Budget Moon Challenge

S

StarNote1

Guest
#1
#1
Simple, Launch from Earth and Land on the Moon, And then launch from Moon back to Earth with successful landing with earth.
- Only the "No Drag" cheat will be allowed.
- Must Launch back to earth immediately after landing on Moon.
- Earth's return may land via-parachute.
- Post Screenshots of each landing.

Rocket Desine with the fewest parts, mass, and thrust will win.
 
Altaïr

Altaïr

Space Stig, Master of gravity
Staff member
Head Moderator
Team Kolibri
Modder
TEAM HAWK
Atlas
Deja Vu
Under Pressure
Forum Legend
#2
#2
Challenge accepted!

I like spatial missions, but as I don't have much money as Elon Musk does, I tend to make small and optimized rockets. Thus, I'm proud to present my LFR (Little F***ing Rocket), that will fly to the Moon, land a small object, collect a few samples, and get them back to Earth for a minimal cost:
01-rocket plan.png

Mission starts, I get quickly into low Earth orbit, and then on a lunar injection trajectory. With those maneuvers, I've already burnt most of my fuel:
02-low earth orbit.png 04-lunar injection.png

I have to burn a bit more fuel to put my ship into lunar orbit. Then, I can separate my lunar module from the main ship and start the descent:
05-Moon orbit.png 07-descent.png

Finally, I land my module. I've spent a bit less than half of my fuel, so I should have enough for the ascent. The scientific mission can begin:
08-moon landing.png

After collecting a few samples, my module lifts off to get into lunar orbit and redock with the main engine that's still in orbit. With no RCS system, and as the other part is uncontrollable, this part is quite technical and requires a lot of precision. Once it's done, I can use the remaining fuel from my lunar module to refill my main tank, and separate the lunar base which is useless now:
10-lunar base separation.png

Then, I just have to quit the lunar sphere of influence, and then, once in Earth orbit, to put my ship on a reentry trajectory. My fuel reserves are really low, but as my ship is very light it's actually far enough:
11-return trajectory.png

See? I even have a bit more fuel left in reserve, but I won't need it anymore, my mission is nearly over. While I am at the apoapsis, I separate the main tank. Managing the descent is a piece of cake:
13-landing.png 14-end mission.png

Mission accomplished! The Little f***ing rocket successfully brought back from the Moon some samples for scientific analysis. Good luck to other challengers! :cool:
 
S

StarNote1

Guest
#3
#3
Awesome accomplishment great mission but as to be fair I will wait one more week to let others post there mission details but I'm pretty sure they all got their work cut out for them.
 
D

Dakkaron

Guest
#4
#4
The Little f***ing rocket weight 43.8t made up of 28 parts. Using ion engines and (ironically) large rocket parts I managed to decrease that number to slightly more than half of that.

This is MicroMoon, a 25.55t two-stage-to-moon-and-back rocket made up of 15 parts.
Screenshot_20180511-161858.png

Screenshot_20180511-161921.png

With this rocket getting to orbit is the hardest part. The first stage has just about enough power to get us out of the atmosphere. From here on the ion engines have to take over.

Now the next problem arises: since we cannot use the solar cells during launch, we only have half a battery full of power left over. And two solar cells are not nearly enough to fully power both ion engines. But by carefully juggling the throttle we manage to get into LEO. From here the mission is a piece of cake. With these incredible ion engines this tiny tank of fuel is more than enough to get to the moon, land there and go back to Earth.
Screenshot_20180511-160510.png

During landing we get into heavy oscillations due to the short length of the rocket, but we manage to land in one piece.
Screenshot_20180511-161205.png
Though maybe not on the right side, but who cares ;)
 
Altaïr

Altaïr

Space Stig, Master of gravity
Staff member
Head Moderator
Team Kolibri
Modder
TEAM HAWK
Atlas
Deja Vu
Under Pressure
Forum Legend
#5
#5
Nice, I didn't think about the ion engines. Actually, a true ion engine would be far too weak to lift off from the Moon, so I didn't even try. Well done, I admit you deserve the win. ;)
 
D

Dakkaron

Guest
#6
#6
You are right about the ion engines^^

I just tried if it was possible to do it using RCS thrusters instead of the ion engines, since that would remove a lot of weight (no need for power management and also the RCS thrusters are ridiculously light), but I got stuck on having too little fuel. They are not very efficient.
 
D

Dakkaron

Guest
#7
#7
I managed to reduce the weight further, down to 21.67t.
Screenshot_20180512-121749.png

Getting into orbit is now really tricky since the first stage tank is much too small for that and the ion thrusters are too weak for the job. But with near perfect flying and a bit of luck it is possible. The third solar panel adds 0.5t to the lander, but it allows for the ion thrusters to operate at 75% continuously. That really helps getting into orbit.

The smaller engine shaves off 2.5t and the short large tanks are the only one (at least according to the documentation) that have a fuel-to-weight ratio of 1:1 instead of 9:10 as all the other tanks.

Ditching the seperator for a tiny dock, which essentially does the same reduced the weight by 0.13t without having to sacrifice anything. Also I reduced the battery size to gain another 0.25t.

I would really like to see if anyone can kmprove on that.

Now the pictures.

After a few tries I managed to get into orbit
Screenshot_20180512-092054.png

Landing on the moon was no problem initially, until I touched down and noticed that extended solar panels now are extremely fragile (contrary to an earlier version where they were near indestructible, which is why I used to use them as bumpers).

Screenshot_20180512-094519.png

Luckily the moon's gravity is ridiculously low, so after my tiny battery was depleted I still had enough power to get into orbit even though I could only use 25% of thrust.

Screenshot_20180512-094808.png

Landing on Earth proved a little difficult, since the parachute is off-center.

Screenshot_20180512-101128.png

But I just had to use a well-timed and one-sided burst of ion power to right my orientation directly before landing and everything should be fine.

Screenshot_20180512-101157.png
This is becoming a habit -.-

Screenshot_20180512-101206.png
 
S

StarNote1

Guest
#8
#8
Dakkaron said:
The Little f***ing rocket weight 43.8t made up of 28 parts. Using ion engines and (ironically) large rocket parts I managed to decrease that number to slightly more than half of that.

This is MicroMoon, a 25.55t two-stage-to-moon-and-back rocket made up of 15 parts.
View attachment 919

View attachment 920

With this rocket getting to orbit is the hardest part. The first stage has just about enough power to get us out of the atmosphere. From here on the ion engines have to take over.

Now the next problem arises: since we cannot use the solar cells during launch, we only have half a battery full of power left over. And two solar cells are not nearly enough to fully power both ion engines. But by carefully juggling the throttle we manage to get into LEO. From here the mission is a piece of cake. With these incredible ion engines this tiny tank of fuel is more than enough to get to the moon, land there and go back to Earth.
View attachment 922

During landing we get into heavy oscillations due to the short length of the rocket, but we manage to land in one piece.
View attachment 923
Though maybe not on the right side, but who cares ;)
Click to expand...
How did u manage to land on moon with the ions low thrust? We’re they able to slow u down enough,.... Nevermind, lol
 
D

Dakkaron

Guest
#9
#9
If the vehicle is small and light enough the ion thrusters have more than enough thrust. It does take a lot longer to slow down than with conventional thrusters, but it is enough. On the moon I only need about 30% of thrust to hover.


Since I had so much fuel left over after the Moon run I figured I might try something a bit harder, so I did an all-moon-run with that vehicle.

Screenshot_20180512-121749.png

First I went to Phobos. Getting there used up a bit of fuel, but not too much. Landing was very easy because of the low gravity.

Screenshot_20180512-125843.png Screenshot_20180512-130405.png

Then I went to Daemos. Landing was a bit more difficult because of the ridiculously low gravity. I had to push down to get there.

Screenshot_20180512-131250.png Screenshot_20180512-131854.png

So the only thing left was the journey back to the moon. That took a few tries to not waste too much fuel. In the end I used Daemos' push to get me towards the moon.

Screenshot_20180512-234930.png

Getting back from there was quite easy even though I used up almost all fuel.

Screenshot_20180512-235857.png Screenshot_20180512-235904.png
I guess, this sideways landing is becoming obligatory by now ^^

Ion thrusters are mighty!
 
S

StarNote1

Guest
#10
#10
Ya Id prrtty much say You won this Challenge.
.. And I learned a few things , so all in all this was a good Challenge idea for surs..
 
N

noire

Guest
#18
#18
I feel BS'd so hard now, i got the probe to the moon, but get this: ofcourse with my luck i land right on a super steep slope, tip over, and explode. Ill try later when im less pissed...
 
S

Space Chicken

Guest
#21
#21
StarNote1 said:
Simple, Launch from Earth and Land on the Moon, And then launch from Moon back to Earth with successful landing with earth.
- Only the "No Drag" cheat will be allowed.
- Must Launch back to earth immediately after landing on Moon.
- Earth's return may land via-parachute.
- Post Screenshots of each landing.

Rocket Desine with the fewest parts, mass, and thrust will win.
Click to expand...
This is kind of late, but this is kind of a harder venus and back challenge
 
You must log in or register to reply here.