Project Prometheus - RSS/RO Lunar Direct Ascent

[celem]

This is my first RSS game, what follows is the story of my first visit to another body.

Ferram Aerospace Research - 0.14.6

Kerbal Engineer Redux 1.0 - 1.0.15.2

Kerbal Joint Reinforcement - 3.1.1

KSP-AVC Plugin - 1.1.5

Procedural Parts - 1.0.2

RCS Build Aid - 0.6.1

RealChute - 1.2.6.3

RealismOverhaul - 7.0.7

RealSolarSystem - 8.5

SCANsat - 1.1

StageRecovery - 1.5.3

TestFlight - 1.2.1

TextureReplacer - 2.2.5

Kerbal Alarm Clock - 3.2.3

Transfer Window Planner - 1.2.3

The space program was still in its early stages when the frequent gossip became reality and the word came down from above that it was time to put a man on the Moon. The engineers scratched their heads, as engineers are want to do, and wandered away to their design boards...

The program had progressed swiftly through unguided sounding rockets breaching the upper layers of the atmosphere to basic 'Shotput' kerolox probes achieving orbit and retrieving data on conditions in space around Earth. Only 3 manned flights had been attempted to date, first 2 brief LEO visits during the development of the 'Hammer' line of launchers which used the LR-79/89 series of Kerolox boosters to lift a 2m RL10 Series Vacuum Engine burning Hydrolox as a second stage. The manned pods retained the AJ10-104D and a small amount of hypergolic propellent as an OMS. When these tests proved men could be placed into orbit and returned a third heavily extended Hammer launcher sent up Jebediah Armstrong who then used a large hypergolic tank to make a fly-by of the Moon (at 37Mm).

It swiftly became clear that a much larger ship would be needed to get to the Moon's surface and back again. Probes were dispatched into polar orbits to map the surface with low-res radar and transmit temperature and x-ray data. Back on Earth the scientists built bigger and bigger engines, chasing something that would lift the amounts of fuel the mission would require. By this time people were wondering when the mission would ever actually happen, so the word came down. NOW! The carefuly planned launch into lunar inclination was thrown out of the window, a random amount of extra fuel was added to attempt to compensate and the beast was rolled to the pad. Jeb, you're up...

I was planning to gather sci from orbital missions until I had the parts I wanted, but it was taking a lot of points to unlock the nodes I needed and I got impatient and just blindly hit Launch with the WIP.

Presenting Prometheus, on a voyage to return the fire he stole from the gods.

Pad Weight: 3,145.82 t

Atmos dV: 11,073

Vac dV: 18,314

Cost: 366,336 Kredits (Recoverable: 236,000)

1st Stage: 10m F-1A Series (Saturn-V style) Kerolox 2mins 17secs

2nd Stage: 5.5m F-1A/B Kerolox 2mins 39secs, Vacuum Tuned SRB-assist 36secs

3rd Stage: 4x J-2S Hydrolox 4mins 3secs, HTP RCS system

Landing Stage: 4m AJ10-137 Aerozine50/NTO 14mins 29 secs, HTP RCS system

Blastoff!

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The massive engine lifts brave Jeb up out of the thickest part of the atmosphere and falls away shortly before true vacuum to be recovered. It comprises almost 2/3 of the cost of the mission even when dry and will splash down at 5ms 100km downrange.

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The single F-1 nozzle takes over the ascent assisted by the 4 Solid rockets as soon as the craft leaves the atmosphere. They burn rapidly to cover thrust deficit while the F-1 empties its tank before falling away to also be recovered. Finally the Kerolox stages finish entirely with 275km apogee and the F-2S cluster takes over. The final F-1 nozzle is lost as it burns up on re-entry.

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The F-2S cluster makes the Lunar Injection at the ascending node, Mission control hasn't come up with anything pretty, its an overshoot and encounter well after apogee, but its an intercept. By the time the encounter comes up it's realised that the closest approach is much worse than thought. The hydrolox stage runs out before Lunar orbit is closed and is dropped on an escape trajectory out of Earth orbit into the Solar sphere of influence, the Landing Stage is prepped for ignition.

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The Landing Stage closes Lunar orbit and moves lower before de-orbiting. The landing burn is long, very long. Jeb sits with his nose about 8 degrees above surface retrograde and manages to scrub horizontal velocity at about a kilometer above the ground. Final descent is somewhat tense, the AJ10 doesnt throttle and landing is a series of freefall/hovers at 100, 50 and then 5 metres. One small step for Jeb...

With the flags and photos done he grabs a little scientific data and eyes the dV. Looks very short, not too thrilled. Blast off directly into an Earth return trajectory and remember the moment the legs leave the ground that they were designed to drop. Bingo, theres the dV we needed. The return voyage was fairly uneventful, a few course corrections under RCS to hit a 75km perigee which led to a smooth aerobrake and re-entry somewhere in the ocean off Indonesia.

Made sure to spend the science I got on landing engines and legs. Got a nice range of deep-throttling hypergolics now. Landing without a throttle sucked. Most of the parts used are RP-O/RO. The particular AJ10 variant used isnt rp-0 however. The legs are scaled stock since I also lacked any legs whatsoever. Next up for my program is probably some long-range probes and an LEO station.

Edited March 10, 2015 by celem