Jonboy

KSP forces you to figure things out. Just as in picking up any real-life skill, you fail a lot. But once you succeed and something starts to "click", you get a sense of real satisfaction. That feeling is sure as hell "addictive". Plus for me, KSP gives me the opportunity to design and fly rockets, which is something I've always dreamed of doing since I was a small child. In other words, if you're the right kind of person, KSP can be a great source of "addictive" satisfaction.

For my ships I found I have to come in a bit higher that 190 km. In the old aero, it seemed you had a fairly large margin of error when it came to aerobraking. With the testing I've done in 1.0.2, it seems that the margin is much smaller, especially when dealing with Jool. I try to just barely dip into the atmosphere, somewhere between 195km and 197km seemed to be the sweet spot. Edit: This is coming in from an interplanetary transfer with a speed of ~8000 m/s.

Back in January, I flew down to Kennedy Space Center for a day to watch the CRS-5 Falcon 9 launch. ISS passed right overhead a few minutes before the launch window, which was awesome. Since it was directly overhead, it was visible for quite a few minutes. Unfortunately, the launch was scrubbed at about T-30 seconds, so I didn't get to see the launch. Overall, it was very cool.

This is a great UFO-story-swapping thread, but what exactly does it have to do with science?

That Altair is just beautiful! Great work!

Until an atmosphere or magnetosphere odds introduced (which would require technology FAR beyond what we currently have), any colony would have to rely on being buried under a thick layer of Martian soil to protect against cosmic radiation and solar flares. IIRC, it would take about 16 feet of Martian soil to provide the same radiation protection as on the surface of Earth. Colonists would be living an underground life, with outside activities limited to only a few hours or less each day. I find it hard to imagine a profitable or successful colony existing in such conditions.

The magnetosphere actually plays a huge role in protecting the Earth from bombardment by solar wind. Most particles are deflected, with some entering near the North and South poles (the cause of most auroras), and others being trapped in the Van Allen belts. But yes, the atmosphere is the main source of protection against high-energy cosmic rays, which originate from outside our solar system. I suspect both an atmosphere and a magnetosphere should be needed, to protect against solar flares and cosmic radiation. The two go hand in hand.

Maybe you're right, maybe you aren't. If you want, why don't you try it for yourself and let us know how it goes? If not, no need to complain. Since the goal is to be as efficient as possible, this challenge is going to be a little tedious and "gamey", but that doesn't make it invalid.

Since when do we start counting people's mistakes? It's generally a pretty good rule to not do to others what you don't want them to do to you, I've found.

What we really need is an Earth Race. While colonization and interstellar travel are appealing, especially to those who are fascinated by space travel, as all of us are, the technology is centuries away, in my opinion. The Space Race resulted in some amazing engineering feats, and did result in some great technological innovations, our real focus in the 21st century should be developing technology to stabilize our own planet. There is no realistic scenario where we colonize other planets, whether inside or outside of our own solar system, within this century. Yet all science points to significant and catastrophic man-made climate change on our own planet well before then. While interstellar travel may be possible, it is astoundingly difficult. If it is possible and profitable, I have no doubt that our species (or whatever evolutionary ancestors are around at that time) will pursue it and accomplish it. But focusing on manned interstellar (or even interplanetary) travel when we can't guarantee the survival of modern civilization in this century is astoundingly foolish. Apparently, most nations do not take impending climate change seriously enough to create real solutions before it might be too late. Perhaps if the danger becomes real enough to enough people, there will be a rush to innovate and solve these problems. Interstellar travel (which is, I would estimate, tens of centuries away) will not solve these issues.

For a few million dollars? Surely you're joking.

How many things can I cook? How many recipes do you have?

Hope you can pull this off. The concept sounds awesome.

Thanks for the explanation. This is in fact how I set mine up. In my case the issue is that I'm very lazy with where I slap my maneuver nodes for Mun transfers, so I don't get an optimal ejection angle.

Maybe you could even have a Kickstarter? Let me know when I can take my helmet off in Hellas Planitia.

That is the most beautiful free return I've ever seen! All of mine have a super-high Mun periapsis and I have to correct it when I get in the Mun's SOI.

If you're simply changing orbits from one circular orbit to another within a planet's SOI via a Hohmann transfer orbit, the calculation is pretty simple. (A Hohmann transfer orbit, you probably know, is simple the where you burn to change your apoapsis or periapsis to the altitude of your intended final orbit, then burn to circularize once you get there.) - r is the distance of the orbiting body from the center of the central body (this means you have to add the radius of the planet to your ship's altitude, in the case of Kerbin it's 600km) - μ is the Standard Gravitational Parameter of the central body, which is the product of its gravitational constant and its mass. (Kerbin's is 3.5316x10^12 m^3/s^2) The Delta-V for your first burn is calculated with this equation: and the Delta-V for your second can be calculated with this equation: and the sum of these two equations is the total Delta-V required to change from one circular orbit to another within a planet's (or sun's) SOI. R1 is your starting orbital radius and R2 is your destination orbital radius. To make the units work easily, use meters instead of kilometers (multiply by 1,000). And just for fun, I threw together an Excel spreadsheet that allows you to easily calculate the Delta-V between two circular orbits in Kerbin's SOI. To use for another body's SOI, just look up the body's Standard Gravitation Parameter and Equatorial Radius on the wiki and plug those in to the left side of the spreadsheet: https://www.dropbox.com/s/2i5g65ic0ck4ihi/Hohmann%20Transfer%20Delta-V.xlsx?dl=0

Impressive. Most impressive.

If I remember correctly, it's about 450 m/s of Delta-V. Edit: I stand corrected, see below

Although the objects technically do not collide, you can think of them as colliding if it helps you. The gravity assist is essentially a perfectly elastic collision, just as noted. Just like in a perfectly elastic collision, so conservation of energy/momentum applies. - - - Updated - - - It can in fact change your overall velocity relative to the sun. You are "stealing" kinetic energy from the planet as you swing alongside it (and the planet loses an equal amount of kinetic energy), and this increases your velocity relative to the sun.

Yes. The planet transfers some of its kinetic energy to the spacecraft. Since the spacecraft is FAR less massive than the planet, the effects of this kinetic energy transfer are far more noticeable. There is no net change in energy between the planet and the spacecraft, the planet loses as much energy as the spacecraft gains.

As a probe or other spacecraft approaches a planet, it begins to speed up as it is pulled by the planet's gravity. As it "zips" past the planet and moves away, it again slows down. However, the planet is moving in relation to the Sun, and as the probe flies by the planet, some of that momentum and kinetic energy is transferred to the probe. In other words, the planet pulls the probe along for a sjort time in its orbit around the sun, giving it a boost in speed relative to the sun. The total amount of kinetic energy and momentum is conserved. The planet loses some momentum and kinetic energy. But the effect on the planet is not noticable because of its large mass in relation to the probe. Edit: Gravity assists can also slow a spacecraft down in relation to the sun. If a boost in velocity is required, the spacecraft will travel alongside the planet in the same direction as the planet's orbit. If a decrease in velocity is required, it will travel in opposite direction of the planet's orbit and the planet will "drag it back" in relation to the sun.

Install an information mod like Kerbal Engineer Redux. It really should be stock for just this reason.

Here's the simplest way in your situation: V=R*sqrt(G/(R+h)) R is the radius of the planet, which for Kerbin is 600,000 meters. G is the acceleration due to gravity on the surface, which on Kerbin is 9.807 m/s^2 (the same as on Earth). "h" is your height above Kerbin. So using a 100 km orbit as an example: v = 600,000 m * sqrt( 9.807 m/s^2 / ( 600,000 m + 100,000 m ) = 2,245.8 m/s (Just keep in mind that this assumes a perfectly circular orbit, and a satellite of negligible mass compared to the planet.)

While I share OP's enthusiasm for a Europa mission ... yikes. That title. Just stick "maybe" in there and it wouldn't be so misleading.