<P> In 2011, Jean - Marc Salotti published a new proposal for a manned Mars mission, with a release in 2012 . The 2 - 4 - 2 concept is based on a reduction of the crew size to only 2 astronauts and the duplication of the entire mission . There are 2 astronauts in each space vehicle, there are 4 on the surface of Mars and there are 2 once again in each return vehicle . In addition, at every step of the mission, there are 2 astronauts ready to help the 2 others (2 for 2). This architecture simplifies the entry, descent and landing procedures, which are known to be very risky, thanks to a significant reduction of the size of the landing vehicles . It also avoids the assembly of huge vehicles in LEO . The author claims that his proposal is much cheaper than the NASA reference mission without compromising the risks and can be undertaken before 2030 . </P> <P> In 2012, Conceptual Space Vehicle Architecture for Human Exploration of Mars, with Artificial Gravity and Mini-Magnetosphere Crew Radiation Shield was released, laying out a possible design for a human Mars mission . Components of the architecture include various spacecraft for the Earth - to - Mars journey, landing, and surface stay as well as return . Some features include a several unmanned cargo landers assembled into a base on the surface of Mars . The crew would land at this base in the "Mars Personnel Lander", which could also take them back into Mars orbit . The design for the manned interplanetary spacecraft included artificial - gravity and an artificial magnetic field . Overall, the architecture was modular and to allow for incremental R&D . </P> <P> In 2012, a Dutch entrepreneur group began raising funds for a human Mars base to be established in 2023 . One difference from many other humans - to - Mars projects is that the mission is intended to be primarily a settlement mission with no return trip to Earth planned . Astronaut applications were invited from the public all over the world . </P> <P> The initial plan included that a telecom orbiter and ISRU demonstration lander would be sent in 2018, followed by a rover in 2020, and the base components in 2024 . The base would be powered by 3,000 square meters of solar panels . Mars One suggested it could use a SpaceX Heavy rocket to launch flight hardware, . The first crew of four astronauts were to land on Mars in 2025 . Then, every two years, a new crew of four astronauts would arrive . Plans included selecting and training candidates, and that the entire mission is to be filmed and broadcast back to Earth as a media event . Revenues from broadcasting would help fund the program on top of private investments and monetizing IP rights . In April 2015, Lansdorp admitted that their 12 - year plan for landing humans on Mars by 2027 is mostly fiction . </P>

How long is a trip from earth to mars