Transhuman Space is a science fiction setting, with advanced tech and space travel, so shouldn't there be aliens? We're so used to humans mixing with aliens in our science fiction that it seems almost unnatural that there are none in Transhuman Space. So let's start with the strong reasons not to have an alien spaceship warp into your game.
A major theme in the books is human, or sapient, diversity. Bioroids, posthumans, and AIs take the place of elves and dwarves, and the cultural differences can be just as extreme. But aliens, whether broadcasting "we come in peace" or "resistance is futile", draw a line between us and them. Why, it's often speculated that alien contact would unify humanity under a single government, a horrifying prospect for transhumanists.
FTL would be disruptive too, with or without aliens attached. The Deep Beyond shapes the Transhuman Space setting. The inner worlds rely on the slow and steady rhythm of He3 shipments. Knowing that a vast expanse exists where one can get away from it all changes the thinking of everyone. Safety valve, escape hatch, dumping ground – it is humanity's frontier. FTL would shrink the solar system to where it could no longer contain all the parts. So along with no representatives of alien civilizations, no FTL.
(Unless of course you really want to. Adapting to drastic change is also a theme in Transhuman Space.)
So aliens aren't necessary, and need to be added with caution. That doesn't mean you shouldn't. The first part of this article describes how your players might go looking for aliens, while the second part will cover how aliens might find your players.
FTL is only necessary for interstellar travel if you're impatient. In Transhuman Space the technology exists to reach the stars.
Generation ships are an idea that dates back to Robert Heinlein's "Universe" from the 1940s. With a big enough ship and crew, whole generations live and die during the hundreds or thousands of years necessary for the journey. While technically possible, these don't seem a good fit to Transhuman Space. Generation ships are"planetary chauvinism" thinking, the assumption that habitats in space are a poor substitute for living on Earth or terraformed equivalent. For the most part the inhabitants of the Transhuman Space habitats don't want to live on a planet, and will not be enthusiastic about a long and dangerous voyage in search of one.
More likely is an interstellar vessel carrying the crew and passengers in nanostasis, with perhaps extra genetic material to be grown in exowombs on arrival. An NAI runs the systems, and wakes up the flight crew if there is an emergency. The vessel needs to be reliable with a lot of redundancy, but doesn't have to be a giant. If the drive is capable of reaching 0.25c, 1/4 of the speed of light, the known Earth-like planet 61 Virginis III can be reached in 112 years.
The biggest single cost is going to be the drive and fuel. The maximum delta-V, the speed which can be reached and slowed down again, for existing military vessels with antimatter drives is in the 70 to 100 mps range. The experimental Japanese Rei has a delta-V of 154 mps. Our proposed interstellar vessel has a delta-V of 45,000 mps!
That is a lot of antimatter. The first step for our would-be pioneers would seem to be becoming dictator of a medium sized country, or majority shareholder and CEO of a big aerospace corporation.
Skipping over the ambitious sociopath phase, assume that the vessel has been built and is ready to go. (The designs of Charles Pellegrino, which inspired the antimatter-powered interstellar spaceship in the movie Avatar, would make good templates.) The PCs are placed in nanostasis in the solar system and wake up in orbit around "Virginia" ready to build their new lives. Easy, right?
Well, as GM you have a century or more to mess with history in between. Perhaps there is an alien civilization on 61 Virginis III, which hadn't reached 20th century tech levels, detectable radio emissions, etc by Earth year 2100, but has since. Perhaps the more extreme alien contact and survivalist memes are right. The PCs find that 61 Virginis has a human population, kept hidden to hide them from the truly dangerous aliens. Who blew up Sol, our sun, some years ago; so there won't be any more ships.
Any infomorphs reading this are probably asking why we meat-based sapients are so obsessed with moving physical bodies around. And they have an excellent point, as the various AIs, ghosts, and shadows can already travel interstellar distances, at light speed if desired.
The Exogenesis Starswarm project would have launched infomorphs into space at 0.25c in the form of a nanobot swarm. And the proof of concept test was successful, although the only ones who know this are the Axon Group. A PC group who are all infomorphs, or willing to be ghosted, could find this interesting. Perhaps the Axon Group is building a new launcher on Triton, giving up the struggle against Nanodynamics in favor of starting a new infomorph civilization around another star. All the PCs have to do is find them. And prove their loyalty to the cause.
Survivalists in Transhuman Space worry that aliens will detect radio and TV emissions from Earth and attack us, either seeing other life forms as rivals or simply being offended by the content. This is unlikely, as the signals degrade and become meaningless after a few light years. This is bad news for infomorphs beaming themselves to the stars in hope of being picked up by extraterrestrial SETI. Still, the technical obstacles are much less daunting than for interstellar vessels. The signals need to be modulated and encoded in a self-repairing, self-decoding format that can be reconstructed by any beings who receive it. The transmitter needs sufficient power and tight focusing to cross interstellar distances, which is the aspect most likely to draw attention from others. The PCs could be an investigative team from any number of intelligence or security agencies, sent to discover why a previously harmless hypervolutionist group is constructing a death ray.
Precursors, as described by Jonathan Woodward in GURPS All-Star Jam 2004, can bring your PCs into contact with alien artifacts and technologies in manageable quantities and without actual aliens. Drastically simplifying the original article, the Precursors were extremely advanced beings who lived eons ago. Although the Precursors themselves have all vanished, younger races such as humanity occasionally stumble across long abandoned ruins. This is where the PCs enter, most likely as prospectors in the Belt or the smaller moons of a gas giant, but possibly as a genuine scientific mission, with orders to keep quiet. (Even the most liberal government would like some time to consider the memetic implications of proof that aliens exist before releasing the news.)
What the PCs discover is up to you, although I would recommend sticking to what Jonathan Woodward calls "Pretty but Inexplicable" rather than awesomely powerful gadgets. Play it as an archeological dig of sorts, exploring a mystery rather than treasure hunting. If you do want to reward them, a room-temperature superconductor would be extremely valuable without pushing the solar system into a new Wave.
Patient exploration isn't going to suit everyone. It will be a lot more interesting for your PCs if they realize that they're actually the second group to discover the site. Whoever got there first ignored the alien shopping trolleys and waffle irons, but did take away something about 6' x 4' x 4', weighing a ton, and connected to an impressive (but non-operational) electrical power outlet. How did they know it was here, and where did they go?
Or you could have a Precursor site which is literally just passing through, like the giant alien ship in Arthur C Clarke's book Rendezvous with Rama. The characters in that book are not specialists but they were the only ones with a ship that can match course and send explorers aboard. With only a brief time window available, they are forced to make choices and take risks instead of searching everything. The aliens themselves are never encountered and their ultimate destination remains unknown. In Transhuman Space, the PCs could be passengers on a fast interplanetary liner in the right (or wrong) place and get diverted on a similar mission. Traditional archeologists have careful routines, and the explorers in Rendezvous With Rama are very respectful. PCs may be rather more acquisitive and willing to take direct measures against obstacles in their way. If you as GM think they're not following proper protocol, you can always unleash shoggoths on them.
Yes, shoggoths. Strip off the colorful prose and you've got a biological bush robot, created by advanced aliens as utility workers and guardians. Just what Precursors would leave behind to look after their homes, or far traveling aliens use to keep would-be hitchhikers off their nice spaceship. For extra amusement, point out that a shoggoth may be the most valuable thing that the PCs will ever find, so they should try to capture, not kill. Oh, and they'll have to feed it afterwards...
A small scale alien encounter could be the discovery of a probe. Perhaps an alien generation ship approached our solar system a few centuries ago and sent out robotic scout probes. These probes reported intelligent life and the aliens, being benevolent types, diverted to somewhere else. One or more probes, though, didn't return and eventually the batteries ran down. The probe can be a classic MacGuffin plot element: it doesn't really matter what it does or where it came from. What is certain that lots of people will make life very interesting in the vicinity. The PCs could be representatives of a private buyer, a government team sent to to obtain it and suppress knowledge, investigative journalists, or security hired to keep it safe.
Or the PCs may not know, at first, that they are dealing with an alien artifact. The adventure starts as a Duncanite contract enforcement. The salvage vessel "Malibu" was bought in the Trojans by Old Kim who has fallen behind on the payments. The last reported location of the Malibu was near Hyperion, Saturn (yes, that's a long way away), and the PCs are sent to bring it back. They find the ship and Old Kim.
As contract enforcers the PCs can be armed, which will come in handy. Old Kim made the find of a lifetime on Hyperion, a genuine alien probe. The USAF are claiming that the probe is stolen and want it back. In an effort to keep things quiet they would prefer to rely on Beings In Black, but Predator AKV Charlie Sparrowhawk will also be tailing Old Kim.
If the PCs seem outmatched, help arrives from the Chinese PLAN-SF. Unknown to everyone but the Chinese is that the probe is an elaborate fake. The USAF does have alien technology on Hyperion, and the Chinese know it but can't get near. Their agent inside Titan USAF wants the fake probe to be revealed with maximum publicity, as the subsequent upheavals, inquiries, and changed procedures will create opportunities to get at the real stuff. (This seemed to make sense when I started writing it. Oh well, nobody said interplanetary espionage was straightforward.) But while the Chinese presence will restrain the USAF to some extent, they will also spread word of the alien probe and its heroic owners far and wide.
And finally, for a real and indisputable alien encounter I suggest taking inspiration from the movie Repo Man. Start with the same contract enforcement scenario, but this time it is an actual alien that has gone missing from the USAF Hyperion base. The alien – or aliens, it's not exactly clear – is not very big and often dead or inert. At other times it glows, and sometimes emits bursts of Cherenkov radiation in apparent frustration. Somehow the alien can communicate with Old Kim, although this seems to be causing a rapid deterioration in health. The conceptual differences are so, well alien, that the only idea that can be conveyed is that it wants to go somewhere. The Io Plasma Torus.
The tone should be as close to Call of Cthulhu as Transhuman Space can get. At the end, the alien(s) use the tremendous energies of the Io Plasma Torus to ascend or transcend or something, and the PCs try to explain what happened while suffering from massive radiation poisoning.
An alien encounter in Transhuman Space are like a powerful spice. It won't be to everyone's taste, but a small and carefully measured dose can create a memorable experience.
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