Month: June 2014
Sure you can build big rockets and send them to exciting places but can’t you also do the same with pocket-sized rockets? Probably not but you can do it with rockets that use only ‘tiny’ sized parts!
I’ll be doing three tiny missions, one into orbit, one to land on the Mun and one to land and return from the Mun. Stock tiny parts in KSP are pretty limited, they’re only really intended to push around little probes and such in vacuum, not for the launches themselves. There’s only one real fuel tank to use and that’s the Oscar-B. There’s a few more choices for engines but essentially my designs are limited in scope with stock parts. I’ve enjoyed used them before in my Icarus mission and have wanted to try them again ever since.
Anyway, here are my missions;
My orbiter has three stages, all of which consist of varying sized stacks of oscar-B tanks with tiny engines. There’s a gap at the top stage because the super-lightweight LV-1 liquid fuel engine (Only 30kg!) doesn’t seem to like being attached to decouplers properly.
The rocket blasted off from the pad. The main problem with tiny parts is that the tanks themselves carry quite a chunk of weight when empty. Because you have to use so many of them it adds up once a stage nears it’s endpoint. This means that, unlike in medium or large rockets, when the stage is down to around 1/4 fuel, thrust:weight ratio isn’t massively better than it is when full, making the rockets less efficient.
Still, this rocket did it’s job and shoved the final stage into space.
The LV-1 engine puts out a pathetic 4 thrust (compare that with 3200 for the KS-25×4 Engine Cluster!) but the little probe is so light that this is more than enough to achieve a nice orbit.
There was even enough fuel left over to de-orbit and do a powered landing on Kerbin
Next stop, Mun.
Micro Mun lander
Since the orbiter managed it’s mission with fuel to spare, I figured the design I have already was on it’s way to be enough for a Mun landing. So instead of a redesign, I simply added fuel to each stage of the rocket. This was safe to do as each stage had plenty of thrust to keep it moving. Landing struts were added to the top stage and the lander was ready to go.
The rocket made it to orbit with almost all of the final stage’s fuel intact.
Despite the very low weight of the final stage, most of the fuel was used up by the time an orbit was established around the Mun. I feared the worst but pressed on in the hope that what little remained would be enough to slow the little probe down for a landing.
As altitude dropped, I realised I wasn’t going to make it and sure enough the probe hit the Munar surface at around 50m/s with no fuel remaining. But it didn’t explode…
The probe was so light that, despite my expectations, the flimsy landing legs survived the crash. The probe bounced and travelled to the bottom of the crater before bouncing again. By the third impact it was travelling slowly enough that it could right itself and land! I guess by this point it was so light (0.18T) that the legs could take the strain.
So I now have a newfound respect for the LT-5 micro landing struts!
The Mun landing was an unexpected success and the Kerbals gathered their wits for the final tiny mission, to land a probe on the Mun and return it.
Micro Mun landing and return
This was going to be slightly trickier design-wise. I couldn’t simply add more fuel to the stages as the engines wouldn’t be able to handle the extra weight. So I needed an extra booster stage. Initially when I tried to attach Oscar-B’s to a radial decoupler, they refused to attach. The same thing happened when I tried to use girders attached to the decouplers, the Oscar-B’s simply wouldn’t latch on.
The only small part I found that would allow radial attachment was the M-Beam 650 I-Beam. I have no idea why this worked when nothing else did but oscar-B’s could be attached to the underside of these.
The only other conundrum I faced was whether or not to fit a parachute. The smallest parachute available would have done the job, however, at 0.1T, this would have been a very significant addition to the weight of the lander. In the end, I decided to try a powered landing instead.
With it’s new booster stage taking it above 7000m, the rest of the rocket was able to achieve orbit around the Mun with the final stage still full of fuel.
There was still (hopefully) plenty of fuel left to return to Kerbin (around 3/4).
By the time Kerbin’s atmosphere was reached, only 2 units of liquid fuel remained. This proved to be just barely enough for a powered landing in Kerbin’s oceans
Jeb looked at all this nonsense with ant size rockets that seem to propell ditty little probes with the power of wet farts and scoffed. “I bet it couldn’t handle a Kerbal” he said in his smuggest astro-celeb voice.
The rocket scientists of course took offence to this and decided to prove him wrong by sending one of their own to Minimus and back with a micro rocket.
There’s only one way to keep the payload light enough for these engines and thats with a frikkin space-chair. Now even Kerbals know that it’s just not safe to go into space on a chair but they found a volunteer who was unlikely to return. Lets call him…. Ensign Startrek (the Kerbals don’t yet have red jumpsuits but just imagine one).
Here he goes…
After strapping himself in that alarmingly named external chair, Ensign waves farewell to the KSC crew and gives the finger to Jeb.
The engines fire…
Luckily, Ensign is pretty badass and not generally afraid of heights. But this takes the biscuit. If anyone has ever been on this type of ride you’ll know sort of how he feels (it wobbled around a lot too during early flight)
Eventually however, he pulled himself together and got down to the business of spaceflight.
His fears behind him for now, Ensign approaches Minimus.
Thrilled with his achievement, Ensign calls Jeb back on Kerbin and says I told you so.
After some obligatory low gravity arsing around, Ensign re-boards his craft and returns to Kerbin.
As he approaches Kerbin he begins to contemplate why on earth external chairs aren’t used more often in space programs, they’re so light after all!
It’s about this point that he notices Kerbin’s atmosphere.
Ensign had had a blast on his mission so far. Alas, all good things must come to an end.
Miraculously, Ensign survived the brutal trauma of re-entry. He was going to make it!!!!
Unfortunately, from the word go, the micro craft had an unforseen design flaw. It was designed to make a powered landing using the fuel left in the tank. Unfortunately, the tiny parts don’t hold enough fuel in them to make the craft bottom heavy. In fact the heaviest remaining part of the rocket was Ensign himself. So naturally, he ended up this this.
With no RCS or parachute, Ensign was, unfortunately, doomed.
So was this mission a failure? As the smoke from the landing site clears the wreckage remains.
Although brave Ensign gave his life for this programme, he did prove one thing. You CAN use tiny parts to get Kerbals into space.
Just not back down again.
After the Kerbals sent a set of probes to Jool, they couldn’t wait to get a closer look at Laythe. With it’s blue oceans and abundant Kerbal-babes it seemed an ideal location to send the intrepid Jeb, greenest of all Kerbals. So it was that he was strapped to yet another tubular wad of explosives and sent back into space.
(For once, nothing went wrong in this mission. It’s relatively straightforward and so this entry is mainly picture based.)
Flight 15: Laythe landing
Laythe has it’s own atmosphere and a decent gravity well. It therefore required a reasonably large lander to get Jeb back home safely. The weight of the lander combined with the distance to the Jool system meant that a large ship was needed to get the job done. This is that ship:
It consists of SLS parts to reach orbit, a rockomax-sized interplanetary stage and finally the lander itself.
A burn was set for Jool and the lander arrived without a hitch.
Luckily, I wasn’t aiming for a slingshot from Jool, I just wanted to stop in it’s neighbourhood. So, once inside Jool’s SOI, I burned again, aiming to pass it at 110km above the ‘surface’. This is inside the atmosphere, allowing my ship to bleed off it’s huge interplanetary speeds and establish an orbit around Jool.
Another quick burn and another aerobrake put Jeb in orbit around Laythe.
The lander was detached and Jeb aimed for one of the small continents dotted around Laythe’s huge oceans.
Jeb puts her down on one of the many sandy hills covering this continent.
From his angle, Jeb reckons he’s pretty close to the water. Since the eggheads back home say there’s at least a 62% chance that Laythe’s oceans are safe. So, he decides to pop down for a paddle.
Jeb was a bit disappointed that no green babes were spotted on this trip but to be honest he had always suspected those images were photoshopped. Probably boffin propoganda to get more Kerbals into space exploration, as it they need a reason!
So now Jeb has travelled to Laythe. He doesn’t know where he will go next but he’s damn sure it won’t be anywhere as blue as Jool’s marble.
Jool is an interesting planet in KSP. Based on Jupiter, it is a gas giant with several moons. One of them; Laythe, has oxygen, liquid water and an atmosphere similar to that of Kerbin (but thinner). The other moons I know little about at this point, I’ve tried to avoid ‘spoilers’ about what they’re like. I do know that there are 5 moons in total and that Laythe is the only one to have an atmosphere. I want to send manned missions to the area but knowing so little about Jool it seemed the right and space-programmy thing to do would be to send out some probes to study the planet and its moons first before sending hapless Kerbals.
I could have done 6 different missions but why do that when it would be more fun to try and do it all at once in one giant probe-a-thon!?
This will be a ‘high risk mission’. Basically that means that I have no idea what I’m doing. I haven’t tried something like this before and know very little about Jool so I expect at least some fails. But my main aim is to learn about Jool so hopefully my failures will teach me as much as the sucesses!
Flight 14 – Jool Probe-A-Thon
After designing a ship to carry all 6 probes (one for Jool and one for each moon), I plopped it on the launchpad for a final check-up.
The probes themselves are simple affairs, they are not meant to return to orbit so they only need enough equipment to succesfully land on the Jool bodies. They are all identical (so that the craft is balanced) with the exception of one that is destined for Laythe and so has it’s own parachutes. Other than that they consist of a small fuel tank, an engine, some scientific instruments, a solar panel and a probe body. They also had three landing legs which didn’t work out so well! But more on that later. The mid-stage that will take them to Jool is based on my standard interplanetary design, modified to be able to carry all the probes. The launcher was all SLS parts as the whole ship needs a lot of fuel and is a heavy beast!
After checking that all the stages made sense and Laythe parachutes weren’t going to deploy as I lifted off from Kerbin, the craft set off.
On reaching the Jool system the first thing to do is perform an aerobrake around Jool. This is one of the main advantages of visiting Jool, establishing an orbit with other planets is often a fuel hungry business but using Jool’s atmosphere to slow down to more sane speeds saves a lot of that fuel. Looks cool too.
Once in orbit around Jool, the craft adjusted itself to be ready to release it’s first two probes. The probes were released in pairs to keep the main ship balanced. So the first two to go were those destined for Jool and Laythe (the innermost moon). Neither of these would require much fuel (The Jool probe would simply be falling to it’s death and the Laythe probe would use it’s parachutes to land) so around 3/4 of their fuel was transferred to the main stage. Of course I could have just included less fuel from Kerbin launch but…. I didn’t think of it back then so…. shush.
Jool is a gas giant so this probe wouldn’t be landing as such. Much like my sun mission, this probe was meant to simply descend as far as it could while sending back information to the Kerbals back home.
Jool looks very good (especially with the visual enchancements mod) and I managed to catch the greenest sunset I’ve ever seen whilst descending.
The atmosphere is crazy thick, at 5000m the probe was freefalling at a mere 50m/s!
After the probe was inevitably crushed in the Joolian atmosphere (At 300m on the altimeter), it was time to move on to the next probe.
The Laythe probe probably had the easiest job of all the probes. I intended it to parachute through the atmosphere for a nice splash down in one of the oceans that dominate Laythe. All that was needed was to burn a bit of fuel to point it on a collision course…
From orbit, the probe spotted bits and pieces of landed dotted around that would make great landing sites for future Kerballed missions.
It also noticed that nights on Laythe looked awesome.
Back at home Jeb is very happy. His last interplanetary trip to Dres left him a bit disgruntled. He worried that all the other solar system bodies would be as gray and boring but after seeing the amazing colours of Jool and Laythe he couldn’t wait to get out here! He expected that the other moons would be equally as…colourific. He was incorrect.
The main stage left near-Jool orbit and aimed for an orbit in between it’s next two targets; Vall and Tylo.
Vall looked pretty small from orbit and sure enough only a small amount of fuel was needed to get into orbit and start a burn for the surface. The probe had almost a full tank available for a powered landing and Vall’s gravity wasn’t pulling it down too vigorously.
It was only after landing on Vall that I noticed a major flaw in my probe design. The landing legs which had looked like a good tripod formation from the Kerbin launchpad were in fact…. lopsided. They couldn’t keep the probe upright and I realised I was going to have the same problem in all my probe landings. Oops! Oh well, a bit late to send an extra leg or two from Kerbin, they would just have to rest on their sides. It didn’t look good but the legs were enough to cushion the impact so the probes could at least serve their function of giving me practise landing on and information about Jool’s moons.
The probe landed with about 1/4 of it’s fuel still left, as long as the remaining moons weren’t too much more massive there should be no problems.
Next up… Tylo.
Hard to tell from this angle but…. Tylo does indeed look significantly more massive. Uh oh 😦
Sure enough no matter how hard I tried I couldn’t seem to get the probe to land. Establishing an orbit itself took quite a chunk of fuel and little guy simply didn’t have enough left over to land on Tylo. The gravity was high enough that my LV-909 engine barely had enough thrust to fight it. It couldn’t operate at full blast for long and so inevitably, the probe disappeared and became part of the dust of Tylo. Weirdly, the GRAVMAX did report that Tylo had ‘lower gravity than expected’. How much frikkin gravity were they expecting!
Well, that didn’t go well but at least I learnt a thing or two about Tylo and no Kerbals had to die to do it!
The main stage powers to it’s next orbit, between Bop and Pol.
Pol is the outermost of Jool’s moons and turned out to be a bit weird. Landing wasn’t too difficult and turned out to be about the same as on Vall. Plenty of fuel was left over. The surface of Pol wasn’t colourful… but it was interesting.
The ground was covered in spiky rocks. There was no atmosphere so I have no idea how such things would have been formed. Pol might be an interesting place to explore with a rover. Unfortnately I couldn’t keep an eye on it using the probe. The probe landed without issues. I had some science equipment strapped to it but not enough solar panels to run the antenna constantly so I used time dilation to speed up the transmission of data back to Kerbin. Unfortunately, as soon as I returned to normal time the probe violently detonated!
Only the probe body and a landing leg survived the blast but of course with no rocket they didn’t survive the fall back down to Pol’ surface. So I had lost my eyes on Pol but no matter, at least I had landed on it!
Bop was the final destination for the probe-a-thon and represented an unusual challenge. The problem is summarised in these two pics:
All of Jool moons are on pretty much the same plane. Except for Bop. It’s the ‘special’ moon of the family and isn’t anywhere near being on the same plane as the others. The probe has a small supply of it’s own fuel but I was worried that the chunk of fuel needed to correct it’s inclination wasn’t going to leave enough left for a landing (especially after my experience with Tylo). Luckily, the interplanetary stage still had a little fuel left. I used this to correct the inclination while carrying the last remaining probe. Unfortunately, only having one probe made the ship horribly unbalanced and a lot of RSS fuel and gentle thrusting (eww) was needed to keep it pointed in the right direction. Eventually though, the inclination matched that of Bop and the final probe was released as the main stage gave up the last of it’s fuel.
Bop has to be the most lumpy thing in space. I mean just look at this:
Despite how weird it looked from space, Bop wasn’t much to look at from the ground.
Still, perhaps one day some enterprising space-racer will set up an awesome dirtbike course and make use of dem epic rampz. Until then though…
So that’s it! All the bodies of Jool visited with varying degrees of success. I like that in KSP even failures make you feel like you’ve achieved something. I could have found much of this information on forums and wikis but nothing beats learning for yourself what the different moons are like and what would be involved in future missions to them.
Already Jeb is preparing for his triumphant return to a colourful destination!
I love what SpaceX is trying to do, Elon Musk seems like the best chance humans have of expanding horizons into space. Currently, he is moving towards taking low earth orbit tasks from NASA so that they can concentrate on more ambitious missions such as the Orion Programme. To that end, he has developed Falcon launch vehicles that can take payloads into orbit and has already resupplied the ISS using SpaceX craft (the first commercial entity to do so). Future plans involve a manned space presence in the Dragon space capsules. SpaceX also aims to reduce the cost of space flight by making their craft as re-useable as possible and landing their ‘used’ craft and rockets back at their space centre, rather than landing/splashing them in faraway locations which requires expensive and time consuming recovery and retrofitting. Rather than use parachutes, SpaceX uses a rocket’s own power to bring it down to a precise location, with parachutes only being used as an emergency failsafe.
Anyway, I wanted to emulate this in KSP and thanks to the glorious modding community I can! I’m using the SpaceX launch pack by LazTek for these missions. This provides all the parts needed for a SpaceX mission and is damned impressive at copying their look and function.
Flight 12 – Re-useable rockets
SpaceX uses a rocket’s own engines to land each stage after it is used as shown in this video. So the first thing to do seemed to be to try that myself!
There was no way I was going to do this with a full tank (I did try, the landing legs couldn’t take the weight!) and thats not the way it’s designed to work, it should be coming down on fumes. So I started out with an almost-empty tank on the launch pad.
I powered the rocket up to 1000m (the same as in SpaceX’s real test) then cut the engines down to minimal thrust.
The rocket started to descend under the lower thrust. Actually the rocket was so light and had so many engines that the main problem was finding a balance between cutting the engines entirely and having them push the rocket back up!
A bit of vectoring was needed near the launch pad to guide the rocket back onto the flat centre of the pad.
But eventually (after three or four tries!) the rocket landed smack onto the launch pad. The rocket can now be quickly refueled and ready to fly again in no time!
Flight 12 – KSS resupply
SpaceX has already made a few supply runs to the ISS and plans to do more with astronaughts on board. In this mission, I want to copy this type of mission: Awesome SpaceX animation
I have a space station already in orbit around Kerbin so my mission will be to dock a dragon capsule to it and return to the KSC.
The falcon is a sleek and simple-looking beast. The payload (in this case a dragon1 capsule) is protected by the casing on top of the rocket.
Once the first stage clears the atmosphere, it detaches and begins it’s fall back to Kerbin. I couldn’t do the landing myself as this would have meant abandoning the rest of the craft and risking it disappearing as the physics machine monster ate it up. However, I imagine that some boffin back on the ground sucessfully piloted it back safely, I left him some fuel at least!
The second stage powers the capsule into a steady orbit and aims for the KSS (which orbits at 500km)
The Capsule uses rcs fuel to move itself towards the station and dock.
Imaginary crews were swapped and historic pictures were taken including this one which I must say is the most realistic screenshot I’ve ever taken.
After their docking, the 7 Kerbals waste no time in returning to the KSC.
The capsule itself contains draco engines that use monopropellant but are much more powerful than rcs thrusters. They are used to de-orbit the capsule and make it head towards the KSC.
This version of dragon capsule was designed for a soft splashdown (as opposed to the V2 capsule used in the next flight) so parachutes and draco engines are used to guide it to the water just outside the KSC.
The Kerbals then have a short swim and a quick walk down the beach to get home. Might not be that pleasant in full space-suits but still.
The re-fitted rockets are prepared for their next mission…
Flight 13 – Musk to the Mun
SpaceX eventually plans to go to Mars and may well take people to the Moon as a stepping stone towards that goal. Their Falcon Heavy rocket is able to carry the biggest loads into space since the Saturn V’s that NASA used to land on the Moon so in theory might be able to attempt such a mission. Falcon heavy’s can be made in LazTek’s mod but they are overkill for a Mun landing in KSP! Instead I’ll be using a regular falcon rocket with a V2 capsule attached. This is the newest version if the dragon capsule unveiled in may 2014 by SpaceX. It is designed to carry 7 crew and perform powered landings without the need for a parachute.
Here’s my attempt at what a SpaceX Mun landing would look like…
The draco engines are able to steer the dragon capsule to a good spot and give it a soft landing. All 7 Kerbals are able to get out (easily the most I’ve ever landed at a time!) for a big ole group selfie.
Melburry Kerman (thats the one at the back there obviously, not all Kerbals look the same you racist!) Wasn’t happy that his face wasn’t really visible in this pic so decided to be more prominent in the second picture.
All the other Kerbals of course simply stared ahead with their creepy, happy smiles.
After a blast off from the Mun, the Kerbals aimed their craft back to the KSC.
Using the draco engines to get the capsule straight to the launchpad was….fiddly. Like, unbeleivable fiddly. This was compounded by the fact that there was very little fuel left after returning from the Mun. However, many many tries later, I managed a powered landing back on the launcpad.
I can’t wait until this happens in real life. Musk already has some of the re-useable rockets, the contracts to supply the ISS and of course the cool blue lights. I hope one day he can take all that to Mars!