How many kilometers (km) does it take a spaceship to travel from Earth to the nearest planet?

Question

I think the closest planets are Mars and Venus.

Answer 1

Some of the other answerers seem to believe that you can just wait until Mars is in opposition to the sun, with respect to Earth (i.e., closest approach) and then... ZIP!... go across. Nope. That can't be done.

To be accurate, you'd have to integrate the distance formula along an actual transfer orbit from the point of departure to the point of arrival.

To use MARS as an example, if the transfer orbit has a semimajor axis of 1.2615 AU and an eccentricity of 0.20729291, and if departure and arrival are on exactly opposite sides of the sun, then the integrated path distance is 3.920 AU, or 586.5 million kilometers. The transit time in this orbit is 258.751 days, so the average sun-relative speed along the transfer orbit is 26.2325 km/sec.

To use VENUS as an example, if the transfer orbit has a semimajor axis of 0.861665 AU and an eccentricity of 0.1605438 and if departure and arrival are on exactly opposite sides of the sun, then the integrated path distance is 2.966 AU, or 443.7 million kilometers. The transit time in this orbit is 146.069 days, so the average sun-relative speed along the transfer orbit is 35.157 km/sec.

Those examples, for Mars and for Venus, both involve the Hohmann transfer orbit, which is the minimum energy ellipse likely to be used by NASA for a manned interplanetary mission because NASA is a cheap, rinky-dink outfit that won't pay for anything faster.

Answer 2

41,700,000 km to Venus.

78,450,000 km to Mars.

These are nearest distances; but the distance the space ship travels depends on its designed path, primarily since Earth nd the other one are moving all the time.

Answer 3

The planets nearest to Earth are Venus and Mars. Venus is 0.27237AU from earth and mars is 0.524au from earth. So that gives us venus for our spaceship to travel to. One(1) au is 150 million km. so 0.27237au is around 41,505,000km. Assuming a spaceship has to achieve a velocity of escape of 40,000km/hr. and maintain that speed throughout the flight, that gives us an approximate value of 1038 hrs. or 43.25 days. Im not a space engineer though...Ohhh you're asking only for the distance...its 41,505,000km.