Why does NASA (have to?) do things so much more complicated than in KSP?

[Themohawkninja]

I know that everything is scaled down, and that the physics are a "bit" different, but why exactly is it that NASA had to make a craft that un-docked with one section, flipped around, re-docked, then later on un-docked again to land on the Moon, lift off leaving a lander behind, re-dock again, and return to Earth (Apollo 11), whereas in KSP, you can do all of that with one stage. Secondly, why did NASA come up with such complicated solutions to land a rover on Mars (ranging from an omnidirectional airbag to a "skycrane"), whereas in KSP some parachutes and a pad to land on (to keep the rover tires from breaking) is perfectly sufficient?

[Tommygun]

Well the multi part approach to landing on the Moon was to reduce weight.

It is much easier to land a 14 ton lander on the Moon than a 45 ton multi purpose vehicle.

[Themohawkninja]

Well the multi part approach to landing on the Moon was to reduce weight.

It is much easier to land a 14 ton lander on the Moon than a 45 ton multi purpose vehicle.

True, but for being the first time ever attempting something, it would appear that there would be much more that could fail than if you had a lesser-staged system.

[abihoooo]

In reality you cannot use a parachute to land a 1 ton rover on Mars. Mars has .6% the atmospheric pressure of Earth, compared to Duna's atmosphere which is 20% of Kerbin's atmosphere. It would require a ridiculously large parachute to land a 2,000 lb rover going in re-entry speed.

[TheShadow1138]

One of the original plans for going to the Moon included an Apollo spacecraft that would have landed on the Moon with one stage. The reason they went with the Lunar Orbit Rendezvous (LRO) approach was because it cut down on the amount of fuel that would have been necessary to accomplish the Direct flight profile. Cutting down on the fuel required, cut down on the mass that the Saturn V needed to lift, which would also save money. Really I think a lot of it came down to a question of accomplishing the same mission in a manner that saves mass and money more than can we do with say a direct ascent. We definitely would have been capable of landing on the Moon with a Direct Ascent, but it may have taken longer and cost more money. I'm not well versed in the arguments that were made back then for Direct Ascent or LRO, but I believe that is the gist of the debate.

As for the rovers on Mars, I don't know that I'd call their methods "complicated", but I think at least a part of the reason is that the parts in KSP are a lot more resilient than in real life. The Martian atmosphere is much thinner than Earth's and so to slow down the rovers to survivable velocities requires much larger parachutes than say on the Soyuz. These larger parachutes would add mass, probably not much, but some. Also, for the parachutes to stay attached until touchdown the chutes could obstruct the rover's ability to exit its "capsule" so you'd have spent millions of dollars to place a rover on Mars only to have it sit there with no may to untangle the parachutes. Using the skycrane method or omnidirectional airbags ensures that the rover makes it to the surface in one piece, will be operational upon arrival, and will be able to leave its container.

[astropapi1]

...It would require a ridiculously large parachute to land a 2,000 lb rover going in re-entry speed.

Plus, that parachute wouldn't just "disappear" as soon as you touch the ground.

On the LOR choice, the lunar module was as simple as it gets.

[nettcod]

The planets and distances between them in KSP are 10x smaller than real life, so it takes a lot less Delta-V to get to places than in real life. Going to the moon in real life is more like an interplanetary trip in KSP than going to the Mun. Lunar Orbit Rendezvous was the easiest and cheapest method.

[7rex]

They used the skycrane to land the rover on Mars so the rocket exhaust would not dig massive holes in the ground that the rover could get stuck in.

[abihoooo]

Did some parachute size calculations, it would take a parachute about 21,500 square meters to safely land a 1 ton rover, which has a radius of 82 meters.

[nyrath]

Well, the short answer is that NASA spacecraft have to work in the real world, and NASA cannot afford to take any risk that even remotely threatens the life of an astronaut. Unlike KSP

[Yourself]

They used the skycrane to land the rover on Mars so the rocket exhaust would not dig massive holes in the ground that the rover could get stuck in.

Well, no, it's so the rockets wouldn't kick up a bunch of dust that would cover the rover and mess with the sensitive equipment on it. The rockets would not dig holes that deep, but they would create a pretty huge cloud of dust.

[Nuke]

if you had an apollo 13 type scenario where the rocket was a single multipurpose vehicle, the crew would have died. one of the benefits of having a modular vehicle is it allows for contingencies that would have otherwise not been possible.

[jwenting]

Had NASA not gone Kerbal and reused damaged components retrieved from Apollo 1 to build Apollo 13, most likely that flight would not have had the trouble it did...

Same with Challenger. Had they not gone ahead with the launch despite weather conditions being outside safe operating parameters, the O-ring would not have been frozen, causing it to crack which eventually caused the loss of the flight and its crew.

So yes, NASA sometimes has its Kerbal moments, and they're not the moments we want to remember them for.

[Thaniel]

They also have their Mcgyver moments, using ductape and and socks and such, and those moments are the ones that make them shine.

[Albert VDS]

Secondly, why did NASA come up with such complicated solutions to land a rover on Mars (ranging from an omnidirectional airbag to a "skycrane"), whereas in KSP some parachutes and a pad to land on (to keep the rover tires from breaking) is perfectly sufficient?

In KSP you don't need to worry about the parachute landing on your rover, dust storms or other weather phenomenon, big/pointy rocks, dust, hardware failure, g-force, temperature, solar/cosmic radiation, etc.

You only have to worry if you enough fuel, can I slow down fast enough and not explode/break a wheel.

[Themohawkninja]

In KSP you don't need to worry about the parachute landing on your rover, dust storms or other weather phenomenon, big/pointy rocks, dust, hardware failure, g-force, temperature, solar/cosmic radiation, etc.

You only have to worry if you enough fuel, can I slow down fast enough and not explode/break a wheel.

How would cosmic radiation effect it? I know that coronal mass ejections from the Sun might have a detrimental effect on the computers, but what could cosmic radiation do?

[Albert VDS]

Just like solar radiation, it can damage electronics.

[Bacterius]

How would cosmic radiation effect it? I know that coronal mass ejections from the Sun might have a detrimental effect on the computers, but what could cosmic radiation do?

Even our computers here are regularly getting memory bits randomly flipped by cosmic radiation. It's not as unlikely as it sounds, some studies suggest it occurs once in 256MB of RAM over a month on average. You just don't notice it because it usually does not result in any data corruption, though if you have an unexplained crash, this could plausibly be it (unlikely, but the probability is far from negligibly low). Now Earth has a thick atmosphere, and a heavy duty magnetic field to protect us from the more powerful stuff. Mars has an exceptionally weak magnetic field at the poles only, and an extremely thin atmosphere. While rovers have more resistant equipment, hardened memory cells, and lots of error-correcting hardware and software, they really do get hit hard by all this radiation, and eventually will succumb to it.

[RoboRay]

I know that everything is scaled down, and that the physics are a "bit" different, but why exactly is it that NASA had to make a craft that un-docked with one section, flipped around, re-docked

Because NASA cares about keeping the crew alive. If there's a big lander on top of your crew capsule during the launch, it's impossible to rocket the crew up and away from an exploding or crashing launch-vehicle. Launch-Escape System tower goes on top, then the people-tank, then their lander below them. But once you're in orbit, you need to be able to use the spacecraft's main engine, which won't work well if there's a lander attached below it. So, you flip around and put the lander on the nose, now that the LES tower is gone.

It would have been possible to use another motor below the LM for the mid-course correction and orbital capture burn instead of the CSM's SPS, but that would have required carrying two big powerful motors instead of one, which would have been quite heavy and increased the performance requirements for the launch vehicle.

then later on un-docked again to land on the Moon, lift off leaving a lander behind, re-dock again, and return to Earth (Apollo 11), whereas in KSP, you can do all of that with one stage.

KSP is easy-mode. A "direct ascent" lander that's easy to build in KSP would have required a launch vehicle considerably larger than the Saturn V in the real world.

Secondly, why did NASA come up with such complicated solutions to land a rover on Mars (ranging from an omnidirectional airbag to a "skycrane"), whereas in KSP some parachutes and a pad to land on (to keep the rover tires from breaking) is perfectly sufficient?

Again, because KSP is easy-mode. Duna has 25 times as much atmospheric pressure as Mars. Parachutes are damn near useless on Mars. They can slow you down a little and stabilize your descent in the proper attitude, but you pretty much need rockets to land on Mars. The airbags and other tricks are ways to minimize how much rocket you need to land, as well as increase the survivability prospects in case of a mishap during landing.

Edited August 12, 2013 by RoboRay

[Kimberly]

There's also the fact that, with large projects, some ideas have to work within the confines of designs not made with that idea in mind. Take the lunar rover: the idea proved troublesome during testing and they scrapped it. Some intrepid General Motors designers wanted to change NASA's mind, but by then the lunar landing module had already been designed. So there simply was very little space for the rover; not to mention the fact that its weight had not been accounted for, so every bit of weight added to the lander meant that the lunar module would have less time to find a safe landing spot before it ran out of fuel. (Recall that Apollo 11 landed with just seconds to spare.)

They ended up building a car that weighed only 210 kg and could fold up to be only 30 cubic feet. Nevertheless, it could carry two astronauts, equipment, and could be used to bring back samples.

In short, the real engineers work with lots more limitations than you have in KSP, and yet they come amazing solutions to every problem.

[Mr Shifty]

Had NASA not gone Kerbal and reused damaged components retrieved from Apollo 1 to build Apollo 13, most likely that flight would not have had the trouble it did...

The problem on Apollo 13 was an O2 tank that had originally been installed on the Apollo 10 SM, but was removed before Apollo 10 flew so that it could be modified to reduce electro-magnetic interference. During removal, a bolt that attached the tank to the O2 shelf was left in place, which caused the mounting fixture to break and the tank dropped 2 inches to the ground. In a distinctly un-Kerbal-like response, the incident was recorded, the tank minutely inspected, and analysis was performed to see if the drop would have caused damage to the tank. It was certified safe and had no subsequent problems during extensive mission testing until a couple years later. During a countdown demonstration test for Apollo 13, the tank was filled normally, but failed to vent after filling and pressurization. Again, the incident was recorded, analysis was performed, with a loose filling line internal to the tank (possible caused by the 2 inch drop) the suspected reason for the problem. After trying multiple times to vent the tank normally, it was decided to vent it by heating the tank up with its internal heater to boil off the oxygen. And here's where the real failure occurred. In the original design for the O2 tanks, the heaters were to be operated at 28VDC. This was later revised to 65VDC to speed up boil off times during testing, but the thermostat relay specifications were never changed to match the new voltage, NASA signed off on the new designs, and the relays were never tested under load. So when Apollo 13's O2 tank heater was turned on, the thermostat saw the temp rise to 80 degrees, then tried to open the relay to shut off the heaters. The relay was unable to open under a 65 volt load and the contacts fused shut, so the heater stayed on. The temperature inside the tank probably got to around 1000 degrees during the boil-off, which no one noticed because the thermostat only went up to 80 degrees. The high temperature damaged the Teflon insulation around the wires leading to the tank mixing fan, and the rest is history.

Note that the commission never would have been able to determine the cause of the incident if there weren't documentation of every component's history from manufacture to installation, all tests performed, every failure analysis, telemetry graphs, etc etc etc. Keep in mind that all this was done with paper; no computer storage. Just the data management for Apollo is a phenomenal feat. Apollo wasn't done Kerbally.

[Moon Goddess]

In addition to the post above I don't find the Challenger disaster to be very "Kerbally" either. (plus I strongly agree with bac9 that this whole talk of "Kerbally" is disastrous for the game.)

If you want to talk about a disaster which is "Kerbally" meaning careless and casual regard to disaster then look at the Columbia disaster. "They'll probably be fine, but if they're not there's nothing we can do about it, maybe. So lets not even look to see if they're gonna be ok, cuz we'd rather they die not knowing." http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster#Conclusions

[magnemoe]

Compared with my last missions the Apollo moon landing was very simple.

Tylo landing as part of grand tour.

Match orbit and rendezvous upper stage who arived from Val with main stage in Tylo holding orbit.

Undock large lander from upper stage and dock with main stage, dock upper stage and transfer fuel to upper stage and large lander. Top up upper stage with rcs.

Change in plan instead of using main stage to do the Pol burn the main stage is used to do the deorbit burn for the Tylo lander.

Undock the small lander from main stage, undock upper stage and dock it with the small lander. Do eva to large lander and prepare for decent.

After running fuel in main stage down to 360 liter, abort autopilot, transfer fuel from main stage and balance tank to Tylo lander, decople and continue decent.

[Albert VDS]

But now you are comparing a walk to the local supermarket with a vacation to some exotic destination on the other side of the planet.

Now what you could do is compare your Moho mission with a real life manned mission to Mercury. Ok there is no mission to Mercury, but you could imagine what it would take

to create such a mission.

[Superfluous J]

For NASA, there is only one bottleneck: Money. If the super complicated way saves a half a million dollars, they're going to do it because that money can go to other things. They may be unique in all the US government for that attitude.

For us, there are a near infinite number of bottlenecks, and money is one of the few things that is unlimited. So if we want to fly directly to moho and then ignite 8 mainsails to slow down, nothing but the physics engine is stopping us.