  Galaxy clusters are the most recently formed and most massive,
gravitationally bound structures in the universe. The number of galaxy clusters
formed is highly dependent on cosmological parameters, such as the dark matter
density, $\sigma_8$, and $\Omega_m$. The number density is a function of the
cluster mass, which can be estimated from the density and temperature profiles
of the intracluster medium (ICM) under the assumption of hydrostatic
equilibrium. The temperature of the plasma, hence its mass, is calculated from
the X-ray spectra. However, effective area calibration uncertainties in the
soft band result in significantly different temperature measurements from
various space-based X-ray telescopes. NuSTAR is potentially less susceptible to
these issues than Chandra and XMM-Newton, having larger effective area,
particularly at higher energies, enabling high precision temperature
measurements. In this work, we present analyses of Chandra, NuSTAR, and
XMM-Newton data of Abell 478 to investigate the nature of this calibration
discrepancy. We find that NuSTAR temperatures are on average $\sim$11% lower
than that of Chandra, and XMM-Newton temperatures are on average $\sim$5% lower
than that of NuSTAR. This results in a NuSTAR mass at $r_{2500,Chandra}$ of
$M_{2500,NuSTAR}=3.39^{+0.07}_{-0.07}\times10^{14}$ $M_{\odot}$, which is
$\sim$10% lower than that of $M_{2500,Chandra}$ and $\sim$4% higher than
$M_{2500,XMM-Newton}$.
