Forget About Mars, When Will Humans be Flying to Saturn?
It may be difficult to believe right now, but human exploration of the solar system will not end with the Moon and Mars. Our descendants will eventually spread throughout the solar system – for those interested in space exploration, the question is only when, not if.
A new paper published on arXiv by a group of researchers from the United States, China, and the Netherlands seeks to answer that question. Their approach is highly theoretical, but it is likely to be more accurate than previous estimates, and it provides a reasonable estimate of when humans might be seen in the outer solar system. They believe we will reach the Saturnian system by 2153.
It’s difficult to even begin such a calculation, so it’s best to start with the fundamentals, which in this case include some calculus. The authors needed two variables to understand when humans will reach further out in the solar system: distance and time.
In this case, distance is defined as the distance that humans have traveled from Earth, and time is defined as beginning at the start of the Space Race in 1957, when no human had yet left Earth.
Another crucial data point is when humans first landed on the Moon in 1969. At a distance of .0026 AU, it wasn’t very far into the solar system but was a start. The next step in exploration is still speculative, but the authors present two scenarios for when humanity will reach Mars. Given the launch windows, they estimate that the first humans will set foot on Mars in 2038, which is when NASA’s Artemis program is planning to launch. They also acknowledge that, given the recent history of delays in the human space exploration program, it could be as late as 2048.
Using this separate starting point, they develop a “delayed” timeline of the rest of the exploration steps, and, as it is exponential, it has a correspondingly big impact on the dates of other milestones.
Reaching Mars isn’t the only factor influencing exploration of the rest of the solar system. The authors also consider NASA’s budget and the level of space exploration technology.
Using NASA’s budget may appear to be somewhat biased, as the agency only represents one country, even though that country has the world’s most extensive space program. However, it can act as a proxy for space exploration funding more generally, though the private sector has been gaining more attention recently. There is no doubt that the first person on Mars will be from a government agency. In either case, using NASA’s budget as a variable in the equation reveals a relatively simple linear relationship between time and a non-inflation-adjusted budget.
Technological progress is more difficult to quantify, but the authors use a model of the number of papers published in a given year mentioning deep space exploration as a proxy for the level of technology required to complete those missions. The relationship they discovered for that metric of the number of papers over time is exponential, with a recent high of nearly 2,000 papers per year.
This combination of linear and exponential relationships generates an equation that can be solved by plugging in the data points for the start of the space race, the first crewed landing on the Moon, and the (still hypothetical) first crewed landing on Mars. From that model, dates of milestones begin to tumble out. The Asteroid Belt could be reached in 2073, Jupiter’s system in 2103, and Saturn as early as 2132.
As previously discussed, there are some significant potential differences due to the uncertainty surrounding the planned Mars landing. Still, as long as we maintain our current levels of technological progress and budgetary levels, the general trend is one of exponential exploration. That would be music to any space fan’s ears.