Are you confusing random access memory (RAM) with mass storage (disk) free space? 41G would be a high-end workstation, but is not a lot of free space on a 1TB disk.
The error message refers to org.jblas.NativeBlas.dgemm. You may need to install a fortran library, see https://forum.step.esa.int/t/error-with-applyorbit-operator-with-ers-envisat-slc-from-esar-on-the-fly-system/15141/2