From Earth to Saturn: How long would it take to reach the ringed planet?
Last Updated: September 29, 2023
When considering the planets, Saturn stands out due to its brilliant rings, making it a favorite among many. When we gaze at objects in space, we often wonder and dream about visiting them. But, how long would it take to get there? Let’s dive into the various factors to determine how long it would take to get to Saturn!
The basics of space travel
When calculating travel time you use two basic measurements: the distance and the speed of the vehicle. The average distance between Earth and Saturn is 886 million miles (1.4 billion kilometers) and “only” 1.2 billion kilometers at its closest distance from us. Saturn is 9.5 astronomical units (AU) away from the Sun and therefore 8.5 AU from us since 1 AU is the distance from the Sun to Earth at 93 million miles.
Related Reading: How Far Away Is Saturn From Earth Now?
However, just as it is here on Earth, travel time highly depends on the route you take.
In particular, there are typically four factors when considering a more precise flight duration to any astronomical object:
- If the spacecraft launches directly toward the object or sent to other celestial objects either for scientific studies and/or a gravity assist using a slingshot flight maneuver. While a gravity assist maneuver will increase the spacecraft’s speed, any flybys and certainly any time spent studying will also mean time not spent on the journey to the final destination. Therefore while a quick flyby mainly for the purpose of a gravity assist will dramatically increase speed and decrease travel time, time spent studying that planetary system becomes a little more complicated in terms of its actual impact on average velocity and travel time.
- The launch vehicle capabilities as the majority of the speed of the aircraft (disregarding gravity assists and thruster adjustments) will be determined by the speed the rocket can attain after escaping Earth’s gravity, which requires a minimum of 7 miles/ 11.2 kilometers per second (25,000 mph or just over 40,000 km/ hr) just to reach Earth’s escape velocity. As a baseline, the Apollo spacecrafts reached a speed of 8 km/sec.
- Slowing down requires time either reverse-firing thrusters in space or utilizing atmospheric re-entry if landing. A simple flyby will be shorter than an orbit insertion (which is the best we can do for Saturn since it is a gas giant and therefore we can’t land on it since there is no surface) or officially landing on the surface of an object
- A planet is not a fixed point in space like a house since it is constantly moving around the Sun. So, we can’t only plan to reach the end destination based on the distance when we launch, but where it will be by the time we reach it. This calculation also has to be done for any gravity assists that will be planned along the trip.
While theoretical flight plans are helpful, what real flight plans can we compare to better understand more realistic travel times to Saturn?
Past missions to Saturn
There have been 4 missions that have either included Saturn in their flight plan or had it as the final destination and one of note sped past it on its way to the edge of the solar system. Let’s dive into the travel times, but also factors of each of these missions to understand a better realistic average of travel time to Saturn.
Related Article: How Much of Space Have We Explored So Far?
Along with its sister spacecraft Pioneer 10, Pioneer 11 was focused on studying the outer solar system. Pioneer 11 was the first spacecraft to study Saturn up close after a flyby and gravity assist from Jupiter.
The spacecraft was designated Pioneer-G weighing 570 lbs (258.5 kg). It was launched on an Atlas Centaur rocket derived from the SM-65 Atlas D missile with a Centaur upper stage, which was the first upper stage to use high-performance liquid hydrogen for fuel. In addition to the Pioneer sisters, the Atlas Centaur is known for launching Surveyor 1 and Mariner 4. It continued being developed and improved into the 1990s and its last direct descendant was the Atlas II.
Mission Log of Relevant Key Dates:
April 6, 1973
after the boost from the TE-M-364-4 engine, Pioneer 11 traveled away from Earth at a velocity of about 32,000 miles per hour (51,800 kilometers per hour)
April 11, 1973 and April 26, 1974
Flew through asteroid belt
Dec 3, 1974
Jupiter flyby closest approach, gravity assist
about 26,400 miles (42,500 kilometers) from the planet’s cloud tops, traveling at more than 106,000 miles per hour (171,000 kilometers per hour), faster than any human-made object at the time
May 26, 1976 and July 13, 1978
August 31, 1979
Detected Saturn’s magnetic field and bow shock
about 932,000 miles (1.5 million kilometers) from the planet
September 1, 1979
Crossed Saturn’s ring plane and then passed by the planet for a close encounter and gravity assist to head to interstellar space
about 13,000 miles (20,900 kilometers) from the clud tops at a relative velocity of about 71,000 miles per hour (114,000 kilometers per hour) at the point of closest approach
Crossed the orbit of Neptune
Last data received
So, in total, from launch to Saturn was 6.5 years for Pioneer 11, keeping in mind the Jupiter flyby and gravity assist. Some of Pioneer 11’s greatest discoveries about Saturn include a new narrow ring around Saturn, overall temperature readings at minus 292 degrees Fahrenheit (minus 180 degrees Celsius), and data which indicated a more featureless atmosphere than that of Jupiter and that the planet was primarily made of liquid hydrogen.
The Voyager spacecrafts were created to perform a “Grand Tour of the Outer Solar System”. Due to budget and other concerns, the missions were whittled down from their original Grand Tour plans, but still took advantage of a rare planetary alignment to study the outer solar system up close before heading off into interstellar space. Both carried a copy of the Golden Record, a 12-inch/ 30 centimetres diameter gold-plated copper disc which contained a message from humanity to space including examples of life on Earth, greetings, and music as well as instructions on how to play the samples.
The Voyager 1 spacecraft weighed 1,592 pounds (721.9 kilograms) and was launched on top of a Titan IIIE-Centaur rocket. This rocket system was also used to launch the Viking probes and the Helios spacecraft. Voyager 1’s mission focused on studying Jupiter and Saturn before launching toward interstellar space. To this day, it is the spacecraft that has traveled the farthest in space.
Mission Log of Relevant Key Dates:
September 5, 1977
February 10th, 1979
Officially crossed into the Jovian moon system
Jupiter imaging mission began when it was about 165 million miles (265 million kilometers) from the planet
March 5th, 1979
Jupiter flyby closest encounter
about 174,000 miles (280,000 kilometers) from the cloud tops and studied multiple moons on the way out
April 9, 1979 and October 10, 1979
Course corrections to Saturn
Voyager arrived at Saturn
initial Saturn flyby, discovering 5 new moons and photographing several others
November 12, 1980
Flyby to perform a gravity assist and launch toward interstellar space
closest approach at a range of about 78,290 miles (126,000 kilometers); after the gravity assist, it launched toward interstellar space at a rate of about 3.5 AU (325 million miles or 523 million kilometers) per year
Voyager Interstellar Mission officially begins
February 14, 1990
Captured about 60 images of the Sun and the planets to create the first “Solary System Family Portrait” at about 40 AU from the Sun (3.7 billion miles or 6 billion kilometers)
including the famous Pale Blue Dot mosaic of images
February 17, 1988
Became the most distant human-made object
after overtaking NASA’s Pioneer 10 at a distance of 69.4 AU from the Sun
December 15, 1977
Officially crossed into interstellar space
All in all, launch to Saturn was 3 years and 2 months for Voyager 1, halving the record set by Pioneer 11. Some of Voyager 1’s biggest discoveries include a thin ring around Jupiter, 2 new Jovian moons (Thebe and Metis), 5 new moons of Saturn, and a new ring (G-ring) at Saturn.
Despite being named Voyager 2, it actually launched earlier on August 20, 1977, versus Voyager 1’s launch date of September 5th, 1977. Voyager 2 completed more of the Grand Tour of the Outer Solar System originally proposed for the project, targeting Jupiter, Saturn, Uranus, and Neptune before launching into interstellar space, again, taking advantage of a rare planetary alignment.
It is still the only spacecraft to have studied all four of our solar system’s gas giants at close range. The Voyager 2 Spacecraft mass and launch vehicle type were the same as Voyager 1 (1,592 pounds/ 721.9 kilograms and the Titan IIIE-Centaur.
Mission Log of Relevant Key Dates:
August 20, 1977
December 15, 1977
Passed by Voyager 1
meaning Voyager 1 actually exited the asteroid belt earlier
April 24, 1979
Began transmitting images of Jupiter, and made close passes to the Jovian moons on its way to the planet
July 9, 1979
Jupiter flyby and gravity assist and course correction 2 hours later
closest approach at a range of about 400,785 miles (645,000 kilometers)
August 22, 1981
imaged the moon Iapetus, beginning its encounters with Saturn’s system
August 26, 1981
Saturn flyby and gravity assist; flew behind and up past Saturn through its plane of rings; photographed several moons
closest approach at a range of about 63,000 miles (101,000 kilometers); was bombarded by thousands of micron-sized dust grains which shifted the attitude and required multiple firings of the attitude control jets to stabilize
Uranus flyby and observations
Neptune flyby and observations; trajectory adjusted to enter interstellar space
Officially entered interstellar space
All in all, launch to Saturn was 4 years for Voyager 2 with a Jupiter flyby and gravity assist. Some of Voyager 2’s greatest discoveries include a 14th moon at Jupiter, 10 new moons and two new rings at Uranus, and five moons, four rings, and a “Great Dark Spot” at Neptune which was gone five years later when Hubble imaged Neptune. Both Voyager spacecraft reached a speed of 17 km/ sec with the aid of gravity assists.
Cassini was launched specifically for long-term observations of Saturn, along with the Huygens Probe which would study and even land on its largest moon, Titan. NASA features an amazing interactive 3-D visualization of Cassini that allows to explore the various parts of it as well as a fantastic Saturn and Titan Resources Page that lets you explore in a variety of ways.
The Cassini orbiter weighed 4,685 pounds (2,125 kilograms) and sat on top of a Titan IV-B rocket which was part of the Titan IV family of heavy-life space launch vehicles. The Titan IV rocket family was primarily used for Department of Defense projects, were retired in 2005 due to high costs and concerns of the toxic hypergolic propellants, and replaced with Atlas V and Delta IV launch vehicles.
Mission Log of Relevant Key Dates:
October 15, 1997
April 25, 1998 and June 24, 1999
Venus flybys and gravity assist maneuvers
August 17, 1999
Earth flyby and gravity assist
December 1999-April 2000
Traveled through the asteroid belt
Began exploring Jupiter
Performed a camera test on Saturn 20 months before arriving
177 million miles away (nearly twice the distance between Earth and Sun)
November 2002-June 2004
Performed several observations of moons as well as storms on Saturn
June 30, 2004 in CA (July 1st in UTC)
Cassini successfully inserted itself into orbit around Saturn
Huygens Probe detached
January 14, 2005
Huygens Probe landed on Titan
descended through Titan’s atmosphere for 2 hours and 27 minutes and survived for 72 minuts on the surface
February 2, 2010
September 15, 2017
Grand Finale/ mission end
While it is difficult to summarize the amazing contributions of Cassini is such as small space, one of its most impactful was the detection water, actual H20, in vapor, liquid, and ice form on one of Saturn’s moons, Enceladus. In fact, Enceladus spews plumes of water vapor and ice particles into space, which collect in the rings and is one of the reasons its rings are so bright.
The presence of water in so many forms increases the likelihood of Enceladus being a habitable world in some form either now or in the future and there was concerns over contaminating either existing life or contaminating it with life from Cassini. Due to this, Cassini’s end of mission was altered to have it burn up in Saturn’s atmosphere called the Grand Finale in 2017.
All in all, launch to Saturn was 6 years and 9 months, with observations and gravity assists from Venus and Earth. Cassini spent 20 years in space, with 13 exploring Saturn and its system, unearthing valuable information about its rings, mangetosphere, moons, weather, and more. The Cassini-Huygens probe became the first to land in the outer solar system and sample an extraterrestrial ocean as well as confirm that Titan has an comparable “water” cycle with lakes, oceans, rivers, and weather but made up of other elements. Some of its historic stats include:
- 4.9 billion miles (7.9 billion km) traveled since launch
- 6 named moons discovered
- 294 completed orbits
- 162 targeted flybys of moons
- 453,048 images
- 360 engine burns
The New Horizons spacecraft’s mission is focused on the dwarf planet Pluto, its moons, and the Kuiper Belt, an icy asteroid belt past Neptune. While it did not stop at or study Saturn, it is often cited in estimations of space travel because it’s one of the most recent and therefore most advanced propulsion systems, particularly when considering travel to the outer solar system.
The New Horizons spacecraft weighed 1,054 pounds (478 kilograms) and utilized the Atlas V 551 launch vehicle. It was the first mission in NASA’s New Frontiers program, which also includes Juno which studied Jupiter and OSIRIS-REx which completed an asteroid sample retrieval from Bennu.
New Horizons launched on January 19, 2006, and after reaching its initial Earth orbit, the Centaur upper stage fired (for a second time) for nine minutes to boost the payload to an elliptical orbit that stretched to the asteroid belt. A second firing of the Star 48B solid rocket accelerated the spacecraft to a velocity of about 10.1 miles per second (16.26 km/ s) or 36,400 miles per hour (58,536 kilometers per hour), the highest launch velocity attained by a human-made object relative to Earth.
New Horizons performed a gravity assist at Jupiter on Feb 28, 2007, increasing velocity by about 9,000 miles per hour (14,000 kilometers per hour) and shortening its trip to Pluto by three years. Shortly after, it was put into hibernation mode.
New Horizons crossed Saturn’s orbit 2 years and 4 months after its launch on June 8, 2008. Again, we need to remember that it did not stop at Pluto and therefore this is not an accurate estimate since it does not include measures to slow down which we would need to do if we were trying to get to Saturn.
General Estimate for Probes
As we have seen, the travel time to Saturn greatly depends on the route, launch vehicle, gravity assists, and method of arrival. However, the general estimate for if we launched a probe today would be 4-7 years.
What about crewed spaceships?
It is important to note that none of these missions has had human occupants. We need to go slower to accommodate our fragile bodies. In fact, the fastest that humans have ever traveled in space is 24,791 mph (39,897 km/ hr), which was achieved by the returning Apollo 10 astronauts in May 1969.
Think of how you are pushed back into your seat during take-off in a plane, but then are comfortable during the flight once a steady cruising speed is achieved. So, we have to survive the G forces of take-off, which astronauts currently experience at between 3 and 8 Gs between takeoff and atmospheric re-entries, but once we reach a steady cruising speed such as 16,150 mph (26,000 kph) in orbit/ space, G-forces are no longer a concern because the speed is constant.
It takes an average of 6 hours to three days for astronauts to travel on a Soyuz rocket to the International Space Station which sits at an altitude of about 253 miles (408 km) traveling around Earth every 90 minutes at a velocity of 17,500 miles (28,000 kilometers) per hour.
However, the SpaceX launches to the ISS currently average 24 hours. In May of 2022, SpaceX Crew-4 mission made it in less than 16 hours. There are a number of variables that determine how long a trip will take, but the reduction in travel time to the ISS due to the partnership with the private space company is a prime example of how human innovation is constantly working to fine-tune and adapt to reach further heights.
The new NASA SLS system designed to bring humans back to the moon has a top speed of over 6 miles/9.7 km per second which roughly equates to over 21,600 mph or 34,920 km/hr, but that may change as the missions continue to develop over the next few decades and as technology continues to improve, not just in engines, but also in protecting the human body.
Since the SLS current max speed is about 35% of the speed of the Voyagers, a spacecraft with humans onboard would likely take 8-12 years to reach Saturn for now. It is important to remember that the ongoing and upcoming missions to return humans to the moon also prepares us to go to Mars by the 2040s. These future missions will help us adapt and innovate to further innovate human exploration of the solar system.
Theoretical Light Speed
Finally, light from the sun takes about 80 minutes to travel to Saturn, so if in the future we could travel at the speed of light, which the current understanding of physics says is an impossibility for anything besides light, it would be an 80-minute trip.
Saturn, sits at an average distance of 886 million miles (1.4 billion kilometers) from us, 9.5 times the distance from the Sun to Earth. While a simple travel time calculation puts this at 8 years, the calculation is highly dependent on the speed achieved, the route, the number of “stops”, the number of gravity assists, and the approach procedure in which we slow down. Do we go straight to Saturn or utilize gravity assist maneuvers from other planets?
Based on previous spacecraft missions to Saturn (with Saturn as the final destination, a “stop”, or a landmark on the journey to other planets), we’ve seen a range of answers depending on the factors of each trip with most being about 4-6 years and a record-breaking 2 years and 4 months when the newest of the spacecrafts (New Horizons) passed Saturn’s orbit. For humans though, it would likely take closer to 8-12 years to safely travel there due to what our bodies can withstand, but that number will likely decrease due to innovations by the time we are actually considering sending a human to the famous ringed sixth planet or one of its moons.
If one thing is clear from calculating the time it would take to get to Saturn, it is that human ingenuity allows us to accomplish amazing feats and surpass even what were once our greatest achievements. Within the next decade or two, this timetable could be very different, and that is the beauty of scientific progress.
Sarah Hoffschwelle is a freelance writer who covers a combination of topics including astronomy, general science and STEM, self-development, art, and societal commentary. In the past, Sarah worked in educational nonprofits providing free-choice learning experiences for audiences ages 2-99. As a lifelong space nerd, she loves sharing the universe with others through her words. She currently writes on Medium at https://medium.com/@sarah-marie and authors self-help and children’s books.