Luna 2: The Quest for Kethane

Luna 2: Doin' it Right.

 So, way back during the first Heinlein mission, you might recall me vaguely mentioning having brought along a probe named Luna in the nosecone of the craft.

Now, Luna was constructed using parts from the fairly popular Kethane mod for Kerbal Space Program, an add-on that adds resource gathering gameplay to the game, allowing you to essentially create fuel in-situ in a properly designed craft.

The Luna probe, with its clumsily slow Ion drive and not enough power to really run it, wasn't all that helpful in finding the kethane from orbit, since its orbit wasn't very efficient. If you want to scan the whole surface of a body, orbit it pole-to-pole. As it rotates underneath you, your flight path moves across the surface, and after a number of revolutions you'll have pretty well mapped the whole thing.

Barbara on the Richeleau Heavy

Heinlein II: The Jeb-Squared Law

Rebels without a Clue

 When last we left our intrepid crew of Bertred, Dunmore, and Huddrin Kerman on the surface of the Mun, their Heinlein I landing vehicle had toppled over under the force of a gratuitously fast landing combined with an impractically top-heavy landing stage design. Stranded on the Mun with no help of repairing their broken, battered spacecraft, there can be no other help for these heroes than for the brave astronauts that follow them to be their saviours - even when they themselves failed the task!

The Heinlein Mission to the Mun

The 83-m Heinlein System

 Pretty much anyone who was born before me and who had an enjoyment of Science Fiction is going to recall an author by the name of Richard A. Heinlein, who in his heighday was one of the most revolutionary writers in the field, and from whom we derive the fantastic spacer adage "Once you're in orbit you're halfway to anywhere."

What Heinlein meant by this is that the single most onerous task in space travel in terms of the fuel required is breaking into orbit around a planet - such as what we do on almost every single flight, breaking orbit of Kerbin. The "burn" for this maneuver requires a delta-v of 4550 m/s, which can be quite a bit to squeeze out and is usually the largest burn on any mission.

Third boosting stage.

Heinlein favoured the moon in his writings, and I thought that today, instead of more fiddling with sattellites, it might be fun to launch a mission to the Mun. Credit being where it was do, Toddicus decided the name of the ship for me, and all this preamble about Heinlein has very little to do with anything related.

The rocket ascended rather well, powered by four titanic solid rocket boosters and two seprate liquid-fuelled rocket boost stages. In fact, thanks to having sat done to do the math beforehand, the initial maneuvering went very quickly.

 Getting a capture window I actually liked took a bit longer. I had the bare minimum amounts of delta-v required for the mission, mostly because the ship's double-payload was probably a bit over-ambitiously heavy, and I didn't want to resort to asperagus staging to get the damn thing into orbit if I could absolutely avoid it.

One you have a window though, it's as simple as pointing the rocket onto the maneuver prograde node and burning when it tells you to. Getting to the Mun is not really an achievement compared to some of the further-out missions.

Coasting in the void, farings deployed.

Sunrise and Farewell.

Why two payloads? The short answer was that I could. The longer answer is in parts - I'd never delivered a two-part payload to the Mun before and I wanted to see if it could be done at all - it can. I also have ambitions for the moon in keeping with Heinlein, namely the production of fuel from Kethane, because shipping that fuel from the moon to a low kerbin orbit would still be cheaper than flying it up from the surface of the planet itself. Physics hates space travel.

Luna spreads her wings ahead of Heinlein

So, the second part of the payload is actually a sattelite the astronauts are going to dump into Low Munar Orbit once they get there, ideally at about 14 KM. Now, this is a bit low for groundscan, but the sattelite itself has no propulsion system of any real utility, so I had to circularize the lander and the satellite in one shot. A future mission may be planned to push the process a bit further, if I can't make some adjustments with what little fuel the probe itself has.

So, with solar collectors unfurled and the burn complete, there was little to do other than to time accelerate and coast onward, but not without first taking some pretty pictures.

In orbit of Mun, post-separation

Very unfortunately, the taking of pretty pictures did not extend so far as watching the separation of Luna and Heinlein proper, since I wasn't expecting the sheer force that my decoupler was going to impart upon the satellite. I'm reasonably certain that the faring base has a decoupler pre-installed, which might save some effort on future flights.

I was actually pleasantly surprised that we made it to the moon with as much fuel as we did. I was always planning to kill the velocity on the landing stage with the same stage I used for the transfer and capture burns, but I wound up with something on the order of a third of a tank - the equivalent of a couple hundred extra meters per second of delta-v.

De-Orbit Burn, as scheduled.

What followed later was the usual space travel trope - a good ten minutes of boredom followed by a moment of sheer terror for the crew and a proper laugh for me, here related in the form of a proper story.

"Luna is away." Danburry, the Payload specialist, commented dryly for the benefit of the flight data recorder. "TLM is all good. Solar cells to full power, streaming kethane sensor data to KSC via Athos."

Inches from the surface

Flight Commander Hilbert Kerman nodded slightly, sucking a bit of overly-dry air through his helmet filters. "Roger. Rotate through one-eight-zero yaw... complete. De-orbit burn in three, two, one..."

Well, now what?

The de-orbit burn went smoothly - taken a bit longer than originally planned. Working purely on the fly, Hilbert had calculated that the remaining fuel on board was simply going to be too heavy, and would cause the landing legs to collapse under the force of the impact at the projected landing speed.

"Moving sideways a little faster than I would like," he muttered. There was only so much he could angle sideways while burning - the landing stage only had one thruster! Still, the overall surface speed was well within the calculated tolerances of the landing legs. 100m to go, then 50, then 25...

It suddenly hit home that Hilbert was to be the first kerbal to ever walk upon the Mun. He grip the steering mechanisms with a bit more anticipation than a moment ago, cutting out the fuel feed to the landing stage rocket motor.

There was a horrendous crash and a bang, a great roar of rent metal, and the whole ship was suddenly going ass over teakettle as the rocket nozzle dragged across the ground, tearing it from the ship which landed sideways with a vast impact.

Hilbert laughed a moment later, once a very agitated Samdred Kerman got done checking through his life systems. "They send up a ship with no damn ground clearance and we hit the one rock on the whole Mun!"

Now, there is some good news in this whole process. As near as I can tell the return stage and crew capsule weren't actually damaged, and I happen to be on a bit of an incline. I think there's enough torque in the system that I could potentially take off on an angle... with a perfect transfer orbit and generous aerobreaking on kerbin, there's no reason it wouldn't work.

We might try that next time, since they have no way of calling for a rescue mission.

Project ASARTES, Part 2: Conclusion, or, "Stationary".

Maneuver nodes take the guesswork out. Sorta.

 So, when we left off, we had an elliptical and highly eccentric orbit courtesy of my sloppy insertion burn. The first thing I did was say "Okay, Let's Circularize!".

Easiest way to make any change to orbit in the vanilla GUI is to use maneuver nodes. Since I haven't quite caved in to using MechJeb yet, I grabbed a node at apoapsis and plotted out the yellow orbit in the image on the left.

Then, I accidentally clicked space, giving us the present situation you see in the image, where my maneuver isn't actually on orbit. Whoops. I then time accellerated to get up there, whipped myself around so fast the probe batteries died, and had to reload the save. Hah.

Aramis under sail - Richeleu is "falling" away.

After about ten minutes of Ion Drive. Middle line is a debris.

Service Established!

 Oh well. Such things as these happened. What isn't shown is the three attempts of me playing with different orbit plans until I got the ship in a workable position, or the separation of Aramis from the carrier vehicle.

Once we got up there, though, I had the foresight to grab an image of Aramis burning under its nifty ionic engine - this thing takes some high voltage and uses it to accelerate Xenon ions at high speed. This I like, because the fuel lasts virtually forever, affording tons of Delta-V to the person willing to wait long enough for it to add up.

It was at around that point that I realized Richeleau wasn't going to de-orbit the way it is meant to. However, because I could EASILY have used more ion drive and less chemical rocket in the orbit, I reasoned it wasn't that unreasonable to imagine I had done so, and manually truncated it from the control center.

Space after we "correct" Richeleau

After another twenty minutes of play (comprising about a full day of Kerbin time), I more or-less circularized in KEO. I say more or less because it's not perfect... it is, however, close enough for our purposes, within about 10 km altitude on either side. As long as the ships themselves are properly in phase, it won't really matter anyway - one will always be in view of ground control.

So, for purely roleplaying purposes that have no point since SAS doesn't apply once you leave the perspective of the ship, I pointed Aramis at Kerbin and popped the antenna.

Then, off we went to the space centre to trim out the things that aren't meant to be in orbit.

The final orbit wouldn't naturally degrade. Woops.

Which brings me to the next problem I had. KEO isn't really exciting to shoot. I mean it was fun to do - way more fun than my usual attempts to just get to orbit with way too much kit. I won't be showing the other launches. It's just too tedious. To be honest, I'm going to cheat them into place using the in-game debug menu, and put them into place with the much faster chemical rockets. I know it's a little silly, but I don't want to spend another hour getting them all aligned correctly.

Next: What exactly did we need our own TDRS system for, anyway?

Project ASARTES: Kerbin Orbit Communications Network, Part 1

D'Artagnan, the ASARTES prototype. Differs from
Launch Version.

 So, yesterday some of you would have seen me doing commentary on the TDRS-L launch. TDRS is the NASA-administrated system of communications satellites that help ensure around-the-clock space-to-ground communications, which is pretty important if you find yourself in space, or if you're trying to do any sort of orbital research.

Kerbal Space Program has an equivalent to the orbits that TDRS occupies, called KEO, which is a Kerbin-stationary Equatorial Orbit, at a height of about 2.7 million metres. I've never really done any KEO projects for a number of reasons, so I thought, for giggles, a good first set of missions for the publicized version of the Zaxton Space Program would be establishing our own, much less populated, version of TDRS, which I am calling ASARTES.

We call this launch vehicle the Richeleau

 So, I designed a small satellite with lots of communications gear, and we're going to strap it onto a launch platform and put it in orbit. At present, there's no real point to this. My current modset doesn't bother calculating range or alignment for radio systems, so there's no "good" reason to do this, except that it's cool.

There were a few false starts with the same basic launch rocket design, owing to a few problems with aerodynamics and some other things I didn't fully understand. We eventually got around that by reducing the number of Solid Rocket Boosters attached to the Richeleau from 4 to 3. When there were four boosters, the vessel was prone to spinning.

If you haven't played KSP yet, or played around with KV Rocketry mod, I recommend it. There's a very satisfying khawump when you touch off the solid-state boosters.

Now, this design is actually well-balanced... it accelerates at just about the right speed, initially, that it is always just about at the terminal velocity for that altitude, under SSB power. I highly recommend giving thought to such designs as these. The lifting body of the rocket has its own probe core, in addition to that on the satellite, which is going to allow me to control it after the probe seperates, meaning I can de-orbit it and keep my space nice and clean.

 My only complaint about the boosters I used is that their lifespan seemed a bit limited, and I spent more time than I would have liked burning vertically against gravity on the main engines, before I got to the 10km altitude at which I like to do my gravity turns. In the future I might use larger SRBS.

Shown on the right is the moment of SRB-Sep, and you can see the main engine kick in. This engine is from KV rocketry. It's less powerful than I am comfortable with, but very fuel efficient, and actually does make a good main "boost" stage for a rocket of this size.

 This photo is a little less clear - I couldn't hit F1 fast enough to get a good screen capture of the moment of seperation between stages. The engine on the Orbital Stage pretty much tore me out of the first stage faster than the decoupler could push me.

I was pretty nervous at this point. I was hoping to make orbit, or at least a 70km apoapsis, on the first stage. I didn't show the map here, but I'd only done about half that by the time I flamed out from lack of fuel.

Aramis takes his first look at the stars.

I also screwed this up, too, and wasted a bit of fuel lugging around the mass of this faring. Basically, you want to blow the faring the instant you're out of atmosphere - once you don't have to worry about aerodynamics, it's just extra mass to waste thrust on.

I'm very happy with the way that KV Rocketry models farings and peels them away. This faring actually had four segments - a modification to the probe made it artificially taller than I thought it would be, which was another modification from previous designs. Not strictly a problem, but I broke a few spacecraft design rules with it, and we'll see if that was worth the effort.

Unfortunately, I actually have to pack house today, so I didn't go much further than this yet. I'd started the launch to see if the rocket even worked, and once I got it into a semistable orbit, I thought it would be a good time to take a break.

I quicksaved here and closed the application, concerned about that low periapsis, which would de-orbit me, but I didn't feel it prudent to wait the half-hour (or time accellerate) to get arouind the other side of the planet and boost it. This could work in my favour, though. I was thinking I would barely make low orbit (70km) on the launch vehicle, and I'm still on the second stage of it.

The plan moving forward will be to milk all the delta-V I can out of what's left of the chemical rocket, then proceed on the satellite's own thrust system. I have no doubt we will get to KEO in short order.