```r
r_stack = stack(raster_in_memory, raster_on_disk)
r_stack
#> class : RasterStack
#> dimensions : 1428, 1128, 1610784, 2
#> resolution : 30, 30
#> ...
#> names       :   layer, landsat.1 
#> min values  :       1,      7550 
#> max values  : 1610784,     19071
```