Freelance Traveller

Osgood-class Long Range Scout

by Jeffrey Schwartz

This article originally appeared in the July/August 2023 issue.

Hundreds of years ago, a much younger Third Imperium ran a TL12/J3 X-boat route. As technology improved, those X-boats were run on shorter routes until it was worthwhile to standardize on the modern TL14/J4 X-boats, at which point the older J3 ships were mothballed.

In 1113, the IISS found them in old inventory and checked the parking orbit. They were neatly shut down and in long term storage.

A group of engineers over drinks started playing with the idea of making some kind of good use of them.

Examining them, there were a few interesting things. For one, concerns about mis-jumps meant the ships carried a reserve 10 tons of fuel for a J1 to hopefully find civilization if they found themselves off course.

For another, they were intended to carry more high-priority cargo, and had a cargo lock at the back of the ship to allow large objects (Navy spare parts for example) in and out in one piece.

The older tender design didn’t internally dock the X-boats, instead latching to them with grapples. The idea was put forth to use those grapples to handle subcraft.

And thus the Osgood class was born...

The power plant and J-drive at TL-12 predated reliable room temperature superconductors. Modern spare parts were used in the refitting, greatly reducing the size of the drives. As a bonus, drive fuel usage was reduced. There was no real way to convert fuel space to usable hull volume, so the total bunkerage was maintained.

There was, however, no good way to install an M-Drive. There just was not the large exterior fitting space needed in the shapes needed for it to work.

Instead, the cargo lock at the rear of the ship was converted. A TL-13 superconducting conduit was put in to handle plasma from the fusion reactor, and a set of pipes to handle fuel from the tankage.

Both of these went to a modern (TL-14) version of a HEPlaR (High Energy Plasma Rocket). The extra fuel bunkerage would give two usable “burns”—enough to go from 100D jump point, to a stable 10D orbit around a world, and back out to 100D. The HEPlaR would max out at 2G,which was well within the existing inertial dampener performance.

The grapples would hold a refuelling drone and an exploration lander, with the third grapple left open for future use.

When refit cost, fueller cost, and lander cost were totalled up, the conversion would be just a bit less than a new Type-S… but when fully fuelled, could make a total of 5 parsecs without refuelling. This would be useful on survey missions which involved crossing rifts, or exploring inside rifts for brown dwarf refuelling points.

Overview

The TL-12 X-Boat predates the TL-14 “ice cream cone” design, but there are some similarities. The Osgood has a spherical front section, with an open-frame “tail” that originally held the folding radiators used to dump fusion plant heat before room temp superconductors reduced the problem to more manageable proportions.

When the fusion plant was powered down to idle, the grapples on the long tail were used to externally dock to a tender for refuelling. In those ancient TL-12 days, major repairs were EVA rather than inside the tender’s hangar.

(Visual : Picture the Discovery from 2001: A Space Odyssey, but with no engineering section at the back)

With the tech upgrade, the radiators are removed, and the grapples along the frame are used for the subcraft.

The Osgood is a 10 meter radius globe with a 30 meter long, 3 meter by 3 meter truss trailing it. There are grapples every 10 meters on the upper side of the truss.

Inside the globe, from bow to stern, are:

• Deck 1:
  • Bridge: 3 spacious consoles and a Model 2/bis computer. A hatchway in the floor leads to the lounge.
• Deck 2:
  • Central lounge: 4 dtons
  • Ventral from the lounge is a 1dton fresher.
  • Port is a double stateroom intended for passengers. Often used by Captain and XO. Considering that in normal ops, the XO is off in the lander about half the time.
  • Starboard is a 0.7 dton room with a medical console (mini-autodoc) and a Counsellor (small booth with a Psych-doctor AI)
  • Dorsal is a 6 dton, luxurious cabin intended for the X-boat pilot who would be living aboard ship for a year, with its own private fresher. In practice, most Osgood long range survey Captains don’t use this cabin, and bunk with the XO in the double stateroom. This cabin gets rotated through the crew for a week at a time… nominally. This gives a little vacation and de-stressing. On other ships, it’s used as a game room/destress zone.
  • The ladder from Deck 1 continues down
• Deck 3:
  • 42 dtons fuel
  • TL12/Mod Type-B fusion plant
  • TL12/Mod Type-B jump drive
  • A total of 11 dtons of unrecoverable space. These are a few cubic meters here and there, little of which are a continuous dton. Enough space was found to put in 4 spacer niches, for expanded crew. In the Osgood long range scout concept, the random spaces are filled with spare parts and expendable life support items to increase the ship’s range before resupply.
• Deck 4:
  • 3 dton cargo bay
  • 1 dton cargo vault
  • 1 dton ship’s locker optimized for emergency repairs
  • Dorsal is a personal lock for passing to/from the tender.
  • Ventral is a 1 dton life capsule with 150 person/days of life support, a single use de-orbit rocket and parachutes. This is an off-the-shelf design with very cramped seating for 10 people.
  • In the center of the deck is a vac-hatch to the tube that runs down the tail. This used to be part of the cargo hatch system in the old design.
• Tail:
  • A 1.5 meter diameter tube, left in zero-G
  • At 5, 10, and 25 meters back are 90 degree turns to dorsal which lead to the grapples. These are small (2 meter diameter) docking locks that allow egress/ingress with the subcraft. Outside the tube and inside the 3×3 meter truss is lots of piping.
• HEPlaR:
  • This is a 3 meter in diameter engine bell at the end of the tail. There is no hatch to this device, any service must be done EVA

Refuelling drone

This is a 14 meter diameter, 9 meter long stubby cylinder with fins that unfold. It has a grapple point on the “port side”,and a rounded nose with obvious fuel scoops.

It is G-Drive powered, pulling a max of 6G when within 10D of a world, and 0.06G outside the 10D limit.

The G-Drive takes up the core of the cylinder. Just behind the nose is a small cockpit with a cramped console, but the computer 0/bis is set up as a dedicated autopilot/automatic fuel scoper so this cockpit is rarely used.

The drone does have a purifier and pump system aboard. The pumps are powerful enough to allow the 15 tons of fuel in the tankage wrapped around the engineering core to be flooded into the ship’s tanks fast enough to treat the pod as a drop tank. (i.e., fuel can be used directly for jump)

Sensors are limited to very short range radar/lidar.

The drone is set up to be able to land in water for water-world refuelling, and has wilderness landing legs to allow it to be fuelled from starports, even type-X ports. (It's a tail lander, with a hatch on the underside)

The drone brings aboard 15 dtons of fuel at a time… the parent ship can hold 42, so it could take as many as 3 trips to refuel. A typical refuel cycle for a gas giant is about 7 hours down, 2 hours scooping and 7 hours back up.

Lander/Explorer

Externally very similar to the refuelling drone: 9 meters long, 14 meters in diameter. Landing legs for tail-landing, fold out fins. The tail hatch is upgraded to a full airlock.

The Explorer uses a 3G M-Drive as found in the common ship’s boat.

The small bridge at the nose has 2 standard consoles and a third (cramped) engineering console. A Model 0/bis computer is aboard,patched into the Scope (S7), EMS (S7), Deep Radar (R7) sensors.

At the nose is a remote-operated triple turret. As initially built, no weapons are mounted. The intent was pulse laser/missile/sand.

The deck below the nose has a 0.5 dton fresher, 4 spacer niche micro-cabins, and a small common/galley area. Life support covers 300 person-days.

The next deck down contains a 2 dton medical clinic and an air/raft hangar. (The IISS is very insistent that survey teams have an air/raft)

The deck below is a 3 dton cargo bay, limited by the personal airlock on the “port” side floor, so only 2m×2m×2m objects can be loaded/unloaded. There is a simple winch mounted on the deck head above the floor airlock. One wall of the cargo bay has the ship’s locker, which is mostly loaded for planetside operations.

One key feature of the gravitics on the Lander: the central ladder/shaft is set up so that it can easily be set to zero-G, even if landed planet side. The logic here was that in an emergency, a casualty can be brought in the airlock, and “shoved” all the way to the medical clinic without them having to climb or be carried.

Operational concept

Day 0:

Jump into system, 100D from refueling point
Initial HEPLAR burn to begin move to refuelling planet. (1.6 dton fuel)

Day 1-2:

Coast. Crew uses Ship and Lander sensors to do local survey. May deploy lander to get a longer baseline between scopes.

Day 3:

Orbit entry/circularization HEPLAR burn. (0.16 dtons fuel)
Deploy refuelling drone
Deploy Lander to nearest interesting world

Day 4-5:

more system survey while en route
Refuelling drone finishes refuelling ship

Day 6:

Lander orbits and begins close survey

Day 7:

Lander finds landing point, does planet side survey

Day 8-16:

Lander crew continues planet side survey

Day 17:

Lander lifts.

Day 18-20:

flight back to Ship. More local survey.

Day 21:

HEPlaR burn to break orbit, head for 100D point (1.6 dtons)

Day 22-23:

coast

Day 24-30:

Jump for next destination

(The tables above are from the author’s construction spreadsheets)