Sunday, October 12, 2014

Wilderness Refueling

A squadron costing 900 billion credits (they got 10% off for using standard plans) has to refuel from a local gas giant. In order to be considered capable of refueling on a squadron level 10% of their fuel tankage must be carried on partial or fully streamlined hulls. Trillion Credit Squadron says the squadron refuels in one week. Too long? Let's run some numbers.

First assuming the squadron can make 3 gees a trip to the nearer gas giant (600,000,000 km) will take 78 hours or about three days according to the Traveller Book (TTB p. 54). The Ancients set up gas giants at this distance to standardize refueling operations and it was a bitch.

That leaves four days to conduct refueling of the squadron. That means in four days the refueling vessels will make 10 trips. they could have more time to refuel if the system has a Hot Jupiter orbiting close to to the star. If you decide to refuel from a Hot Jupiter with any other options you've messed up big time.

I assume the refueling ships are staying close to the atmosphere to rendezvous with their friends running on bone dry tanks. This cuts down on travel time and lets the squadron stay under the planet's radiation belt. Anyone working outside will be able to have children who will appreciate this. So a fuel scoop run, rendezvous, fuel transfer and return to scoop lasts about ten hours. How much of this is spent actually scooping hydrogen? TCS says that pumping fuel from a collapsible tank into your regular tanks for jump takes about three hours (TCS p. 13). Figuring another hour to rendezvous and dock means you're looking at 6 hours to fill your tanks.

Wilderness Refueling
Local gas giant.

A. Achieve orbit.
This may not be as simple as it sounds. You must be prepared to deal with:
debris from rings
e-m radiation
particle radiation

The orbit will be near the cloud tops. A trip out to the jump limit is 5 to 10 million klicks and will take several hours for a ship that makes 3 gees. This is of concern to Navy operations and anyone else afraid of an attack deep in a well where they can fall back call on the Jump Fairy to get them out of a tight spot. You could have part of your squadron at the jump limit and let only the ships needing refueling enter a close orbit and retreat to the jump limit when done.

Of course any SDBs waiting in the gas giant are waiting for you to split your forces. 

SDBs have it relatively easy. They aren't in a hurry to be somewhere else. They can loiter in relatively calm regions of the gas giant's atmosphere. They can pump in hydrogen as they need it for their power plants. Traders and interested others are trying to get fueled and get out fast and are bound to make mistakes.

 B. Refuel.
Great you made it this far! be prepared to deal with:
downdrafts
life forms- gas giants do not usually produce intelligent life. Traveller canon does mention one race. Be careful you don't suck someone important into your fuel tanks. Beware the referee who reads H.P. Lovecraft.
contaminated fuel- the good thing about contaminants in fuel is that you can usually smell them. That ammonia leak might cause concern but it also indicates your fuel tank has a leak.
lightning strikes- lightning strikes are the natural enemies of starships.
diamond storms- theory holds that Jupiter and other gas giants have carbon cores that under incredible pressure become diamond. Convection might throw diamond bits into the upper atmosphere. The bad news - this can damage or wreck your ship. The good news - the diamonds are probably poor quality so you don't need to worry about destabilizing the gem market.
communications going out - they will at some point.
sensor blindspot - probably near where the comms go offline.
SDBs - yet again.
pirates - sauce for the goose, my friends.

I have no idea what kind of target numbers you need to roll to avoid damage or maintain control. I'd set them at 10+ and make the damage of concern but not immediately fatal.

Keep in  mind many people skimp on armament for their fuel tenders. In this case a 600 ton SDB might immobilize a 100,000 ton dreadnought by taking out its fuel tenders to deny it fuel.

C. Set course to major world or outsystem.
Yes. Please.

Note that this sort of piloting can be stressful and tiring to pilots. A 24/7 fueling operation might see pilots being rotated between the tenders and the fleet or they might be willing to let their tenders make mistakes while docking our handling cryogenic and inflammable materials.

Some gas giants will have orbiting weather satellites to help ships chart safe courses to refuel. Usually these are not found at C starports who want to sell you their rotten contaminated fuel. If the system has an A or B starport, a Navy or Scout base they have satellites orbiting the nearer gas giant. 

Weather satellites could also keep a record of ships refueling or be part of a defense system (mines).