Jump to content

How will you get to one of the planets?


Candre

Recommended Posts

I have an onion-style ship that can achieve kerbin escape velocity but I am not sure about landing on a planet rather than a moon. There is always the 2 ships method, send one with just enough fuel to land on the planet and rendevous, and the other would stay in orbit and have enough fuel to return.

However, first I want to do a grand tour using gravity slingshots with a probe like in novas mission.

Link to comment
Share on other sites

The red planet (Mars equivalent): relative easy to reach, although not the closest planet to Kerbin. Gravity and atmospheric pressure are in favour of a succesfull return-trip. A well designed middle-sized ship would be sufficient I think.

The charred planet near Kerbol: requires lots of fuel to reach this destination or a bi-elleptic transfer. I assume gravity and atmospheric pressure aren't too bad either for a return-trip. Don't know if solar heat will be simulated in 0.17 however.

Eve: not too difficult to reach I guess, but gravity and dense atmosphere makes return-trips an extremely difficult task. Eve could be a purple hell if temperature simulation gets implemented. Mission with 2 ships required ... ?

Gas Giant: large amount of fuel required but the SOI is probably large; makes the planet easier to target ...

Link to comment
Share on other sites

If they are at a similar distance, Eve will require more Delta-V to reach than the Mars-like planet. It takes more Delta-V to raise your orbit around Kerbol than to lower it. Also, the gravity will require that you burn off a lot of Delta-V to land. In the absence of realistic atmospheric heating, you could just aerobrake your way down though.

Link to comment
Share on other sites

I think I'll use the two-craft solution to get there and back, but I might use one of the more radical old-school lander designs- ablative lithobraking. Just strap a few dozen SAS modules to the bottom of your "lander" to cushion the impact.

Link to comment
Share on other sites

My plan is first to orbit all the planets and return from those orbits, then probably go for landings on the moons, from that point I'll have a decent idea on fuel consumption. Then...I will probably try for the Mars-like planet first, the lower gravity and atmosphere will make it easier to return.

Link to comment
Share on other sites

Flight plan:

1. Liftoff with some giant rocket.

2. Jettison solid rocket boosters and set up a low Kerbin orbit.

3. Transfer orbit to planet.

4. Make the long journey.

5. Set up an orbit.

6. Undock planetary module from command module and apply retrograde to enter planet.

7. Land.

8. Do tasks.

9. Liftoff from planet.

10. Rendezvous and dock with command module.

11. Transfer back to Kerbin and just make a direct safe re-entry approach. No orbits.

12. A few hours before re-entry, jettison rockets and leave only the planetary and command modules together.

13. Re-entry and landing procedure.

14. Success!

Link to comment
Share on other sites

  • 3 weeks later...

With only stock parts (no docking), but with a fuel transfer mod, my mission profile would look something like this:

1) Launch a tanker ship into standard 300km orbit around Kerbin.

2) Launch two tanker ships into orbit around target planet, one in high orbit (#2), one in low orbit (#3)

3) Launch interplanetary crew vehicle (ICV) into 300km rendezvous orbit with tanker 1

4) ICV refuels from tanker #1

5) Hohmann transfer orbit from Kerbin to target planet

6) ICV enters high orbit around target planet

7) ICV refuels with Tanker #2

8) ICV decent burn and landing (utilize parachutes on atmospheric planets to reduce fuel usage)

9) ICV crew performs EVA on surface

10) ICV launches from the surface (multistage to orbit launch profile for high gravity/atmosphere planets, single stage to orbit for low gravity planets/moons)

11) ICV refuels with tanker #3 in low orbit

12) Escape burn and Hohmann transfer to Kerbin

13) Maneuver for Kerbin re-entry, parachute decent

Link to comment
Share on other sites

I've been building vanilla rockets lately, even with the fuel bug fix, that have absurd amounts of delta-v. I think I could build a single rocket that can get to another planet, land, ascend, and get back to Kerbin, all in one mission. Plus, everyone keeps saying it's impossible, even you seasoned kerbonauts. (you know who you are ;)

Link to comment
Share on other sites

I've been building vanilla rockets lately, even with the fuel bug fix, that have absurd amounts of delta-v. I think I could build a single rocket that can get to another planet, land, ascend, and get back to Kerbin, all in one mission. Plus, everyone keeps saying it's impossible, even you seasoned kerbonauts. (you know who you are ;)

Depends on the planet you want to travel to. I'd say most will be so hard they may as well be impossible to reach and return using stock parts only and a single launch.

Link to comment
Share on other sites

I have no idea why so many people seem to think it's going to be impossible, for one thing, you don't even know what the new parts are going to be, and for another thing, you can already build ridiculously powerful rockets with the stock parts we do have.

Link to comment
Share on other sites

It's the delta-v budgets that are required. I'll use Eve as an example. Taking the information that Nova's given out about Eve, we know that it's gravity is 1.7x that of Kerbin's, whilst it's atmosphere is 5x as dense. Since it already takes about 4300m/s to achieve Kerbin orbit (with an efficient launcher) I think you'll need at least 5-6km/s of delta-v to lift off from Eve and attain orbit.

To leave Kerbin's orbit you'll need about another 1000m/s and head for Eve (assuming it orbits somewhere around 6-7Mm from Sol). Being conservative, lets say you assign another 500m/s for mid-course corrections and terminal maneuvering. Because of the thick atmosphere we'll say we don't need to reserve any delta-v for braking into orbit/landing (though I'd sure want some spare just in case the parachutes I pack won't slow me enough). Once you've landed, and ascended back into Eve orbit you'll need another 1000m/s or so for a Kerbin injection burn. Again I'll assign another 500m/s or so for mid-course corrections.

So here's the breakdown:

~4500m/s to reach LKO

~1000m/s for Trans-Eve injection

~500m/s mid-course correction(s)

~5500m/s to reach LEO

~1000m/s for Trans-Kerbin injection

~500m/s mid-course correction(s)

That's a rough delta-v budget of 13km/s for a Kerbin->Eve->Kerbin mission. It's based on much conjecture but I'm sure if you ran the numbers my estimation wouldn't be too far off. Not impossible with stock parts (and as you rightly said we don't know what new parts we may or may not have coming our way). However that's still a huge amount of delta-v to build into a single rocket design. I imagine most people's computers will practically grind to a halt trying to launch such a behemoth. Trying to keep the whole rocket in one piece at initial lift-off is another challenge (I've found large rockets are quite inefficient in KSP largely due to the careful ascent needed).

I never said it would be impossible, just close enough to it that it may as well be for many players.

Edited by Excalibur
Link to comment
Share on other sites

Having gigantic challenges is half the fun. I have a feeling this was the best $18 I ever spent. This is my type of game!

Completely agree with you - I think too many recent games are too easy. Once finished they leave your memory pretty quickly with no sense of accomplishment. As long as a game doesn't have goals that are actually and truthfully impossible then I don't mind how difficult they get. The number of friends I know whom have become addicted to Demon/Dark Souls due to the difficulty...

I only spent $10 back in the day for this game - I'd happily have paid $100 (roughly the price of BF3 + Premium) for it. In fact I think I've spent way more hours in KSP than Battlefield, and I've got over 100 hours logged online in that game.

Link to comment
Share on other sites

Here is my 'prototype' Duna manned mission. I tried making one huge ship that can go to Duna and back again, but anything approaching that capability would murder my poor PC's framerate. Because of this, the plan is to send two ships, a lander and a Kerbin return vehicle, launching them in quick succession.

screenshot0.png

screenshot1.png

screenshot5.png

The outer fuel tanks have enough fuel to boost the ship to a hohmann transfer to the supposed orbit of Duna (27,068,880,512m) with plenty of fuel to spare.

I have no idea about Duna's atmosphere density, but I hope to be able to slow the ship by aerobraking and place it in a stable orbit around Duna.

While the first ship is en route (as soon as possible), I send the second ship, the one-crewmember lander:

screenshot8.png

screenshot13.png

I plan to aerobrake the lander into a stable orbit and rendezvous with the Kerbin return vehicle. Its 3 crewmembers will EVA and enter the lander's crewtank. After this, the lander will deorbit and land:

screenshot14.png

screenshot15.png

screenshot21.png

screenshot22.png

screenshot23.png

After they chill for a while, performing research and waiting for the planets to align for a return trip, the lander takes off again:

screenshot24.png

screenshot25.png

screenshot27.png

The lander performs another rendezvous with the return vehicle, and all 4 crewmembers transfer to it.

screenshot6.png

screenshot7.png

Of course, this is all speculative. Both vehicles have plenty of extra fuel and the lander is capable to land on Kerbin and establish orbit again. However, I have no idea if aerobraking into a stable orbit around Duna will be possible. Luckily, Nova mentioned that one of the scenarios being implemented in 0.17 will be of a ship approaching Duna so I will be able to experiment with aerobraking and see what can be done...

Also, I have no idea if old parts will be rebalanced or if we will get new parts that will make all this much easier. Since the lander can receive 6 kerbalnauts, I might send another ship carrying a rover for the Kerbals to explore or something. God, I can't wait for 0.17 :D :D :D

Edited by Awaras
Link to comment
Share on other sites

Completely agree with you - I think too many recent games are too easy. Once finished they leave your memory pretty quickly with no sense of accomplishment. As long as a game doesn't have goals that are actually and truthfully impossible then I don't mind how difficult they get. The number of friends I know whom have become addicted to Demon/Dark Souls due to the difficulty...

I only spent $10 back in the day for this game - I'd happily have paid $100 (roughly the price of BF3 + Premium) for it. In fact I think I've spent way more hours in KSP than Battlefield, and I've got over 100 hours logged online in that game.

This is exactly the reason I bought Minecraft within days of discovering it. It offered unlimited creative potential and a very nearly unlimited world. Since buying it I have said many times that it was the best $20 I had ever spent on gaming.

KSP is the only other game to match the potential of Minecraft. Where Minecraft's biggest feature is practically unlimited creativity, KSP's main feature is that you not only get to do fun and sometimes crazy things with rockets but that you also actually use your mind to play it. Sure, it's possible to land on both of Kerbin's moons without doing the math, however I'm finding it refreshing to see a game that actually rewards you for taking the time to learn and do the math, thus saving tons of fuel, learning to build better and more efficient rockets, Etc.

Mind you I only bought this game a bit over a week ago and like Minecraft, I just cannot get enough of it.

For the first time I am actually planning to save up and get a joystick.

Link to comment
Share on other sites

However, I have no idea if aerobraking into a stable orbit around Duna will be possible. Luckily, Nova mentioned that one of the scenarios being implemented in 0.17 will be of a ship approaching Duna so I will be able to experiment with aerobraking and see what can be done...

If Duna has enough atmosphere this should be possible. If you're using Mechjeb, the landing autopilot can predict your apoapsis after aerobraking. Just open the landing autopilot window, adjust your periapsis so that your predicted apoapsis reaches the desired orbital altitude, aerobrake, move to your new apoapsis and circularize into your stable orbit. At least with Kerbin this works fine. :)

Aerobraking without this apoapsis prediction is hard, because small changes in your periapsis usually translate into huge changes of the apoapsis after aerobraking.

Link to comment
Share on other sites

If Duna has enough atmosphere this should be possible. If you're using Mechjeb, the landing autopilot can predict your apoapsis after aerobraking. Just open the landing autopilot window, adjust your periapsis so that your predicted apoapsis reaches the desired orbital altitude, aerobrake, move to your new apoapsis and circularize into your stable orbit. At least with Kerbin this works fine. :)

Aerobraking without this apoapsis prediction is hard, because small changes in your periapsis usually translate into huge changes of the apoapsis after aerobraking.

Mechjeb will probably not be able to do that for Duna until the atmospheric properties of Duna are discovered and Mechjeb is updated.

Link to comment
Share on other sites

I'm planning a probe to attempt an aerocapture maneuver on one or more of the planets...I'll then use the knowledge gained from it to plan "proper" missions. It'll probably go wrong and end up as either an aerobrake or an aerocrashintotheplanetanddie. I have done simulations on Kerbin using ultra-fast approaches with an apoapsis as low as 17km to get into an 85km orbit.

I'm also planning my manned missions as 2-parters. One ship to go there, take off, get into orbit...a rendezvous...and then EVA transfer to a second craft in orbit. Maybe even try rigging the ascent stage to self-destruct.

Link to comment
Share on other sites

I'll try out getting to all these planets through lots of trial, error, explosions, failed designs and lots and lots of Kerbalnauts making the, "I'm screaming because this is seriously the scariest thing I've ever encountered!" face. And possibly a lot of static-y "KIA" screens...

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...