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TAU class extrasolar exploration vessel

TAU One – Daedalus

In 2033, the Secretary General of the New United Nations declared an unqualified success of the planet-wide effort to divert the Swarm, a group of large asteroids which threatened to impact Earth over a three-year period. The world came together to prevent an extinction level event, putting aside geopolitical concerns for the greater good. As the program required more than just the “greatest” nations to be successful, citizens of poorer states & regions experienced a paradigm shift regarding their place in Humanity’s future; they demonstrated their importance and value through technical expertise, labor provisions, and geographically-advantageous orbital-launch facilities, proving economic parity was not a requirement to be seen as an equal on the world stage. Nascent regional partnerships with no alignment to either the Eastern Coalition or the Western Alliance began forming, providing a global voice for the underserved who were equally critical in saving all life on the planet.

Collaborative organization was a proven concept. The Americans were well aware of this, having been a founding and leading member of the greatest alliance operating at that time. However, the opportunity to take a breath following the events of the Swarm prompted the United States to conduct an evaluation of its future leadership role in the world and found it lacking. The country had a proud tradition of trail-blazing, which included the benchmarks set with their lunar landings and orbiter program. However, since 1988, the role of the US as a space leader had been dramatically upset by the Chinese/Great Khanate DY program. Additionally, significant space achievements after the Augment Era were accomplished singularly by, or in cooperation between, the European Space Agency, the Western Alliance, and the International Space Agency. The US government wanted to set a new record, something that the world would observe with bated breath and record for posterity as yet another great American triumph.

The target was to escape the solar system. While the goal would not necessarily result in the planting of an American flag, the concept promised the unprecedented historical moment NASA was tasked with meeting. Setting foot on other planets’ moons had been done before; a new landing would be nothing spectacular. Speed and endurance records were frequently broken and poor contenders for creating an enduring legacy. However, the first crew to pass beyond the heliopause would achieve something that could not be one-upped.

The vessel, designated “Thousand Astronomical Units” (or TAU) as a grandiose declaration of bold intent, needed to be something clearly and boldly American, without needing to incorporate technologies and hull designs which were new and unproven for the expected duration of the crewed flights. There was no need to spend a great deal of funds modifying an inner-system vessel to accomplish the endurance task required of an extra-Kuiper transit. The TAU spacecraft needed to travel beyond Neptune, with initial missions tasked with exploring the Kuiper Belt 30 to 50 AUs away and follow-on missions set to cross the heliopause itself (123 AUs), with a final target distance of 350 AUs from Sol assigned to later expeditions.

NASA looked back to its Apollo and shuttle roots and came up with a modular concept that incorporated the design philosophy of both, achieving the sought-after “American familiarity”. The modularity feature incorporated mostly tested and trustworthy technologies in a manner where modules in the development and manufacturing stages could pivot to meet evolving mission planning. A forward element based on the NASA orbiters would serve as the flight deck and operational nerve center. Attached directly behind that was the docking module (referred to as a “ring”), where up to four independent auxiliaries could be parked. These usually included repurposed capsules modified to serve as sensor-laden drones and Mars-style landers—equipped with surface anchors but not rovers—to allow exploration of planetesimals positioned along the established route of the TAU flight.

The “off-duty” living spaces for active crew members were located entirely on the habitat module. This component was the only one to incorporate centrifugal gravity, providing a 0.4 g environment through a rotation speed of 3.79 RPMs. The habitat module included eight individual sleeping compartments, a gymnasium, shower and sanitation facilities, a semi-automated medical bay, galley, entertainment theater, and personal communication space. When the operational tempo required more than eight crew members to be active, hot-bunking was the expectation. Crew members could also utilize the rotation to jog along the central pathway of the habitat module.

Immediately following the habitat module was the cargo section comprising eight modular pods, three of which provided individualized Singh-type cryogenic hibernation chambers for the crew. For TAU One, the mission called for all 15 personnel to enter the hibernation state shortly after the trans-orbital thrust phase began. As the mission progressed, the ship’s main computer would wake up select members of the crew for predetermined mission events or in the event of an emergency. The other five pods were packed with various provisions, such as food, medical supplies, and spare parts. Accessing the stores required a pre-planned procedure for unpacking and re-packing all intervening materials, a labor and inventory-intensive process. This led to a concept of pre-staging certain materials in what crews called the “pantry”, but was otherwise known by mission control as the “Ready-Consumables Corridor Module”.

Aft of the cargo section, the enormous rocket bell-shaped life support module served as an armored cowl for the eight large oxygen tanks and externally-mounted equipment necessary for preserving life on the ship. The added protective mass on this particular module aimed to minimize the effect of any impact event upon those specific critical functions, thereby freeing up the crew to prioritize and resolve other damage control issues the vessel might suffer. The enormous and rotatable panels aft of the bell were designed to radiate waste heat away from the ship and were mounted on the support structure built around the central corridor module. This cage was intended to provide not only structural support for the ship while under thrust, but also served as adaptable equipment rails for most any add-on experiment, sensor, or other asset elected to be added to a TAU flight.

Habitable spaces accessible from the aforementioned corridor included the auxiliary control & distribution module and the engineering module. The former served exactly as indicated, overseeing the generation of electricity—including from the set of atomic batteries just forward of the engineering module—and its utilization by the ship and crew. The latter section provided internal access to the central bus units for both communication dishes (mounted dorsally and ventrally, above the four external hydrogen-2 fuel tanks), as well as the Fine-Structure Constant (FSC) transmitter. This device was a key component of the TAU missions: while the goal was to cross beyond the heliosphere, the FSC transmitter served as one of the methods to observe the outside universe. The subspace dimension, discovered in 2022, was still poorly understood, so the TAU missions were incorporated into the system-wide initiative to explore how objects in normal space might distort the perceptible fields from this new realm. Observing differences in the strength of the electromagnetic interaction between elementary charged particles, variances in gravity wells, radiation sources, or other fundamental forces might provide scientific guide posts to why measurable distortions (quantified as cochrane units) occur. The TAU missions were tasked with surveying readings from the various points outside the heliosphere, serving as potential baselines for later voyages into the Oort cloud (2,000 to 100,000 AUs out) and beyond.

The engineering module also served to regulate and maintain the functionality of the four AmJet SJ-79 fission- and one P&W F100 central fusion-powered ion thrusters. This control was conducted across the same thruster superstructure that supported the massive transfer coils supplying energy to the electrical converters and provided the mandated safety distance from the two gas-core reactors (Block D and Block A, respectively), also manufactured by Pratt & Whitney. On both the dorsal and ventral sides of the superstructure, whip antennas were installed to transfer both active and passive signals to the interferometers located in the engineering module. Sixteen Type T fuel cells (for the reaction control system) ringed the reactor module itself.

Primary boost from Earth orbit was provided as an operational test of the much more efficient fusion-fed ion thruster. The adoption of this divergent propulsion technology was deemed an acceptable and minor gamble when weighed with the PR reward of highlighting “American ingenuity”. The centrally-placed engine would remain at full thrust from the point of orbital departure until halfway to the heliopause. The TAU vessel would then rotate to face Sol over a 223-minute revolution and re-engage the fusion ion thruster to slow the craft to a full stop on the far side of the heliopause. When the mission was again in a transit (but extrasolar) phase, the fission engines would be engaged either as a pair or a quad set of movers, since the established nuclear technology was still regarded as more reliable for medium and short distance propulsion demands. If the fusion-powered ion engine failed to provide sufficient thrust at any stage of the post-orbital or return-to-Earth phases, the fuel supply for the fission engines was more than adequate to compensate. The recessed RCS would handle the restricted maneuvering demands for approach to Kuiper Belt objects of interest.

Ideally, the United States wanted to develop and build each of the TAU craft domestically. However, a great deal of expertise in spacecraft design, procurement, assembly, launch, and operations had matured worldwide since 2026 and the American administration at the time knew that garnering short-term political capital for the next election cycle (by launching a functional mission quickly) required leveraging that mastery. Sizable contracts were established with corporations in partner nations—most notably Canada, Germany, Italy, New Zealand, Ukraine, and the United Kingdom—in order to fast-track the construction of five modules of each type. Launch facilities in Chad, Gabon, and San Tome were paid handsomely for front-of-the-line scheduling to loft these modules and the assembly infrastructure that preceded them. Despite this being an international effort, it remained nominally an American one and not at all associated with the Western Alliance.

This was diplomatically troubling for some nations. Both China and India saw this as an about-face from the global effort to work in space in a cooperative manner. France was strongly vocal in its denouncements regarding its complete program exclusion. Then there were the non-governmental organizations that had stomached the negative global impacts of a massive space industry on the ground during the Swarm crisis, but stood up in protest when this new American effort slipped in right behind the General Secretary’s victory proclamation and threatened to continue the same practices. China adroitly co-opted Greenpeace as a proxy force by providing training and submarine assets to insert activist “operators” to sabotage TAU mission components en route to Africa. At the orbital assembly facility, Russia was suspected of employing mercenaries in a successful heist of the five experimental EM field generators meant to provide micro-collision protection for the TAU vessels.

In February 2036, under an enormous amount of media attention (just as had been sought) the TAU One mission—dubbed Daedalus by the crew—boosted from orbit for the Kuiper belt along the solar ecliptic. In order to prolong the media’s attention, each of the fifteen crewmembers entered cryogenic sleep on successive days, following the broadcast of farewells to their loved ones and Earth. Updates were provided by NASA public relations as each milestone (typically planetary orbits) was passed. Inspiring views from external cameras and tracked sequences that swept through the ship were common features on newscasts. Haunting images were shown of the slumbering astronauts, reminding everyone of the Human aspect of the mission.

In late July that same year, NASA acknowledged that contact with Daedalus had been lost. When three days had gone by with no resolution, experts assured viewers that an algorithm had been written to address just such a technical error, and that Communications Specialist Moreno Raud would be awoken to fix the problem. Weeks passed with no updates until NASA convened a press conference in late August with alarming news: space-based observations of TAU One’s exhaust plume indicated the ship continued to burn well past the time for its flip and had visibly and dramatically accelerated, as its position was already past the initial Kuiper belt destination. Additionally, sudden and intermittent telemetry bursts from Daedalus revealed a series of onboard fires and subsystem failures, certainly accounting for the breakdown in automatic propulsion controls. No more data was received from Daedalus and space experts forecasted the day the craft most likely entered the far-flung and vast Oort Cloud. The vessel and her crew were declared lost, most likely destroyed.

TAU Two – Betelgeuze

All components for the TAU Two mission had been assembled at the orbital facility. The initial connections of all habitable modules were taking place when contact with Daedalus was first lost. Staging and assembly of Betelgueze continued while the lost vessel’s recovered telemetry was studied. When it was concluded that a massive charge buildup was the fatal cause, all progress was halted on the ship.

The engineering solutions were relatively simple: additional plasma contactor units (PCUs) were installed on the dorsal antenna base above the engineering section.These PCUs generated a slow, neutral plasma bath around the craft, multiplying the discharge field by a factor of three. Radiator panels were borrowed from a ground-based Ares static model and modified with embedded gold-based leads to channel environmental static discharges to grounding units located on either end of the panel and the mid-point. A toroidal tank—surrounding the ready-consumables module—was added to treat, supply, and circulate the particular coolant that serviced the (otherwise) always scalding panels. Additional mission batteries joined the original set, with each enlarged slightly by rubber shielding encasing every cell and each of the cargo/hibernation pods were updated with better radiation shielding. The most significant change was the new mandate for two active members to be overseeing all ship’s operations at every stage, ensuring a better response time to any emergent issues.

TAU Two proved to be a successful mission: all crew returned safely (proving new cryogenic enhancements along the way) from the six-year journey into interstellar space just beyond the heliopause with a plethora of new environmental data sets. The mission was intriguing for the many benchmarks set. A notable one, though far-surpassed by establishing the most distant recorded point any Human had yet (knowingly) ever traveled, was that none of the eighteen crew-members ever interacted with all of their crewmates during any operational part of the mission. Due to only waking those with the skill sets or experimental knowledge necessary for any given scheduled (or unscheduled) event, the most crew ever active at any one time was seven, during periods of turnover from waypoint transit to station-keeping observation points. The only times the entire crew were fully active as a complete team was during pre-mission training, pre-boost orbiting, and post-mission recovery.

Unrealized TAU mission

In between TAUs Two and Three, there existed a brief consideration to shoehorn an additional mission in order to access Department of Defense funding via the Air Force Research Lab. The AFRL was exploring the idea of creating a system-wide positioning network (similar to the global navigation satellite systems servicing Earth) that would provide a quicker return than contemporaneous electronic star fixes. A proposal to place a test beacon out past the orbit of Neptune was presented to NASA, with the hefty device comprised of an extremely powerful transmitter and a bulky and barely-shielded atomic battery. While the launch timetable for the TAU program met the laboratory’s aspirations, the particular craft assigned to deliver the beacon to its precise target would have to have its fore-to-aft architecture significantly altered in order to keep the cargo’s hazardous nature as far removed from habitable spaces as possible. An initial computer model of a TAU ship was drafted that would carry the experimental beacon on a trailing release brace, but it required offsetting the thrust superstructure between the engineering and propulsion modules. This would have also impacted the hydrogen-2 tanks, reducing fuel capacity by 25% and range by over 30%.

The predominant arguments against the navigation proposal asserted that future computers would certainly perform faster at determining star fixes and that an artificial constellation of the required scale would both be exorbitantly expensive to install and face near-impossible technical challenges to maintain.

The program was canceled early in the design phase; an initial draft profile of the variant is shown above.

TAU Three – Charybdis

TAU Three—dubbed Charybdis—suffered an apparent similar fate as TAU One. Launching on July 23, 2037, under the command of Colonel Stephen Richey, the vessel transited for the heliopause along an angle of ten degrees above the ecliptic. Its secondary mission was to utilize the scientific packages attached to the mid-section support rails to search for signs of extraterrestrial civilizations, specifically the artificial ion trails left by alien ships utilizing comparable propulsion technology.

Instead, in early February of 2038, final telemetry received by NASA from the Charybdis indicated the fusion engine had burned to accelerate the ship to twelve times Solar Escape Velocity. The official report read: “Assumed vehicle was lost with consumables run out, 20% possibility of crew survival with hibernation systems at low usage mode.” It was not until 2365, when a Klingon cruiser detected debris from the vessel in the upper atmosphere of Theta VIII, that any outcome for the mission was recorded. Col. Richey, the only known survivor, awoke from hibernation and found himself within a simulation of a locale from Hotel Royale, a novel he had brought along. In surviving logs, Richey hypothesized that an alien life-form created the simulation under the assumption the novel described what he considered to be the ideal world. He lived the remainder of his life in that limited environment. No other details as to how the Charybdis arrived at that location, nor about the alien culture behind the simulation, have ever been determined.

TAU Four – Phlebas

TAU Four (Phlebas) launched in December 2037 along a route seven degrees below the ecliptic. Two months later, it received orders from Mission Control to disengage its fusion thruster immediately and continue along its pre-determined route on the fission drives only. Mission Control then ordered the deployment of the ion detectors mounted on both sides of the auxiliary control module to track the Charybdis for as long as possible. Phlebas reported it was able to pinpoint Charybdis’ ion plume to be well into the Oort Cloud before the plume suddenly vanished. TAU Four continued along with its initial mission through the heliopause, though fuel concerns necessitated its early return.

TAU Five – Jacob

The fifth TAU vessel, the Jacob, had a delayed launch of August 2038 due to an extensive review of both the physical fusion propulsion system and every line of code that controlled it. The investigations led to significant improvements in both and revealed no intrinsic faults which could have resulted in the over-thrust incidents that led to the loss of TAUs One and Three. Faith in fusion technology slowly recovered, even though the mystery of the lost vessels remained unsolved. The original mission goal for TAU Five was changed to a route that followed the ill-fated Charybdis. After multiple stops to execute calibration deployments for the ion detectors, mission control decided that the point at which the trail was lost—approximately 27,000 AUs down-range—could only be explored at some future point by a far-more capable vessel.

The Jacob was the only one of the series to take on additional missions: TAUs Six, Seven, and Eight. The last one launched in early 2063, returning to Earth in 2069, having traversed over 350 AUs from Sol and being passed on its return by outbound Earth warp vessels of five different designs.


Vessels of the TAU series were named after mythological characters.

  • Daedalus – TAU One (2036): presumed lost
  • Betelgeuze – TAU Two (2037-2043): successful heliopause mission
  • Charybdis – TAU Three (2037-2038): lost; remnants found orbiting Theta 116 VIII
  • Phlebas – TAU Four (2037-2042): heliopause mission; mission conclusion unrecorded
  • Jacob – TAU Five, Six, Seven, Eight (2038-2069): Charybdis search mission; follow-on Oort cloud missions; mission conclusions unrecorded


TAU One – Daedalus

TAU Two – Betelgeuze

Author: RevancheRM

Illustrator: Adrasil

Original Inspiration: Mike Okuda (TNG: “The Royale”); Kris Trigwell

Permission is granted to save and use above images. While permission to download files with Delta Dynamics’ label is granted, re-hosting or provision of the files (or any parts contained within) must include proper citation of Delta Dynamics or the name of the relevant artist, at a minimum.

Last Updated on 2403.21 by admin