It's one more canon aspect of Traveller, handed down from Marc Miller, pbuh: Individual Travellers may seek immortality, and might even find it through some form of technology, but immortality is never for the masses.
However, I can well imagine routine rejuve treatments being made available in high tech worlds: pop in, spend a few hours in a tank having your telomeres torn apart and reset, and when you come out you'll be physiologically whatever age you set your body as, but your aging clock's been reset at zero, and you get one free term with no aging rolls before the aging rolls begin all over again.
It'd be available to anybody, but there is a waiting list - and the waiting list is notoriously long (you could suffer an aging roll before you get to 100th place in the list), so the race would always be on to obtain bootleg rejuve booths and to reverse engineer rejuve technology.
Aging pirates might risk everything - capture, spacing, destruction of their ships - just to obtain one data crystal containing reliable blueprints for a working rejuve booth, so they could get their own rejuve operation going and rake in millions from those few people who have more cash than sense, and who would pay a fortune to reset their nonagenarian bodies with their aching joints and give them even a few months of moving freely and not stinking of liniment for a time. Never mind the thrill of capture and being held for ransom, or being blackmailed afterwards for supporting organised crime.
Think of how the Travellers could be hired for such an endeavour.
Edit: AAAAND just as I posted this, I thought "Sarcophagus technology from Stargate."