DITAN: A TOOL FOR OPTIMAL SPACE TRAJECTORY DESIGN Massmano Vase Deparmen o Aerospace Engneerng Gasgow Unversy Gasgow Ruedger Jehn ESA/ESOC
Inroducon o DITAN Fna Remarks Agenda Oune
DITAN (drec Inerpaneary Trajecory Anayss s a genera purpose oo or he souon o opma conro proems. I mpemens a Drec Fne Eemens Transcrpon (DFET o he opma conro proem no a nonnear programmng proem (NLP The souon o he resung NLP s perormed y he sparse SQP opmser SNOPT The specc opma conro proem mpemened n DITAN aows o desgn ow-hrus mupe gravy asss rajecores. Inroducon o DITAN
Deveoped under ESA/ESOC conrac or ow-hrus mupe gravy asss rajecores Open sysem or genera rajecory desgn ased on Drec Fne Eemen Transcrpon (DFET and SSQP Forran 77 code has SNOPT (source code as NLP engne Severa dynamc modes consrans and ojecves can e mpemened Auomac mesh grd adapvy s ncuded Inroducon o DITAN
user s/w core Dynamc Mode Agerac Consrans DFET Dscresaon Boundary Consrans Phase Assemy eerna Ojecve Funcon NLP Proem Inpu Frs Guess NLP Sover Pos Processng Oupu DITAN: Soware Logc
Boundary Nodes Gauss Pon s Boundary gap s The Tme doman s decomposed n ne eemens eadng o a poynoma deveopmen o he souon on specra ass (Gauss Pons D N D ( 1 1 Drec Transcrpon y FET
Boundary Nodes Gauss Pon s Boundary gap s Derena consrans are epressed n weak orm eadng o dsconnues a oundares Hgh Inegraon order 2n = 2k+2 w T F d w T ( Drec Transcrpon y FET
Opma Conro Proem DFET NLP Proem mn J(y c( y where c ( y q 1 s G ( (! s w ( k u s ( T s y u y=[u ] T ( w k ( T F ( s 2 j w T p 1 j w T 1 j 1 SSQP Sparse Sequena Quadrac Programmng Drec Transcrpon y FET
DITAN aows he ncuson o a genera se o rea parameers and reaed consran and ojecve uncons J ( p L ( u p d mn J( y ẋ F( u p G( u p c( y y u ( p y=[ s u s p] Paramerc Opmsaon
Inroducon Muphase Approach ( J u Inerphase-nk Consrans ( u F ẋ ( u G ( ( ( ( ( 1 1 1 ( nk Phase Assemy NLP Sover ( p DITAN aows he souon o proems wh a ne numer o dsconnues mupe reerence rames mupe dynamc modes and mupe ojecves hrough a muphase decomposon o he rajecory. Phases can e sequena or parae.
Mupe swng-y ow-hrus Trajecores: SOLO Bep Coomo Europa Mars Eooogy Puo Proe NEO Rendezvous Rousness Opmsaon Opma NEO nercepon and devaon Muojecve and Pursu-Evason Proems Mars ree-reurn Trajecores Moon WSB Transers Eampes o Appcaons
3 varaes and consrans or he NLP proem 4 o 7 swngys resonan ors more han 2 swchng pons Eampe o Maa oupu or a BepCoomo Trajecory SOLO and BepCoomo
6-7 varaes and consrans or he NLP proem 14 swngys resonan ors varae hrus Varae reerence rames Europa
1-7 varaes and consrans or he NLP proem parae phases mupe ojecves Mupe swngys Puo Proe Two Inerpaneary parae phases rajecory a Juper passage
1-3 varaes ad consrans. Varae hrus and varae I sp Mean ora eemens or muspra escape rom he Earh NEO Rendezvous
1-2 varaes and consrans mupe ojecves mnmsaon o he unceranes and o he epeced vaue o he ojecve Rousness Opmsaon
Zero-sum derena game Mupe ojecves Reconsrucon o he correc agrangan mupers o he opma conro proem Muojecve and Pursu-Evason Proems
2-4 varaes and consrans 1-14 swngys Impusve and ow-hrus Mars ree-reurn Trajecores and Lowhrus Cycers
1-15 varaes and consrans Hghy nonnear and unsae dynamcs Impusve manoeuvres Moon WSB Transers
New eaures: Improved user nerace: easer edng o he npu es New graphca user nerace or rajecory represenaon Transer coas arcs can e anaycay propagaed: aser souon o MGA wh chemca propuson Transer arcs can e mpored and eded New Feaures
New eaures: Eended daaase o ceesa odes: aserods and comes daaase updaae New ses o oundary condons: numercay or anaycay propagaed ors New se o ojecve uncons: or nseron v wh gravy osses sagng. Amospherc egs: aerocapure Resrced hree-ody dynamcs New Feaures
DITAN has een eecvey apped o he souon o many msson desgn proems. A maon ess on he mamum dmenson o he proems ha can e soved. An mproved NLP sover s requred and s under deveopmen a presen Snce many proems have a hyrd srucure (med neger-rea varaes he new NLP s conceved o acke hyrd proems.