▁with ▁four ▁reaction ▁whe els ▁and ▁twenty - four ▁thrust ers ▁with ▁ 1 , 3 4 6 ▁kil og rams ▁of ▁prop ell ant . ▁The ▁prop ulsion ▁system ▁is ▁a ▁ ▁high ▁thrust , ▁mon om eth yl ▁hyd raz ine / nit ro gen ▁t etro x ide ▁b ip rop ell ant ▁system ▁for ▁larger ▁man eu vers ▁and ▁a ▁lower ▁thrust ▁hyd raz ine ▁mon op rop ell ant ▁system ▁for ▁minor ▁orb ital ▁corre ctions ▁during ▁the ▁mission . ▁Of ▁the ▁b ip rop ell ant ▁thrust ers , ▁four ▁located ▁on ▁the ▁a ft , ▁provide ▁ 4 9 0 ▁new tons ▁of ▁thrust ▁for ▁course ▁corre ctions , ▁control ▁of ▁the ▁space craft ▁during ▁the ▁Mars ▁orb ital ▁insert ion ▁man eu ver ▁and ▁large ▁orbit ▁corre ctions ▁during ▁the ▁mission ; ▁another ▁four , ▁located ▁on ▁along ▁the ▁sides ▁of ▁the ▁space craft , ▁provide ▁ 2 2   new tons ▁for ▁cont rolling ▁roll ▁man eu vers . ▁Of ▁the ▁hyd raz ine ▁thrust ers , ▁eight ▁provide ▁ 4 . 5   new tons ▁to ▁control ▁orbit ▁trim ▁man eu vers ; ▁another ▁eight ▁provide ▁ 0 . 9   new tons ▁for ▁offset ting , ▁or ▁" des atur ating ", ▁the ▁reaction ▁whe els . ▁To ▁determine ▁the ▁orientation ▁of ▁the ▁space craft , ▁a ▁horizon ▁sensor , ▁a ▁ 6 - sl it ▁star ▁sc anner , ▁and ▁five ▁sun ▁sens ors ▁were ▁included . ▁ ▁Communic ations ▁