Differences from Real life

[tomf]

I'm curious about what factors make KSP harder and easier than their real life equivalents. I think the balance overall is pretty good and that most of these factors cancel out

Its a game

• Building a rocket is done with a mouse not engineering, tools and materials
  
• The only failures you need to worry about are simple, structural failures and bad design
  
• quicksave and load
  
• currently no life support
  
• no room full of people monitoring every aspect of the mission.
  

Physics things that make it easier

• Everything is small, the delta-v to leave Kerbin is smaller than earth, it takes less delta-v to visit all the bodies than RL equivalents
  
• Drag model doesn't penalize un-aerodynamic designs
  
• Free fuel pumping - makes asparagus designs practical
  
• Ion drives are more powerful than RL
  

Physics things that make it harder

• The engines have slightly low ISP / don't use LH2 - 280s mainsail vs 363s space shuttle main engine in atmosphere
  
• Low thrust to weight ratio of engines - mainsail 27 vs f-1 75
  
• Heavy tanks - ksp orange tank has wet/dry =9, Space shuttle orange tank = 28
  
• heavy payloads - the apollo CM mass is pretty close to the commandpod -mk1-2 with rcs etc included - this isn't to scale with engine power
  
• drag model - I've not tried FAR but I hear that a more realistic drag model gives much lower drag for most craft.
  

Does anyone have any other suggestions?

[musicpenguin]

Cats. Not enough cats so it's unrealistic.

[dr_jt]

Kerbals are not well understood

Edited June 6, 2013 by dr_jt

[comham]

[*] The only failures you need to worry about are simple, structural failures and bad design

I would say this is probably the most important factor. You can always rely on a KSP part, there's no worry of tiny valve #273 being installed upside down and the engine exploding, or line #7093 in the gimbal code having a runtime error and your rocket which took 7 years of planning falling into the sea.

[dr_jt]

Kerbals are not well understood

Edited June 6, 2013 by dr_jt

[ShachonianX]

I've been told Kerbals ate cats to extinction and that is why there are none.

I will avenge you LOLcats! I WILL AVENGE YOU! (gets out giant lasers)

[dr_jt]

Imagine Kerbals

Edited June 6, 2013 by dr_jt

[AceGamer]

A very accurate summary also if you kill a few Kerbals not too much of a problem kill a few astronaut and that's a lot of paper work and money.

[Tw1]

Unlike me, I guess you don't have a family that stands around behind you and laughs at you as you kill even more Kerbals in your comical attempts to get them into space.

Hahaha. Good point.

I imagine there are kerbals in that windowed section of the VAB who act like the mission control. That Gene Kerman guy from the tutorials is probably there.

[ComradeGoat]

Have been chatting with an actual rocket scientist about this, specifically re aerocapture. He says IRL it's really risky because of weather and other atmopsheric uncertainties. Once you know the right height to use in KSP, it's pretty reliable.

[comham]

Have been chatting with an actual rocket scientist about this, specifically re aerocapture. He says IRL it's really risky because of weather and other atmopsheric uncertainties. Once you know the right height to use in KSP, it's pretty reliable.

Yeah, the atmosphere being a set of concentric perfect spheres of different densities, that's certainly handy.

Very true and while designing and assembling every aspect of an engine or tank would appeal to a few it would not to the majority of users. I like the level it is now at and consider it a big picture simulator. Unlike some I wouldn't want to have to run a half hour long checklist flipping switches and such prior to taking off. It's kind of like playing a RTS game where you decide on movement of you assets and don't have to control every single unit at the micro level.

It's not really possible to do at the moment, we need even more processing power. You might be able to do a simple full simulation if you had a custom-built engine that used GPU-accelerated physics, but KSP can't even multithread or use more than 3gb of ram due to using Unity. Obviously that was unavoidable, being first time devs with only tentative/prospective funding it's not realistic to expect Squad to code their engine from scratch.

[Crush]

One factor which makes KSP a lot easier than real life is the total lack of atmospheric re-entry heat.

In real-life, atmospheric reentry is one of the most dangerous phases of a space mission. Special care must be taken to ensure that a vessel is capable of surviving re-entry and the reentry vector has to be planned properly. In KSP however it's totally harmless.

Edited May 2, 2013 by Crush

[geb]

In KSP all navigation data is read directly out of the game engine. It's not quite perfect since there is a little floating point accuracy error, but it is very close to perfectly accurate.

In reality, you have to navigate using data from startrackers, radar, laser rangefinders, telescopes, and maybe GPS too if you're close enough to Earth. There's a lot of uncertainty, a lot of room for error to creep in. It's hard to be really certain where you are and where you're going.

[Jokurr]

One factor which makes KSP a lot easier than real life is the total lack of atmospheric re-entry heat.

In real-life, atmospheric reentry is one of the most dangerous phases of a space mission. Special care must be taken to ensure that a vessel is capable of surviving re-entry and the reentry vector has to be planned properly. In KSP however it's totally harmless.

I believe the heat effects of atmospheric re-entry are going to be added in at some point, so it won't always be as harmless as it is now.

That said I doubt it will be as dangerous as in real life. Re-entry maneuvers can be quite complicated, with changes in altitude, rotations, etc. to relieve the heatload on any given part of a craft.

[SkyRender]

Real life also does not feature a pair of keys that let you force time to flow more or less quickly. If you send out a 50-year mission from Earth, you don't get to mash > and wait an hour to reach that point. You get to wait half a century for it to get there. And of course, Earth also features constantly-changing technological progress, meaning that the mission you sent out 50 years ago is probably horribly out of date by then and likely had a huge number of systems failures as well.

[razark]

No budget constraints. No political bullcrap. No program getting cancelled halfway through. No ground testing. No paperwork. No research. No material failures. No bidding on contracts. No systems testing. No worries of integrating Part A by one contractor with Part B from another contractor, running with System C by an agency in another country, all controlled by software from yet another contractor. No worrying about getting parts on time. No worry on not having parts in stock. No worries about crew health. No worry about the crews' Garn levels. No worry that the oxygen tank might explode. No worrying that the radio won't let you talk between two buildings. No kerbals hanging lemons on the simulator. No simulator. No training. No hatch blowing early. No torque meter to check that each screw is installed just right. No crew selection. No crew getting bumped for having measles. No pissing contest with the another country. No micrometeorites. No congressional committees when the rocket fails. No two year wait when a kerbal dies. No weather constraints. No public relations. No 1201 alarm. No trying SCE to Aux.

But that's just a few differences off the top of my head.

[zarakon]

Real rocket engines generally can't throttle all the way from 0% to 100%. Often there is no throttle control at all, just on or off.

Real engines can usually only be restarted a limited number of times, or not at all.

[comham]

No worries of integrating Part A by one contractor with Part B from another contractor, running with System C by an agency in another country, all controlled by software from yet another contractor.

Well, there's mod incompatibilities.

[dr_jt]

Consider Kerbals

Edited June 6, 2013 by dr_jt