MaxL_1023

I didn't think returning was planned - usually you want to send a probe lander or two before trying for a return mission. If you want to return, Ike is somewhat easier than Duna. Gilly is a good idea as well if you are confident with rendezvous - the gravity is almost nil so you can land and take off using RCS thrusters.

Assuming you can get to Mun and Minmus, Eve is probably the easiest planet to get to. It has a strong gravity field, so you don't need as much delta-v or transfer precision to be able to make orbit. It also has a thick atmosphere, so assuming you have a heatshield you can re-enter and land on parachutes. Duna usually needs some rocket assist to land safely, and has Ike orbiting which can throw off your approach if you are not careful.

If you have a strong RCS system or a lot of torque, try pointing your pod's nose about 15 degrees above retrograde. Your pod should generate some lift during re-entry and follow a shallower profile in the lower atmosphere. If you wanted to be hilarious, put a 2.5m shield under your 1.25m pod. 4 times the surface area with less than twice the overall pod mass = twice as much deceleration.

Jeb! Why are you sitting Outside!!! Wait...shouldn't there be ONE engine??? Bob, Bill...Grab on to Something!!!

The best way I can think of to get to a retrograde orbit is to encounter jool in such a way as to pass just in front of it, getting a reverse gravity assist. Make a burn at Jool Perapsis (you will be travelling due retrograde relative to the sun) and you should be able to match the solar perapsis you need. Then, match orbits at your Kerbol PE. 3 Burns (Jool Transfer from Kerbin, Jool PE and then your orbit matching burn). Time might be an issue here however. When in doubt, strap a seat and a couple gigantors to a xenon tank and ion engine, then fly by Eve to save delta-V and kill some of your horizontal velocity. Eve can probably come close to throwing you retrograde on its own if you skim the atmosphere.

[quote name='Alshain']Not true. If you come in too shallow you will spend more time slowing down and therefore more time burning. If you come in steeper (but not too steep) you will burn hotter, but nothing the shields can't handle and less time burning. You should come in not too steep but not too shallow either because they you will not slow down fast enough. Try coming in shallow on Eve and you will not survive. Most of the time the mass of the shield is irrelevant for the parachutes. The mass of the decoupler on your fuel efficiency and it's cost is actually a bigger concern. If you are coming down with nothing but a pod on Kerbin, the nose cone parachutes appropriate to that pod are more than enough.[/QUOTE] I thought his problem wasn't burning hot, but not bleeding off enough speed before hitting the ground. A shallower angle gives your pod more time to slow down when your heatshield can take it. Maybe I am used to the RP-0 heatshields - one of those is almost as heavy as your pod.

In RSS, one of my Kerbals survived a skydive from 30km during re-entry. I was EVA trying to repack a chute which failed, and the Kerbal fell off. 30km straight down onto solid rock, and he got up and walked away.

You want the shallowest re-entry angle possible, minimizing your vertical velocity and giving the atmosphere more time to bleed off your horizontal velocity before gravity pulls you down. It has lower G-loads, but at the same time higher heat loads. If you are using a heatshield you should be fine on the heat end assuming you are not trying to do a 1-pass re-entry from escape velocity. De-coupling your heatshield once you slow below ~1000 m/s is a good idea anyways - you need a much smaller parachute to slow down and the aerodynamic force on the one you have is less for a lighter pod, meaning you can deploy it while moving somewhat faster. If you have access to something small and heavy, you can stick it on the side of your pod and try for a lifting re-entry. That also will give you more time to slow-down.

Have you tried having gimbals simply subtract a value from the TWR? The physical gimbal mechanism would scale in size with the loads it would bear, which would roughly scale with the amount of thrust the engine is producing multiplied by the available gimbal range - a 5 degree thrust shift would basically put 5 times the load on the gimbal as a 1 degree shift, using the small angle sine approximation and assuming thrust tangential to the direction of motion would need to be transmitted through the gimbal to the rocket as opposed to the pre-existing structure which transmits prograde force. Ex: Gimbal Size = 2-3% of engine weight (assuming gimbal tech scales with engine tech) * gimbal angle in degrees. A 5 degree gimbal would add between 10-15% of the engine weight, with thrust and ISP being constant. A direct trade off, as all you are really doing is adding some heavy stuff to the engine, not changing the fuel flow, combustion chamber or other infrastructure that much.

I would like to see a nuclear reactor in stock - basically all it would do is produce a set amount of power (maybe 50 ec/second) forever, but be really heavy (~20 tons?). It would be useful for very large ion probes or permanent bases which need a lot of charge, but are out near Dres/Jool/Eeloo and solar arrays are not very effective.

Hello Everyone, I am playing KSP with RO and RSS, but this applies to KSP in general. Is there a mod or calculator out there which can find gravity assist windows? I just launched a flyby mission to Neptune and needed a direct burn of over 10k delta-v to get there inside of the 15-year contract deadline. If I could have used Jupiter/Saturn or something I bet I could have shaved off 20-30% of that. Is there help for this, or do I need to make every outer-system launch with a rocket larger than the Saturn V? Thanks, Max

What engine did you use that gave you 3.6 kN of thrust? Do the 1 kNs get that high at tech level 7?

The RP-0 institutes "tech levels" to RCS thrusters and the Procedural SRBs. Essentially, if you have certain tech tree nodes researched, you can buy better performance using the same part. The upgraded part costs more (and has an unlock cost) but lets older engines stay competitive for quite a while. With actual engines, it is modeled by unlocking later real-life models. An example applied to stock: Terrier Vacuum Engine at unlock: 60 Thrust 350 ISP Terrier Mk II, unlocked at the Mainsail Tech Level 70 Thrust 355 ISP Terrier Mk III, unlocked at the Rhino Tech Level 70 Thrust 365 ISP -10% Engine Weight Sustainer like the Swivel and Skipper could gain a wider vectoring range and lighter weight, while launch stage types such as the Reliant and Mainsail would gain thrust and gain sea-level ISP. Basically, you keep the same picture models (for simplicity, maybe a decal or something gets added on) but you get your competitive high-tech engine. It would also give squad more chances for humorous part descriptions. " After a 3 day snack bender, Korolev Kerman discovered a way to stick multiple combustion stages into the same engine. He was immediately committed to the insane asylum, until tests using a reliant engine showed a significant improvement in both sea level thrust and efficiency. He was then released and hired as Kebrodyne's director of rocketry research." (References staged combustion, a real-life early improvement to rocket engines)

Aerocapture is one of the hardest maneuvers to accomplish, especially when you are often on a highly sub-optimal trajectory. It would probably be easier to try and pass by the Mun to lose some energy - a 50km flyby should be doable using just 5-10 m/s of delta-V if you apply it early enough and you could lose easily a couple hundred m/s of delta-V doing it. Most probes to Jupiter or Saturn would fly by a large moon to help with orbital insertion, and use flybys to slowly change their orbits using minimal propellant.

I am using RP-0 0.40. I was getting "in space high" when actually inside the atmosphere, as when you are on a hyperbolic trajectory it apparently does not let you collect atmospheric science. I would suggest setting in space low at ~2000 km, and for Saturn it should be anywhere inside the rings.

One thing - Titan does not have an "in space low" biome. The atmosphere starts at 600km (my probe cut it close to burning up at a PE of about 500km) and that is still in the "in space high" range. Should titans atmosphere really stretch that high?

Remember that all the velocity values in KSP are scaled down by roughly a factor of 3 (the square root of 10 to be more precise - 3.162). Kerbin is 1/10th actual size with normal gravity, so orbital velocity is only about 30% as high. Your 1500 m/s in KSP is the equivalent of ~5000 m/s, or about 2/3rds of orbital velocity. This is ICBM range speed, and they DO need heatshields to survive a ballistic re-entry. Normal planes would fail at around 1000 m/s and burn up by 1500 m/s - the SR-71 needed high heat alloys to survive the 1000 m/s range so at 1500 you would need some ablator. Also, what altitude are you flying at? That SR-71 example is at 25000m - are you trying this at 10000m where the air is over 10x denser?

Was the boiloff rate for liquid oxygen adjusted in the last update? Previously I had no boiloff with a Kerolox engine using a normal tank, now I need a cryogenic for anything later than an orbital insertion stage. Using procedural tanks, cryogenic is fairly late in the tech tree (it comes with the 5.6m diameter upgrade node I believe) - is there a way to get better insulation for the launch period in early tech? I use hypergolics for long duration flights anyways, but some kerolox engines have better performance especially early in the tech tree.

Hello, I am using RO 10.5 with RP-0 0.40. When 1.05 came out, KSP automatically updated and broke everything (obviously). I reverted to 1.04 on steam and re-installed all the mods (most of the RO and RP-0 set). However, now in any career mode the procedural stack decouplers don't work. I tried reverting to RP-0 0.39 and Procedural parts 1.16 (the last "working" configuration for me) but they are still broken. I stage them, they make the sound effect and smoke comes out, however they do not separate anything and I can't stage past them. Manually deploying them does not work either. The tt-38k radial decoupler is also broken. Is this a known issue? Should I try uninstalling KSP and reinstalling 1.04 from somewhere? Thanks, Max

Unless I am missing something, isn't this trivial? Put 2 gigantors on a probe core with some batteries and a big xenon tank and light up the ion engine. Once you are in orbit all it takes is delta-v, and ion craft have more of that than anything.

The amount of air getting to your engine is a mass flow rate, equal to the air density * intake area * effective airspeed. Simplistically, the faster you go, the higher you can get before you flame out as the higher airspeed counters some of the density dropoff. More intakes don't really help however, as the extra mass and drag slows your plane down enough that you are unlikely to get to the high-speed optimal thrust zone to begin with. I recommend going with a single circular intake on your nose like the F-86 Sabre, or perhaps a ram intake on each side if you plan to try for supersonic flight. The performance of the intakes change with air speed due to effects which are complex - mainly remember that at supersonic speeds everything gets messed up relative to "low and slow". The ramjet engine can get you to well over 1000 m/s and an apoapsis above 50 km if you time a ballistic climb to pass through your max-TWR velocity/altitude. This is basically halfway to orbit, and high enough to use a vacuum engine like a Terrier without losing too much efficiency.

Try setting it so that your Apoapsis is about 90 degrees ahead of the Mun's current position, then slide it around from there. When you get a trajectory which will encounter the Mun (you see a circular symbol on your projected path, then a color change and probably another "Pe" icon) stop burning. Try using RCS or low-throttle to fine tune to get the approach distance you want. The most foolproof way to enter Mun orbit from your encounter is to wait until you are at closest approach, then just burn retrograde until you close an orbit. You can then circularize later on - you won't lose your orbit once you close one.