Issues of data integrity are handled by error-control codes. The first pictures transmitted from the back side of the Moon in the late 1960's were in black and white, and of poor quality. More recent pictures returned from much greater distances using the Voyager series of planetary probes were beautiful high-resolution color images with no apparent lost data. Supercomputers perform billions of operations per second, and must store and retrieve vast amounts of data. But mostly better mathematics.
Larger computers can often correct multiple errors.
The error-correction capabilities of the Voyager project were far greater than have thus far been required and have resulted in thousands of flawless pictures being sent back to Earth to be analyzed. Improvements in computer hardware since the 1950's have been incredible. In pushing technology to its limits, we are restricted by the physical size of atomic particles and the speed of light. Scientists are now considering the use of clean rooms in orbit to eliminate the few stray particles that contaminate Earth-bound labs. In spite of these dramatic changes, the increase in speed due to improvements in mathematical algorithms have been even more spectacular.