The problem is largely logistical. Solutions have, for the most part, been worked out on paper,
but the problem is only half getting a manned crew there - the other half is getting them back (it takes six months each way). The expense would be, by several orders of magnitude, beyond anything NASA has ever attempted. This answer just hits the high points of "why it hasn't been done yet" - there are many more reasons.
No, Mars is not the most visited planet in our solar system. The most visited planet is Earth, followed by Mars and Venus. Multiple spacecraft have been sent to Mars to study its surface and atmosphere, but Earth remains the most visited due to human presence and satellite communications.
One of the spacecraft that has visited Mars is the Mars Curiosity Rover. Launched in 2011 by NASA, its main mission is to explore and assess the Martian climate and geology, and investigate whether Mars could have ever supported microbial life.
Pluto will be visited by the spacecraft New Horizon in 2015
No, not yet. So far, we've only managed to send machines there.
No human has visited Mars yet. However, there are plans by space agencies like NASA to send astronauts to Mars in the future using advanced spacecraft and technology.
As of yet, there have been no manned Mars spacecraft at all.
Humans have visited the Moon, Mars, Venus, and multiple spacecraft have traveled to Jupiter, Saturn, Neptune, and Pluto. However, manned missions have only reached the Moon and Mars.
Mars has constantly been visited by spacecrafts. The first spacecraft to visit Mars was the Mariner 4. After that Mars has been visited by numerous spacecrafts like: Mars Pathfinder, Mars Global Surveyor, Mars Odyssey, Mars Express and the Mars 2 which was the first spacecraft to land on Mars.
Humans, no. Unmanned spacecraft, yes.
yes
Yes, several spacecraft have visited Mars. These include the Mars rovers (such as Curiosity and Perseverance), landers (such as InSight), and orbiters (such as the Mars Reconnaissance Orbiter and MAVEN) sent by various space agencies, including NASA and the European Space Agency. These missions have provided valuable data about the planet's atmosphere, geology, and potential for past habitability.
The mars rover landed in 2004 and i dont know the other one
venus was the first planet visited by the American spacecraft
If you mean "Who"...then no-one. But, I think there's a manned mission to Mars planned in the next few years.
I think that they have tried but failed. But i could be wrong...
It's the closet and rather similar to the earth.
No, Mars is not the most visited planet in our solar system. The most visited planet is Earth, followed by Mars and Venus. Multiple spacecraft have been sent to Mars to study its surface and atmosphere, but Earth remains the most visited due to human presence and satellite communications.