Pure Ion Challenge

D

Dakkaron

Guest
#1
#1
How far up can you launch your rocket that is only powered by ion thrusters?

You cannot use any other engine or wheels, but you are allowed to add charging infrastructure that does not need to be launched. So you can build a charging structure that can be detached before launch.

Please post screenshots of your accomplishments!
 
Altaïr

Altaïr

Space Stig, Master of gravity
Staff member
Head Moderator
Team Kolibri
Modder
TEAM HAWK
Atlas
Deja Vu
Under Pressure
Forum Legend
#15
#15
I know I'm already beaten, but here is my tentative. My best altitude is 2491 meters.
Screenshot_20180516-002805.png


Air resistance is what really killed me I think.
 
S

Strychnine

Guest
#16
#16
According to my experiments, in Earth's atmosphere, there is a curve. Anything I add on over that specific design gives diminishing returns. Adding more engines means you run out of fuel first, and adding a fuel tank means you have to add more engines, which means more weight, which means a lower altitude. There may be a better design, but I got bored.
 
Altaïr

Altaïr

Space Stig, Master of gravity
Staff member
Head Moderator
Team Kolibri
Modder
TEAM HAWK
Atlas
Deja Vu
Under Pressure
Forum Legend
#20
#20
Strychnine said:
According to my experiments, in Earth's atmosphere, there is a curve. Anything I add on over that specific design gives diminishing returns. Adding more engines means you run out of fuel first, and adding a fuel tank means you have to add more engines, which means more weight, which means a lower altitude. There may be a better design, but I got bored.
Click to expand...
Actually I expected the air pressure to mainly apply on the upper part, so I added aerodynamic cones. Then I added lots of engines, batteries and fuel tanks to compensate. Of course, that doesn't change the thrust to weight ratio, but it makes the aerodynamic pressure and the weight of the cones lower in proportion. Well, at least that's what I thought, but it seems aerodynamic pressure doesn't work that way. At least I tried :)
 
flefliker

flefliker

Discord Staff
TEAM HAWK
Atlas
Under Pressure
Registered
#22
#22
Altaïr said:
Actually I expected the air pressure to mainly apply on the upper part, so I added aerodynamic cones. Then I added lots of engines, batteries and fuel tanks to compensate. Of course, that doesn't change the thrust to weight ratio, but it makes the aerodynamic pressure and the weight of the cones lower in proportion. Well, at least that's what I thought, but it seems aerodynamic pressure doesn't work that way. At least I tried :)
Click to expand...
I found there to be a specific ratio that you cannot breach with the Ion thrusters on Earth. Sacrificing fuel gives a better TWR but they run out sooner. Adding fuel and more batteries obviously gives you more time but then your TWR is too low for them to do anything. You have to find the sweet spot and I will tell you it does involve some math.
 
Altaïr

Altaïr

Space Stig, Master of gravity
Staff member
Head Moderator
Team Kolibri
Modder
TEAM HAWK
Atlas
Deja Vu
Under Pressure
Forum Legend
#23
#23
flefliker said:
I found there to be a specific ratio that you cannot breach with the Ion thrusters on Earth. Sacrificing fuel gives a better TWR but they run out sooner. Adding fuel and more batteries obviously gives you more time but then your TWR is too low for them to do anything. You have to find the sweet spot and I will tell you it does involve some math.
Click to expand...
Yes, you're right about the TWR, but the problem was really the aerodynamic. Just for the fun, I've run a test with the "no drag" cheat, and here is the result:
Screenshot_20180516-213130.png
It's not that bad isn't it? :)
And I still had the aerodynamic cones even if they are useless in that case. I've started a few tests on aerodynamics, and I think I start to understand the problem: actually, each row of batteries was submitted to the dynamic pressure, not only the upper one. Thus my design was really poor on this point.
 
You must log in or register to reply here.