We report precision mass measurements of neutron-deficient gallium isotopes approaching the proton drip line. The measurements of <math><mmultiscripts><mi>Ga</mi><mprescripts/><none/><mrow><mn>60</mn><mo>–</mo><mn>63</mn></mrow></mmultiscripts></math> performed with the TITAN multiple-reflection time-of-flight mass spectrometer provide a more than threefold improvement over the current literature mass uncertainty of <math><mmultiscripts><mi>Ga</mi><mprescripts/><none/><mn>61</mn></mmultiscripts></math> and mark the first direct mass measurement of <math><mmultiscripts><mi>Ga</mi><mprescripts/><none/><mn>60</mn></mmultiscripts></math>. The improved precision of the <math><mmultiscripts><mi>Ga</mi><mprescripts/><none/><mn>61</mn></mmultiscripts></math> mass has important implications for the astrophysical <math><mrow><mi>r</mi><mi>p</mi></mrow></math> process, as it constrains essential reaction <math><mi>Q</mi></math> values near the <math><mmultiscripts><mi>Zn</mi><mprescripts/><none/><mn>60</mn></mmultiscripts></math> waiting point. Based on calculations with a one-zone model, we demonstrate the impact of the improved mass data on prediction uncertainties of x-ray burst models. The first-time measurement of the <math><mmultiscripts><mi>Ga</mi><mprescripts/><none/><mn>60</mn></mmultiscripts></math> ground-state mass establishes the proton-bound nature of this nuclide, thus constraining the location of the proton drip line along this isotopic chain. Including the measured mass of <math><mmultiscripts><mi>Ga</mi><mprescripts/><none/><mn>60</mn></mmultiscripts></math> further enables us to extend the evaluated <math><mrow><mi>T</mi><mo>=</mo><mn>1</mn></mrow></math> isobaric multiplet mass equation up to <math><mrow><mi>A</mi><mo>=</mo><mn>60</mn></mrow></math>.< Réduire