Astrogation, knowing where you are, astronomy, travel maps: Important questions

[sporegnosis]

Acording to the astrogation skill, you can find your bearing and position in a galaxy with astrogation. Really? There's no task described that does so anywhere.

Consider:

After using an abandoned ancient orbital portal/stargate that leads into an unknown system 200?-300?-X? parsecs away from our last position, how can we find out about our new location? (the locals don't help or they don't exist).

Where are the rules that describe this task?

stellar observations/mapping with imperial tech levels:

how do you find how many systems are near (1-10 parsecs?) to you and if they have a water source/gas giant? There are no stellar observation ACS modules, and no rules in place for utilising such a crew location/post. There are also no stellar sensors with ranges in parsecs... wait what?!?!?

If you are truly lost, and you don't know if the system you are about to jump to has a gas giant, water source etc, you are risking a sudden end in the campaign, yet there are *no* tools in the rules to help you.

2 cases:

1. Galactic information mastery.
TL 15 civs instantly know/aquire all travel information about the stars in their galaxy by just looking at a star. Even without astrogation a ship computer can always triangulate and pattern-match all stars,quazars,nebulae, etc around it to give you an exact location provided you can see the stars and know the patterns from a galactic databank.
also:
All ships come with an app similar to google sky with limited "travel type" stellar information like gas giants, water sources, red zones (not complete world IDs/surveys) for the entire galaxy.

Mind you! if I can have such a map in paper today for a few cents, the imperium, TAS or other merchant/ tourist organizations would also make and give such a map for free as well. Even an outdated map (50-100 years old) is invaluable, stellar bodies stay in their places. (relatively speaking)

2. Blind rat.
You are lost and without asking around, you gamble your life and ship at each jump. You need double or triple fuel tanks for dead-end jumps. i.e. no TL 15 telescopes.

You can only buy survey data for systems within 1-5 parsecs from your last spaceport.


I always found case 2 silly and at our table we always used case 1 in the past. My new traveller 5 referee went with case 2 last night when the question came up and we wasted a lot of game time trying to convince him about case 1 to no effect.

I just hate it when the game system fails to answer such crucial questions about the game world and about the intended *feel* of traveller 5. I wish I was wrong. Please tell me that there are more answers to be found hidden in the bowels of that behemoth/monster class traveller 5 rule book.

 

[Bloo]

1. Galactic information mastery.
TL 15 civs instantly know/aquire all travel information about the stars in their galaxy by just looking at a star. Even without astrogation a ship computer can always triangulate and pattern-match all stars,quazars,nebulae, etc around it to give you an exact location provided you can see the stars and know the patterns from a galactic databank.
also:
All ships come with an app similar to google sky with limited "travel type" stellar information like gas giants, water sources, red zones (not complete world IDs/surveys) for the entire galaxy.

Mind you! if I can have such a map in paper today for a few cents, the imperium, TAS or other merchant/ tourist organizations would also make and give such a map for free as well. Even an outdated map (50-100 years old) is invaluable, stellar bodies stay in their places. (relatively speaking)

This one. And probably at below TL 15.

There have been discussions here, or in the past on the TML, that with a library of known pulsars and similar phenomenon, it shouldn't be too difficult to plot your approximate position. With a 3D map of known, even easier. Computers do pattern matching real good.

And it does make Astrogation pretty much a "can read maps" skill, which isn't much of a skill. From a design perspective, an astrogation computer interface more complicated than sat/nav, google maps, etc., and by voice, would be a failure.
"Ship: plot a course for Regina. Go."
"Ship: take us to <touches crater on small planetoid in the 3D holo map interface> here. Go."
And not a lot for a pilot to do 98% of the time.

 

[Reban]

I would assume that using the Astrogation skill for finding your bearing and position in a galaxy requires the use of tools. What exactly those tools are I'll leave to someone better versed in astronomy.

I can take a guess though. Every ACS ship comes fitted with Radar, a Communicator and portholes. You could use the Communicator as a rudimentary radio telescope, find three or more pulsars, measure their period and bearing to get a fix on your position. The IISS propbably publish a catalog of all the pulsars in the galaxy with their periods in the same way navigation charts show all the lighthouses around a coast with the period of their flash and color.

There are no ACS stellar observation modules but you can use the sensor rules and ThingMaker to create some. I'm not sure you have the right idea about range. If you read the Ship Combat chapter it explains the sensor range as the distance it can resolve and identify a ship sized (or smaller) object. Farther away it may see something farther away but not identify it. At stellar distances EMS, HoloVisors, Scope and Visor can probably pick up objects the size of stars at parsec ranges. You could use Astrogation and other science skills in combination with these types of sensors to figure out spectral class and other useful information.

If I recall correctly T4 or MT had expanded sensor rules for this kind of astronomical observation. CT Grand Survey has good background on using ship sensors to do survey work (at system ranges), use them as a guide for astronomy just expand the time needed for observation.

I think all the tools are there, but its up to you to figure out how to use them. If you are the referee you can create the task to "Locate your position in the Galaxy" and set the difficulty and mods to reflect the character's situation.

On a side note I'd think that star maps work more like simulations because everything in space is in motion. Plug the chart into the computer and it references the ships clock to calculate where everything is.

 

[lspitz]

Pulsars work fine to triangulate your position, but so do supergiant stars. The big ones are visible over hundreds of parsecs.

Using pulsars is always going to require radio equipment, and the analysis of the signal is difficult and tedious (although certainly not impossible) without a working computer.

Bright "beacon" stars can be seen with the unaided eye. Humans can identify the magnitude of a star reasonably accurately without instruments. Get a fix on three that you recognize and you can pin down your position to a general volume of space (maybe as small as half a subsector) with just your eyes and a few distance/brightness calculations that you can do in your head. If you have instruments that can give you a really accurate brightness reading, you can figure out exactly which star system you're in.

 

[esampson]

Astrogation

For the immediate question people have provided multiple good answers. Triangulation with pulsars and super-giant stars are excellent examples of how an astrogator can locate where the ship is. There's also the fact that in most cases the ship will be within about 30 parsecs of where it was expected to be (since the most common reason for a loss of bearing is a misjump). Of course that's not the case with the given example.

As for just being 'able to read maps' I would suspect the skill goes quite a bit beyond that. Being able to read a map tells you where you're at but it doesn't necessarily tell you how to get to where you want to go. An astrogator has to figure out a course that will get the ship from point A to point B while not passing within 100 diameters of anything that might be in the way. This includes rogue planets in deep space, dark stars, and other hazards that are not easily detectable when the trip starts. Complicating this is the fact that to all appearances a ship cannot really maneuver within jump space and so the course plotted has to be something of a ballistic course (where no changes can be made in flight). This course has to deal with the fact that not only do the objects mentioned above exist but that they are in motion and at distances of multiple lightyears where they 'are' at the moment you leave is not the same as where they 'are' at the moment you land. And the change in position is not by a week's worth of travel, either. According to physics they will have traveled a distance equal to their velocity multiplied by the difference in lightspeed distance between positions, so if position A is 2 light years from the object and position B is 4 light years from the object then the object will have traveled a distance equal to its velocity over a 2 year period in reverse! And that's ignoring how the object moves relative to the ship if the ship's location in jump space has some sort of analogous component to locations in real space (which is probably does since you need to be concerned about objects in the way, but the exact mechanism is unclear)

Add in the fact that simply arriving at the new system isn't really enough but that a skilled astrogator probably drops the ship out of jump space with a velocity relative to the final destination that is useful (landing 100D in a trailing orbital position of the planet you are heading towards with no orbital velocity is inefficient since the ship will have to accelerate to catch up to a planet that is running away from it. Landing 100D away from the planet you were heading towards with an excessively high velocity on a collision course with the planet could prove deadly) and you're probably looking at something that is an awful lot of art in addition to the science and numbercrunching.

 

[sporegnosis]

Nerfed sensors

I would assume that using the Astrogation skill for finding your bearing and position in a galaxy requires the use of tools. What exactly those tools are I'll leave to someone better versed in astronomy.

I can take a guess though. Every ACS ship comes fitted with Radar, a Communicator and portholes. You could use the Communicator as a rudimentary radio telescope, find three or more pulsars, measure their period and bearing to get a fix on your position. The IISS propbably publish a catalog of all the pulsars in the galaxy with their periods in the same way navigation charts show all the lighthouses around a coast with the period of their flash and color.

There are no ACS stellar observation modules but you can use the sensor rules and ThingMaker to create some. I'm not sure you have the right idea about range. If you read the Ship Combat chapter it explains the sensor range as the distance it can resolve and identify a ship sized (or smaller) object. Farther away it may see something farther away but not identify it. At stellar distances EMS, HoloVisors, Scope and Visor can probably pick up objects the size of stars at parsec ranges. You could use Astrogation and other science skills in combination with these types of sensors to figure out spectral class and other useful information.

If I recall correctly T4 or MT had expanded sensor rules for this kind of astronomical observation. CT Grand Survey has good background on using ship sensors to do survey work (at system ranges), use them as a guide for astronomy just expand the time needed for observation.

I think all the tools are there, but its up to you to figure out how to use them. If you are the referee you can create the task to "Locate your position in the Galaxy" and set the difficulty and mods to reflect the character's situation.

On a side note I'd think that star maps work more like simulations because everything in space is in motion. Plug the chart into the computer and it references the ships clock to calculate where everything is.

I've read through space combat and sensor design a few times before posting the OP. There's nothing beyond size 9 (moonlet) and nothing beyond S=20 (oort cloud) in the rules (p.43).

The horrible thing is that the space range metric is broken. it starts with each number being a x10 of the previous and it ends up to x3 or so. No amount of stage effects can push a sensor to S=21 to reach 1 parsec let alone scanning 4-5 parsecs away. Also the sensors task has R-S and there's a huge difference between interstellar distances S and gas giant and planet size R, so that check is always impossible (negative result is no check possible) with those rules.

Back to reality: the hubble orbital telescope (late TL 7, 11t including ALL mission support equipment, frame, radiators and solar panels, can detect stars and gas giants kiloparsecs away..

 

[robject]

I've read through space combat and sensor design a few times before posting the OP. There's nothing beyond size 9 (moonlet) and nothing beyond S=20 (oort cloud) in the rules (p.43).

[...]

Back to reality: the hubble orbital telescope (late TL 7, 11t including ALL mission support equipment, frame, radiators and solar panels, can detect stars and gas giants kiloparsecs away..

This is a common topic, crops up every five or so years.

Consider that the Hubble is probably not a combat sensor. Put another way: consider that the sensor rules are primarily, or even exclusively, for the purposes of space combat. If the sensors are available and working, then I assume an easier mechanic could be used for non-combat use; a simple Astrogation task check, for example? But I'm sure a determined referee could think up all sorts of ways of making it work.

 

[Bloo]

As for just being 'able to read maps' I would suspect the skill goes quite a bit beyond that. Being able to read a map tells you where you're at but it doesn't necessarily tell you how to get to where you want to go. An astrogator has to figure out a course that will get the ship from point A to point B while not passing within 100 diameters of anything that might be in the way.

Which any modern smartphone has an order of magnitude of processing capacity greater than needed to do. That's just data. Realistically (which of course has problems in Traveller) sophonts doing astrogation would only be necessary when all the software has failed (or is unable to function), and even then, the astrogator needs data and a calculator.

Autopiloting of a spaceship, in normal circumstances, is likely to be less complicated than autopiloting a car, which we're getting close to.

 

[Shonner]

After using an abandoned ancient orbital portal/stargate that leads into an unknown system 200?-300?-X? parsecs away from our last position, how can we find out about our new location? (the locals don't help or they don't exist).

The key phrase is "unknown system". Not "mapable system". Not "easy to return from system". What kind of ship did you do this with? What scientists were brought on board before committing? What equipment do you have? Did the referee have a Plan B or C before committing? Or did everyone just paint themselves into a corner?

 

[rancke]

After using an abandoned ancient orbital portal/stargate that leads into an unknown system 200?-300?-X? parsecs away from our last position, how can we find out about our new location? (the locals don't help or they don't exist).

Take bearings on several neighboring galaxies and you can fix your position just fine.


Hans

 

[HG_B]

Consider:

After using an abandoned ancient orbital portal/stargate that leads into an unknown system 200?-300?-X? parsecs away from our last position, how can we find out about our new location? (the locals don't help or they don't exist).

Easy-peasy in Trav. Simply get a fix on a few known Pulsars and Bob's your uncle.

 

[robject]

Yeah, 300 parsecs is no biggie.

 

[esampson]

Which any modern smartphone has an order of magnitude of processing capacity greater than needed to do. That's just data. Realistically (which of course has problems in Traveller) sophonts doing astrogation would only be necessary when all the software has failed (or is unable to function), and even then, the astrogator needs data and a calculator.

Autopiloting of a spaceship, in normal circumstances, is likely to be less complicated than autopiloting a car, which we're getting close to.

True that it is just data. However somewhere along the line there comes certain decisions that have to be made and prioritized. Is it better to follow line A which wanders to within 110D of an obstuction (which possibly will not be where it is suppose to be due to unforseen circumstances) but which results in a better exit (location and relative velocity to target) or is it better to follow line B which doesn't come any closer than 300D to any obstructions but dumps the ship out at the edge of the system on a bad vector?

 

[sporegnosis]

This is a common topic, crops up every five or so years.

Consider that the Hubble is probably not a combat sensor. Put another way: consider that the sensor rules are primarily, or even exclusively, for the purposes of space combat. If the sensors are available and working, then I assume an easier mechanic could be used for non-combat use; a simple Astrogation task check, for example? But I'm sure a determined referee could think up all sorts of ways of making it work.

complete (all of them) complement on TL-15 sensors on a 1000t ship
2 astrogation consoles with astrogator + a wafer jacked crewman with +9 astrogation upload.

Since each tech level is an order of magnitude bigger that it's previous, i'd expect our 60-70t of sensory TL-15 equipment would be enough even without commiting lots of time. I asked to do the task over the course of a day and the referee sait that extra time wouldn't be of any consequence.

Our determined referee came up with all sorts of ways of making it NOT work.

 

[esampson]

Oh yeah, one other thing;

The astrogator is probably a lot like the navigator on a commercial flight. Sure, the airplane has a GPS that a pilot can look at and you have all those helpful people in the various control towers as you fly around telling you what heading to take and what altitude to fly at, but there's still a navigator on board for when things break. Both the handle the navigation while the equipment is broken as well as to recognize that the equipment is broken because the plane isn't where it is suppose to be.

If memory serves it was possible in CT to purchase pre-programmed jump routes that you just loaded up into your computer. I could be thinking of some other setting, however.

 

[lspitz]

If memory serves it was possible in CT to purchase pre-programmed jump routes that you just loaded up into your computer. I could be thinking of some other setting, however.

You are remembering correctly. Specifically, they were "self-erasing cassettes" (and when I read that, I always picture eight-track tapes).

Don't know of anyone who ever used that option.

 

[HG_B]

Oh yeah, one other thing;

The astrogator is probably a lot like the navigator on a commercial flight. Sure, the airplane has a GPS that a pilot can look at

Commercial airlines dumped the Navigator position YEARS and YEARS ago. It's all computerized now.

 

[esampson]

Commercial airlines dumped the Navigator position YEARS and YEARS ago. It's all computerized now.

Well bang goes that theory.

No, in all seriousness however they were redundant for a very long time before they were dumped. The position continued to exist for quite some time as a sort of 'backup' to the machines.

I don't know if Naval midshipmen are still required to take a course in navigation but I do know that years ago my friend had to despite the fact that the warships of the time had multiple redundant systems to help them locate exactly where they were. The reason given was simply that it had to be possible for the ship to navigate with just some very basic tools if all the high tech stuff became broken or in some other way unusable.

How that translates to requiring Astrogation when everything is working fine...I couldn't really tell you. I've always been kind of irked at the storyline of the ship bounced hundreds of lightyears through space and now they have no idea where they are (this is assuming a ship that normally is designed to navigate between stars) for the exact reason that I know that pinpointing your location under those circumstances shouldn't be particularly difficult.

 

[sporegnosis]

You are remembering correctly. Specifically, they were "self-erasing cassettes" (and when I read that, I always picture eight-track tapes).

Don't know of anyone who ever used that option.

Jump tapes are still in. check page 623.

 

[arentol]

One thing people always forget is just how ridiculously large space is and how ridiculously small everything in it really is. It is not nearly as easy as you think to scan even a single (new) solar system to find and ID the larger stellar objects like planets and asteroid belts with a ship-sized sensors, let alone identify and navigate around all the minor flotsam and jetsam you will find floating near the inner planets of a habitable system.
Consider this.... We are supposedly TL 8 and even with the multiple massive land and space telescopes we are currently using we STILL haven't identified all planetoids in our solar system and have found only about 1-2% of all objects inside Mar's orbit that are 100+ meters in diameter. It won't be until we are well into TL9, perhaps 2040-2050, before we can say we are certain we have identified all objects in the solar system that would be a significant threat to a TL12+ Starship.

So lets assume a ship that has just arrived in an uncharted solar system with the intent only to identify major stellar objects in the inner and middle orbits as well as a safe route from their current location to a Gas Giant for refueling, then to a planet in the Habitable zone for a closer survey, then back to the edge of the system to leave safely, after further checks of the outer system to identify the immediate area is clear of large objects. Below are my rough estimates for the various TL's.

TL9 = 1 year to identify all major objects, 3 months to plot each course safely.
TL10 = 4 months for objects, 1 month for each plot
TL11 = 2 months for objects, 2 weeks for each plot
TL12 = 1 month for objects, 1 week for each course.
TL13 (Grav sensor) = 1 week for objects, 2 days for each course.
TL14 = 2 days for objects, 12 hours for each course.
TL15 = 12 hours for objects, 3 hours for each course.
TL16 = 4 hours for objects, 1 hour for each course.

A good Astrogater would be able to "Hasty" these checks to cut the time in half, but that is about as fast as one could hope to go (though two ships working together would be an automatic TL higher, and Hasty would cut that in half). This is just how I would approach things, because space really is that ridiculously big..... There is a reason Scouts have to spend 4 years to MAYBE find a valuable discovery. Even at TL15 a full initial scan of a system would take a week or more and then proper individual planet surveys would be another week each, so a system survey would easily take over a month, and at TL13 it is more like 4-6 months.