Tag: orbital science

Mining Part 2, Mining Colony

by aubreygoodman, posted in Asteroid Mining, Kerbalism, Mission Planning

Vimeo: https://vimeo.com/324381843

YouTube: https://youtu.be/1MprhkvcIaw

Welcome to Kerbalism! I’m your host, Aubrey Goodman. In this episode, we upgrade a manned surface station into a mining colony.

In our last episode, we landed a construction core on Minmus, ready to expand itself to support higher volume resource processing. Now, it’s time to grow our station into our first mining colony. We need a manned presence to enable ongoing mining operations, extracting resources from the surface.

With asteroids, there is a much smaller opportunity for resources. If the asteroid is only one thousand tons, we spend a lot of energy and time with finite benefit, equal to the mass of the asteroid. We must repeat this for each asteroid we wish to harvest. If the asteroids are small, we may use more resources capturing them than they yield from processing.

Moons are different. Resource abundance on the moon surface is effectively limitless, compared to the cache in the asteroid. Once we’re settled in at a good location, we can produce an arbitrary amount of fuel and send it back to orbit. We’ve chosen Minmus because its surface-to-orbit delta-v is very small. The cost of sending resources from the surface to orbit is much lower than Mun or Kerbin. From the surface of Minmus, we can launch into low planetary orbit for about one third the cost of launching from the planet directly.

The construction core is designed for expansion. The goal is to land the bare minimum mining gear and use it to build the rest on-site. Our station core has both radial and vertical expansion options. After we add processing components, we expand outward with more support struts with the same radial and vertical options. These become new expansion points and we repeat as needed.

Of course, expansion comes with its own challenges. Our first expansion of processing equipment was lost when it overheated and exploded. Fortunately, no other nearby parts were damaged. The expansion plan must include increased solar and thermal management. We also need to leave room for ships to land for refueling. These vessels will not be docking in the traditional sense. They simply land near the station and connect via fuel hose. The hoses are limited in length, so ships will need to land close to the hub and wait for colony crew to attach the hose before fuel transfer can begin. Once attached, the station can transfer stored fuel or make new fuel on-demand, until the ship’s reserves are full. Then, it’s simply a matter of detaching the fuel hose and blasting off to Minmus orbit to rendezvous with an orbital fuel station.

Using this technique, we can deliver fuel within our planetary system to support the needs of any ships traveling between the planet and its moons. As we expand to other planets, we create new mining colonies on moons as needed.

As always, thanks for watching Kerbalism!

Stations Part 3, Nearby Planets

by aubreygoodman, posted in Kerbalism, Mission Planning

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!

Stations Part 2, Lunar Orbit

by aubreygoodman, posted in Kerbalism, Mission Planning

Vimeo: https://vimeo.com/309137882

YouTube: https://youtu.be/YZj6RmCgXJ8

Welcome to Kerbalism! I’m your host Aubrey Goodman. In this episode, we deploy orbital stations to our moons.

In our quest to explore our solar system, we seek new information to help us make sense of the universe, to expand our understanding of physics. Having a manned station in orbit around a moon helps pave the way toward increased traffic to the moon and acts as a support point for missions to its surface.

Just as we did for planetary stations, we first send an unmanned fuel pod into low lunar orbit. This will help prepare for future missions. Deploying a manned science station at the same altitude but on the opposite side of the orbit helps increase utility. The fuel pod acts as a last ditch option for crafts running critically low on fuel. Having both stations on the same orbit at opposite ends effectively doubles the chance a struggling craft can dock with a station.

Orbital science stations act as a staging point for science missions to the surface. We want to make sure we have docking ports of all sizes on these stations, again to maximize utility. Also, since this station will be supporting other smaller craft, it needs a large cache of fuel, monopropellant, and electricity.

After the station is assembled in planetary orbit, with all its supporting craft docked, we’re ready for transfer orbit. With fuel reserves adequately filled, we plan and execute our lunar transfer maneuvers. This means a prograde maneuver from planetary orbit and a retrograde maneuver to settle into a low circular orbit around the moon.

From here, we can send our unmanned support craft to the surface to explore and gather samples. We can also ferry tourists to the surface for a space selfie. Tourism helps generate revenue to stoke the financial furnace to pay for our science missions.

We’ve spent a considerable amount of resources just to deploy stations to our moons. It’s going to take a lot more funding to build and deploy manned stations to other planets. In our next episode, we send a manned station to Duna, which is a lot like Mars. Don’t miss it!

And thanks for watching Kerbalism!

Stations Part 1: Planetary Orbit

by aubreygoodman, posted in Kerbalism, Mission Planning

Vimeo: https://vimeo.com/308821250
YouTube: https://youtu.be/gIWuT522JG4

Welcome to Kerbalism! I’m your host, Aubrey Goodman. In this episode, we deploy a station to planetary orbit.

So far, we’ve only sent small things into space. Now, we’ll start to experiment with larger objects. The best place to start is a station in low planetary orbit. As you may have noticed by now, this will be pretty much the beginning of any mission. The first step will often be stable low orbit. From there, we have options.

One of the most important components of a successful spacefaring society is a system of orbital fuel depots. These unmanned stations act as storage containers for extra fuel. We will use them for future missions, where it makes sense to refuel in space after launch before continuing on a mission.

This technique will be the foundation for all advanced missions. By staging fuel and other components at key locations, future missions can take advantage of pre-staged resources. The goal is to deploy sufficient equipment to extract and refine the natural resources available in space and on the surface of other orbital bodies. But that’s a lot of work!

We’ll start with a simple orbital fuel pod. This needs to have docking ports, some kind of attitude control system, and enough solar panels to keep it powered. Ships docking with this fuel depot may need to top off various different fuels, so keeping a little of everything on hand is helpful. Our example shows only monopropellant and liquid fuel storage.

A fuel pod is a great start, but we need to start sending manned missions now that we have infrastructure in place. This means we’re ready to send science missions! By launching scientists into orbit, we begin to explore the effects of zero gravity on materials and living tissue. This can be a great accelerator, pushing the cutting edge of our technology ever faster.

Still, just as in real estate on terra firma, location is key. There’s only so much to be learned in low orbit. In our next episode, we expand to consider stations in lunar orbit around a moon. So stay tuned!

And thanks for watching Kerbalism!

Satellites Part 2: Lunar Orbit

by aubreygoodman, posted in Kerbalism, Orbital Basics

Vimeo: https://vimeo.com/307753956

YouTube: https://youtu.be/qCvHz1n0qxU

Welcome to Kerbalism. I’m your host, Aubrey Goodman. In this episode, we’ll review the deployment of satellites to lunar orbit.

First, let’s expand to consider the nearest moon. It requires more deltaV to get there, and more still to stabilize in a circular orbit. The good news is our Kerbin orbital satellite is over designed for its task. Its first stage does almost all the work, and we have plenty of fuel left over in the second stage for transfer orbit burns.

Once the craft is in planetary orbit, we need to perform two maneuvers to stabilize into orbit around Mun. If we do a really good job executing the maneuvers, we will settle into a circular orbit.

Orbital transfer between Kerbin and Mun can be done really at any time from a mostly equatorial orbit. This refers to the inclination of the orbital plane relative to the rotation of the body. Kerbin and Mun have very similar inclination, making it convenient to transfer between them. As we’ll find later, Kerbin’s other moon, Minmus, has a different inclination.

While a transfer can be made between Kerbin and Mun at any time, there are optimal points along the orbit where fuel use can be minimized, due to favorable alignment. Sometimes, we can save a huge amount of fuel simply by waiting for 20-30 mins.

Once we find a transfer orbit we like, with a destination periapsis at the desired altitude – that means the periapsis of the resulting orbit around Mun – once we find that periapsis, we can proceed with executing the maneuver at the appropriate time. Even perfect execution will result in slight misalignment with your designed objective. This is expected. If necessary, you can make corrections with RCS, but this is generally not required.

Now, after some time has passed your craft has traversed its path and is now approaching the periapsis of the destination orbit. You must burn retrograde until you slow down enough to stabilize into an elliptical orbit. Then, bring the apoapsis down to around the same altitude as the periapsis, resulting in a circular orbit.

Kerbin has a second moon, called Minmus. Its orbital inclination is about 6 degrees higher than Kerbin, so any craft headed there must also perform a maneuver to align its inclination. This is ideally done during orbital ascent, which reduces the inclination difference.

Our over designed satellite has enough fuel to enter stable orbits of both moons. But it also does very little. As we add capability to our satellite, the payload mass increases, and the first stage fuel requirements increase exponentially.

So that’s it for lunar satellites. In the next episode, we’ll focus on solar satellites; that is, satellites on an orbit similar to a planet. Those will lead us to a place where we will be able to establish a relay network of satellites that allows us to explore a wider part of the solar system. So stay tuned for that and much more!

And thanks for watching Kerbalism!

01 – Intro

by aubreygoodman, posted in Kerbalism

Vimeo: https://vimeo.com/305384440

YouTube: https://www.youtube.com/watch?v=wMqwyPoBY5k

Space is dark, lonely, and cold… most of the time. Rockets are dangerous; sometimes they explode. Atmospheric re-entry is violent. Sometimes parachutes don’t deploy. In short, space is hard.

From the very first rocket tests in the 1930s, rocketry has been a dangerous field. Early rocket tests had no passengers of any kind. We didn’t want to risk sending humans into the unknown.

After the early rocket tests started to stabilize and launches were starting to succeed more frequently, we expanded to biological payload. Yes, we sent a monkey into space. While we may want to believe he looked like an astronaut in a space suit, in reality it was different. The world saw it on the cover of Life magazine in 1961.

Once we proved we could keep a monkey alive, we started sending manned missions. Over the years, many brave men and women gave their lives so we could learn how to protect living passengers. The stakes are very high, and even the smallest mistakes can lead to catastrophe. Make no mistake, this is a high risk high reward scenario.

We continue in the face of adversity because the benefits are nearly limitless. The cultural and scientific value of visiting other planets is hard to imagine, let alone calculate.

You can read about all the heroes, tragedies, and triumphs in history books. You can also read textbooks about orbital mechanics. But how do we make it easily accessible to everyone? With games! Video games rely on simulated environments to represent the physical world with stunning accuracy.

We can use tools like Kerbal Space Program (KSP) to learn more about space in a fun and emotionally compelling way. It empowers intrepid explorers to design, build, and fly rockets and experience the challenges of space flight in a hyper-realistic way. Before we get into the details, let’s start with something we can sketch on paper.

Here’s a thought experiment: draw a small circle beside a larger one and label them Moon and Earth, respectively, and ask people to draw the path a spacecraft might follow in order to travel from the Earth to the Moon. Many will draw a straight line from one circle to the other. Few will connect the two circles with an ellipse.

While you could try to aim your rocket straight at the Moon, your path would be anything but a straight line. This is because of the immense power of gravity. Inside the sphere of influence of any massive body, everything moves along clean mathematical curve shapes.

As long as you’re not actively accelerating using engines of some kind, your spacecraft is adrift in the cosmos, confined to a fixed orbit forever. In many cases, this is the final goal of the craft, to maintain a stable orbit around some stellar body.

This is achieved by executing a series of maneuvers, where we burn fuel to accelerate and change to a different orbital curve. Then we wait for gravity to pull the craft to an intersecting point on another curve. The rules are simple, but there are a lot of variables to consider when designing a launch system.

And that’s the trick – we’re never just designing the spacecraft; we’re designing the craft, as well as the plan to execute its successful deployment at some point in spacetime. We’re not just driving on paved roads to the local supermarket. Launch planning sometimes involves several maneuvers, docking with other craft for fuel, supplies, and crew transfer. Orbital alignments wait for no one.

This is the essence of Kerbalism. Thanks for watching and stay tuned!