The 2x Gravity SSTO Challenge

[Kergarin]

I remember how it felt building my first SSTO, and it was a great challenge and experience. But after a while, building SSTOs becomes really easy.

Now I have found a way, to get this feeling back. Set the gravity to 2x!

You will end up with small payload fractions and a challenging reentry. The game feels brand new and a little more real.

If you also want to have this experience, I challenge you to:

press ALT+F12
Activate hack gravity and set it to 2.00
Build an SSTO 
Fly it into a stable orbit above 70x70km
Fly it back to ground

No part/physics mods or things like that. Visual and informational mods are ok.

Post screenshots or videos with ALT+F12 menu always open.

If enough people participate in this challange, i will add additional goals / scorings and maybe a badge. 
(like smalles manned craft with closed cockpit, smallest craft with orange tank as payload or maybe just highest payload fraction etc.)
(do not try to leave Kerbins SOI, hack gravity is not compatible with SOI changes)

 

 

Here comes my verry basic entry with around 5% payload fraction:
 

https://imgur.com/a/HPmj5
 

For comparison here is my 1G version with more than 33% payload fraction:

Edited February 25, 2018 by Kergarin

[JacobJHC]

I may attempt this.

[quasarrgames]

Can't speak for 2g SSTOs, but i've recently been trying to make a 3g SSTO:

Closest i've gotten was about 700m/s short of orbital velocity with a completely barebones craft. Typically i'd put a nerv or two on a craft like this but it needs thrust more than efficiency. Maybe i could scale it up massively and add a rhino to it, but that'd take away from its tenuous atmospheric thrust to weight ratio. It's brutal.

[Kergarin]

On 18.2.2018 at 1:16 AM, JacobJHC said:

I may attempt this.

Looking forward to see your results 

12 hours ago, quasarrgames said:

Can't speak for 2g SSTOs, but i've recently been trying to make a 3g SSTO:

Closest i've gotten was about 700m/s short of orbital velocity with a completely barebones craft. Typically i'd put a nerv or two on a craft like this but it needs thrust more than efficiency. Maybe i could scale it up massively and add a rhino to it, but that'd take away from its tenuous atmospheric thrust to weight ratio. It's brutal.

2G is verry doable, 3G is challenging 

I see the main problem at 3G in a too short runway. It forces you to build a less efficient design with more wings or thrust, if you want to reach takeoff speed until the end of the runway.

Edited February 19, 2018 by Kergarin

[Cunjo Carl]

I'm in! What's the call on VTOL/parachute landing? Also, what level of clipping is ok? For example, can I clip shock cones into the backs of my rapiers? I'm happy either way, but I'd like to know from the start.

[Kergarin]

1 hour ago, Cunjo Carl said:

I'm in! What's the call on VTOL/parachute landing? Also, what level of clipping is ok? For example, can I clip shock cones into the backs of my rapiers? I'm happy either way, but I'd like to know from the start.

I think VTOL and parachutes are ok.

Clipping should only be used for esthetical reasons, it should not give you an unfair advantage.

Looking forward to see your results 

[Cunjo Carl]

I made it up! Time to (*gulp*) try to get back down.

This was a fun one! One of the tricky parts is that it shifted and shuffled all my normal tried-and-true altitudes for breakthroughs and engine switchovers. I kinda had to relearn it, which was fun. I based the plane design off the cargo version of my escape velocity airplane, working on the assumption I'd need some rather amazing heat tolerance on the way back in. Not surprisingly, this turned out to be true! Probably the funniest part of the journey was on the way back in- it actually fully circumnavigated while trying to bleed off speed! Luckily, it all lined up to a lovely landing zone. The rather miraculously named Kergar Kerman made plenty of funny faces, which made for some nice pictures.

Oh! I switched the original craft's inline intakes for an intake in the airspace of the heat shield so all the engines would line up and give it a square look. It felt in the spirit, but figured I should mention it.

 

   
     Kergar Kerman isn't so sure about the new nuclear reactor spars.                      But they work! Time to (*gulp*) try to get back down.            

 

   
     Unlike any other SSTO of my design, it actually descends well.                                           Success! Alright time to taxi home.

 

Thanks for the challenge, @Kergarin! I think I may try to make a mk3 cargo version next. I feel like 1 panther (wet), 2 whiplashes and 4 nukes may work nicely and am curious to give it a try.

Edited February 25, 2018 by Cunjo Carl

[Kergarin]

Congratulations @Cunjo Carl 

That craft looks really interesting.

I'm happy to hear you had fun too. I also had to relearn everything, that's exactly what this challenge is for  if you are bored because you can build SSTOs  with crazy payload fractions while sleeping, this makes you feel like back in the old days when the game was new and you had to figure out everything. 

Reentrys are verry exciting now, aren't they? 

[Cunjo Carl]

On 2/25/2018 at 3:58 AM, Kergarin said:

Congratulations @Cunjo Carl 

That craft looks really interesting.

Thanks! One of my favorite parts of KSP is how everyone makes their own styles and specialties for planes and rockets. Speaking of which, best of luck with your reusable no contract career!

I kept working with 2g and made it to Minmus!

I tried out an LF-only mk3 variant, and while it looked super snazzy the mk3's crazy drag just wasn't gelling with the anemic whiplash+NERV combo. Those two are great with long low climbs for which the parasitic drag of the mk2/mk3 parts are just too severe.

So I put a bit more work into the size1 model, and wound up with a craft that had plenty of deltaV to land on Minmus! I learned rather quickly that the game bugs out if you change SOI with hack gravity on, so I approximated it by bringing the craft out to a Minmus shaped/sized/inclinded orbit, then cheating it in to very high orbit around Minmus, and landing from there. I haven't been this surprised/happy to land on Minmus in quite a while .

It's occurred to me that bringing cargo up is quite the challenge for a 2g SSTO. The parasitic drag from the cargo bays gets much more serious teeth when you need to go 3km/s in atmosphere!

[Kergarin]

That's impressive @Cunjo Carl and looks like something from star wars 

Yes, SOI changes are really a big problem. 
Originally I was trying to do a 2G career game, and it was really fun. Everthing felt new and challenging, but SOI changes just don't work.
I switched in my career game to Sigma Dimensions and changed the size of everything to 2,5x, which gives you almost the same difficulty level.
But I thought it was easier for this challenge to use alt+F12 insted of installing a mod.