The MID-Q Challenge. Munar impact done quick

[Nefrums]

And I even tried adding another ring of booster around it, but my computer did like that.  

With close to 600 parts the game is running at 1/8 normal speed.  But that about dubbels as the first stage drops out of draw distance.

[killakrust]

OK, so I had a shot at it. I didn't want to start building some massive extra fast craft to get on top of the leaderboard, I recon it would be too time consuming. Instead I have focused on what Jeb would have needed for the job:

1. Something cheap (maybe made of parts already lying about)

2. Fast (needs to impact Mun in under 30 mins)

3. Reasonable accurate science return (hypothetical)

So I built an impactor with 4 data return antenna (apparently hitting the Mun at +6000m/s makes it difficult to send much data back); added some boosters, and ended up with this:

Total cost was 9970 kerbucks. Time was a little longer than intended at 32 minutes 29 seconds.

Was good fun. Thanks for the challenge.

Edited February 14, 2016 by killakrust
added buleprints

[totalitor]

So I made a huge rocket, 3242 t and I got WORSE result! In paper it looked good, deltav 17653 m/s but it took so much time to accelerate that my smaller rocket (700 t) did it faster (about 19 min). So automatically bigger rocket is not better. So I continued planning. Now I have 1252 t rocket (deltav is 13997 m/s) that takes 16 min 53 s to hit the Mun. I have to little throttle down in atmosphere so the rocket doesn't explode.

Pictures later, planning tomorrow more.

[Nefrums]

yes, more twr less d/V might be better.

Hmm....   less fuel tanks also means less parts,   less parts mean that i might be able to add another ring or two of boosters...

 

[totalitor]

Two plans:

A. Long acceleration, top speed achieved later, more deltav.

B. Shorter acceleration, top speed achieved earlier, less deltav.

 

I am trying plan B, I don't know if it is a right way. I still have quite small (1253 t) rocket and I can make it 16 min. It is very hard to make better time.

[numerobis]

19 hours ago, totalitor said:

A. Long acceleration, top speed achieved later, more deltav.

B. Shorter acceleration, top speed achieved earlier, less deltav.

Approximate it on the back of the envelope with this simplification: assume option A and option B have infinite acceleration, but option A only fires at the end of its burn. Which one gets there first?

For example, let's say that option A is an Ant-based stage that takes 5 minutes to burn and produces 2.5 km/s versus option B is a sepratron-based stage that takes 5 seconds to burn and produces 1.5 km/s (numbers are approximate). For five minutes, option B is going 1.5 km/s faster. Afterwards, option A is going 1 km/s faster, but is 450 km behind. According to the simplification, option A catches up to option B if there's at least 7.5 minutes to go after it burns out.

Both simplifications favour B, so if A still wins under that calculation, you're certain that A is better. If A loses, it might still be better, but you need to do a more complete calculation.

Oh, and I assume both options have roughly the same mass. Otherwise, you need to take account of the effect on lower stages too.

[Edit: oh right, this ignores gravity too. That generally favors B as well, as per the Oberth effect.]

Edited February 16, 2016 by numerobis

[Atlanticrash]

My entry to MID-Q, with a time of 20:44!  This was my first speedrun (and second attempt), so I'm pretty happy with how this turned out! 

 

 

[killakrust]

1 hour ago, Atlanticrash said:

My entry to MID-Q, with a time of 20:44!  This was my first speedrun (and second attempt), so I'm pretty happy with how this turned out! 

Good time. Looked like your probe core was still attached to the engine at the end though?

[Atlanticrash]

4 hours ago, killakrust said:

Looked like your probe core was still attached to the engine at the end though?

Sorry, didn't see that in the rules.  Here is my new and improved submission, complete with an unattached probe!  My time is now not only legal now, but much lower at 18:48

 

 

Edited February 18, 2016 by Atlanticrash

[totalitor]

My time: 16 min 05 s. Rocket mass 1253 t and it has deltav 15936 m/s. I have been working with upper stages but I can't get more speed of this. Maybe I need to add more boosters to improve. But I like "small" rockets...

I'm using Mammoth with large tanks, then Mainsail - Vector - LVT45 - 487S. Top speed 14325 m/s.

 

 

Edited February 18, 2016 by totalitor

[KerbonautInTraining]

If somebody wants to make a badge it could say something like "I passed (through?) MID-Q!" And it could show the Mun with a probe "crashing" into it. Any better ideas? 

I can't be bothered to make a badge, never even used a photo editing software before 

Edited February 19, 2016 by KerbonautInTraining

[Atlanticrash]

12 hours ago, KerbonautInTraining said:

If somebody wants to make a badge it could say something like "I passed (through?) MID-Q!" And it could show the Mun with a probe "crashing" into it. Any better ideas? 

I can't be bothered to make a badge, never even used a photo editing software before 

This would be pretty cool!  I don't have much experience or taste with photo editing software, but here's my take on it.