Drop Tanks and Kapy Rock
Feb. 29th, 2024 06:07 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
the_sky_callsI had made a simple rover to gather some science around the Space Center and suddenly I had a mission completed and got another one; to send a lander can to Kapy Rock. So, I slapped a few wheels on a Mk1 "Explorer" Lander Can and put it on a rocket, planning to just drop it on the target and drive the rest of the way.
But then I got to thinking about drop tanks.
A rocket engine such as the RE-M3 "Mainsail" has a lot of power. And when you build a rocket for medium diameter parts with enough fuel for the mainsail to eat up in a core stage, that rocket can be pretty tall. Well, maybe I don’t want a rocket that tall and, once that core is half empty, don’t want to carry those tanks all the way into space.
The answer is drop tanks. It’s like Asparagus staging but without the booster engines.
I can use six radially mounted pairs of FL-T800 fuel tanks with a Fuel Line feeding into the core to replace the equivalent of three X200-32 Fuel Tanks stacked on top of the core and then just dump them when they are empty.
In KSP1, you could right click on those drop tanks during flight to see when they were empty but KSP2 doesn’t implement that feature. So, to know when to drop the tanks I empty the fuel from the core tanks in the VAB and pay attention (via Micro Engineer) to how long the engine will run on the fuel only in the drop tanks. In this case, it’s 1 min 31 sec.
Mission Designation : KB-1
Rocket Model : Kapybara KH-I
Total delta-V : 4,864 m/s
Surface TWR : 1.18
Total Mass : 119.81 t
Dry Mass : 22.5 t
Part Count : 88
Height : 17.42 m
Width : 5.50 t
Length : 5.50 t
Mission Objectives : Land at Kapy Rock
Crew : Derrie Kerman
I like drop tanks.
Kapy Rock is located in the small desert region at the south of the continent opposite the Space Center. (Kapybara Desert? Kapy Desert?) To reach there, the trajectory is pretty much south from KSC. After passing over the south polar region I build a maneuver node to use up the over 2,000 m/s of delta-V left in the rocked, targeting beyond the landing zone.
KSP1 had a mod called Trajectories that would apply atmospheric effects to determine an accurate landing point. It would also display that on the flight view so you could land more precisely. I really respect those people in KSP (both 1 and 2) who are able to land Falcon-9 like rockets back at the space center without something like Trajectories.
Me? I landed 8.5 km away from the landing zone. I expected that, though. That’s why I brought wheels. Except that the design is awful. Attempting to drive forward, the top-heavy capsule will roll back, sometime literally falling over. The reaction wheel in the lander can has enough power to right itself., though.
At sunset, there is an interesting effect of sparkly lines appearing in the distance. Like ball lightning, ley lines, or St Elmo’s Fire. Rendering artifacts.
I wasn’t close enough to the destination for the batteries to get me all the way there over night and, waiting till morning, I didn’t have enough solar panels to complete the job either. Plus, the tippy rover couldn’t manage the hill so I abandoned it and walked the rest of the way.
Thankfully, the mission objectives are to launch with a lander can, not that the lander can itself to the destination, which is good because at some point I got a message that the craft was on a crash trajectory and literally just disappeared.
Remember; KSP2 is Early Access.
If this is supposed to be a capybera, I don’t really see it. More like a duck.
But then I got to thinking about drop tanks.
A rocket engine such as the RE-M3 "Mainsail" has a lot of power. And when you build a rocket for medium diameter parts with enough fuel for the mainsail to eat up in a core stage, that rocket can be pretty tall. Well, maybe I don’t want a rocket that tall and, once that core is half empty, don’t want to carry those tanks all the way into space.
The answer is drop tanks. It’s like Asparagus staging but without the booster engines.
I can use six radially mounted pairs of FL-T800 fuel tanks with a Fuel Line feeding into the core to replace the equivalent of three X200-32 Fuel Tanks stacked on top of the core and then just dump them when they are empty.
In KSP1, you could right click on those drop tanks during flight to see when they were empty but KSP2 doesn’t implement that feature. So, to know when to drop the tanks I empty the fuel from the core tanks in the VAB and pay attention (via Micro Engineer) to how long the engine will run on the fuel only in the drop tanks. In this case, it’s 1 min 31 sec.
Mission Designation : KB-1
Rocket Model : Kapybara KH-I
Total delta-V : 4,864 m/s
Surface TWR : 1.18
Total Mass : 119.81 t
Dry Mass : 22.5 t
Part Count : 88
Height : 17.42 m
Width : 5.50 t
Length : 5.50 t
Mission Objectives : Land at Kapy Rock
Crew : Derrie Kerman
I like drop tanks.
Kapy Rock is located in the small desert region at the south of the continent opposite the Space Center. (Kapybara Desert? Kapy Desert?) To reach there, the trajectory is pretty much south from KSC. After passing over the south polar region I build a maneuver node to use up the over 2,000 m/s of delta-V left in the rocked, targeting beyond the landing zone.
KSP1 had a mod called Trajectories that would apply atmospheric effects to determine an accurate landing point. It would also display that on the flight view so you could land more precisely. I really respect those people in KSP (both 1 and 2) who are able to land Falcon-9 like rockets back at the space center without something like Trajectories.
Me? I landed 8.5 km away from the landing zone. I expected that, though. That’s why I brought wheels. Except that the design is awful. Attempting to drive forward, the top-heavy capsule will roll back, sometime literally falling over. The reaction wheel in the lander can has enough power to right itself., though.
At sunset, there is an interesting effect of sparkly lines appearing in the distance. Like ball lightning, ley lines, or St Elmo’s Fire. Rendering artifacts.
I wasn’t close enough to the destination for the batteries to get me all the way there over night and, waiting till morning, I didn’t have enough solar panels to complete the job either. Plus, the tippy rover couldn’t manage the hill so I abandoned it and walked the rest of the way.
Thankfully, the mission objectives are to launch with a lander can, not that the lander can itself to the destination, which is good because at some point I got a message that the craft was on a crash trajectory and literally just disappeared.
Remember; KSP2 is Early Access.
If this is supposed to be a capybera, I don’t really see it. More like a duck.
