1 wp4 – Assembly Integration Verification of the System Testbed for Trial 2 Barcelona 3/03/05 Marco Bobbio Pallavicini Carlo Gavazzi Space SpA

2 Upper Part of the Stratospheric Carrier System architecture is frozen All the subsystems necessary for flight mission operation are defined – No criticalities for procurement The system will be assembled and verified at the launch site Interfaces between the upper carrier and the nacelle are limited to a mechanical joint and three RS422 links (MIL-C connectors) System will include also: GPS system, sending data at the ground station, available in real time to the ground users EBASS communication system, providing transparent RS 422 link between PL and the ground users Atmospheric Data System for monitoring environmental parameters during the flight mission Radio beacon for reliable localization of the system after landing Balloon Balloon ATC Cutter Parachute TM/TC System Ballast System Argos GPS Transponder Beacon Strobelight Radar Reflector Mechanical Link Equipped Nacelle Stratospheric Carrier (Upper Part) > 70m Gas Release Valve

3 Flight Mission

4 Environmental parameters

5 Nacelle mainframe Volumes allocation for OPT PL system was re- defined OLD: 500 x 600 x 1000 mm NEW: 800 x 350 x 500 mm

6 RF Payload mechanical integration Geometry frozen Installation envelope (including thermal protection) 400 x 500 x 300 mm Free field on a cone 140° solid angle, with apex at the base of the antenna lens and axis nadir pointing Weight frozen <15kg To be defined CoG location To be defined the mechanical interfaces between the (aluminium?) box containing the equipment and the Nacelle mainframe. Mechanical IF shall be able to sustain the 10G shock at parachute opening. Interface drawings Checked the danger of electrical discharge of the antenna in stratospheric environment?

7 OPT Payload mechanical integration Geometry of the integrated Pod driven by requirements from Trial 3 Actual installation envelope 800 x 350 x 500 mm. To be frozen after confirmation from NiCT/JSC Free field on a cone 140° solid angle, with apex at the base of the periscope mounting and axis nadir pointing Weight of the fully integrated Pod shall be anyway <25kg. To be investigated possible reduction to <20kg To be defined the mechanical interfaces between the composite Pod and the Nacelle mainframe. Mechanical IF shall be able to sustain the 10G shock at parachute opening. Pod to be preserved by damages for easy reuse during Trial 3 after slight refurbishment

8 EPS system for RF Payload Requirements accepted: Single power bus Supply 28V DC Maximum Power need W CGS will provide a dedicated single power bus (TBC, within tomorrow?): Battery pack, 6 x 8 SAFT LSH20 elements (lithium-thionyl chloride) Operational temperature: –60°C / 85°C (nominal) Nominal voltage: 28.8V 2mA per cell, +20°C) Operational Voltage Range: current suction, -40°C max.29.6V open Design power output: continuous 4.3A approx. Peak power: >240W (8.6A) Design capacity range: min. -40°C, max. -20°C Design duration: full power Notice Despite the proposed EPS system is suitable for high pulses / high drain applications, as a matter of reliability it is desirable to start the RF system at take off and require a continuous current drain during all the mission Check for possible ionising problems while climbing Evidenced a possible problem with a single component (power 5W approx.), not accepting input voltage lower than 24V

9 EPS system for OPT Payload Requirements accepted: Developed system for Trial will be consistent (or somehow simulating) with single power bus 28V DC, available on Trial 3. Possible solutions to be investigated out of further interactions with NiCT/JSC Maximum Power need W (details about possible power heating TBD) CGS will provide a system based on battery packs, supplying two independent main busses at 28.8V 2mA per cell, +20°C), to be integrated with converters, in order to provide the different voltage busses with the proper stability necessary for the OPT PL system The two main busses (28.8V, power TBD) will be dedicated respectively to: Feeding the controllers and actuation of the PAT system Feeding the remaining subsystems Definition of the EPS system at OPT PL subsystem level is a common activity CGS/DLR, agreed as cooperation between WP4.3 and WP3.4, and linked with thermal design of the PL itself

10 Thermal boundary conditions for RF Payload Requirements accepted RF equipment to remain at a temperature range TBC (UOY, 11/03/05) for 6h from take off CGS will provide a thermal protection of the RF payload box (considered as a whole) in order to cope with requirements, provided the following clarifications Design of thermal protection will be subsequent to precise definition of the thermal dissipation of the RF equipment during the whole considered mission time. Definition of thermal dissipation will be provided by the responsible for RF PL assembly (UOY). CGS will consider the provided nominal ‘time profile’ for heat dissipation to calculate the need for thermal insulating the RF PL box, in order to remain within the suggested temperature range. The lens antenna underneath the RF PL box will remain as direct interface with the air. Therefore, thermal characteristics of such item will be provided to CGS, before starting the calculation CGS will possibly suggest the need for any heater within the RF PL box, in case the heat dissipation of the system itself were not sufficient to keep the box within desired range The power need for possible heating will be provided by the EPS system defined for RF PL, without extra power installation

11 Thermal boundary conditions for OPT Payload Requirements accepted OPT equipment to remain at a temperature range TBD for 6h (TBC) from take off CGS will provide a thermal protection of the OPT payload pod (considered as a whole) in order to cope with requirements, provided the following clarifications Design of thermal protection will be subsequent to precise definition of the thermal dissipation of the RF equipment during the whole considered mission time. Definition of thermal dissipation will be provided by the responsible for RF PL assembly (DLR). CGS will consider the provided nominal ‘time profile’ for heat dissipation to calculate the need for thermal insulating the RF PL box, in order to remain within the suggested temperature range. The periscope underneath the RF PL box will remain as direct interface with the air. Therefore, thermal characteristics of such item will be provided to CGS, before starting the calculation CGS will possibly suggest the need for any heater within the OPT PL box, in case the heat dissipation of the system itself were not sufficient to keep the box within desired range The power need for possible heating will be provided by the EPS system defined for OPT PL, without extra power installation

12 Thermal design of OPT Payload Agreement CGS-DLR to spend extra-effort in designing the PL to be possibly consistent with both Trial 2 and Trial 3 flight missions  Two sets of requirements (2 missions), implying different boundary conditions for the thermal environment  Combined design (EPS system – Thermal control) Thermal design to be discussed between CGS and DLR, with few missing inputs from NiCT/JSC related to:  Mechanical connection between the pod and the airplane wing  Characteristics of the EPS from the airplane (possible need for powering some heaters) The thermal design process for of the OPT PL is not modifying the schedule for system thermal design of the integrated nacelle. The two processes will run in parallel, as soon as the geometry of the pod will be frozen, out of final IF requirements from NiCT/JSC

13 Data communication via TM/TC Unit GPS data provided real time at GS Data stream provided via LAN (IP) to the experiment ground stations Data stream provided according to NMEA-0183 standard Functional test, option 1: to simulate a data flow as input to the experiment ground station in order to check the consistency with format and syntax Functional test, option 2: to connect the experiment ground station with the data stream from a real flight Transparent RS422 link Three full duplex, asynchronous, transparent serial connections Each line will go through a RF line (nominal MHz, Frequency Modulation)  guaranteed a BER end-to-end better than 10^-5 First end: connector to the PL onboard (possibly MIL-C connectors) Second end: connector to the experiment GS Link test: to verify the end-to-end link by connecting aerial and ground modules of the experiment respectively to the TM/TC Unit and to the RS422 at ground, out of the Flight Control Station

14 AIV process Complete functional test of the RF experiment (aerial system + ground station) – UOY/CSEM facilities Complete functional test of the OPT experiment (aerial system + ground station) – DLR facilities Shipment of the RF PL and the OPT PL to CGS facilities (Milano/Tortona, TBD) Mechanical integration of the RF PL, the OPT PL and the EPS system within the nacelle mainframe – CGS Electrical integration (either Flight Model or Engineering Model of the EPS) and verification - CGS EMC check for the integrated nacelle (possible interference between the two PLs, critical for OPT PL the range 0-500KHz, to be preliminary checked by UOY whether RF PL is generating such IF) - CGS Integration of thermal protection for the integrated nacelle - CGS Possible connection with TM/TC Unit and Flight Control Station for end-to-end link test – Launch site, Esrange Possible compatibility check with the GPS data stream – Launch site, Esrange

15 AIV Plan Schedule See Gantt Major deadlines Define test procedure for TM/TC link preliminary test (UOY, DLR 18/03/05) Define test procedure for testing the IF with GPS data stream (UOY, DLR 18/03/05) Define a time period for TM/TC and GPS test (CGS 15/04/05) Define max.dimensions and weight for the ground segment to be installed at Esrange facilities (UOY, DLR 25/03/05) Define the requirements for external EPS for functional tests (UOY, DLR 25/03/05) Time-critical points Procurement EPS system elements (CGS)

16 Deadlines and Actions Volume/Weight allocation within nacelleCGSFrozen General thermal Reqs from PLsDLR/UOYTBC11/03/05 Definition mech. I/F PL-NacelleDLR/UOYTBC11/03/05 Definition Power/Thermal mission plan for PLDLR/UOYTBC11/03/05 Request for preliminary system test (Esrange?) DLR/UOY18/03/05 System thermal design CGS31/03/05 ? EPS designCGS31/03/05 ? Details and further updates will be kept in the internal document associated to milestone M0065, ‘Operative scheme of the test process (2)’

17 Notes Both RF and OPT PLs shall have the possibility to switch off in case of interference problems DLR would require a map of the lakes in the test area, for solving possible problems with the onboard PAT system Flight batteries will not be connected till when at launch site. Therefore an external electric power Supply is necessary for any functional test before SVT.