Jupiter is one of the five planets visible to the naked eye at night. Along with the Sun and the Moon, it has been used by many cultures to signify a day of the week, which may also be why we have seven days in a week.
Today, Jupiter is regarded as the “king” of planets in the Solar System due to its gigantic size: excluding the Sun, it has a mass that is two and a half times that of all the other planets in the Solar System combined.
Jupiter is regarded as the “king” of planets in the Solar System
According to historical records, we know that humans have observed and studied Jupiter for over 2,000 years. In the early 17th century, Galileo Galilei’s discoveries overturned the old worldview that all objects in the Solar System revolved around the Earth, reinforcing Nicolaus Copernicus’ heliocentric theory.
Nowadays, we are no longer satisfied with merely observing planets through telescopes, leading to the birth of many space exploration missions, including missions to explore Jupiter. But how much longer will it take for us to accomplish this mission?
If we want to know how long it would take to travel to Jupiter, we need to understand the distance involved. Since both Earth and Jupiter are in constant motion, the answer regarding the distance will always change. The closest distance between the two planets can be 365 million miles (nearly 587 million km), and the farthest can be 601 million miles (980 million km).
The fastest speed humans have ever traveled (with a crewed spacecraft) is 24,800 miles per hour (nearly 40,000 km/h) during the Apollo 10 mission. If we could travel at that speed for the entire journey, it would take between 613 days and 1,009 days, depending on the positions of the planets.
In the 1970s, four separate spacecraft were launched: Pioneers 10 and 11, and Voyagers 1 and 2. All four probes traveled directly to Jupiter’s orbit at extremely high speeds. In 2006, the New Horizons probe traveled at speeds between 36,000 and 47,000 miles per hour and approached Jupiter’s orbit in 405 days before continuing on to Pluto.
While all these probes reached Jupiter, none of them remained in a stable orbit around it. The Voyager probes later left the Solar System, and New Horizons continued towards the Kuiper Belt.
So far, only two spacecraft have ever traveled to Jupiter and stayed there: Galileo and Juno. Both probes took a more coherent trajectory to reach Jupiter, using the gravitational pull of other planets to gain the necessary speed, and flew past the asteroid belt to enter Jupiter’s orbit. Galileo took more than six years to reach Jupiter’s orbit, and Juno achieved the same in about five years. However, these are just probes; what we are truly aiming for is to undertake crewed missions.
A trip to Jupiter would take over six years just for a one-way journey.
In reality, the extent of our crewed space missions has only reached the Moon. The nearest human trip there was in 1972, and in the future, we plan to return there in 2025 (at the earliest) with the Artemis 3 mission, which is expected to take about three days. NASA’s clear plan is to use these missions as a foundation for missions to Mars in the 2030s.
According to NASA, the simplest and most fuel-efficient route to Mars would take nine months for a one-way trip and 21 months for a round trip.
If we extrapolate the methods used to calculate this route, then a similar trip to Jupiter would take over six years just for a one-way journey. NASA also estimates that a crew of four would need 8,000 pounds (almost 3,629 kg) of food per year, meaning a trip to Jupiter with four people would require carrying 48,000 pounds (21,772 kg) of food just to get there, and even more for the return journey.
However, the reality is not that simple, as food and all life-supporting and scientific equipment need to be launched into space from Earth. That weight would take much longer to catch up with the speed of the ship in motion, and the potential mission duration would also be much greater than the straightforward calculations we just mentioned.
If we could overlook the issues of weight and food, the journey to Jupiter would still not be simple.
Astronauts leaving Earth’s gravitational field would face numerous challenges. One of the main dangers is radiation. In addition to the continuous bombardment of radiation from the Sun, astronauts would encounter a barrage of cosmic rays that could lead to genetic damage and cancer.
Spending extended periods in space also presents psychological challenges. Long-duration space travel can lead to anxiety and deteriorate interactions with other crew members. Isolation from family and friends, combined with a monotonous work schedule, only exacerbates these symptoms. These are the issues that contemporary astronauts face. We will have to address these challenges and new ones before considering sending anyone to Mars, let alone Jupiter.
Spending extended periods in space also presents psychological challenges.
Despite facing numerous challenges, why do we still want to go to Jupiter?
One of the things that fascinates us about Jupiter is that it resembles a miniature model of the Solar System. Just like the countless planets orbiting the Sun, Jupiter also has a retinue of celestial bodies accompanying it on its journey around the Sun. Although Jupiter is a gas giant with no solid surface to land a spacecraft, it boasts up to 79 moons that we can explore.
Four of these moons are significantly larger than the others, with gravity similar to that of our Moon. The first three satellites – Io, Europa, and Ganymede – are too close to Jupiter and receive too much radiation, making landings here unsafe for humans. However, the fourth moon, Callisto, receives significantly less radiation than the other three moons. It is also suspected that it has a subsurface ocean of liquid water that could support life.
In the early 2000s, a study was conducted to assess the feasibility of a crewed mission to Callisto. They concluded that this would not happen until at least the 2040s and would require new types of propulsion systems that had not been tested in space before. However, assuming everything could be realized as calculated in this study, a round trip mission to Jupiter could take between 652 and 1,661 days.
