The space race (but literally)

[M_Rat13]

Ok, so I get now people can get anywhere in KSP, and build amazing crafts for the jobs. Let's push that:

This is a literal race. Your start line is the surface of Moho, your finish line is the surface of Eeloo. Your route and craft have no limitation, bar two. It must be manned by a Kerbal, and it must be 'stock', paid DLC counts.

You can get your craft to the start line however you like. However, once you've set off, you're stuck in that one craft. No craft switching after that point, and no docking to other crafts.

You'll need one screenshot of you on the start line, with the start date showing, and one screenshot of you on the finish line, with the end date showing.

If there is somehow a draw (unlikely, but not risking it), the craft with the highest crew count will win (please show Kerbals in screenshot at finish line).

If that is also a draw, I'll think of something....

Ready? Set? Go?

Edit:

Leaderboard (first to last):

@purpleivan 229 days.

 

Edited March 28, 2019 by M_Rat13

[vyznev]

Just brainstorming here. Given the distance from Moho to Eeloo, this basically sounds like a delta-v maximization challenge. Nobody's going to fly all the way there under full thrust, so the time needed for the acceleration and deceleration burns is of relatively little importance. What matters is how fast you can coast the middle portion of the flight.

Thus, I suspect the winning entry will feature a single command seat, a Dawn engine and a bunch of disposable xenon tanks. And lots and lots of patience.

I wonder what the most mass-efficient way to supply power to the Dawn engine out at Eeloo is: RTGs, big solar panels or a big stack of batteries fed by smaller panels?

Of course, we also need to get the whole thing off Moho and land it on Eeloo. For the latter, I'd be tempted to attach a couple of Sepratrons to the command seat and do a suicide burn after decoupling everything else (except for the reaction wheel and battery needed for attitude control). And maybe have the Kerbal get off the chair after the Sepratrons burn out and finish the landing with the EVA jetpack.

[M_Rat13]

4 hours ago, vyznev said:

Just brainstorming here. Given the distance from Moho to Eeloo, this basically sounds like a delta-v maximization challenge. Nobody's going to fly all the way there under full thrust, so the time needed for the acceleration and deceleration burns is of relatively little importance. What matters is how fast you can coast the middle portion of the flight.

Thus, I suspect the winning entry will feature a single command seat, a Dawn engine and a bunch of disposable xenon tanks. And lots and lots of patience.

I wonder what the most mass-efficient way to supply power to the Dawn engine out at Eeloo is: RTGs, big solar panels or a big stack of batteries fed by smaller panels?

Of course, we also need to get the whole thing off Moho and land it on Eeloo. For the latter, I'd be tempted to attach a couple of Sepratrons to the command seat and do a suicide burn after decoupling everything else (except for the reaction wheel and battery needed for attitude control). And maybe have the Kerbal get off the chair after the Sepratrons burn out and finish the landing with the EVA jetpack.

Different people will have different methods. But, I'm pretty sure a Kerbal on EVA counts as a different craft? Also, IF there is a draw, if someone managed to bring two Kerbals to the finish line, they'd win over the single seat designs, and are people willing to risk that?

Edited March 25, 2019 by M_Rat13

[Aeroboi]

Why does nobody use...

People are always complaining about longer burn times but I almost never see reports from people using the higher physical timewarp option using bettertimewarp mod.
You can create custom physical timewarp settings of up to 100x
If your vessel is small (few parts) and rigidly strutted using autostruts you can use a 1 ION engine drive with 0.04TWR where every second is 100 seconds (without kraken)

That means that 0.04 * 100 = 4.00 (you effectively play with 4.00+ TWR instead of 0.04TWR in real time.
I did a continuous full thrust ION burn at 100times physical timewarp from Kerbin to Duna and it didn't take surprisingly long tbh while using Mechjeb smart A.S.S. autopilot to hold navigation.

I wouldn't bother to use this on a mission specific ION craft and get the highest score but now that I mentioned this utility using the above mod I'm sure more people will follow.
 

[vyznev]

37 minutes ago, M_Rat13 said:

Different people will have different methods. But, I'm pretty sure a Kerbal on EVA counts as a different craft? Also, IF there is a draw, if someone managed to bring two Kerbals to the finish line, they'd win over the single seat designs, and are people willing to risk that?

Hmm, good point. Arguably, landing the chair may be necessary. Feels like a shame to waste all that delta-v from the EVA pack, but rules are rules.  

I very much doubt there will ever be two missions with the exact same time down to the second, so I doubt the tie breaker matters. Certainly not enough to justify wasting delta-v on bringing two Kerbals.

[M_Rat13]

2 hours ago, vyznev said:

Hmm, good point. Arguably, landing the chair may be necessary. Feels like a shame to waste all that delta-v from the EVA pack, but rules are rules.  

I very much doubt there will ever be two missions with the exact same time down to the second, so I doubt the tie breaker matters. Certainly not enough to justify wasting delta-v on bringing two Kerbals.

It's your ship, I just made the race. I'm glad we agree on a Kerbal on EVA being a different craft, it makes me feel secure about my decision (as in not going to cause a massive despute).

As you said, the chances of the same time are minute, but it'll be fun to see if people worry about a tie break or not.

[purpleivan]

I've entered quite a few of the "get to planet X in shortest time" challenges, so I might give this one a go. That being said, it's been quite a while since I did (pre-ion nerf-ing, so using a bunch with lots of xenon tanks wasn't so painful) so my build method might change a bit.

The screenshot on the finish line... does it really have to include smiling kerbals, couldn't it just be wreckage and a huge explosion.

Those smiling face will cost a lot of time

[M_Rat13]

18 minutes ago, purpleivan said:

I've entered quite a few of the "get to planet X in shortest time" challenges, so I might give this one a go. That being said, it's been quite a while since I did (pre-ion nerf-ing, so using a bunch with lots of xenon tanks wasn't so painful) so my build method might change a bit.

The screenshot on the finish line... does it really have to include smiling kerbals, couldn't it just be wreckage and a huge explosion.

Those smiling face will cost a lot of time

If they are in a command chair, your craft picture will show them, without getting them out. Although 2 seperate screenshots could also work.

Edit:

And can someone explain to me this Ion fascination. I get that neither Moho or Eeloo have an atmosphere, but don't you need a TWR of >1 to get off a planet? Which is going to be hard with ions. I look forward to people's attempts though.

Edited March 25, 2019 by M_Rat13

[purpleivan]

Just now, M_Rat13 said:

If they are in a command chair, your craft picture will show them, without getting them out. Although 2 seperate screenshots could also work.

I'd have to time it just right though... catch that split second of touchdown, between happy Jeb in a chair and the inevitable explosion, when he hits the surface at 30,000+m/s

[M_Rat13]

4 minutes ago, purpleivan said:

I'd have to time it just right though... catch that split second of touchdown, between happy Jeb in a chair and the inevitable explosion, when he hits the surface at 30,000+m/s

Why this fascination with explosions? 

If you want to show a wreckage, add, I dunno, a year to your time.

[swjr-swis]

9 hours ago, vyznev said:

I wonder what the most mass-efficient way to supply power to the Dawn engine out at Eeloo is: RTGs, big solar panels or a big stack of batteries fed by smaller panels?

Shouldn't need to wonder: at distances that make solar panelts irrelevant, a small tank of LFO and a fuel cell wins this every time.

[bayesian_acolyte]

5 hours ago, Aeroboi said:

If your vessel is small (few parts) and rigidly strutted using autostruts you can use a 1 ION engine drive with 0.04TWR where every second is 100 seconds (without kraken)

What about with a heavier craft? It seems that roughly half your dV would need to be used on the initial leg, and since there is no size limit that might mean using ion engines on a pretty huge craft.

I've never used an ion engine, done a race challenge, or even used a command chair, so this would be some fun firsts for me. But it seems that designing, launching, and flying a multi-kiloton craft using lots of ion engines would take a ludicrous amount of time. If better time warp could really reduce that by a few orders of magnitude I might give it a go, but if it was only one order of magnitude (due to kraken) then it still might be too much of a time commitment. 

Of course there is always the option of just not trying to min-max in order to save time, but that's never been my style. I wish there was a weight limit.

[Aeroboi]

12 minutes ago, bayesian_acolyte said:

What about with a heavier craft? It seems that roughly half your dV would need to be used on the initial leg, and since there is no size limit that might mean using ion engines on a pretty huge craft.

I've never used an ion engine, done a race challenge, or even used a command chair, so this would be some fun firsts for me. But it seems that designing, launching, and flying a multi-kiloton craft using lots of ion engines would take a ludicrous amount of time. If better time warp could really reduce that by a few orders of magnitude I might give it a go, but if it was only one order of magnitude (due to kraken) then it still might be too much of a time commitment. 

Of course there is always the option of just not trying to min-max in order to save time, but that's never been my style. I wish there was a weight limit.

Well, the reason I build ION ships at all is for fast crew transport, otherwise what is there to need ION engines for other then correction burns (custom rcs), small probes or as you prefer big ships?
For a fast crew transport you would only need several parts like a inline crew cabin, mk1 pod, xenon tanks, 1 battery, 1 dawn engine, and a few gigantors (for deep space)

If properly strutted such a vessel should be able to do 100x physical timewarp allowing fast crew transports. Usually I have a xenon fuel depot in orbit of the target planet to refuel for the lap back home.

Still, on larger ships (define large?) I was consistenly able to do 20 to 50x physical timewarp (50-100part vessels)
The more compact the vessel is the better. So don't make it long but in a cube for all I care. Sorry if it messes up your design specifications
The trick is to have your root part at the center and have most parts strutted to root and joints to grandparent. Apart from that you should try and fiddling beyond those guidelines anyway as I found out that certain autostrut settings will allow much higher physical timewarp settings.

Edited March 25, 2019 by Aeroboi

[sevenperforce]

@M_Rat13 A proposal.....

In order to encourage low-part-count and low-mass solutions, why not have multiple classes? So it's still a race, but you have a "10 tonne or lower" class, a "50 tonne or lower" class, etc.

[M_Rat13]

4 minutes ago, sevenperforce said:

@M_Rat13 A proposal.....

In order to encourage low-part-count and low-mass solutions, why not have multiple classes? So it's still a race, but you have a "10 tonne or lower" class, a "50 tonne or lower" class, etc.

With the way this thread has been going, I think there will be plenty of low mass participants. Also I don't want to feel like I'm forcing people down a certain path. You wanna make a huge build with mammoth engines, go for it. You want to be the ultimate minimalist, nothing's stopping you. Your imagination should be the limitation, not me.

[sevenperforce]

Just now, M_Rat13 said:

With the way this thread has been going, I think there will be plenty of low mass participants. Also I don't want to feel like I'm forcing people down a certain path. You wanna make a huge build with mammoth engines, go for it. You want to be the ultimate minimalist, nothing's stopping you. Your imagination should be the limitation, not me.

My concern is that this will end up being a competition over who has the biggest computer. Adding classes would not constrain imagination (you can have a "no limits" class) but it would give a new chance to compete.

[M_Rat13]

57 minutes ago, sevenperforce said:

My concern is that this will end up being a competition over who has the biggest computer. Adding classes would not constrain imagination (you can have a "no limits" class) but it would give a new chance to compete.

But isn't there diminishing returns the bigger the craft? 

It's not that I'm against classes, but I personally don't see much point in them. The numbers just support craft that won't unleash the kraken.

[bayesian_acolyte]

I was messing around in the editor and built an 11 ton ship capable of Moho ascent and Eeloo descent with full electric power for every stage. Every part is at most 3 away from the root and it only has 38 parts total for time warp stability purposes. The crazy part, at least to someone who has never used ion engines and command chairs... it has 53,000 dV and over 29 hours of burn time.

At 100 times speed that would be about 18 minutes, but if you include time to split burns, separate stages, the ascent and decent, and figuring out burn timings and locations, it's still a pretty big task as you'd have to spend a lot of time below 100x speed. Maybe I'll get it down below 10 tons and try it out but currently I'm leaning away from it, at least until there are other entrants to compete against.

7 minutes ago, M_Rat13 said:

But isn't there diminishing returns the bigger the craft? 

It's not that I'm against classes, but I personally don't see much point in them. The numbers just support craft that won't unleash the kraken.

Let's say you have a 50 ton craft, why not add a 50 ton first stage for some free dV. Or you have a 5000 ton craft, why not add a 5000 ton first stage for more free dV. There are  diminishing returns but if two designs are close that extra stage will likely make the difference. Especially if one person stops at 100 tons and another stops at 10,000 tons. You can add a massive amount of dV from 100 tons to 10,000 tons, even if that final 100 tons is most of the total dV.

[sevenperforce]

58 minutes ago, bayesian_acolyte said:

Let's say you have a 50 ton craft, why not add a 50 ton first stage for some free dV. Or you have a 5000 ton craft, why not add a 5000 ton first stage for more free dV. There are  diminishing returns but if two designs are close that extra stage will likely make the difference. Especially if one person stops at 100 tons and another stops at 10,000 tons. You can add a massive amount of dV from 100 tons to 10,000 tons, even if that final 100 tons is most of the total dV.

Right. It just becomes a question of making bigger and bigger LVs.

[Klapaucius]

6 hours ago, purpleivan said:

The screenshot on the finish line... does it really have to include smiling kerbals, couldn't it just be wreckage and a huge explosion.

Those smiling face will cost a lot of time

There is precedent in the racing world:

 

https://www.grandtournation.com/cars/audi-r8-wins-race-upside-down-nd3687/

Edited March 25, 2019 by Klapaucius

[M_Rat13]

1 hour ago, bayesian_acolyte said:

I was messing around in the editor and built an 11 ton ship capable of Moho ascent and Eeloo descent with full electric power for every stage. Every part is at most 3 away from the root and it only has 38 parts total for time warp stability purposes. The crazy part, at least to someone who has never used ion engines and command chairs... it has 53,000 dV and over 29 hours of burn time.

At 100 times speed that would be about 18 minutes, but if you include time to split burns, separate stages, the ascent and decent, and figuring out burn timings and locations, it's still a pretty big task as you'd have to spend a lot of time below 100x speed. Maybe I'll get it down below 10 tons and try it out but currently I'm leaning away from it, at least until there are other entrants to compete against.

Let's say you have a 50 ton craft, why not add a 50 ton first stage for some free dV. Or you have a 5000 ton craft, why not add a 5000 ton first stage for more free dV. There are  diminishing returns but if two designs are close that extra stage will likely make the difference. Especially if one person stops at 100 tons and another stops at 10,000 tons. You can add a massive amount of dV from 100 tons to 10,000 tons, even if that final 100 tons is most of the total dV.

Do you really need that much Dv? Burning that long might give you a high top speed, but you'll need to also slow down. Oh, and TWR is also important. TWR allows you to do less burns to defeat gravity, which reduces Dv requirements also.

TWR is also easier to raise with a lighter craft.

[purpleivan]

1 hour ago, bayesian_acolyte said:

Let's say you have a 50 ton craft, why not add a 50 ton first stage for some free dV. Or you have a 5000 ton craft, why not add a 5000 ton first stage for more free dV. There are  diminishing returns but if two designs are close that extra stage will likely make the difference. Especially if one person stops at 100 tons and another stops at 10,000 tons. You can add a massive amount of dV from 100 tons to 10,000 tons, even if that final 100 tons is most of the total dV.

You mean something like this... dont know it's mass exactly, but fair to say it's a lot.

It took 5 1/4 days to get to the surface of Eve... of course that was back in the day, when hitting the planet's atmosphere at 30km/s didn't instantly vaporise your ship.

[Klapaucius]

2 minutes ago, purpleivan said:

You mean something like this... dont know it's mass exactly, but fair to say it's a lot.

 

I did not know Soviet architecture was a basis for interplanetary rocket design.  Then again, it is Moscow State University and they are opening a new space science department.

http://eurasiatx.com/lomonosov-moscow-state-university-to-open-new-department-of-space-sciences/

 

[vyznev]

Well, here's my half-baked first iteration:

The first two chemical stages are for taking off and escaping from Moho, because screw doing that with ions. After that, it's all down to just the one Dawn engine and a bunch of cast-off xenon tanks.

The first two ion stages, with a combined delta-v of 23.8 km/s, are for the acceleration burn from Moho to Eeloo and are mainly solar-powered. The remaining stages are for deceleration at Eeloo, and are powered by two RTGs. As the RTGs only put out about one fifth of the maximum power demand of the Dawn engine, that's going to be a long slow burn. I could add more RTGs to make it go faster, but that would eat into my delta-v budget.

Finally, after reaching low Eeloo orbit, with the final xenon tank hopefully about 10% full, I'll stage off the RTGs and land the craft on battery power. The last stage has a TWR of about 2 on Eeloo, which is enough for a careful landing. This is actually the only part of the mission which I'm confident will work without any issues, since I already test flew it once:

Unfortunately, I don't have time to fly the full mission quite yet, and I fully expect I'll probably need to tweak the vessel further after testing. Also, with over 12 hour burn times, I'm definitely going to have to install that BetterTimeWarp mod if I'm going to have any chance of actually flying this mission.  

[M_Rat13]

@vyznev what's your TWR for your first stage? Out of curiosity.