The Apollo missions reached the moon in 4 days. Why is Chandrayaan taking more than a month?

The Apollo missions reached the moon in 4 days. Why is Chandrayaan taking more than a month?

The above path was taken by Saturn V of Apollo mission. It is a direct path and a shortest possible distance.

1. The rocket lifts off and utilizes 1st and 2nd stages placing the 3rd stage, service module and crew module along with lander in a Earth parking orbit.

2. Now the space craft will wait for perfect time to launch.

3. Upon reaching the perfect time, the third stage starts and moves towards moon. This is called Trans lunar Injection.

4. This journey towards moon takes roughly 3 days. Meanwhile the Astronauts on board will perform a maneuver which attaches the crew module to service module by doing a 180 degree flip.

5. Now third stage is jettisoned and the service module along with lander and crew module enters Moon's gravity. Service module is the stage which has propulsion system for future use.

6. Now these three achieves a parking orbit around the moon. Now the lander carrying two of its crew separates with crew module begins to perform landing maneuver. And one crew member stays in service module which has a control module in the parking orbit only looking after the mission.

7. The crew lands on moon, collects samples and gets back into space craft. They launch the space craft leaving landing gear on moon itself.

8. After reaching the parking orbit the crew module attaches with service module. The other astronaut monitoring the entire process gets into crew module joining the two.

9. With the help of propulsion in service module they initiate Trans Earth Injection.

10. Now after reaching the Earth, service module separates allowing the crew module alone to enter the earth's atmosphere.

11. The crew is reached out in the sea by NASA.

This needs lot of fuel and a big rocket. This raises the cost of the launch. As it is the shortest possible distance it takes less time. Right now ISRO does not have such powerful rocket.

Slingshot. It uses the help of earth’s gravity and is thrown towards moon at a perfect time when the moon reaches that position as you can see.

when the satellite comes near the earth it is pulled by earth’s gravity. And if the engines of the satellite are fired at this time, the combined effect of engines and gravitational pull will throw the satellite even further thus raising the orbit gradually towards the next big elliptical orbit. This process is continued until the combined effect of earth and Engines throw the satellite so far that it reaches the moon. Now after the satellite reaches the moon it is under the influence of Moon’s gravity which will not allow the satellite to return the earth as it previously did. That means until the satellite goes under the moon’s influence it comes back to earth under Earth’s gravitational influence.

1. First the GSLV MK 3 India's present most powerful rocket which is 3 stage lifts off.

2. The two solid strap-on boosters will separate and two Vikas liquid fuel engine will ignite in second stage.

3. After the second stage , the 3rd stage which is Cryogenic stage(ISRO's angry baby) ignites.

4. This stage will put the spacecraft into a 170×39120 km orbit. Now the cryo stage will be separated. This is an elliptical orbit, the satellites when comes near(Perigee)the earth is 170km away and when moves far(apogee) it will be 39120 km away from the earth.

5. When the space craft comes near the earth it's on board engines will ignite and burn for few seconds changing 39,120 km into a bigger number. So now the space craft reaches the newly achieved Apogee which is now more than 39120 km. Now after reaching the new Apogee it returns back to earth increasing it's speed. Again when it reaches to its Perigee again the Engines come into play and create a new Apogee point. Thus the space craft has to gradually increase the apogee point through the process of such successful engine starts in multiple stages. This is called orbit raising maneuver.

6. This will continue until space craft reaches 140,000+ apogee.

7. Now the space craft has reached 140,000 km away roughly. It will start moving back towards earth increasing it's velocity. By the time it reaches it's perigee it will reach it's maximum velocity.

8. Now the engines ignite and burn for few seconds making the velocity go up. Now the spacecraft will get such a velocity it will reach moon. This maneuver is similar to a pendulum swing. When a person pushes the pendulum it will move even further thus raising the height it swings.

9. Upon reaching the moon a parking orbit is achieved with 100×100 km orbit. Here the the Vikram lander along with Pragyan Rover separates from the orbiter. The orbiter moves along this orbit doing its job like photos and other remote sensing activities.

10. The Vikram lander applies brakes by reverse thrust. Smoothly lands on surface.

11. Pragyan Rover comes out and takes photos.

12. In this Pragyan communicates with Vikram. Vikram communicates with Orbiter. Orbiter communicates with ground stations on Earth eventually sending information to ISRO.

As the satellite or Space probe should always come towards the earth to take Gravitý’s help, this takes more time to reach the moon.