This streamlined 300-ton (SM +7) vessel is actually an aircraft rather than a spacecraft. Transported by cargo ship to a Saturn-type gas giant, it is released into the atmosphere to function as a mobile gas-mining system.

The aircraft is propelled by nuclear thermal engines operating in ramjet mode, which use the atmosphere as reaction mass. It remains aloft for years at a time. The cruiser has provisions for the crew that performs onboard maintenance, usually working in nine-month shifts, but some operations use robots.

Mining operations take place just below the lower cloud layer where the pressure is about 10 atmospheres. The refinery’s reactor-powered pumps suck in atmospheric gas, which is cooled and liquefied by refrigeration units. The hydrogen is then separated from the helium and used as part of the cooling mechanism, after which it is dumped. Next, the rare helium-3 is separated from the more abundant and heavier helium-4, a process possible because the lighter isotope behaves differently at cryogenic temperatures. The helium-3 is stored for retrieval and the helium-4 dumped overboard. About 130,000 tons of raw atmosphere yields one ton of helium-3. As the Tempest’s refineries process 20 tons an hour, this takes about 270 days.

The Storm Bird-class shuttle rendezvouses with the cruiser every nine months to retrieve the helium-3, but it can store up to 11 years' worth (15 tons) of helium-3.

Front Hull System

• [1] Metallic Laminate Armor (dDR 5).
• [2-3] Fuel Tank (15 tons each; used for raw atmosphere).
• [4-6, core!] Chemical Refineries (five tons/hour each).

Central Hull System

• [1] Metallic Laminate Armor (dDR 5).
• [2] Habitat (one cabin and one bunkroom).
• [3] Engine Room (one workspace).
• [4] Habitat (one-bed automed sickbay and fivetons cargo).
• [5] Control Room (C5 computer, comm/sensor 5,and three control stations).
• [6] Fuel Tank (15 tons; used for processed helium-3).

Rear Hull System

• [1] Metallic Laminate Armor (dDR 5).
• [2-3] Nuclear Thermal Rockets (ram-rockets; 0.5G acceleration each).
• [4-6, core] Fission Reactors (one Power Point each).

It is winged. Crew consists of a pilot, an engineering officer, and four refinery technicians.