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-26482 connectors)

System will include also:GPS system, sending data at the ground station, available in real time to the ground usersEBASS communication system, providing transparent RS 422 link between PL and the ground usersAtmospheric Data System for monitoring environmental parameters during the flight missionRadio beacon for reliable localization of the system after landing

Balloon

Balloon ATC

Cutter

Parachute

TM/TCSystem

BallastSystem

Argos GPS

Transponder

Beacon

Strobelight

RadarReflector

MechanicalLink

EquippedNacelle

Stratospheric Carrier

(Upper Part)> 70m

Gas ReleaseValve

3

Flight Mission

Trial 2 Trial 3 RemarksAltitude range 330-20000m S.L. 0-20000m S.L.Take off Dynamic launch by crane. Vertical lift-off Smooth roll off from runaway Possible dust at ground

operationsClimb Duration >1h. Ascent rate maintained

between 4 and 7m/s.Possible yaw, up to 6rpm

Duration 5h. Initial ascent speed 0.7m/s, maximum ascent speed 1.4m/s . Flight speed ranging from 7m/s at ground level, to 28m/s nominal speed at 20000m altitude

Trial 2 will experience two-axes pendulum movement, deminishing significantly during ascent.

Loitering Duration 4-6h. Possible yaw up to 6rpmPossible two-axes pendulum, 2°amplitude

Duration 3h. D-shape path, 3-4km radius, 7km straight path, 28-41m/s speed

Trial 2 will experience no relative airspeed

Descent Duration <1h.Descent by parachute (10G load at parachute aperture), vertical speed up to 7m/s

Maximum descent speed 1.16m/s . Flight speed ranging from 28m/s nominal speed at 20000m altitude to 7m/s at landing

Duration 7h.

Landing 7m/s vertical impact speed at ground (grass or gravel)

Autonomous landing on runaway, low-G impact (TBD)

Worst case Trial 2 could end up with impact onto a three!

4

Environmental parameters

5

Nacelle mainframe

Volumes allocation for OPT PL system was re-defined

OLD: 500 x 600 x 1000 mmNEW: 800 x 350 x 500 mm

6

RF Payload mechanical integration

305.00 mm

120.00 mm

230.00 mm 240.00 mm

120.00 mm340.00 mm

65.00 mm

45.00 mm

65.00 mm

65.00 mm

45.00 mm

Geometry frozenInstallation envelope (including thermal protection) 400 x 500 x 300 mmFree 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/JSCFree 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 busSupply 28V DC Maximum Power need 125.58W

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: min.23.04V @max. current suction, -40°C max.29.6V open circuit @20°C, Design power output: continuous 123.4W @ 4.3A approx.Peak power: >240W (8.6A)Design capacity range: min. 27Ah @ -40°C , max. 33Ah @ -20°CDesign duration: 7h @ full power

NoticeDespite 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/JSCMaximum Power need 138.46W (details about possible power heating TBD)

CGS will provide a system based on battery packs, supplying two independent main busses at 28.8V (nominal @ 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 systemFeeding 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 acceptedRF 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 calculationCGS 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 acceptedOPT 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 calculationCGS 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 stationsData 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 syntaxFunctional test, option 2: to connect the experiment ground station with the data stream from a real flight

Transparent RS422 linkThree full duplex, asynchronous, transparent serial connectionsEach line will go through a RF line (nominal 402.2 MHz, Frequency Modulation) guaranteed a BER end-to-end better than 10^-5First end: connector to the PL onboard (possibly MIL-C-26482 connectors)Second end: connector to the experiment GSLink 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

ScheduleSee Gantt

Major deadlinesDefine 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 pointsProcurement EPS system elements (CGS)

16

Deadlines and Actions

Volume/Weight allocation within nacelle CGS Frozen

General thermal Reqs from PLs DLR/UOYTBC11/03/05

Definition mech. I/F PL-Nacelle DLR/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 CGS 31/03/05 ?

EPS design CGS 31/03/05 ?

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.