Challenge: maximum aerodynamic deceleration on reentry

[Fabri91]

Hello! Here\'s my first proposal for a challenge: obtain the maximum pain deceleration on reentry, on any trajectory you wish.

To prove your attempt, post a screenshot of the 'end flight' dialog, showing the 'Maximum Gee Force Endured', before touchdown, as the impact might skew this figure.

Bonus points if you were using only stock parts! (The only mod I used was the Killmaster Edition chute)

[andydouble07]

I\'m not sure if it still exists, but there was a bug where G Forces would increase to rediculous levels when you got really far from the planet. Might want to limit the maximum altitude to 1 Mm or so to prevent that.

[Jarnis]

Not really a good challenge, it is fairly easy to get completely ridiculous G loads with mega-rockets that are unstable (the simulation gets stuttery, SAS starts to jerk stuff around, G-meter goes up and down like mad) - it is fairly easy to peak the G-loads that way.

Besides, 70G should mean that the capsule turned into a can of kerbonaut paste...

[Tiberion]

Thats assuming that Kerbals aren\'t ultra-dense like their planet

[Kryten]

Not really a good challenge, it is fairly easy to get completely ridiculous G loads with mega-rockets that are unstable (the simulation gets stuttery, SAS starts to jerk stuff around, G-meter goes up and down like mad) - it is fairly easy to peak the G-loads that way.

That doesn\'t affect the actual G-forces; it\'s only the gauge on the UI that changes like that-it\'s a glitch which the gauge system only.

[Fabri91]

As mentioned, the gauge is the only thing that jerks about, the figure in the 'end flight' dialog keeps making sense.

In that particular try, speed at entry interface was about 4,2 km/s.

As for maximum height...would it make sense to limit it to 5000km? Reaching such a distance would take quite a bit of time if one planned to actually get back to Kearth. Or would a higher maximum height be more appropriate?

[Kryten]

As for maximum height...would it make sense to limit it to 5000km? Reaching such a distance would take quite a bit of time if one planned to actually get back to Kearth. Or would a higher maximum height be more appropriate?

It isn\'t necessary-that bug was removed.

[rdfox]

I didn\'t grab a screenshot, but I nailed 20.6G today with my usual menagerie of addon parts and a freefall from about 450km and 500 m/s. I was still at +3G when I deployed the \'chute at 3km.

[Zeroignite]

42G

Redlining the G-meter is fun.

[r4m0n]

72.9G, stock parts only 8)

Kerbals must be made of titanium, Jeb was smiling all the way down ;P

[Fabri91]

86.2G, stock parts only, apart from the modified textures.

Must have been pretty interesting feeling in the capsule...

[Jarnis]

Bah, amateurs. First try, by no means 'maxed out', had to dump the last stage unused as the ground was coming up really, really fast... - five kilometers a second is quite a lot of velocity when you are less than 30 kilometers from the ground... ???

Most Gee Force Endured: 103G 8)

All _used_ parts were stock parts (my Mun rocket design) but the uppermost stage ('lander', minus ascent stage, ascent engine and the legs) used the Mun lander pack fuel tank + engine - but those never fired.

Landing... uuh... Jeb forgot to press the 'open parachutes' button. Yeah... Unfortunate accident. Well, that or the Kerbonauts were somewhat liquefied due to the G-loads...

And no, this is by no means the maximum this rocket could do... 150G is my next goal... Edit: 2nd try in progress. 800km and still climbing 1km/s, with plenty of juice in the tank for some slight boosting on the way down...

[r4m0n]

Bah, amateurs. First try, by no means 'maxed out', had to dump the last stage unused as the ground was coming up really, really fast... - five kilometers a second is quite a lot of velocity when you are less than 30 kilometers from the ground... ???

Most Gee Force Endured: 103G 8)

All _used_ parts were stock parts (my Mun rocket design) but the uppermost stage ('lander', minus ascent stage, ascent engine and the legs) used the Mun lander pack fuel tank + engine - but those never fired.

Landing... uuh... Jeb forgot to press the 'open parachutes' button. Yeah... Unfortunate accident. Well, that or the Kerbonauts were somewhat liquefied due to the G-loads...

And no, this is by no means the maximum this rocket could do... 150G is my next goal... Edit: 2nd try in progress. 800km and still climbing 1km/s, with plenty of juice in the tank for some slight boosting on the way down...

Not bad... But try to check the max G BEFORE crashing, as now we can\'t tell if that was atmospheric deceleration or just the pod crashing to the ground

You\'ve got the spirit anyway, good luck on the next try(ies)

[Jarnis]

I\'m quite sure it is atmospheric. The final collision at 120m/s produces nowhere near this kind of figures. My 2nd try finally completed... here is my little re-entry at 6.8km/s...

Most Gee Force Endured: 215.5G

Jeb pulled the chute too early - the ground was coming up at a very very very scary speed, so he paniced. Chute went one way and the capsule other way... still, even without it, the capsule went from 6.8km/s to sub-200m/s in under 15km of altitude, so...

Edit: But if you insist... third rocket going up. Maybe this time Jeb won\'t panic and it will be a soft landing. Will take shots pre-landing and after it.

[Jarnis]

Well, if you think that the collision spiked that, you can scratch the previous two. This one is only 6.6km/s so I\'m fairly sure that the above 215G one is not influenced by the splat, but this one definitely was not.

Most Gee Force Endured: 170G 8)

A couple of shots along the way included. Oh, and the Kerbonauts are protesting that this is uncomfortable...

[r4m0n]

My best so far: 190.5G, still 100% stock parts 8)

Your 215G result above is definitely not from crashing in the end, as I\'ve made a few tests like that too ??? It can probably be the parachute failure though, as I\'ve got similar spikes in the max G in a couple of trigger-happy accidents...

I\'ve also noticed the attitude of the capsule on re-entry also affects the results, but haven\'t found out the best configuration so far (30 mins/attempt isn\'t exactly friendly to testing :\'()

[Jarnis]

True, I could see the parachute popping open during the heaviest deceleration spiking the G load even more for a moment until the parachute rips away. :\'(

But anyway, all that is needed for more is higher velocity on re-entry, which requires more available fuel for use after the flip (and possibly the flip happening slightly further away). We need a bigger rocket! More boosters!

[r4m0n]

True, I could see the parachute popping open during the heaviest deceleration spiking the G load even more for a moment until the parachute rips away. :\'(

But anyway, all that is needed for more is higher velocity on re-entry, which requires more available fuel for use after the flip (and possibly the flip happening slightly further away). We need a bigger rocket! More boosters!

Totally agree! Unfortunately, it seems I can\'t add even 1 booster to my rocket without it falling to pieces... I probably can still shuffle things around to get a bit more of dV, but I think we won\'t get much farther than maybe 7kms on re-entry with only stock parts...

[Jarnis]

I did 175G on my first try with fully stock rocket, gonna try another tomorrow... the turnaround time on this challenge is kinda looooong... >

[Jarnis]

Rocket design perfected to a new level (100% stock parts). Bigger rocket! More boosters! Excess weight stripped (Less SAS!) Re-entry speed bumped up to Jeb-scaring 7800m/s and the results are in...

Kerbonauts got squeezed to a pulp with Most Gee Force Endured: 234.4G

Not a crash, not a jolt from parachute getting ripped off. Just pure speed on re-entry. I await your feeble attempts at beating this! 8)

[r4m0n]

Rocket design perfected to a new level (100% stock parts). Bigger rocket! More boosters! Excess weight stripped (Less SAS!) Re-entry speed bumped up to Jeb-scaring 7800m/s and the results are in...

Kerbonauts got squeezed to a pulp with Most Gee Force Endured: 234.4G

Not a crash, not a jolt from parachute getting ripped off. Just pure speed on re-entry. I await your feeble attempts at beating this! 8)

Niiiiiice

Your rocket has a LOT more dV than my current design, time to scrap it and see if I can come up with something even bigger ???

[Jarnis]

Niiiiiice

Your rocket has a LOT more dV than my current design, time to scrap it and see if I can come up with something even bigger ???

I omitted the launchpad shot on purpose to keep this interesting - but as a starting point... it fires 11 LFEs and 8 solid boosters on liftoff and just barely gets off the ground at full thrust... no need to manage throttle to avoid aerodynamic drag, it won\'t go that fast until it is out of the lower atmosphere 8)

(And I can guarantee it is 100% stock parts and I have a pic on file...)

[r4m0n]

r4m0n Astronomics is proud to announce it\'s newest payload delivery system, the deltaV! 18 LFEs boosted by 2x21 SRB takes any payload up, and fast!

Our brave test pilots are still recovering from an 'unexpected' deceleration of 273.8G after a 8400m/s reentry, but they seem well enough. Jeb still claims it don\'t have enough boosters, though.

I can indeed add more boosters, but the rocket editor get really slow when the monster is loaded, so I guess I\'ll keep it that way for now 8)

PS:

Still only stock parts, and even coming from 1.5M high, I still jettisoned around 1/4 tank, so I can keep crushing them a bit more ???

[Jarnis]

Impressive. Most impressive.

But you know what this means, right?

To the VAB! More Boosters!

[illectro]

How about this video I made with non-stock parts, and the old atmosphere model showing rockets getting torn apart by re-entry forces:

I get 130,000 g\'s or thereabouts on the last attempt.