Atv Jules Verne Mission Maneuver Plan
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ATV JULES VERNE MISSION MANEUVER PLAN P. Labourdette, E. Julien, F. Che a a, D. Carbonne Centre National d‘Etudes Spatiales 18, Avenue E. Belin, Toulouse, 31401, Cedex 9 On 03/09/2008, the first ESA Automated Transfer Vehicle (ATV , so-called Jules Verne, lifted off from Kourou aboard the Ariane 5 launcher towards the International Space Station (ISS . Af- ter several phasing, par,ing and rende-vous demonstration da.s, the ATV autonomousl. com- pleted its doc,ing to ISS with success on 04/03/2008. On 09/05/2008, the ATV undoc,ed ISS, then performed maneuvers to re-phase with the ISS and finall. initiated its reentr. over 0acific Ocean on 09/29/2008. This paper deals with the description of the actual maneuver and attitude plans computed b. the 12ES 3light 4.namic Team all along the mission. 1. INTRODUCTION ATV is a European Space Agenc. (ESA funded program5 the spacecraft is designed and built b. EA4S ASTRI78 Space Transportation and operated at ATV 1ontrol 1entre (ATV-11 b. the 3rench Space Agenc. (12ES . ATV is an unmanned vehicle contributing to the servicing of the International Space Station b. de- livering pressuri-ed cargo, providing ISS refueling, ensuring ISS re-boost and attitude control and, eventuall., removing the general waste no longer used on the station. In spite of the autonom. of man. subs.stems, for ATV-JV mission, man. maneuver plans were cal- culated b. the Tra9ector. team (TRA and up-loaded to contribute to the success of the mission. This paper will focus on the description of the maneuver plan designs and the solutions that have been set to cope with the Jules Verne mission, including the non nominal situations that have been met during the flight (debris avoidance, maneuver postponements . The detailed maneuver values have been described in :1;. This paper will also describe the 34S/TRA activities to compute the attitude profiles for forecasting and monitoring purpose and to generate the reference on-board frames. 1.1. Mission features AT generic mission. The generic ATV mission covers five phases5 • Launch and Earl. in-Orbit 0hase (LEO0 • 0hasing to Rende-vous interface • Rende-vous and 4oc,ing (R4V&4 • Attached 0hase • 4eparture / Re-entr. 1 Control Center. 4espite the fact that man. ATV vehicle subs.stems are autonomous, for all the phases (except the attached phase , man. 3light 4.namics activities are nevertheless performed on ground. The 3light 4.namics Subs.stem (34S , one of the ATV-11 components is mainl. in charge of ATV tra9ector. than,s to activities li,e ATV Orbit 4etermination (O4 , maneuvers computation and chec,ing of their reali-ation, attitude profiles forecasting and chec,ing, operational forecasting, G21 monitoring, debris collision anal.sis :2;. On the other side, the ISS absolute tra9ector. is provided b. the 8oscow 8ission 1ontrol 1enter (811-8 and the Houston 8ission 1ontrol 1enter (811-H . The accurate debris collision probabilit. is also provided, when needed, b. 811-H (TO0O based on the ATV tra9ector. provided b. ATV-11 (34S . Rende%vous and docking overview . A s,etch of the R4V phase is depicted in 3igure 1. One impor- tant point is the one that ma,es the interface between AOn-ground controlB and autonomous phase is called the R4V interface ( named S-1/2 . 2 1 Keep Out Zone (KOZ) ESC ESC 20 m (3500m, -100m) S4 V-Bar S2 250 m S3 Closing (39km, 5km) Approach Ellipsoid (AE) S-1/2 S S Homing 0 1 R-Bar Proximity link (R~30km) Figure 1. Rendezvous Phase Overview This R4V interface with the non autonomous phases is a point located on an ISS co-elliptic orbit, 5,m below and 39,m behind the station. This point, tuned at mission anal.sis level, is the result of a trade-off between the minimi-ation of the R4V phase duration and the necessar. time for the conver- gence of the Relative G0S navigation filter. This point must be reached with a prescribed accurac., to be compliant with the on-board algorithms (G21 and ISS safet. monitoring . AT propulsion. The ATV engines locations are presented in the vehicle overview showed in 3igure 2. The propulsion is composed of5 4 main engines (O1S - Orbital 1ontrol S.stem, isolated b. pairs 2x2x503.C2 that can be used dur- ing 0hasing, 0ost-escape and Re-entr. and for maneuvers exceeding 5 m/s. This ,ind of maneuvers reDuired a vehicle orientation (slew maneuver along the reDuired maneuver direction. 28 engines (A1S - Attitude 1ontrol S.stem, on the rear part 4 pods of 5 A1S, on the front part 4 pods of 2 A1S to perform guidance maneuvers less than 5m/s, attitude maneuvers and attitude control. 2 OCS Thrusters Rear ACS Thrusters Front ACS Thrusters Image: ESA/D. Ducros Figure 2. ATV Overview 3or the design of the maneuver strateg., propulsion dispersions are in Table 15 Table 1. Propulsion errors for scenario design O1S O1S O1S A1S A1S Thrust (along-trac, (cross-trac, (slew (along-trac, (cross-trac, 4uration E3F E3F E2G0.2 m/s E9F E5 F E4.3F 1.2. ATV specific first flight The first ATV mission, so-called Jules Verne (ATV-JV , differed from the generic mission5 ° It involved the demonstration of the ATV capabilit. to safel. underta,e rende-vous (4emo4a. 1 and 4emo4a. 2 both ending the proximit. operations with an escape maneuver , and the three successive approaches before 4oc,ing needed two ISS fl.-around, A0ost-Escape 1 (0E1 B or ATransfer to 442B with a duration of about 48h then A0ost-Escape 2 (0E2 B or ATransfer to 4oc,ingB with a duration of about 72h, (3igure 1 and 3igure 3 ° it had to demonstrate the capabilit. to perform a 1ollision Avoidance 8aneuvers (1A8 with the ISS (performed during the phasing , ° it reDuired a dedicated A1S test maneuver (AT to chec, a long propulsion as it is per- formed for the escape maneuvers (ES11, ES12 , ° as the Shuttle STS-123 mission was scheduled during the nominal phasing period, in or- der to compl. with flight rules of vehicles servicing ISS and to be robust to Ariane 5 launch de- la., a 0ar,ing 0oint was targeted after the phasing, waiting for the AGO 4ecisionB to start the proximit. operations, ° the Reentr. phase reDuired an ATV undoc,ing on the 5 th of September (before the scheduled 0rogress 300 doc,ing , as well as to target a reentr. area in eclipse optimi-ing the air- plane observationI this implied a 3 wee,s in-flight duration up to the reentr. instead of one or two da.s for the generic mission, ° the Reentr. phase reDuired an ATV re-phasing with ISS allowing the astronauts to ob- serve this phase than,s to 3IALKA experiment :1;, :2;. The Rende-vous proximit. operations during the 4emo4a.s 1 and 2 as well as the mission design implication reDuired b. the ISS safet. have been described in previous papers :1;, :2;, :3;, :4;. 3 2. OVERVIE, OF T-E MISSION P-ASES The overview of the whole mission is depicted in the 3igure 3. REENTRY RE-PHASING UNDOCKING DOCKING ATTACHED DEMODAY 2 PE2 UNDD DEMODAY 1 PE1 2 ESC PARKING 1 LEOP PHASING ESC R P -1/2 -1/2 -1/2 S S AP AP S Launch CAMD .2Sep .0 29Sep .0 .1Apr.0 .9 Mar .9 .0 13.0 Mar 19.0 Mar Mar 29 .0 29.0 Mar Figure 1. Mission Phase Overview ATV-JV was launched to the ISS from the European spaceport in 3rench Guiana b. an Ariane 5 launcher on 9 8arch 2008 at 4503504 G. The launcher placed the spacecraft into a 2C0,m circular orbit at 5509543. The ISS orbited on a 355,m circular orbit. The orbital period (T was about 90 minutes. The LEO0 phase lasted around 2 revolutions encompassing several vehicle operations to get read. for the first transfer of the phasing period. The in9ection parameters were inside the 3 σ expected disper- sions. 1. P-ASIN4 1.1. Phasing duration The phasing duration depended at first order on the differential altitude and on the phase angle be- tween ISS and ATV. 8oreover, there was onl. one launch opportunit. each da. as the launch had to be performed on time. In order to be robust to a launch dela. and to the uncertaint. of the doc,ing da., maneuver schemes had to fit with an. phasing angle. 3urthermore, these schemes had to target the same Aimed 0oint (A0 in case of a launch dela. up to 3 da.s. In order to save fuel, nominal drifting orbit below in9ection orbit had to be avoided. The aimed point arrival time had to compl. with constraints as Russian Ground Segment visibilities and no da--ling of the sensors. All these constraints led to a minimum phasing duration of about 10 da.s. G All times in the document are given in 7T1 time 4 The traffic of spacecraft in the period of the ATV doc,ing opportunities led to aim at a par,ing point (A0 0 , instead of the nominal S -1/2 . The 0ar,ing 0oint was chosen as a stationar. point located 2000,m in front of ISS. This point permitted to compl. with ISS safet. constraints and necessitated few Station Keeping (SK maneuvers. As there was no constraint for the A0 0 then the arrival time was fixed on the 03/19/08 at 12500500 (phasing durationJ10.3da.s Indeed for operational simplicit. and robustness (procedure, training of operators , it was decided to ,eep the same phasing duration and maneuver schemes.