What would logistics and container ships look like?

In my opinion 1mg may be too little?
Maybe add another set of 20 MPDs burning xenon or krypton that have higher thrust/power on the opposite end of the ship?

1mg can escape from all but deepest gravity wells; you just have to ignore Hohmann transfers and constantly do short, outwards+forwards burns. It's horridly dV inefficient, but with MPD you have dV to burn and no thrust at all.

Or you can use tandem drive.

Here are some offerings from Altarris Heavy Industries:

"The ingenious engineers of Altarris's Ne Plus Ultra Special Projects Department have returned once again, this time in the purely civilian Virgo Product line. Today, we announce our newest release, the [Virgo] Highliner - the fastest Saturine-Martian Passenger transport in existence! For a mere 1.03 Gigacredits, this luxurious and absurdly fast transport can be yours!"



"Like all Ne Plus Ultra designs, the Highliner generates 200 gigawatts of power to pump an MPD, achieving incredible fuel/speed efficiencies, and dramatically cutting travel times."

"However, we are aware that some retarded special needs captains may wish to take their ship deep within a planetary gravity well, instead of having his passengers board via personnel shuttles or dV-minimizing orbital tetherhooks. For these situations, they can activate up to six Methane Nuclear-Thermal torches and produce nearly 90 miligravities of acceleration, more than sufficient for Hohmann transfer from even Venusian low orbit! Please be aware that applying full drive thrust while in low Jupiter or Uranian orbit is beyond the safe structural integrity rating of the Highliner's Frame and may void your warranty."




"Moving over twenty thousand passengers in luxury, the Highliner has seperate Economy, Business, and First Class sections, in addition to seperate Crew Compartments. In a pinch, the Highliner's 7 kiloton cargo bays (normally for shipping First Class client's belongings) can load additional passengers. And of course, the Highliner includes the Award-winning "CancerBGone¹" Anti-Radiation Armor Schema, featuring heavy Boron and Lithium-6 shielding; guaranteed under 25 mSv yearly dosage!"

1. Guarantee does not apply to travelling in Van Allen Belts, within Io's orbital Shadow, or sustained nuclear bombardment. Please refer legal questions to the Ganymede Department of Justice. 

"For mercantile captains that can't put up with crowds of other people not strictly under their control (we feel your pain) Ne Plus Ultra has developed the [Virgo] Megafreighter!"



"New colony ran out of XY or Z? Both sides of a civil war want to buy missiles from you? Want to hide a fleet in your cargo bays? Carrying up to seventy kilotons of cargo (not counting fuel delivery possibilities), the Megafreighter's possibility of making money is only limited by your imagination, and has won the Capitalist of the Year award from New Libertarian Magazine! Buy now for a low introductory price of 634 Megacredits²!"

2. Offer available while supplies last. Promotion is unavailable in Mercurian and Uranian Orbits. Additional Shipping and Handling expenses may be added for Cerean deliveries.




"And, of course, the award-winning Radiation-shielding scheme has shown to increase crew morale by 43%! Imagine that, a crew deciding not to mutiny simply because they aren't dying of radiation poisoning! Who would have thought?"

"Finally, the long awaited Methane conversion of the original [Cygnus] Ultratanker; the [Virgo] Ultratanker. Found yourself with a futures contract for 300 kilotons of Methane? We're here to help!"



"Avoid Bankruptcy! Go really fast! Refuel other multi-hundred kiloton Methane hogs! The Ultratanker, now utilizing the most widespread Civilian fuel, is available for only 772 Megacredits!"

---

I'll post up more tomorrow. In addition to 300kt 200 GW long range monster craft, I've designed an extensive line of smaller, cheaper refuelers and utility vessels. [Altarris] is my tag for most military objects, using Decane, [Cygnus] is granted to Decane-propelled unarmed logistics vessels, whilst [Virgo] is the purely methane-using Civilian line of products.

Contrary to what you might think, I think a cargo ship would have at least marginal armour - in order to protect against micrometeorites.

Also, those reactors seem maybe a bit unreasonably powerful for what a civilian ship could have - I do not think civvies would be allowed to run weapons-grade fuel, maybe 10% enrichment maximum.

My [Cygnus] line use Decane because they support Decane-fueled warships (which use Decane to reduce cross section and increase armor efficiency).

I see civilian ships using Methane if we enter a energy-rich version of CoADE or where the gas giant systems are heavily exploited; it doesn't leak the way hydrogen does, and is far more easily extracted/processed/stored than Hydrogen. Plus, production of Hydrogen usually means the catalytic destruction of water - another precious resource in space.

Thus, the [Virgo] line uses Methane propellant.

Who an enforce enrichmment limits when reaction wheels running 10 times faster then any modern isotope separation centrifuges are avaliabe? Magnetic bearings in 0G with plenty of power are a child's play.

Yes I see a noticeable difference.  Don't have time right now to make examples.  I'm guessing 25GW methane MPD would only get up to the 180Km/s ballpark.  I've also been assuming that cargo ships would want to minimize propellant mass ratio for a given delta-V to maximize cargo capacity. 

Why use nuclear-thermal instead of resistojets? You should have enough available power from the (now unused) MPDs, resistojets are way lighter and cheaper, and you can reach higher temperature, and as such higher efficiency.
My dual-engines are always MPD/resistojet for this reason.



You do like ominous ship names, don't you?
(Also, does it come with pre-installed hypometric weapons?)