Elon Musk has been a busy man in recent years. In September of 2016, he unveiled his company’s plan for a super-heavy launch vehicle – the Interplanetary Transport System (ITS). The following year, Musk presented the world with an updated design of the vehicle, which had been renamed the Big Falcon Rocket (BFR) and the Big Falcon Spacecraft (BFS). This past November, the launch system was renamed yet again to the Starship.
Musk also recently indicated that his company would be building a smaller version of the Starship to test the design. As the mission architecture has evolved, Musk has kept the public apprised of the progress of the ship’s construction. As usual, the latest update was provided via Twitter, where Musk shared images of the pieces of the mini-Starship ( aka. Starship Alpha) being rolled out in preparation for construction.
In September of 2016, Musk treated the world to an early sneak-peak at his proposed super-heavy launch vehicle. Previously known as the Mars Colonial Transporter, the renamed Interplanetary Transport System (ITS) was the centerpiece to Musk’s long-term vision of conducting commercial trips to orbit, to the Moon, and even to Mars. Since that time, the mission architecture and even the name of the system have changed a few times.
For example, in September of 2017 – during a presentation titled “Making Life Interplanetary” – Musk presented the world with an updated design of launch system, which had been renamed the Big Falcon Rocket (BFR) and the Big Falcon Spacecraft (BFS). And just recently, Musk announced the system will henceforth be known as the “Starship”, and its rocket the “Super Heavy“.
I have a new exercise routine where I watch Star Trek: The Next Generation most mornings of the week while doing my thing. Besides serving as awesome distraction, the episodes do get me thinking about how humans would talk to extraterrestrials. It likely wouldn’t be as easy as the show portrays to zoom across space to conduct diplomatic negotiations at the planet “Parliament”, for example, so interstellar communication would be a problem.
Luckily for non-engineers such as me, there are folks out there (on Earth, at least) that are examining the problem of talking between stars. David Messerschmitt, of the University of California at Berkeley, is one of those people. A new paper by him on Arxiv examines the issue. Note this is a preprint site and not a peer-reviewed journal, but all the same it provides an intriguing addition to how to communicate outside of Earth.
Across greater distances, however, you lose information, the interstellar medium gets in the way, and stars shift due to relative motion. Besides all that, at first you wouldn’t know how the other civilization designs its systems and you could therefore send a message that wouldn’t be picked up.
He further explains that starships and civilizations would have different communications requirements. Starship communication would be two-way and based on a similar design, so success comes by having high “uplink and downlink transmit times”. The more information, the better it would be for scientific observations and keeping down errors.
Civilization-to-civilization chats, however, would present headaches. As with all diplomatic negotiations, crafting suitable messages would take time. Then we’d have to send the message out repeatedly to make sure it is heard (which actually means that reliability is not as big of a problem.) Then the ISM would have to be contended with (something that pulsar astronomers and astrophysicists are already working on, he said).
In either case — talking to starships or other civilizations — one can assume there’d be a lot of energy involved, he added. “Starships are likely to be much closer than the nearest civilizations, but the cost of either a large transmit antenna or transmit energy is likely to be considerably greater for the starship than for a terrestrial-based transmitter,” he said, suggesting that a solution would be to minimize the energy delivered to the receiver. Other civilizations may have found more efficient ways to overcome this problem, he added.
You can read more details of the research on Arxiv, where Messerschmitt talks about Gaussian noise, channel coding and other parameters to keep in mind during communication.