A difficult if not impossible contract

[Anquietas314]

So here's a contract I've just been offered. Anyone know if it's even possible? (without a crazy 500t+ rocket!)

I've seen a couple designs for an eve lander in 1.0, but nothing designed to actually carry a payload (let alone one this heavy).

Edited May 6, 2015 by armagheddonsgw

[Sirrobert]

Possible? Sure. But you'd probably need a CPU melting monster

[Poofer]

well, given the fact that it's divided in "stages" you may be able to exploit it to complete it without leaving eve.

- land at eve and mine 2700 ore units

- use a second ship to mine 2700 ore units from anywhere you like.

- land second ship at gilly

[Tahib]

a new challenge was born xD

[Anquietas314]

Poofer:

I think the idea is that you need to use the same vessel for the whole thing... even if technically you don't I would consider that cheating

Update btw, so far the only vessel I've been able to make that can theoretically get the job done (~7.5km/s vacuum deltaV, high initial surface TWR) weighs in at a little over 1000t :/

[maccollo]

Poofer:

I think the idea is that you need to use the same vessel for the whole thing... even if technically you don't I would consider that cheating

Update btw, so far the only vessel I've been able to make that can theoretically get the job done (~7.5km/s vacuum deltaV, high initial surface TWR) weighs in at a little over 1000t :/

I also made threw together an EAV. Came out at roughly the same mass. However, you may be able to get away with less delta V. The larger parts seem to have much less of a problem with drag, so you may able to shave off 1 km/s or so if you're lucky, perhaps even more if you can find ore anywhere above 1 or 2 km. Also, since you have to mine ore. If the deltaV can be lowered by a large amount then you can shave of a significant portion of the lander mass.

[RexKramer]

I have seen a couple of contracts like that, although obviously have not attempted to lift anything from Eve. I'm pretty sure the game requires the ore to actually have come from Eve. Simply mining some on Eve, and then delivering some other ore to the destination probably won't complete the contract.

Part of navigating the contract system is determining which contracts you are actually capable of completing. I was once offered a contract to test a parachute, while flying, altitude 20-25km, speed 400-500m/s. At the Sun. Ok, it was possible to complete, using a lot of cheats, but without cheats that one obviously is not really possible to complete.

Personally, I really like the fact that the contract system makes you think before accepting contracts. Lifting ore from Eve would be very challenging to say the least.

[Anquietas314]

I also made threw together an EAV. Came out at roughly the same mass. However, you may be able to get away with less delta V. The larger parts seem to have much less of a problem with drag, so you may able to shave off 1 km/s or so if you're lucky, perhaps even more if you can find ore anywhere above 1 or 2 km. Also, since you have to mine ore. If the deltaV can be lowered by a large amount then you can shave of a significant portion of the lander mass.

https://dl.dropboxusercontent.com/u/22015656/ultraEAV.png

What's the surface TWR on that design? The best I've came up with so far is 1.38 (in atmosphere), although with slightly excessive deltaV (I had a fun idea: use LV-Ns late in the ascent. No idea if they'll overheat in 1.0.2, but it does make the rocket quite a bit smaller ). One not-so-insignificant problem that occurred to me after building it: this thing has to make it at least to Kerbin orbit on its own... I've never tried to lift something this big, even empty (I can't just use it to launch itself - the early stages burn out far too fast).

Part of navigating the contract system is determining which contracts you are actually capable of completing. I was once offered a contract to test a parachute, while flying, altitude 20-25km, speed 400-500m/s. At the Sun. Ok, it was possible to complete, using a lot of cheats, but without cheats that one obviously is not really possible to complete.

Heh, nice. Yeah I've seen a couple absurdly difficult ones, but I think this one in particular might just be feasible enough to attempt - but I'm not sure, hence the thread .

[silenced]

We all know Real Life, right? Even there you can get contracts that are impossible to complete. Why not in KSP aswell? Sure, it MAY be possible, but at what costs?

[SRV Ron]

While it may be possible to design a rocket that can leave Eve for Gilly, will you make enough money from the contract to cover the cost of that mission and make any kind of a profit?

[Anquietas314]

While it may be possible to design a rocket that can leave Eve for Gilly, will you make enough money from the contract to cover the cost of that mission and make any kind of a profit?

The design I've come up with so far (note: not finished) comes in at a little over the advance payment for the contract; maccollo's rocket (assuming it works) looks like it'd be considerably cheaper. So that leaves a fairly tidy profit. Technically I'm at the point in my save where I really don't need huge amounts of money for anything; the only building I haven't fully upgraded is administration, so as long as the mission pays more than it costs to do I'm not too bothered about the money - more the challenge .

[eddiew]

I used to think nothing was impossible. Then I saw this contract and realised that sometimes, mathematics says no.

Good luck anyway!

[Taki117]

Why not use a Spaceplane? Set up an orbital fuel tank at Eve, descend to Eve and mine your ore (Refine as needed for surface refuel) get to orbit, refuel in orbit, then off to Gilly.

[Anquietas314]

Why not use a Spaceplane? Set up an orbital fuel tank at Eve, descend to Eve and mine your ore (Refine as needed for surface refuel) get to orbit, refuel in orbit, then off to Gilly.

Last I checked Eve's atmosphere didn't contain oxygen, so jets are useless. I can't see a way of making a spaceplane viable otherwise - certainly not one that can lift 32 tonnes or so to orbit.

[Yakky]

What's your strategy for getting the lander to Eve in the first place (and doing it all for less than 2.3 million funds)? If you brute force it with all fuel brought from Kerbin's surface, the launch costs of lifting all that fuel to orbit will probably bust your budget unless you have a very highly optimized SSTO for ferrying up rocket fuel. A more practical option is to refuel using mined ore on low-gravity outposts like Minmus and Gilly -- I actually think that strategy could allow you to turn a pretty handy profit.

This sounds like a cool contract. I'd never attempt it on Hard Mode without quicksaves, though...

[Anquietas314]

What's your strategy for getting the lander to Eve in the first place (and doing it all for less than 2.3 million funds)?

-snip-

This sounds like a cool contract. I'd never attempt it on Hard Mode without quicksaves, though...

Absolutely no idea . So far I haven't even accepted the contract; I'd rather be sure it's doable first (testing designs in sandbox for now). Realistically I think the only serious option is going to be to lift it empty and then refuel it in LKO. Once that's done, getting it to eve should be straightforward just using the main engines. Dealing with reentry heating and landing it is another story though . Of course, that still leaves the question of how to lift such a heavy rocket to orbit in the first place.

[basic.syntax]

I wonder about doing it... more expensively... in several ships.

The economics may not work. And, I'm not sure this will satisfy contract checks, so that is two strikes against trying this

You will definitely need to make a big, asparagus staged lifter, and get that into kerbin orbit. But because you'll be mining ore on EVE, you should** have access to all the fuel you need on the surface. Your EVE lift stages, when lifted off Kerbin, can be nearly empty. They may be 500-1,000t when landed and fully fueled on EVE. This would be a massive job, all around.

** edit: Speaking of EVE, this reminds me of mining missions in EVE Online: they set up a place for you to go that has a SPECIFIC amount for you to mine, nothing more than what the mission asks for. I haven't yet done a mining contract in KSP, so I don't know if they are that cruel

1. land a rover with a claw and ore tanks, for temporary use.

2. land the main mining vessel with ore tanks able to carry all the ore, but after mining it all... transfer what can't be lifted, over to the temporary rover storage tank.

3. Top off your fuel tanks, and lift off with as much ore as you can carry in the first/main ship, and wait in EVE orbit.

4. land other ships as needed, that are able to lift the remaining ore.

5. Drive the claw-equipped rover ore storage tank up to them, and transfer what they can carry.

6. Rendezvous all the ore ferries with the main ship that mined the full amount, fill it up, and take that one to Gilly.

7. (extra credit) Return all lifted stages to safely to Kerbin, for a partial refund on parts costs.

Edited May 5, 2015 by basic.syntax

[tsotha]

Possible? Yes. But the payout is far too small.

[maccollo]

The design I've come up with so far (note: not finished) comes in at a little over the advance payment for the contract; maccollo's rocket (assuming it works) looks like it'd be considerably cheaper.

It doesn't. The sustained stages didn't have quite enough thrust, and the booster stage didn't have enough deltaV. I don't think your will work either if you're starting with a meager TWR of 1.3. The 7.5 km/s deltaV I managed to get was with an initial TWR of 2. The Mammoth engines have much better ISP at the surface of Eve than the mainsails though, so you could probably get away with a little less.

[Sirrobert]

While it may be possible to design a rocket that can leave Eve for Gilly, will you make enough money from the contract to cover the cost of that mission and make any kind of a profit?

For contracts like this, it's not about the money anymore. It's about the challange. It's about proving the computer that you are better than it, that impossible contracts don't scare you

[Anquietas314]

It doesn't. The sustained stages didn't have quite enough thrust, and the booster stage didn't have enough deltaV.

Hmm okay, that's good to know I guess, although it doesn't sound like your design is far off the mark. Here's a completely insane idea; is an Eve SSTO possible? If it is it'd solve a lot of the problems with getting the darn thing to eve in the first place, with the added bonus of nearly eliminating mission costs - I could just return the thing to Kerbin once the job's done.

[maccollo]

Reworked the EAV. Now it works if you can perform an efficient gravity turn, at least from about 1 km. Got to orbit with 100 m/s to spare. Actually I managed to make it lighter than before! Now it's just shy of 1000 tonnes.

Craft file: https://dl.dropboxusercontent.com/u/22015656/ultraEAV.craft

Hmm okay, that's good to know I guess, although it doesn't sound like your design is far off the mark. Here's a completely insane idea; is an Eve SSTO possible? If it is it'd solve a lot of the problems with getting the darn thing to eve in the first place, with the added bonus of nearly eliminating mission costs - I could just return the thing to Kerbin once the job's done.

Single stage to trans Eve injection? Maybe. Probably not this thing though as it's has to much dry mass (to much engine).

Still, the Eve ascent vehicle will easily be able to burn itself to LKO. When empty it will only has a mass of about 270 tonnes. You can then haul it to Eve using a nuclear tug. If you can refuel it with the same ore that it's going to haul out into Eve orbit then this might seem a little less insane.

Anyway, you're gonna have to refuel the last stage in Eve orbit to get it to Gilly. Might be a good idea to see if the game allows you to dock after getting the Ore. If not you would probably have to design some kind of scoop to push it to Gilly without docking. Adding another 1800 m/s of additional delta V to get it to Gilly directly from the surface would really, REALLY sting.

[cantab]

I wonder, for ore mining contracts in general does all the ore have to be mined in one go? Or can it be done in multiple separate ships that ascend into a stable orbit then dock together? If the latter works it would make contracts like this one less processor-torturing.

[Anquietas314]

Single stage to trans Eve injection? Maybe. Probably not this thing though as it's has to much dry mass (to much engine).

Nononono, you misunderstand; I meant a craft that can SSTO from Eve

Anyway, here's something I came up with based on your earlier design that "should" work, although it's not quite as efficient as the one you just posted:

So far untested, but the launch TWR from eve is 1.45 at sea level, or 1.86 if launched from a more reasonable altitude of 3km. I have been able to test the ship's ability to launch itself to LKO though; it passed the test! (though without much room for error and it's a touch wobbly) I already have plans for a refueling system based at Mun, so in theory if it works Eve-side this should be good to go. My eve transfer window isn't for another 90-odd days in my career save .

I'm thinking I should be able to just land a rover setup nearby and dock via the clamp, and then have the rover mine the ore directly into the main ship, with an ISRU converter on the rover for refueling purposes. I've yet to test whether that fits the conditions of the contract though (how exactly would I go about testing that...), but it should be interesting

[Rakaydos]

Nononono, you misunderstand; I meant a craft that can SSTO from Eve

It was mathematically impossible with stock engines in the souposphere for beta and before, I dunno what 1.0.2 will let you do...