Flash memory wears out with use, just as you said. Use being read/write cycles. In the case of a 120GB drive being used as described above a read/write cycle is only going to happen once every 2000 hours. Combine this with the fact that "Most commercially available flash products are guaranteed to withstand around 100,000 P/E cycles before the wear begins to deteriorate the integrity of the storage". Once again doing the math 2000 hours per cycle by 100,000 cycles is about a 200 million hour lifespan of continuous use. 24 hours/day, 365 days per year...so that is somewhere north of 22 thousand years!
Yes, this is all very nice and all that but you must meet the following:
Number of channels ................. 4
Impact tolerance ...................... 3400 Gs /6.5ms
Fire resistance .......................... 1100 deg C /30 min
Water pressure resistance ........ submerged 20,000 ft <<< 8900 psi
That's just the executive summary.