The Leif Ericson provides a model for the Solar Strategic Command Cruiser Mk 1. There are others being introduced. Starship design is relatively new and there is a lot for humans to learn.
Solar Strategic Command Cruiser Mk 2 (Marco Polo)- The Mark 2 cruiser expands on the nose mounted laser emitter. Two wings on either side of the 'sail' each mount a similar emitter which works on the rules given in the Showing the Flag At the Icy Shores (8/15/14.) These emitters increase the chance of damaging the power plant to 11+. Power plant damage may shut down any or all of the three emitters (roll 10+ for each to check.)
The Mk 2 has more extensive wings and has a +1 to rolls made for wilderness refueling.
Solar Strategic Command Cruiser Mk 3 (Omar Bradley)- The Mark 3 replaces the complex arrangement of the triple emitter system with regular triple turrets. The fusion rockets are replaced with 645 tons of additional cargo or additional frozen watch and troops. These ships are often assigned support roles, landing troops, moving cargo or tending smaller scout craft.
Battlecruiser Mk X (No designation made public)- The Mk X is similar to the Mk 2 but has a larger displacement. Most of this is in a sixth deck over and around the shuttle bay/engineering section. No hard data has been released on this vessel.
Rumor- The Mk X is an attempt to address several critical design flaws in the SSC Cruiser. It has no linked emitters like earlier ships. The fusion rocket is removed in favor of more dependable thrusters and the shuttle bay enlarged to operate a squadron of boats.
Rumor- The Mk X has new particle beam cannons in place of the nose and wing lasers.
Rumor- The Mk X has a new extremely fuel efficient jump drive.
Rumor- The Mk X has components back engineered from alien technology found by archaeologists.
Rumor- The 'fuel tanks under the wings are actually probes or jump capable message torpedoes.
Custom drop tanks on the Mk X allow it to perform wilderness refueling while the tanks are in place. The tanks may not be for fuel but liquid cargo or bombs.