Interplanetary travel, especially to Mars, has garnered significant interest from space agencies and innovators. NASA and Elon Musk have ambitious plans for Mars missions, despite the considerable journey duration.
While robotic probes take approximately seven months to reach Mars, human missions could extend to a few years, especially with the formidable challenge of space exploration.
Distance Between Earth and Mars
The time it takes to reach Mars depends on the constantly changing distance between the two planets. While Mars is the fourth planet from the Sun and the second closest to Earth after Venus, their separation varies as they orbit the Sun.
The closest possible approach, theoretically, occurs when Mars is at its perihelion (closest point to the Sun), and Earth is at its aphelion (farthest point), bringing the planets about 33.9 million miles (54.6 million kilometers) apart. However, this alignment has never occurred in recorded history.
The closest documented approach transpired in 2003, with the planets being 34.8 million miles (56 million km) apart. Conversely, Earth and Mars are farthest from each other when they are on opposite sides of the sun, creating a distance of up to 250 million miles (401 million km). The average separation between Earth and Mars is approximately 140 million miles (225 million km).
Uncrewed Trips to Mars From Earth
Mars orbits the Sun once every 687 Earth days, which leads to varying distances between Earth and Mars, with relatively close alignments approximately every 26 months. Due to the elliptical nature of their orbits, some close approaches are closer than others. For instance, on October 6, 2020, Mars was as close as 38.57 million miles (62.07 million kilometers) to Earth.
The duration of a journey to Mars depends on the speed of the spacecraft. For example, the Perseverance rover, traveling at around 24,600 mph (39,600 kph), took seven months to reach Mars. However, this travel time was influenced by the positions of Earth and Mars at the launch and landing times.
If a spacecraft could match the speed of the New Horizons probe, which reached 36,000 mph (58,000 kph) during its mission to Pluto, it could potentially reach Mars in as little as 39 days, contingent on planetary alignment.
As humans have not journeyed to Mars yet, precise travel times remain uncertain. Estimates suggest that human missions will capitalize on favorable planetary alignments, with expected travel durations falling within the range of 150 to 300 days, typically around seven months, mirroring the Perseverance rover's journey.
How Long Will It Take for a Crewed Flight To Reach the Red Planet?
Unlike robots, human crews on a Mars mission require essential supplies like food, water, oxygen, and return provisions, which can significantly increase the spacecraft's weight and duration of the journey.
Presently, NASA's estimates suggest a round-trip crewed mission to Mars, including surface time, may last two to three years, with three years deemed feasible.
However, the American space agency seeks to shorten this timeframe, aiming to enhance human safety and understand the effects of prolonged space exposure on the human body, as the longest consecutive spaceflight record stands at 437 days. Consequently, NASA is investing in innovative propulsion technologies to facilitate faster space travel.
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