This　paper　proposes　a　new　ITPS　panel　with　special　corrugated-core　webs　which　are　designed　with　cutouts　for　weight　saving.　The　structural　design　problem　was　formulated　with　mass　per　unit　area　of　the　ITPS　as　the　objective　function　and　some　functional　requirements　as　constraints.　We　developed　the　optimizer　fulfilling　both　thermal　and　structural　functions　for　minimal　areal　density.　The　optimization　problem　was　solved　by　interpolating　the　residual　error　of　response　surface　approximation　(RSA)　with　Radial　Basis　Function　(RBF)　to　establish　the　improved　RSA　(IRSA).　The　400　preliminary　design　points　were　obtained　using　Latin　Hypercube　Sampling　method.　The　quadratic　polynomial　RSA　of　the　ITPS　sandwich　panel　performance　was　generated　by　the　least　squares　method　(LSM)　based　on　finite　element　results　and　IRSA　was　used　to　optimize　the　constraints.　Transient　heat　transfer,　stress　and　buckling　analyses　were　conducted　using　finite　element　method　(FEM).　Finally,　a　new　ITPS　panel　with　optimal　dimensions　was　obtained.　The　optimization　results　show　that　the　areal　density　of　the　new　ITPS　panel　decreases　by　26.27　%　compared　with　the　previous　research,　which　proves　the　potential　of　this　new　design　optimization　method　for　the　future　spacecraft　vehicles.