Jump to content

How to get to other planets?


Recommended Posts

Help. I can reliably get into orbit, but have no clue how to get to other planets.The maneuver nodes are useless, as they only show escapes beyond a certain point, and not encounters, as far as I can tell. Not being able to go anywhere without HyperEdit is really depressing.

Link to comment
Share on other sites

Couple tools that are pretty helpful for interplanetary transfers http://ksp.olex.biz/ and https://alexmoon.github.io/ksp/
M-nodes will show encounters, but they can be quite fiddly to adjust to get the encounter. You can make fine(ish) adjustments by using the mouse wheel while hovering over one of the points on a m-node (rather than dragging it). Then once you get a rough intercept it's sometimes easier to plot a second m-node to make some more adjustments (and you can put that node closer to the target planet).  Also, double click on the target planet to switch focus to it, which makes seeing the projected orbit easier.
Hope that helps.

Link to comment
Share on other sites

2 minutes ago, katateochi said:

Couple tools that are pretty helpful for interplanetary transfers http://ksp.olex.biz/ and https://alexmoon.github.io/ksp/
M-nodes will show encounters, but they can be quite fiddly to adjust to get the encounter. You can make fine(ish) adjustments by using the mouse wheel while hovering over one of the points on a m-node (rather than dragging it). Then once you get a rough intercept it's sometimes easier to plot a second m-node to make some more adjustments (and you can put that node closer to the target planet).  Also, double click on the target planet to switch focus to it, which makes seeing the projected orbit easier.
Hope that helps.

I'm using the Ne Horizons mod, so I don't think the calculators help :( But ok

Link to comment
Share on other sites

Just now, RedPandaz said:

Does it work with the current version of KSP? I don't think it's on CKAN either...

It works with the latest version of KSP.  If your worried about it not being on CKAN, installing it without CKAN is literally just putting the "Astrogator" folder into the "Gamedata" folder in your KSP directory (if you have KSP on Steam the directory should be something like Steam\steamapps\common\Kerbal Space Program). When its done it should look like Steam\steamapps\common\Kerbal Space Program\Gamedata\Astrogator.

Link to comment
Share on other sites

Are you playing career mode?

Just asking, because some things might not work if the Tracking Station is not upgraded.

Also, try stretching your manuever nodes much further beyond than where you think you might get an SOI hit. Some planets are sloooooooow, other very fast (or your distance is super far away, resulting in some year or two of travel). 

 

This is the case with stock Jool. Hope this helps.

Link to comment
Share on other sites

You can simplify it.

Get into an equatorial orbit around Kerbin. Fire your engines prograde to escape Kerbin. If you are going to an outer planet, fire prograde when Kebin is between your ship and Kerbol to raise your altitude around Kerbol. Fire prograde when you are between Kebol and Kerbin to lower altitude around Kerbol (your ship is pointed retrograde to your orbit around Kerbol). Now you and the planet are both orbiting the same body,  Kerbol. Select the planet as your target by left clicking on it. Match the targets inclination at the ascending or descending node, which ever is closer. Now you have reduced it to a 2D problem which is a lot easier to solve. Your maneuver node will be easy to set up.

You will use a ton of fuel, but not that much more than you might think, and it does teach one a lot about what is involved in flying to another planet.

Link to comment
Share on other sites

58 minutes ago, Ty Tan Tu said:

You can simplify it.

Get into an equatorial orbit around Kerbin. Fire your engines prograde to escape Kerbin. If you are going to an outer planet, fire prograde when Kebin is between your ship and Kerbol to raise your altitude around Kerbol. Fire prograde when you are between Kebol and Kerbin to lower altitude around Kerbol (your ship is pointed retrograde to your orbit around Kerbol). Now you and the planet are both orbiting the same body,  Kerbol. Select the planet as your target by left clicking on it. Match the targets inclination at the ascending or descending node, which ever is closer. Now you have reduced it to a 2D problem which is a lot easier to solve. Your maneuver node will be easy to set up.

You will use a ton of fuel, but not that much more than you might think, and it does teach one a lot about what is involved in flying to another planet.

Actually now that I think about it, it should use less delta-V, because you are performing each maneuver at the optimal time. Maybe the reason they do not do this is because rockets can not just be ignited, shut down, and reignited as easily as they are in KSP?

Link to comment
Share on other sites

On 8/26/2017 at 9:48 PM, RedPandaz said:

Does it work with the current version of KSP?

Yes, versions are available for KSP 1.2 and 1.3. (I have not tested it with the 1.3.1 pre-release, but I also haven't had any bug reports for it yet.)

Quote

I don't think it's on CKAN either...

Yes, Astrogator is in CKAN. That's why its forum thread says: CKAN-Indexed-green.svg

Link to comment
Share on other sites

1 hour ago, Ty Tan Tu said:

Actually now that I think about it, it should use less delta-V, because you are performing each maneuver at the optimal time. Maybe the reason they do not do this is because rockets can not just be ignited, shut down, and reignited as easily as they are in KSP?

Except that may not be the optimal time.  I mean,  doing a inclination change in Kerbin's SoI may be cheaper than doing it in  Sun's SoI because of the lower velocity. OTOH the inclination change relative to the Sun will be smaller than the associated inclination change relative to Kerbin. 

Notice that is highly speculative.  Just something that crossed my mind and I'm expressing in the hope for a comment by someone with better grasp of the math involved.

Another point is that, everything else being equal, two separate maneuvers in different directions are more expensive that  single combined maneuver. 

Link to comment
Share on other sites

2 hours ago, Ty Tan Tu said:

Actually now that I think about it, it should use less delta-V, because you are performing each maneuver at the optimal time. Maybe the reason they do not do this is because rockets can not just be ignited, shut down, and reignited as easily as they are in KSP?

You are forgetting about Oberth. - It's almost always cheaper to burn near a planet than it is to escape and then set up your maneuver. I actually think it is cheaper 100% of the time, but I will say "almost" because some smart-alec will come along and prove me wrong otherwise.

To answer OP's question: Would also recommend Astrogater. You CAN set up interplanetary maneuvers by hand, but it's a pain, Astrogater will pretty much do it for you (although it usually needs slight adjustments)

Edited by severedsolo
Link to comment
Share on other sites

2 hours ago, severedsolo said:

You are forgetting about Oberth. - It's almost always cheaper to burn near a planet than it is to escape and then set up your maneuver. I actually think it is cheaper 100% of the time, but I will say "almost" because some smart-alec will come along and prove me wrong otherwise.

yeah that's the main reason for doing the burn from LKO. the difference is quite large, actually. for example, a burn to Duna from LKO costs maybe 1100 m/s if you launch during a good launch window. burning to solar orbit costs around 950m/s and the burn to force that solar orbit into a Duna encounter can easily cost another 1000m/s. so a burn from LKO isn't just slightly cheaper - it's more like a "buy one - get one free" deal.

Link to comment
Share on other sites

On 1.9.2017 at 1:09 AM, mk1980 said:

yeah that's the main reason for doing the burn from LKO. the difference is quite large, actually. for example, a burn to Duna from LKO costs maybe 1100 m/s if you launch during a good launch window. burning to solar orbit costs around 950m/s and the burn to force that solar orbit into a Duna encounter can easily cost another 1000m/s. so a burn from LKO isn't just slightly cheaper - it's more like a "buy one - get one free" deal.

What I like about KSP - Always something new to learn :D. 

Thanks a lot!

Link to comment
Share on other sites

On 01/09/2017 at 2:02 AM, severedsolo said:

You are forgetting about Oberth. - It's almost always cheaper to burn near a planet than it is to escape and then set up your maneuver. I actually think it is cheaper 100% of the time, but I will say "almost" because some smart-alec will come along and prove me wrong otherwise.

Inclination change is cheaper at lower velocities (higher orbital altitudes).  The Oberth effect play no role there.

Seems more like the opposite of Oberth. But Is just adifferent situation where different factors need to be considered. 

 

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...