The MID-Q Challenge. Munar impact done quick

[KerbonautInTraining]

Administration at the Kerbal Space Center was horrified to hear that Jeb planned on landing himself the Mun before they'd even checked to see what the surface is made of.

Jeb was not pleased with their subsequent decision to cancel his flight. They said at the very least he would need to wait until they had a probe on the surface of the Mun. Jeb hatched a plan.

Your job is to send a probe to impact the Mun as quickly as possible. Soft landings are for wimps.

Guidelines:

• Stock parts only
• "Indestructible facilities" is recommended (Space center-> Esc -> Settings -> Difficulty Options)
• The use of KerbalJointReinforcement is encouraged
• It should go without saying, but no F12 menu or HyperEdit
• The final stage of your rocket must be a probe core (with no engines attached to it) that is jettisoned from the rest of the rocket
• No entries over 1 hour 90 minutes will be accepted
• Include screenshots of your vessel on the pad, a few as the burn progresses, of the final payload on its way to the Mun, and one showing impact in the mission log [F3]
• These guidelines are subject to change

Scoring will be based entirely on time from liftoff to Munar impact. A "featured" scoreboard will be added to highlight any special entries (Single stage, SRB's only, etc)

Tips:

• High TWR is key. It reduces gravity losses and increases average velocity. (Ion and nuclear propulsion are essentially useless) 
• Sort by mass in the VAB to make sure you're not adding unnecessary weight
• Send a "scout" vessel to the launchpad, timewarp until the Mun is directly over the morning side of Kerbin (setting it as target helps), and recover the vessel. This launch window provides the best lighting for screenshots.

Scoreboard:

1. Nefrums: 0:13:58!!
2. FinalHazard: 0:14:53
3. totalitor: 0:16:05
4. Atlanticrash: 0:18:48
5. Reactordrone: 0:22:52
6. killakrust: 0:32:29 (Bonus: Included antennas and reaction wheels on the probe)
7. DoctorDavinci: 0:37:34

 

My 0:16:43 entry (I'd be surprised if somebody could get below 15 10 minutes... but then again I'm probably underestimating the KSP community's love for boosters)

 

Edited February 20, 2016 by KerbonautInTraining

[SpaceplaneAddict]

Count me in.

[KerbonautInTraining]

14 minutes ago, SpaceplaneAddict said:

Count me in.

Whew, I totally thought this was gonna be banished to the Second Page of Death

[DoctorDavinci]

Done and Done ... Stock install

Total real time was just over 10 minutes ... Video of launch to impact can be found HERE

Total Mission Time: 0 Hours, 53 Minutes, 18 Seconds

 

Edited February 9, 2016 by DoctorDavinci

[KerbonautInTraining]

Added your entry to the OP and updated the guidelines to be a bit more specific regarding the final stage 

[Reactordrone]

Had a go this afternoon. Not massively fast at 22 min 52 sec but it gave the Mun a good whack.

[KerbonautInTraining]

5 hours ago, Reactordrone said:

Had a go this afternoon. Not massively fast at 22 min 52 sec but it gave the Mun a good whack.

That's actually really good considering the size of the rocket. I remember trying with a cluster of 5 orange tanks as a lower stage and got like 25 minutes.

[DoctorDavinci]

So I did this again but I waited for the mun to be overhead this time as well as adding MOAR Boosters ... Stock install

0 hours, 37 minutes, 34 seconds

I think I may be able to get it down to around 30 minutes if I time it right and strap on some MOAR boosters

 

Edited February 9, 2016 by DoctorDavinci

[FinalHazard]

I believe this should be possible in under 15 minutes.

my attempt took 15:34

vessel statistics:

mass - 3710.25 tons, 261 parts, 17599 m/s DV according to KER, 8 stages with a burn time of 6 minutes 51 seconds.

 

 

[KerbonautInTraining]

Suggestion before I add your entry: Don't use Rhino's for lower stage engines. Their sea level thrust and ISP is awful, Mammoths are where it's at. (Assuming they don't rip your craft apart)

[FinalHazard]

Oh yea, that was supposed to be mammoths - typo

[KerbonautInTraining]

4 minutes ago, FinalHazard said:

Oh yea, that was supposed to be mammoths - typo

Ah! Ok, entry added.

Also, sepatrons on the decoupler. That's clever.

Edited February 10, 2016 by KerbonautInTraining

[Nefrums]

I was so close  15:07

Almost all engines fire the entire time.

Had to lock some fuel tanks as fuel lines are a bit buggy.

 

 

[KerbonautInTraining]

The probe core has to detach from the final stage, although I'm still gonna add your entry because of the amazing time.

Have you tried "merging" some of the asparagus so it all burns parallel? I've found that that can actually give better times due to the insane TWR and shorter burn time

[FinalHazard]

Success! With some modification of the previous design.

14:53

[Nefrums]

4 hours ago, KerbonautInTraining said:

The probe core has to detach from the final stage, although I'm still gonna add your entry because of the amazing time.

I missed that. 

Will try again with a better design!

 

[numerobis]

My memory from this challenge in 0.18 days:

1. a gravity turn will save you about 1.5 km/s that you otherwise lose to gravity losses
2. the ant on an oscar was the best last stage -- and it's been buffed since (relative to other engines)
3. the bigger the rocket the better, so this challenge quickly turned to "how patient are you"

Are nose cones actually useful in this challenge? I'd expect you would have pretty low drag losses going straight up, so they'd just be a waste of mass (and parts).

In 0.18, jets were able to get much higher TWR for the first little bit, because they cut down on drag loss a lot.

[KerbonautInTraining]

4 hours ago, numerobis said:

My memory from this challenge in 0.18 days:

1. a gravity turn will save you about 1.5 km/s that you otherwise lose to gravity losses
2. the ant on an oscar was the best last stage -- and it's been buffed since (relative to other engines)
3. the bigger the rocket the better, so this challenge quickly turned to "how patient are you"

Are nose cones actually useful in this challenge? I'd expect you would have pretty low drag losses going straight up, so they'd just be a waste of mass (and parts).

In 0.18, jets were able to get much higher TWR for the first little bit, because they cut down on drag loss a lot.

Eh gravity losses are negligible ("only" about 24% on my rocket) and it's much easier to go straight up (im lazy)

I didn't bother with nosecones I found (at worst) I was losing about 0.4 of my 3 G's to drag.

Edited February 12, 2016 by KerbonautInTraining

[FinalHazard]

5 hours ago, numerobis said:

My memory from this challenge in 0.18 days:

1. a gravity turn will save you about 1.5 km/s that you otherwise lose to gravity losses
2. the ant on an oscar was the best last stage -- and it's been buffed since (relative to other engines)
3. the bigger the rocket the better, so this challenge quickly turned to "how patient are you"

Are nose cones actually useful in this challenge? I'd expect you would have pretty low drag losses going straight up, so they'd just be a waste of mass (and parts).

In 0.18, jets were able to get much higher TWR for the first little bit, because they cut down on drag loss a lot.

1. I am hitting the mun with about 1.8km/s less speed than launch DV so only losing about that, maybe only a tad more due to gravity drag. Also I don't think these rockets would handle a gravity turn very well.

2. Maybe, but that stage takes 5 minutes to burn, which probably nullifies the effect of the extra DV.. running a test now. The end result is 5 seconds worse than my sepratron final stage. I can't get it to fly perfectly straight with the ant and just parts attached on the axis of symmetry (how is that possible?), so it ends up flying a less efficient trajectory. Also you need a battery to allow you to disconnect the final stage for a burn that long, adding to the inefficiency.

3. I agree. my last rocket takes a long time to burn the first stage but speeds up significantly after.

the mass should be insignificant on the lower stages. On my upper stages the nose cone mass adds up to -20 DV (so I guess I'll remove them). It will be different for everyone obviously but I think the lower stages definitely need them. The part count isn't helping the real life launch time though.

[numerobis]

Almost all the gravity drag is at the start of your flight, so when you lose 1.5 km/s you lose close to 10% of your flight time. That's the difference between 15 minutes and 13.5 minutes.

When, as with @Nefrums' spacecraft, you're firing on all cylinders, it turns out even pretty ungainly craft can be convinced to turn -- and you can help it by starting tilted using launch clamps. You do get more launch failures and decoupling difficulties.

Back in 0.18, the 5-minute burn of the Ant was worth it. However, the sepratron appears to have way higher Isp than before whereas the ant has only slightly more, so I can definitely believe the "best" has flipped. That, and the need to actually pay for the mass of your battery in 1.0.5 whereas in 0.18 it was massless.

[FinalHazard]

If you could get the thing to fly straight it would probably be better on some rockets. Also I think if you turn off the battery on the probe you can do without the extra battery, just turn it back on to decouple. To me that feels sort of cheaty though.

[totalitor]

Maybe there should be categories for vessels. For example under 1000 t "small rockets" and >1000 giants. I can make it 19 min under 1000 t. If I just make it bigger I can reduce time but it is not fun anymore.

[Nefrums]

I guess this would be in the above 1 kton category then..    a sub 1kton category would be fun as it would be more about efficiency than building the largest rocket.

6618 ton,  

588 parts

20356 m/s dV

Time: 13:58

 

[Heckspress]

this is insane. I love it

 

[KerbonautInTraining]

I immediately burst out laughing when I saw that rocket. My goodness, I never thought it would be taken this far.