2G Career

[tosha]

In another universe... 

Kerbin has a gravity of 19.62 m/s^2. Its inhabitants dream of space. Will you, space program manager, achieve that goal, or will your rockets crash even more spectacularly in the crushing gravity of 2g Kerbin?

Important Note! Hack gravity resets on game launch, but the craft orbits remain the same. Enter another save, hack gravity, then enter the 2g career save. 

RULES AND GOALS:

Hack gravity must ALWAYS  be at 2.00.

Primary goal is to finish STOCK tech tree.

Apart from setting the hacked gravity, debug screen must be left alone.

Mods rules

• No tech tree modifications
• no mods that decrease tech costs in any way
• no extra science instruments
• life support mods are OK
• no warp drive mods/parts
• no LFO engines with ISP > 400s
• no nuclear engines with ISP > 850s
• no engines with ISP > 4200s (excluding jet engines)

Funds rewards can be increased by up to 50% to account for the pressing need for pad/runway upgrades.

Science rewards can be increased by up to 30% to account for slow earlygame and travel problems.

Reputation rewards cannot be increased.

Decline penalty can be turned off or increased.

Suggested

• Plasma blackout and g-force limits
• CommNet on
• Reentry heating on

Otherwise, do whatever with your settings

SCORING CHALLENGES

These can all be done before or after completing the main goal. Submit proof and your score and medal(s) will be updated accordingly.

1000 points: Complete the challenge

300 points: Build an ssto

• 50 extra points for no RAPIERS

1250 points: Land on Tylo

100 points: Complete the challenge in under 25 launches

• 50 extra points for every uneeded launch (i.e. 100 points for 24 launches, 300 points for 20 launches)
• This does not count launches after finishing the tech tree

750 points: fly by all of Jool's moons in one launch

1000 points: accumulate 10000 science points at any one time

600 points: accumulate 6000 science (transmitted and/or recovered) in one mission, plus 150 for no science lab

850 points: accumulate 10000000 funds at any one time

Do a grand flyby tour: 850 points, plus 100 for every landing

Create a massive exploit with the messed up orbits and gravity: 500 points, special badge (WIP)

Eve surface return: 4k points, special badge (WIP)

~~HALL OF FAME~~

@dvader: 2,250 points - Osmium Medal - 22/6/2020

Notable Achievement: First Winner, creative Eve mission.

@ralanboyle: 2,500 points - Osmium Medal 25/6/2020

Notable Achievements: very good documentation of endeavor. First SSTO

@bayesian_acolyte: 4,600 points - Osmium Medal 30/5/2020

Notable Achievements: 3 launches to complete, which is probably the fewest possible, first tylo landing. Current highscore

For proof

Image album or video/video album

Badges: https://imgur.com/a/JJjvfBA

Lead: 1000-1300 points

Wolfram: 1301-1550 points

Osmium: >1550 points

Edited June 30, 2020 by tosha
win3

[ralanboyle]

I'm an experienced player but I have never messed with this type of setting. How do I change the Gravity? 

[linuxgurugamer]

5 minutes ago, ralanboyle said:

I'm an experienced player but I have never messed with this type of setting. How do I change the Gravity? 

Alt-F12, then select the Cheats tab

[DunaManiac]

18 minutes ago, linuxgurugamer said:

Alt-F12, then select the Cheats tab

Then enable hacked gravity, and set it to two.

[ralanboyle]

Thanks,

I figured it out, apparently on my PC its actually CTRL+ALT+F12

 

Also, I have started this challenge. Took me an hour to achieve orbit (Much longer than usual.)

Edited June 1, 2020 by ralanboyle
Edit

[Meecrob]

16 minutes ago, ralanboyle said:

Thanks,

I figured it out, apparently on my PC its actually CTRL+ALT+F12

 

Also, I have started this challenge. Took me an hour to achieve orbit (Much longer than usual.)

Haha, when I first read your post, I took it as your ascent took 1 hour.

[tosha]

59 minutes ago, ralanboyle said:

Thanks,

I figured it out, apparently on my PC its actually CTRL+ALT+F12

 

Also, I have started this challenge. Took me an hour to achieve orbit (Much longer than usual.)

Good Luck! BTW, I seem to recognize you from Youtube. Wrong Way Up? I'm Linux Gamer's Archives, may recognize me

[ralanboyle]

1 hour ago, tosha said:

Good Luck! BTW, I seem to recognize you from Youtube. Wrong Way Up? I'm Linux Gamer's Archives, may recognize me

Yeah, you commented on my double SSTO video recently. You might be a subscriber but I dont know how to tell. Anyway, hello!

[Ultimate Steve]

Ooo, this sounds interesting. If I have the time I may try it!

I wonder how much this will change the Delta-V requirements of the system...

[tosha]

Haha! Made it to orbit. This contract helped a LOT. 4th launch.

[Ultimate Steve]

The career has been started! So far I have gotten to orbit.

Spoiler

Jeb flew on the Aurora 1, a generic early career hopper. Touchdown speed was concerning, but acceptable.

Next up, Valentina flew on the Aurora 2, designed to fly higher in the atmosphere and get goo, barometer, and thermometer science from most of it. We couldn't do all of it because of the pad part count limit. It was also a success.

Next, Bob launched on Aurora 3, designed to get materials bay science from the ground to space, and also to be our first craft to actually reach space. However, due to lack of control, it tipped over. Bob eventually regained control, but space was not reached.

This did, however, get most of the bay science we wanted, so it allowed us to only carry one on Aurora 4, and it also gave us the science to unlock movable fins.

Bill became our first astronaut!

Then we built a plane, called the Avalon, in order to do some surveys because we were just shy of the cost of upgrading the VAB. The plane worked perfectly except for the landing.

Our sixth launch, the Borealis 1, took Valentina Kerman into orbit!

 

 

[tosha]

A rare moment when Jeb seems concerned. Nice job so far!

[doggonemess]

On 5/30/2020 at 5:31 PM, tosha said:

Kerbin has a gravity of 19.62 m/s^2. Its inhabitants dream of space. Will you, space program manager, achieve that goal, or will your rockets crash even more spectacularly in the crushing gravity of 2g Kerbin?

This would certainly explain the Kerbal's odd proportions and height!

[Superfluous J]

Knowing almost nothing about Kopernicus, I wonder how hard it would be to modify the system to just double all worlds' masses.

I know I'd forget to modify gravity on start at some point.

[ralanboyle]

2 hours ago, Superfluous J said:

Knowing almost nothing about Kopernicus, I wonder how hard it would be to modify the system to just double all worlds' masses.

I know I'd forget to modify gravity on start at some point.

I was surprised how easy it was to reach the moon. Then i realized I forgot the reset gravity again on that load. Orbiting at 2300m/s is the dead giveaway. 

[bayesian_acolyte]

I haven't had time to do a full investigation but there are some weird things going on with interplanetary transfers with increased gravity enabled.

First, all the normal tools don't work like Alex Moon's planner and Mechjeb. This is somewhat to be expected, increased gravity increases orbital speeds, which changes the timing and DV of everything. The nice thing should be that despite window timing changing, the required phase angle should be exactly the same (it just happens on a different date), because the transfer orbit and the angular velocity of the target planet increase by the exact same factor and effectively cancel out.

However the odd thing is that despite Kerbin's listed orbital speed appropriately changing when the gravity is changed, it appears to move at the same speed, with one rotation around the sun taking exactly one year. I next tried to run the phase angle math using the modified gravity value for the transfer orbit (because craft still move faster with more gravity), and the default gravity value for the target/origin orbits (because planets apparently don't), but when I tried to set a node to implement that value by holding a protractor up to the screen I still couldn't get an intercept with Eve.

That's as far as I got. Complicating matters is the fact that the "closest approach" markers seem to be worthless with increased gravity, making it impossible to visually fine tune maneuvers to get an encounter. For example this is what things looks like with a Mun encounter extremely close to happening:

And here is what it looks like with the maneuver node moved just a few seconds so there is an encounter:

It's impossible to tell that the 1st image is very close to an encounter, with the "closest approach" markers being wrong in every way. When the encounter is achieved, the visual is still bugged and a bit confusing.

Anyone understand what is going on here? These problems really amplify the difficulty of this challenge.

Edited June 9, 2020 by bayesian_acolyte

[tosha]

I would assume these problems are because increasing gravity can't actually change orbits in a patched conics situation? I might allow a science reward boost to compensate for the fact that getting science from anywhere but kerbin, mun, minmus and sun is really hard.

[dvader]

This was both harder and more fun than expected. You need a lot more power to get off the surface and the rockets get really tall and wobbly at first.

I've only started but I've got a Mun orbit (with return) and a Mun landing (no return) so far. I can confirm the patched conics are unreliable. Sometimes it seems to be alright but sometimes it is way off and "jumpy". For example, after my first Mun orbit, I had trouble leaving the Mun. A couple of seconds after I left the Muns SoI, it suddenly switched back and I was in Mun orbit again.

Here's my progress so far. I think this will take a while to finish:

https://imgur.com/a/uRdcIrr

Returning from the Mun is about as hard as returning from Jool with normal settings. The good news is that the explosions look much nicer than they used to (It's just materials bays...)

 

(I'm using plain normal settings with no extra funds etc)

 

[ralanboyle]

Okay guys, I finally got around to cutting the video of Startup - Mun. Its pure stock settings other than gravity. I do have For Science; it does not increase science, it only automates the collection so I don't have to hit all the buttons.  

 

[dvader]

On 6/10/2020 at 12:25 AM, bayesian_acolyte said:

However the odd thing is that despite Kerbin's listed orbital speed appropriately changing when the gravity is changed, it appears to move at the same speed, with one rotation around the sun taking exactly one year.
<...>
Anyone understand what is going on here? These problems really amplify the difficulty of this challenge.

Yes, I think the planets are "on rails" and not affected by the gravity change. I managed to get a Minmus encounter by using standard 1G Minmus orbital period but calculating my ships orbital period with 2G (using the caveman miss-and-hit method of first missing minmus and then adjusting the orbit to hit Minmus the next time). I haven't tried interplanetary yet but guess the same is true there. An interesting experiment would be to match the Muns orbit perfectly and then just watch what happens.

I think your  protractor version for hitting Eve should have worked. Eve is very hard to hit though since the SoI is rather small. How far off was it?

I'm off to landing on Minmus now so I should get another opportunity to confirm my theory.

[bayesian_acolyte]

54 minutes ago, dvader said:

I think your  protractor version for hitting Eve should have worked. Eve is very hard to hit though since the SoI is rather small. How far off was it?

I don't think it was off at all. I never actually ran any of the maneuver nodes, instead checking all around the window and assuming that it would show if there was an encounter like it did in that screenshot. But I just ran a 2G Mun/Minmus mission and this wasn't the case. It showed the first Minmus encounter via node, but later it refused to show a Mun encounter despite there being one.

After writing the above paragraph I just went and tested it. The +14.4 degree phase angle I calculated to Eve appears to be correct.

However in testing this I encountered another issue: to get to Eve, we eject retrograde to Kerbin, but are still following a similar prograde path around the sun. But our path around the sun is now faster than Kerbin because we are on 2G speed while it's on 1G, so after leaving Kerbin's SOI we run into it again and then leave and re-enter in a never ending cycle. I was able to get around this by using very high time warp with the better time warp mod, and it just skipped over the SOI. 

 

Edited June 13, 2020 by bayesian_acolyte

[dvader]

2 minutes ago, bayesian_acolyte said:

However in testing this I noticed another issue: to get to Eve, we eject retrograde to Kerbin, but are still following a similar prograde path around the sun. But our path around the sun is now faster than Kerbin because we are on 2G speed while it's on 1G, so after leaving Kerbin's SOI we run into it again and then leave and re-enter in a never ending cycle. I was able to get around this by using very high time warp with the better time warp mod, and it just skipped over the SOI.

Oh, that explains it! That was exactly the issue I had when trying to leave the Mun. I had to go much faster than expected to leave the SoI or I would just "jump back" after a few seconds.

[bayesian_acolyte]

I've completed 2 launches so far on a 2G default settings career. I've only used mods to automate science sampling, improve time warp, or add information.

Launch 1: upper atmosphere

Spoiler

I went with an unconventional fins-on-the-top design because I was having difficulty slowing down enough for the parachutes to work. I then had to add a bunch of lower fins to stabilize it after engines were successively burned off.

The parachute wasn't quite big enough to slow our decent above the impact rating of the last booster, so it was sacrificed to the kraken upon impact with the water.

Some funds were spent on upgrading the pad. Here is how the tech points were spent:

Launch 2: Minmus biome hopping plus Sun and Mun orbits

Spoiler

The upper 2 stages were attached to nodes in a line and then translated out to look like it does above. The drag model sees the upper stages as just one long tube, but the more compact form increases stability and allows 3 engines to fire. I thought about doing it for the bottom stage as well, but solid booster stages with no fins are difficult to pilot in the best of times and this type of translation introduces weird torques that make control difficult.

Control was difficult throughout this whole journey with no SAS and every stage being off balance, but the swivel helped during this portion of the ascent.

Once in orbit, I switched back to the KSC and upgraded 3 buildings to unlock patched conics, nodes, and EVAs. I also got a "perform an EVA" contract. Side note, the dV display is not showing the current stage because it is attached behind the engine. Bob has around 3.3 km/s dV here.

The original target of this journey was Gilly, but partly because of the difficulties documented in previous posts, it was re-targeted to Minmus.

Extra tanks discarded, we break for a Minmus descent.

Upon touching down we switch back to the KSC and get lucky to see this contract. We complete it and use the cash to upgrade the research building, which unlocks surface samples. Without this contract we still would have been able to upgrade it by taking out a bunch of contracts we didn't plan to finish. 

Apologies for not waiting till it was daylight.

We get 5 biomes close to where we land with 400 dV spent, but due to poor planning the hop to the 6th biome (shown above) takes 400 dV, and we are only able to get 6 biomes total.

We eject from Minmus in a direction away from Kerbin on a trajectory to leave the system. This gives us some extra science and world first bonuses. 

Once we are out, we point back towards Kerbin and burn back inside the SOI. This takes more dV than normal because of some 2G weirdness. Next up is the Mun, and we decrease our PE from the above image to match Mun's orbit.

Burning at the PE/DN intercept until the encounter flags lined up with Kerbin consistently created an encounter, although annoyingly it would never show the encounter until after it happened. I ended up adding an inclination correction burn at AN after this which was cheap because it was right at the edge of Kerbin's SOI.

Capturing in an eccentric orbit only took 24 m/s, with PE a bit into Mun's "low" space, which let us get more science and world firsts.

We were a bit short of the dV to get back a more traditional way, so instead we eject into a higher orbit and then loop back to the Mun for a breaking gravity assist to get inside Kerbin's atmosphere. Mercifully patched conics worked almost normally here as this would have been almost impossible to pull off otherwise.

Many aerobreaking passes were required at 60+ km in order to not burn up. Better time warp helped a lot. We still almost burnt up on the final descent.

We are left with 2.7k science, 600k funds, and 7 contract slots open. 

 

Edited June 14, 2020 by bayesian_acolyte

[tosha]

Wow, 2 launch to do all that? That'd be impressive even in default gravity! Good job!

[bayesian_acolyte]

I made a table of interplanetary phase angles for 2G. Standard disclaimer, these assume no inclination or eccentricity and are only partially tested. See here if you aren't sure how to use this info.