Vimeo: https://vimeo.com/310704564
YouTube: https://youtu.be/V6dT4-zPk8c
Welcome to Kerbalism! I’m your host, Aubrey Goodman. In this episode, we send a manned station to Duna.
After we have built sufficient infrastructure, we’re ready to take a bold step. It’s time to send a manned mission to orbit around another planet in our solar system. In the real world, we would be going to Mars. For the purposes of our discussion, we’ll go to Duna, which is a lot like Mars.
Just as before, we will construct our station in planetary orbit before sending it on its way. This time, though, we need to use completely different designs for the support craft we’ll be taking with us. The science and tourism landers designed in the last episode were meant for landings on moons.
Duna has significantly more mass than a moon. Its gravity is about twice that of the Moon, so we need extra delta-v to land safely. We do get one huge benefit for free. By landing somewhere with an atmosphere, we can use heat shields and parachutes to slow our descent. This saves a lot of delta-v and reduces the fuel requirements for our landers.
Science landers involving samples will need a reserve of fuel to takeoff and return to the station. For now, we will skip the return trip to save on weight. Until we have a more sophisticated refueling option, fuel is a precious resource. We’re also sending relay satellites instead of tourism landers. Ferrying tourists will have to wait. Besides, the landers are no good if they can’t communicate their findings back to home base.
With our station assembled and all its support craft docked, we’re ready to plan an escape orbit! We could simply burn prograde to accelerate out of Kerbin’s gravity, but this would need a lot of fuel. Instead, we rely on the moon to give us a gravity assist. By flying close to the moon’s surface, we take advantage of the moon’s gravity to accelerate us away from the planet.
It works like this. If we encounter the moon on the leading side, in its direct path, its gravity will slow us down. If we find ourselves on the trailing side, in its wake, we will slingshot around it and gain enough speed to escape planetary orbit.
Now that we’re on a solar orbit, outside of Kerbin’s gravitational influence, we can chart a course to Duna. Unfortunately for us, we have chosen our launch timing poorly. We must wait nearly 400 days before our Duna intercept. Clearly, we’ve glossed over the details about planning to sustain a crew for 2yrs until the next resupply mission can be expected to arrive. In the real world, people need to eat.
As we approach the planetary encounter, the station prepares to perform a retrograde burn to settle into a circular orbit. After assessing our fuel status, we determine we have sufficient fuel to deploy our relays before descending into our final orbit to deploy surface landers.
Now that we have stations spreading throughout the system, we need a sustainable way to harvest fuel in space. After watching time lapse video of refueling missions, maybe you’ve started to appreciate the value of finding fuel sources in deep space. In our next episode, we intercept an asteroid and begin to harvest its resources!
And thanks for watching Kerbalism!
Kerbalism 