T5 Second Survey
With the emergence of TravellerMap (2006), a team led by Robert Eaglestone identified and corrected consistency errors between Sunbane and AOTI astrographic data.
With the publication of the playtest version of the Traveller 5th edition core rule book (2008), Don McKinney, Robert Eaglestone, along with Marc Miller engaged in a project to collect and update the known astrographic data. Since the original three members, others have joined and left this ongoing project.
The T5 Second Survey project takes old data, rewinds back to just what was in AOTI, picks and chooses some later additions, then starts expanding the dataset with T5'isms and additional sectors. It is then shared online via TravellerMap and used as the basis for new products.
This is a meta-story article about game design. For the in-universe article by the same name, please see the Second Survey article.
This project has several goals:
- Update the astrographic data to the current Traveller 5th edition rules, including the new extensions.
- Address several shortcomings in the generation of the data in previous versions, including stellar data and UWPs.
- Produce a consistent and known set of data for current and future Traveller publishers. All of the Mongoose Traveller books published since 2009 have used this data.
T5 Second Survey Adjustments
In order to make the collection of legacy astrographic data more consistent, the project took the approach of overwriting the the previous versions if the new changes made sense. The T5 Second Survey adjustments to the previous versions of data includes:
- Fixing stellar data to match the current understanding of stars. Specific changes would be:
- Replace the dwarf (D) class stars with M class stars
- Reduce the size of some giant stars (OBAF) to more reasonable sizes (GK)
- Fix the M class stars to a minimum of M4 if the world is habitable
- World generation changes include
- Increase the size of worlds with thin or better atmospheres to match the physics that small worlds can't hold atmospheres
- Adjust the TLs of all worlds in the Imperium to be a maximum of 15
- Adjust the TLs of worlds with un-breathable atmospheres (tainted, trace, vacuum, exotic) to support the equipment required to keep the population alive.
- Adjust the TLs and populations of worlds in several sectors to ensure each sector economy falls in a specific range of values
- Apply automated tools to ensure UWP values are within T5 generation ranges, including the new Ix, Cx, Ex values.
- Ix calculations note that the OTU has multiple base codes which mean the same thing from T5's perspective. The most direct example is that S is used for Imperial scout bases and V for non-Imperial scout bases, but both codes refer to what T5 just calls a "scout base". The full rule for Ix from base codes - with parentheses added to clarify the order of operations - is, "+1 Ix if the base codes (contain at least one of (D, W, and/or X)), and/or (contain at least one of (K, N, and/or T) and at least one of (C, M, R, S, and/or V))".
- Trade code changes would include
- Fix the trade codes to match the rules in the T5 Core Rules
- Add the sophont codes to worlds where they are known
- Add the O: (owned worlds) or Mr notation to worlds that are Gov 6
- Apply automated tools to verify the Trade codes are correct.
Traveller astrography is very difficult to document because it has had many overlapping periods about which even the direct eye witnesses and participants sometimes have profound disagreements. The legacy data is the interaction of the official publications, the work of the various Traveller licensees, and the fan works. Because these works fed into each other in various random ways, tracking the exact history of some of the data can be a difficult task. This author can only confess to having reviewed forty years of published materials, spoken with multiple former employees, authors, illustrators, and other participants and tried to piece the best history possible out of the mess. Long live, Traveller! 
Selected T5 Second Survey Members
This not comprehensive lists includes members, both past and present:
- Joshua Bell
- Dan Burns
- Randy Dorman
- Robert Eaglestone
- Andrew Ford
- Roger Howe
- Thomas Jones-Low
- Donald McKinney
- Marc Miller
- Astrographic History
- Astrographic Resources
- Astrographic Software
- Sector File Format