NEXT Lunar Colonisation Program

[Michel Van]

This for Alternate history Story i work on.
and i need advice and help on some details.

NEXT is Lunar Colonisation Program
It reuse the entire Launch rocket and Lunar lander
And orbital refuel for second stage for Lunar Trajectory Injection
To bring 60 metric tons lander to Lunar surface.
The rocket and lander use methalox engine.

The Lander transport 5,7 metric tons to moon and back.
As one way Cargo lander 26 metric tons of equipment.

 

[Michel Van]

This is Next Moonlander concept
I no quite sure if this Design works (help needed)

I use four modified RL-10 (burn Methalox, thrust throttle back)
main issue unsymmetrical thrust on engine out during landing.
other issue the crew cabin lower position the crew has to land on very flat surface.
also balance out subsystem like Life-support, Power system (fuel cell) and others.
Reaction control system fuel is stored in small tanks, also the Lox LH2 tanks for Fuel cells.

Operational time 14 days (fuel cells)
Hibernate mode max 60 day after that too much propellant boil-off
Crew 2 to 4 Exploration phase, then 9 person during Lunar Base phase

For Colonist transport i look option to use Second stage of Next rocket as Lunar lander with bigger cabin.

 

[Michel Van]

I have question about Methalox engines.

I found contradicting data about the ISP.
Like Raptor, Be-4 and others, but those high performance engines.
also about RL-10 on Methalox but that used FLOX 82.5%

Are any data about gas-generator engines with this propellant ?
Is the ISP around 321 sec (3154 m/s2). or lower ?
and about RL-10 on pure Methalox without Fluorine ?

 

[Michel Van]

here the launch rocket in detail.
based to data and calculation from Book Die Grenzenlose Dimension Raumfahrt band 2 by H.O.Ruppe (page 160-176)
all data in Metric

Engine ISP 3106 m/s2 using Methane and Oxygen, thrust 228,227 tons (gas generators cycle)
3803,789 tons lift off Thrust 4564,54 tons by 20 engines
_882,789 tons MECO
_728.618 tons hot stage separation thrust by 3 engines.
_115.615 tons SECO

DV1 = _4536,83 m/s2
DV2 = _5717,785 m/s2
DV3 = 10254,615 m/s2
______-1308,00 m/s2 gravity losses
_______-138,00 m/s2 air resistens
________-20,00 m/s2 losses by various issues
_______8878,61 m/s2 orbit speed (8036 m/s2 needed for 200 km orbit)


Mass brake down first stage

2921000 kg Methalox
__33591 kg unused fuels
__47342 kg fuels tank
__23854 kg structure of all kind
__20000 kg Engines (20) and thrust structure
____200 kg Flight electronic and electric
___7680 kg adapter to second stage
__21513 kg recovery and landing system (parachute airbags)
_154171 kg total empty mass of first stage

Mass brake down second stage

613000 kg Methalox
__9195 kg unused fuels
__9935 kg Fuels tanks
__5006 kg structure of all kind
__8862 kg Engines (3) and thrust structure
__2000 kg Flight electronic and electric
__1950 kg adapter to payload of 65000 kg
_13670 kg recovery and landing system (heat shield parachute airbags)
_50618 kg total empty mass of second stage

_65000 kg Payload