Mission, Flight Mechanics and GNC of IXV

Transcription

1 Mission, Flight Mechanics and GNC of IXV Mariano Sánchez Murray Kerr Davide Bonetti DEIMOS SPACE S.L.U Speaker: Mariano Sánchez Astronet II, June 18 th, 2015 Elecnor Deimos is a trademark which encompasses Elecnor Group companies that deal with Technology and Information Systems: Deimos Space S.L.U., Deimos Imaging S.L.U., Deimos Castilla La Mancha S.L., Deimos Engenharia S.A. and Elecnor Seguridad S.L. 1

2 DEIMOS EXPERIENCE AND CAPABILITIES Atmospheric Flight DEIMOS Space is responsible for the end to end (from launch to splashdown) Mission Analysis and Flight Mechanics of the IXV vehicle. DEIMOS Space is responsible for the end to end (from launch to runway landing) Mission Analysis and Flight Mechanics of the S3 (Swiss Space System) private initiative in Phases A/B1. DEIMOS Space has been involved since 2001 in multiple ESA ascent and reentry programmes (ex: Human Space flight, Exomars, Clean Space) GNC/AOCS DEIMOS Space is co-prime for the GNC of the IXV vehicle. DEIMOS Space is responsible for the GNC and AOCS of the S3 private initiative in Phases A/B1 DEIMOS Space is owner/operator of its DEIMOS-1 & DEIMOS-2 satellites, the first Spanish high resolution satellite DEIMOS Space has been involved since 2001 in multiple ESA programmes for GNC & AOCS (ex: Exomars, Lunar Lander, Proba-3, Euclid, Juice, Galileo) 2

3 DEIMOS ROLE IN IXV DEIMOS Space has contributed to IXV in the following areas: Responsible for the complete Mission and Flight Mechanics Design and Analysis Mission design Flying Qualities Visibility and link budget (with Telespazio) Safety support Flight predictions Co-leader of the Guidance, Navigation and Control (GNC) System Co-leader of the GNC engineering Responsible for the Entry Guidance, Entry Control and DRS triggering algorithm Responsible for the Functional engineering Simulators (FES) Responsible for the verification by analysis of the IXV GNC 3

4 MISSION ENGINEERING SCOPE The overall objective of the Mission Design activity is to provide the End-to-end Mission Engineering for the vehicle, which covers trajectory and Flight Mechanics. This core activity provides inputs for the specification of different subsystems as well as performance verification metrics Challenges: suborbital, narrow corridor, safety constraints AEDB / ATDB TPS GNC sensors & actuators Structure DRS Mission Analysis: trajectories and Flight Mechanics Launcher authority Safety Ground Segment & Operations Layout / MCI 4

5 VEHICLE CONFIGURATION A Robust Flight Mechanics Design: CoG & Trim Line Optimization E-2-E Design solution for Rarefied, Hypersonic and Supersonic flow Robust against uncertainties and AEDB evolutions Considers uncertainties, GNC and DRS needs, couplings Requirement for consolidation of AEDB and flap range derived CoG domain AoA corridor 5

6 MISSION PROFILE A feasible End-2-End trajectory from Lift-off to Splashdown has been calculated, covering Trajectory, Safety and Visibility aspects The required Injection Point confirmed as feasible by the Launcher Authority in all design loops 6

7 MISSION PROFILE Feasible Design trajectories have been identified Complete redesign of trajectory structure to make it feasible (PDR to CDR redesign) Single End-2-End Optimisation (SGRA proprietary code) Integration of ATDB to ensure automatic aerothermodynamics validation Fit within narrow corridor with margins for GNC Safety constraints respected (failure footprint and stages fallout) Compatible with large injection dispersions High fidelity environmental models Sizing trajectories as input for S/S Passive/active oxidation (TPS) Entry corridor

8 NOMINAL TRAJECTORY 8

9 FLYING QUALITIES PERFORMANCES Verification of Flight Mechanics performances (Monte Carlo) Uncertainties on Environment, State, MCI, GNC allocation Detailed validation of design solution (CoG and Trim) and margins: trim, FQ, couplings Identification of WC for GNC design Good FQ down to end of the Descent Recovery System (DRS) window FQ extended to cover DRS events (post-mortar) FQ predictions validated by 6DoF GNC close loop simulations 99% range with 90% confidence level Trim & stability FQ predictions VS GNC performances Monte Carlo campaign of 4000 shots

10 MISSION PERFORMANCES End-2-End Mission Performances (Monte Carlo): Uncertainties on Environment, State, vehicle properties 3 DOF Closed Loop Guidance, Nav & Control PF, 4000 shots From separation of AVUM to splashdown Compliance of mission constraints demonstrated Profile DRS ATD

11 MISSION PERFORMANCES Main trajectory performances: Orbital Entry Descent Phases Compliance of all constrains, in particular ATD, with further margins Guidance successfully compensates large EIP deviations Small dispersions at landing Similar results & conclusions obtained in GNC 6DOF simulations Support to DRS and D&L sequence identification After more than 7000 km of flight within the atmosphere the position error at the parachute deployment is less than 3 km. ACCURACY DESCENT

12 VISIBILITY Fundamental aspect to ensure all data recorded on board was available at ground before splashdown for redundancy wrt the o/b recorder. Visibility considered since first steps of mission design GS network: Fixed Stations: Libreville and Malindi (shared with Launcher Authority) for the orbital arcs Mobile Stations: station on island for the EIP (120 km) conditions station on Recovery Ship (RS) from end-of black-out to splashdown VISIBILITY FROM RS 12

13 SAFETY The target was to ensure no island, habited or inhabited, was falling within the safety footprint in case of failure: 10-7: only inhabited islands 10-5: no islands This design target was considered for mission design since first steps and verified though large safety 6DoF Monte Carlo campaigns. Safety Footprints 13

14 IXV: MISSION & FLIGHT MECHANICS AT OPERATIONS Activities conducted during the launch campaign: Before flight Perform flight preditictions Analysis of weather conditions, particularly in the range km altitude Computation of go/no criteria ISS collision risk go/no criteria Predicted trajectory update (splashdown coordinates) to support ship operations During flight Launcher injection orbit accuracy from IXV Telemetry High fidelity background propagation (splashdown coordinates) from several sources: Exo & Entry (4DoF), Descent (6DoF) Contingency propagations 14

15 IXV GNC Scope DEIMOS is co-prime, with SENER, of the Spanish GNC industrial team, which had to objective to Design, Develop y Validate the complete GNC subsystem for phases C,D,E The GNC subsystem provides the vehicle autonomy during all flight phases: prelaunch, launch, orbital, reentry and descent until splashdown. The key GNC products for IXV are The qualification of the GNC and its configuration for flight; The specification of the GNC for its implementation as code in the OBC; And the facilities for GNC testing: simulator (FES) y test bench (GNC SCOE) 15

16 GNC sub-system: a summation The IXV GNC represents the brain of the vehicle, providing autonomously in-flight the capability to: (G) Guide - know where to go (N) Navigate know where you are (C) Control fly the vehicle This capacity permitted IXV to fly a distance of 27,000 km from launcher separation, without burning up, with velocities up to Mach 30, and temperatures above 1600 degrees, to arrive at a precise point in the pacific ocean, with an error at splashdown of less than 10 km. 16

17 Challenges and Innovations of the IXV GNC Compared to other European re-entry vehicles, such as ARD, the principal technological innovations in the IXV GNC are The increased complexity and autonomy of the system: the vehicle flies 27,000 kilometres without ground intervention, covering multiple flight phases The necessity of new solutions for reentry guidance and control, driven by the use of a lifting vehicle without wings for re-entry gliding flight (first worldwide) and the use of aerodynamic surfaces (a European first) in combination with thrusters for reentry flight control actuation (a European first) Here DEIMOS was responsible for the re-entry Guidance and Control, making use of its heritage in atmospheric GNC 17

18 Verification and Validation of the IXV GNC The verification and validation of the GNC is a key process in the vehicle DDV, given the criticality and autonomy of the IXV GNC In IXV, the approach followed was: GNC algorithms design validation, using the IXV-FES (MIL) GNC functional and performance verification, using the IXV-FES (SIL) GNC subsystem verification and qualification by test, using IXV-FES (SIL) and TEF with IXV GNC SCOE (PIL, HIL) System verification, using PFM 18

19 FIRST RESULTS FROM FLIGHT (1/3) High level results observed during the campaign at the MCC Delayed launch from 13:00 to 13:40 UTC due to launcher operations Highly nominal flight at System level: all systems worked (RCS, TPS, GNC, parachutes, floatation devices, comms ) leading to a nominal the compliance of the mission objectives. Good performances of the launcher in terms of injection trajectory Good performances of the vehicle and GNC in terms of slashdown location

20 FIRST RESULTS FROM FLIGHT (2/3) Much less Black-out period than predicted: signal was received at the Recovery Ship soon after IXV was visible in the horizon (~60 km altitude). The splashdown point location was very close to the last prediction computed before entry (~ 1 km) even considering the passive 26 km descent under parachutes. The splashdown velocity was slightly higher than predicted FLIGHT PREDICTION The vehicle was retrieved successfully, with all data now recovered

21 FIRST RESULTS FROM FLIGHT (3/3) The experimental re-entry flight was successfullly performed using the combination of thrusters and flaps The vehicle performed left/right bank manoeuvres to fly within the corridor very close to the pre-flight prediction Thus, the accuracy reached by the GNC at the parachute deployment is deemed high FLIGHT PREDICTION

22 Conclusions IXV was successfully flown on the 11/Feb/2015, setting a new milestone in European Re-entry technology demonstration. 6 years of intense design and verification work were materialized in a flight of less than 2 h. Mission Analysis, Flight Mechanics and GNC activities have companied the vehicle all along its lifecycle, from design to verification, from verification to prediction and from flight prediction to operation, i.e. from paper to flight. The successful flight of IXV has not only qualified system and subsystems technology, but also the design methodology that DEIMOS has been developing in the areas of Mission Engineering, Flight Mechanics and GNC during the last 14 years. The success of IXV opens the door for Europe to start conceive and develop new novel space transportation systems, building on the heritage of IXV and its flight qualified systems 22

23 Questions? 23