operations, and the Mission Operations Center. Personnel support required for science and mission user flight readiness, launch operations, contingency termination, and possible recovery, control center monitoring, and campaign management shall be provided. SCI-3, SCI-6 SCI-2 There shall be a cutdown capability. Aviation Safety PRO-1

16 Page 16 of 34 MIS-12 Functional Safety MIS-13 Functional Inflation and Launch Operations procedures, workspace, and equipment shall be compliant with safety requirements. The inflation and launch of the balloon shall be consistent with normal inflation and launch operations for a hand-launch zeropressure system PRO-1, PRO-1

17 Page 17 of INSTRUMENT REQUIREMENTS (INS-#) 2.1 X-ray Instrument INS-1 INS-2 Functional Functional X-ray measurements Flux Measurements INS-3 Functional Energy Spectrum INS-4 Functional Calibration INS-5 Functional Time Resolution INS-6 Functional Max Count Rate The BARREL instrument shall obtain measurements of of bremsstrahlung X-rays produced by precipitating electrons in range 100keV-4 MeV. The BARREL instrument shall obtain measurements of X-ray flux on a timescale comparable to the variability of duskside electron precipitation (120 s), with sensitivity necessary to meet the baseline science objectives. BARREL shall measure the energy spectrum of X-rays with energy resolution required to invert the X-ray spectrum. The absolute calibration of the BARREL instruments shall be 30% or better. The BARREL instruments shall have the time resolution required to distinguish X- ray microbursts (250 ms duration) from longer duration duskside relativistic electron precipitation. At count rates up to 10000/s, any countrate-induced spectral degradation shall not adversely affect the spectral inversion process. SCI-2 SCI-1, SCI-4 SCI-2 SCI-1 SCI-4, SCI-7 SCI-2

18 Page 18 of Magnetometer INS-7 Functional Magnetic Substorms INS-8 Functional ULF Waves BARREL will identify substorm onsets during observed precipitation, eliminating BARREL's need for local magnetometer stations. BARREL will measure changes in Earth's magnetic field on ULF timescales, eliminating BARREL's need for local magnetometer stations. SCI-6 SCI-7

19 Page 19 of SYSTEM REQUIREMENTS (SYS-#) 3.1 Mechanical SYS-1 Functional Launchability The mechanical design shall meet any restrictions for a hand-launched vehicle SYS-2 Functional Assembly The payload structure shall be designed for ease of assembling and servicing multiple flight units SYS-3 Functional Payload Strength The mechanical structure and associated hardware shall conform to the CSBF mandated strength requirements defined in the Enclosure 3 of the LDB FY08 Flight PRO-1 Application, Structural Requirements for Balloon Gondolas. SYS-4 Functional Shipping A means for safe shipping of flight critical hardware shall be provided by the project. SYS-5 Functional Documentation Documentation for mechanical structures shall be clearly labeled and identified in accordance with standard practice. PRO Sensors SYS-6 Functional Positioning There shall be a position sensor with the Required for correlated multipoint measurements accuracy to meet science objectives. MIS-3 SYS-7 Functional Altitude There shall be an altitude sensor with the Altitude knowledge necessary for accuracy to meet science objectives inversion of X-ray spectrum. SCI-2 SYS-8 Functional Housekeeping There shall be engineering temperature, voltage and current sensors to monitor health of all payload systems. SYS-9 Functional Time Absolute time referenced to Universal SCI-1, Time shall be available. SCI-3,

20 Page 20 of Data Processing The DPU shall have resources to handle all SYS-10 Functional DPU Resources data input, required processing or formatting, and transfer of data to the telemetry system. SYS-11 Functional Instrument Health Housekeeping data shall be acquired and transmitted to the ground in near real-time to ascertain the health and safety of each payload. SYS-12 Functional Data Acquisition Science data shall be acquired and transmitted to the ground and shall be accessed by the Mission Operation Center. SYS-13 Functional Commanding The Data Processing Unit shall have the capability to receive and decode a real-time cut-down command from the ground. MIS Telemetry SYS-14 Functional Forward Link A forward link shall be provided to support payload commanding for line-of-sight and MIS-11 over-the-horizon phases of the mission. SYS-15 Functional Return Link A return link shall be provided for payload telemetry for both line-of-sight and overthe-horizon phases of the mission. 3.5 Power The power system shall provide the power SCI-1 thru SYS-16 Functional Power System to support the mission. SCI-7 SCI-6, SCI-7

21 Page 21 of 34 SYS-17 Functional Back-up Power SYS-18 Functional Instrument Power Back-up power for flight critical systems, as defined, shall be provided. The power system shall provide stable and clean power for the instruments, such that the rms noise contribution to the magnetometer is below 20nT, the rms noise contribution to the x-ray spectrometer is below 10 kev, and converter noise spikes contribute fewer than 10 x-ray counts/s. Necessary to not degrade spectral resolution 3.6 Thermal Control SYS-19 Functional Temperature Temperatures shall be maintained to the Range specifications of the individual subsystems. SYS-20 Functional Thermal Shock Thermal shock shall be controlled as required for the instruments. 3.7 Electrical and Data Harnessing Harnessing shall provide power SCI-1 thru SYS-21 Functional Power Distribution distribution within the payload. SCI-7 Harnessing shall provide data distribution SYS-22 Functional Data Distribution SYS-12 within the payload. 3.8 Integration and Test SYS-23 Functional Payload I&T Integration and test activities shall be performed to verify all payload subsystems. PRO-12

22 Page 22 of GROUND SEGMENT REQUIREMENTS (GND-#) 4.2 Mission Control GND-1 Functional Data Viewing MIS-1, The facilities for controllers to view data in MIS-2, near real-time shall be provided. MIS-3 GND-2 Functional Facilities and Equipment GND-3 Functional Commanding GND-4 Functional Communications All necessary facilities and equipment shall be available for the control center. The MOC shall be capable of initiating all mission and flight critical commands. A voice link from the MOC to the field teams shall be available 4.3 Science Operations and Data Archiving GND-5 Functional Data Archiving All data returned from the BARREL balloons shall be archived. GND-6 Functional Data Storage All necessary facilities and equipment for secure and reliable acquisition and storage of data shall be provided. GND-7 Functional Data Viewing An open (networked) facility for team and public viewing of data in near real time SCI-3 shall be available. GND-8 Functional Delivery to NASA A copy of all BARREL data shall be delivered to NASA as required. PRO-9 GND-9 Functional Other Users The BARREL team shall provide the tools and assistance necessary for other users to make effective scientific use of BARREL data. PRO-4

23 Page 23 of 34 SECTION THREE PERFORMANCE REQUIREMENTS 1. MISSION REQUIREMENTS 1.1 Mission Design Balloon campaigns shall be carried out in Required for Long Duration MIS-14 Performance Location/Timing the Arctic or Antarctic during summer season Balloon flights which provide longest observing times MIS-5 MIS-15 Performance Launch Sites MIS-16 Performance # Campaigns MIS-17 Performance Balloon Array MIS-18 Performance # Balloons The BARREL launch sites shall be chosen to optimize observations in the region corresponding to the outer radiation belt (L=3-7). Two campaigns separated in time by one year shall be conducted. BARREL shall consist of an array of balloons launched 1-2 days apart on average, with average of 3 balloons aloft at any given time. Minimum of 8 LDB payloads shall be launched during each campaign. Baseline is 20 payloads. Launch sites are also determined by logistical feasibility but to the extent possible, will be chosen to maximize science return. Assuming only Antarctic flights are possible - campaigns take place only once per year. Wind speeds dictate launch cadence based on desired MLT separation. Minimum is set by minimum observing time. Baseline based on desire to maximize conjunctions with RBSP MIS-1 MIS-1, MIS-2 MIS-3 MIS-2, MIS Platform X-ray observations require MIS-19 Performance Altitude The system shall be designed for a altitude as high as possible due to minimum altitude of 90,000 feet (27.5 km). attenuation of atmosphere (100,000 feet derived from MIS-6

24 Page 24 of 34 MIS-20 Performance Duration MIS-21 Performance Balloon Size MIS-22 Performance Flight Train MIS-23 Performance Terminate All flight systems shall be designed for mission duration of at least 10 days. MIS-24 Performance Moved to PRO-14 The balloon size shall be less than or equal to 300,000 cubic feet to allow for handlaunch operations. The flight train shall support the payload in accordance with the LDB FY08 Flight Application, Enclosure 3, and "Structural Requirements for Balloon Gondolas" The flight system shall provide for termination through a global command link required <15g/cm 2 for standard atmosphere ) Rapid turn-around for flights implies payloads must be easy to launch without severe restrictions on surface winds. MIS-5 MIS-12, MIS-18 SYS-3 MIS Operations MIS-25 Performance Flight Rules Operation Flight Rules shall be developed MIS-7, and documented. MIS-12 Training in launch operations, trajectory MIS-26 Performance Launch Training analysis, and impact prediction shall be provided for the launch crew and MIS-7 operations team. MIS-27 Performance Pre-launch testing Functionality of all elements of the each balloon flight system shall be verified at MIS-7 the launch site, prior to launch. MIS-28 Performance An end-to-end comprehensive performance Comprehensive test shall be performed at the launch site Including connectivity to MOC Test prior to launch. MIS-7 MIS-29 Performance Communications There will be a voice link from MOC to the field teams. MIS-8

25 Page 25 of 34 MIS-30 Performance Safety MIS-31 Performance MIS-31a Performance Inflation and Launch Support Requirements Documentation BARREL shall use qualified flight train components including parachute and flight termination systems. Hand-launch procedures shall be carried out as described in the BARREL flight rules All BARREL instrument facility and support requirements shall be documented in the site institution support package (SIP). Arctic or Antarctic operations require inter-agency involvement - NSF support requires filling out support package MIS-12 MIS-12 PRO-6

26 Page 26 of INSTRUMENT REQUIREMENTS 2.1 X-ray Instrument INS-9 Performance Geometric Factor The X-ray instrument shall have effective geometric factor of at least 5cm 2 Sensitivity required to detect -sr at 1 INS-1, relativistic electron precipitation MeV and a zenith-centered field of view INS-2 based on previous measurements (or equivalent) INS-10 Performance Energy Range INS-11 Performance Energy Resolution INS-12 Performance Field of View INS-13 Performance Detector Pile-up INS-14 Performance 2.2 Magnetometer High Altitude Operation The X-ray instrument shall record photons between 100 kev-4 MeV. The X-ray instrument shall have intrinsic energy resolution better than 10% FWHM at 1 MeV. Obstructions within the detector's nominal field of view should not absorb or scatter more than 5% of incoming radiation within the required energy range MeV To preserve the integrity of spectral inversion, for a count rate of 10000/s, the count-rate-induced spectral degradation must not shift analyzed energies by more than 15%. The X-ray instrument must function at nominal float altitude without arcing Detection of relativistic precipitation requires energy range up to several MeV Necessary for calibration using 511 kev line Detector pile-up. High voltage of PMT susceptible to arcing at balloon altitudes. The magnetometer shall measure Component INS-15 Performance horizontal and vertical magnetic field INS-7 Magnetic Field components to 100 nt (3 sigma) with 1 INS-1, INS-2 INS-3 INS-9 INS-6 INS-3

27 Page 27 of 34 minute temporal resolution INS-16 Performance Total Magnetic Field The magnetometer shall measure total magnetic field over the range Gauss to 50 nt precision with 1 second temporal resolution. INS-8

28 Page 28 of SYSTEM REQUIREMENTS 3.1 Mechanical SYS-24 Performance Design The solar panel array shall be attached in a way that will allow hand launch. SYS-1 SYS-25 Performance Payload weight The total suspended weight shall be no Balloon can support 89 lbs. more than 70 lbs (mass of 32 kg). Safety margin applied. MIS-21 SYS-26 Performance Units of Measure The units used for mechanical dimensions shall be clearly identified. SYS-5 SYS-27 Performance Shipping case shall be dimensioned to Shipping allow sufficient padding for safe shipping Containers of each of the completed payloads SYS Sensors The position sensor shall provide balloon Latitude and Instrument field of view is ~200 SYS-28 Performance position information accurate to 30 km SYS-6 Longitude km minimum. SYS-29 Performance Altitude SYS-30 Performance Housekeeping SYS-31 Performance Timing SYS-32 Performance Temperature Monitoring The altitude sensor shall provide balloon altitude accurate to 1 km minimum. Voltage and current measurements shall be accurate to 5% of nominal input voltage for each subsystem. The timing accuracy for each payload shall be 200 ms (minimum), 50 ms (baseline). Timing accuracy for voltage and current sensors shall be better than 2 minutes. Accuracy of the temperature sensors shall be ±2.0 degrees C. 200 ms for X-ray events set by microburst timescale. Housekeeping information does not need precision timing. SYS-7 SYS-8 SYS-9 SYS-8

29 Page 29 of Data Processing The DPU shall bin X-ray events into no Course spectra are required for SYS-33 Performance Spectral Binning fewer than 20 channels, plus 10 bins inverting the continuous INS-3, around the 511 kev line, every 20 seconds, bremsstrahlung spectrum; higher INS-4, (the requirement on 511 kev line could resolution around the 511 kev SYS-10 also be met with periodic high resolution line is required for in-flight spectra once per minute). calibration. SYS-34 Performance Rate Counters SYS-35 Performance Positioning SYS-36 Performance Magnetometer SYS-37 Performance Housekeeping SYS-38 Performance Data Storage SYS-39 Performance Data Playback SYS-40 Performance Timing X-ray data (rate counters) shall be returned at a rate of at least 16 Hz in at least 3 energy bands including one relativistic band (~500 kev-2 MeV) The DPU shall be capable of returning GPS location no less than once per 10 minutes. The DPU shall return magnetometer data once per second. Voltage, current, and temperature sensors shall be sampled at a rate no less than once per 10 minutes Real time data shall be saved in the flight computer so that it can be re-sent as needed. Storage memory should hold at least 2 minutes of data. There will be a capability to play back onboard stored data through the primary global downlink. Transmitted data packets shall contain timing data sufficient to recover the data acquisition time to within an accuracy of 20 ms. Assumes 20 knot winds at float altitude REMOVED REMOVED INS-5, SYS-10 SYS-6 INS-16 SYS-11 SYS-10 SYS-10 MIS-2, MIS-4, INS-5 SYS-41 Performance Downlink The flight processor shall format and SYS-12

30 Page 30 of 34 SYS-42 Performance Uplink transmit data to the downlink telecommunication system The flight computer shall interpret and process all commands received by the uplink communications system. SYS Telemetry SYS-43 Performance Uplink An uplink path shall be provided for commanding SYS-14 SYS-44 Performance Downlink SYS-45 Performance Data Content SYS-46 Performance Data Quality SYS-47 Performance Data Rate A global means of down-linking science data, flight control data and payload health monitoring data shall be provided Science data, flight control data and payload health monitoring data shall be transmitted from the balloon to the Mission Operations Center (MOC) 90% of frames with good checksums are required for duration equal to minimum of 1200 hours of data. Nominal data rate for science data shall be a minimum of 1.9 kbps (including overhead). Recovery of data stored on board may not be feasible for Antarctic flights, thus all data must be telemetered. Driven by rate counters and cadence of X-ray spectrum MIS-14, SYS-15 SYS-11, SYS-12 SYS-1 thru SYS-7 SYS-1 thru SYS Power Energy with margin to support the nominal SYS-16, mission of 10 days to include either stored SYS-48 Performance Mission Duration SYS-17, or generated energy or a combination of MIS-20 both shall be provided. SYS-49 Performance Conductive Interference Conducted interference from any system or component shall contribute less than 10 SYS-18

31 Page 31 of 34 SYS-50 Performance Filtering SYS-51 Performance EMI SYS-52 Performance Power Monitoring SYS-53 Performance 3.6 Thermal Control Short Circuit Protection kev rms x-ray energy, and shall generate less than 10 bogus x-ray events per second. Subsystems shall have power input filtering to minimize conducted emissions as required EMI/RFI from one system or component shall contribute less than 10 kev rms x-ray energy, and shall generate fewer than 10 bogus x-ray events per second. Power to each subsystem shall be monitored. Power to each subsystem shall have short circuit protection as required. SYS-49 SYS-18 SYS-11 SYS-18 SYS-54 Performance Thermal Control Temperatures of all instruments and support systems shall be maintained within defined limits for the nominal operational SYS-19 phase of the mission. Flight temperatures shall be maintained to SYS-55 Performance for scintillator. Temperature specification of individual subsystems Range generally -30 o C to 50 o C except as noted SYS-19 SYS-56 SYS-57 Performance Performance Thermal Shock Rate Scintillator temperature SYS-58 Performance Thermal testing The rate of change of temperature for the NaI scintillator shall be less than 8 o C per hour. The flight scintillator temperature shall be maintained from C to 50 0 C. Thermal testing in the expected flight environment shall be carried out to verify the payload thermal design Sensitivity of instrument decreases with temperature below 0 degrees; >0 deg desired SYS-20 SYS-19 SYS-23

32 Page 32 of Electrical and Data Harnessing A grounding plan shall be developed to SYS-59 Performance Grounding x-ray noise counts below 10/s. keep x-ray rms energy noise below 10 kev, SYS-21, magnetometer rms noise below 20 nt, and SYS-22 SYS-60 Performance Cable Routing 3.8 Integration and Test Routing of cables shall be such x-ray rms energy noise is below 10 kev, magnetometer rms noise is below 20 nt, and x-ray noise counts are below 10/s. SYS-21, SYS-22 SYS-61 Performance Pre-ship test The function of each payload shall be verified and validated as described in the verification matrix prior to shipment for SYS-23 launch. SYS-62 Performance Subsystem Testing Subsystem verification shall be performed prior to integration of each payload. SYS-23 SYS-63 Performance Comprehensive An end-to-end comprehensive performance Test test shall be performed. SYS-23 At the conclusion of the verification program, the payloads shall have SYS-64 Performance Reliability demonstrated minimum reliability by SYS-23 trouble-free performance testing for at least 48 hours. SYS-65 Performance Burn-in test A burn-in test shall be carried out on one MIS-20, payload for a minimum duration of 10 SYS-23 days.

33 Page 33 of GROUND SEGMENT REQUIREMENTS (GND-#) 4.1 Mission Control MOC software shall decode and display GND-10 Performance Data Viewing system health information to operators GND-1 within 1 minute of acquisition of data. GND-11 Performance The facility for up-linking the termination Command command shall be physically secure, and Security the command password-encoded. GND-3 Incoming data shall be monitored by GND-12 Performance Flight Monitoring operators in real-time 24 hours a day 7 GND-1 days a week until termination. GND-13 Performance Voice Link Voice link from MOC to field teams shall be provided on a line available 24/7 for this purpose, and capable of conferencing both field teams at once with the MOC. GND-4 GND-14 Performance GND-15 Performance GND-16 Performance Telemetry Delays UPS back-up Ground System I&T Command uplink and data downlink connections shall have a maximum 1 hour delay. There shall be UPS backup on critical control center stations. The function and reliability of the ground system shall be verified as described in the verification matrix. GND-1, GND-3 GND-2 GND-1, GND-2, GND-3, GND Science Operations and Data Archiving The facility for acquisition of the master GND-17 Performance Data Security GND-6 copy of data shall be physically secure.

34 Page 34 of 34 GND-18 Performance GND-19 Performance GND-20 Performance GND-21 Performance GND-22 Performance GND-23 Performance Redundancy Data Availability Software Availability Version control Data Delivery Help Desk Data shall be recorded on a minimum of two independent devices. Raw data and preliminary quick-look data plots shall be made available on the internet to the BARREL team and public within 1 hour of acquisition at the MOC. The most recent stable version of BARREL data analysis software and secondary databases shall always be available to the public on the internet at all times. All changes to BARREL data, software, and secondary databases from the start of science operations shall be documented and tracked with appropriate version number changes in a way that is transparent to all users. A copy of all BARREL data, software, and secondary databases shall be delivered to NASA on permanent physical media within 6 months of the end of each campaign. A help desk shall be provided that shall assist by all users of BARREL data with a time to initial response of two days or less. GND-5, GND-6 GND-7 GND-9 GND-9 GND-8 GND-9