I mentioned how a Fat Merchant compared to the C-5M and 747 cargo variants.
What about the Shuttle?
The cargo capacity of the Space Shuttle is around 50,000 lbs or 25 sTon. The actual amount of cargo varies a great deal depending on the mission and orbit, but we're going to use 50k lbs. The volume of the cargo bay is near 10,426.15 cu ft or 20.85 dTons. 0.83 sTon per dTon. Much lower density than the assumed break-bulk cargo capacity of any Traveller ship.
It's earth to orbit time is going to stomp most Traveller cargo ships since the solids and mains give between 1.5 to 2.5g during their run and the mains alone build from 1 to just over 3g after dumping the solids. Of course, it's tossing away a huge hunk of the ship in the process of making orbit.
Even the lowliest of small craft in Traveller stomp the living guts out of anything actually flown when you attempt to get past low earth orbit. There's no coasting on a trip to the moon in a 20 ton launch (LBB-2). It runs full acceleration all the way to turn over then full acceleration to make lunar orbit. A whole three and a half hours instead of the Apollo 75.8.
That same launch gets to Pluto in 17.91 days and stops there. It can get there for a flyby in 8.96 days. Our best time to Pluto is nine freaking years and that's sending a robot to take pictures as it flings past (no chance of stopping). We're not going and we don't have the means of going.
All Traveller does to get this amazing performance is to break physics. I'm jealous, I'll tell you what.
Traveller Tuesday officially belongs to Erin, I'm just dangling from her coat tails on the idea.