KSP taught me the basics of orbital mechanics, and then...

[godefroi]

The "position a satellite" contracts from 0.90/Fine Print taught me the rest. It's a dang good thing we have all the markers on the navball nowdays, because for these things, they're necessary! I'm sure MechJeb could line up the orbits more efficiently than I can without, but it sure is satisfying to eyeball the ascending node and burn a few 10s of m/s to fix an inclination.

I've done a few of these now, including a couple at the moon, even without patched conics yet, and I love them!

Seriously, how NASA got to the moon and back without patched conics and a map view is amazing

[TriggerAu]

...

Seriously, how NASA got to the moon and back without patched conics and a map view is amazing

I thought this myself a few times through the new career. Such an acheivement

[Linear]

A massive achievement indeed, but there was an absolutely colossal amount of money involved.

[FlyingPete]

I've got a contract that basically reads 'put a satellite in the Mun's orbit around Kerbin'. Trying to figure out a gravity assist off the Mun to fling the satellite into the right orbit.

[LameLefty]

I've got a contract that basically reads 'put a satellite in the Mun's orbit around Kerbin'. Trying to figure out a gravity assist off the Mun to fling the satellite into the right orbit.

Why complicate with a gravity assist? Just use the Map view to set your apoapsis at the same altitude as the Mün, then burn at apo to circularize.

[rkman]

Seriously, how NASA got to the moon and back without patched conics and a map view is amazing

NASA did use patched conics, just not real-time.

Calculating trajectories for Apollo program

http://www.embedded.com/electronics-blogs/programmer-s-toolbox/4008319/Calculating-trajectories-for-Apollo-program

"published a paper in 1961, which was the second paper published on circumlunar trajectories. We also developed quite a number of rules of thumb, approximations, and "patched conic" methods"

And they did have a map of sorts - at least they did keep track of the location of the vessel.

[LameLefty]

Seriously, how NASA got to the moon and back without patched conics and a map view is amazing

Oribits can easily be plotted by hand with paper, pencil and a little geometry. Admittedly, a slide rule or calculator makes it a lot faster. The toughest things about Apollo mission planning were, in order: #1) TT&C (tracking, telemetry and control) - they used a worldwide network of ground stations, airplanes and ships to keep a lock on a carrier signal for Doppler measurements; those were used for very precise measurement of velocity and distance. And #2) iterative estimates for burns. As we all know from KSP, changing your orbit doesn't happen instantaneously - it changes with every impulsive event, and - again from KSP - we know that mass changes as we thrust due to propellant consumption. So this is a non-linear problem that has not simple formulaic solution. You have to use an iterative calculation to simulate how the orbit will change over the length of the burn. This is trivial now due to advances in computing power - it was NOT trivial in the 1960's. It required long, tedious calculations step by step on paper, or using a room-sized mainframe to do it in several minutes to several hours - the more precisely you want to simulate, the longer the calculations take.

But anyway, yeah - being able to simulate stuff like this in KSP more or less instantly is amazing to this guy - I learned to do it the hard way in college on paper and then used 16 bit PC's to iterate orbit maneuvers and thought it was magic when I got an answer after a couple minutes.

[FlyingPete]

Why complicate with a gravity assist? Just use the Map view to set your apoapsis at the same altitude as the Mün, then burn at apo to circularize.

Partly for the challenge/learning potential for future missions, and partly to save on the size of the rocket. Those rocket parts cost money now you know

[Liowen]

What has always amazed me is that the computers on board the Apollo missions were about as high tech as a hand held calculator, it is kind of frightening knowing that it was more of a fly by your seat than what we have today.

[Vashts]

The "position a satellite" contracts from 0.90/Fine Print taught me the rest. It's a dang good thing we have all the markers on the navball nowdays, because for these things, they're necessary! I'm sure MechJeb could line up the orbits more efficiently than I can without, but it sure is satisfying to eyeball the ascending node and burn a few 10s of m/s to fix an inclination.

I've done a few of these now, including a couple at the moon, even without patched conics yet, and I love them!

Seriously, how NASA got to the moon and back without patched conics and a map view is amazing

http://www.embedded.com/electronics-blogs/programmer-s-toolbox/4008319/1/Calculating-trajectories-for-Apollo-program

an interesting and relevant read.

if .90 has taught me anything its how to eyeball it. before you had upgrades you could just look at the map and let the dynamic system tell you everything. i can now achieve LKO without even opening the map.

[Wallygator]

What has always amazed me is that the computers on board the Apollo missions were about as high tech as a hand held calculator, it is kind of frightening knowing that it was more of a fly by your seat than what we have today.

In reality is was not fly by the seat. It was extremely well planned and programmed. The astronauts basically monitored the performance of the automated systems for the vast majority of the flights. In fact Apollo 13 was planning on allowing a FULLY automated landing - sadly that was not possible due to circumstances.

[LordFerret]

"Despite their low performance, on paper, we got a lot of work out of those old machines. For those used to waiting 15 seconds for a Windows spreadsheet to even load, it's difficult to imagine how much work a 1-MHz computer can do when it's running full tilt in machine language, not encumbered by bloated software, interpreted languages, and a GUI interface. I'm old enough to remember, and look back on those days wistfully." - http://www.embedded.com/electronics-blogs/programmer-s-toolbox/4008319/3/Calculating-trajectories-for-Apollo-program

I can SO totally relate.

Many, many years ago, during the Apollo era, in an IBM headquarters involved with NASA, hung a sign on the wall which read: "Manual is better". No lie. lol

[NecroBones]

"Despite their low performance, on paper, we got a lot of work out of those old machines. For those used to waiting 15 seconds for a Windows spreadsheet to even load, it's difficult to imagine how much work a 1-MHz computer can do when it's running full tilt in machine language, not encumbered by bloated software, interpreted languages, and a GUI interface. I'm old enough to remember, and look back on those days wistfully." - http://www.embedded.com/electronics-blogs/programmer-s-toolbox/4008319/3/Calculating-trajectories-for-Apollo-program

I can SO totally relate.

Many, many years ago, during the Apollo era, in an IBM headquarters involved with NASA, hung a sign on the wall which read: "Manual is better". No lie. lol

This is very true. Plain-old number-crunching doesn't require too many cycles, so tightly-written machine code doesn't need a fast computer to do some math. The days of compact, machine-level elegant programming are long gone.

[Bill Phil]

NASA essentially calculated the transfer orbit Dv, and them they calculated the orbital period, and figured out where the moon needs to be so they could hit it. I believe they also assumed that only the gravity of one body acts on you at a time... Patched conic essentially.

[thyriel]

I think i really need to try these days an apollo style mission only in IVA without using the map

Would be interesting having a mod that displays nodes as pure numbers instead on the navball...

[samstarman5]

Playing 0.90 really brought me back to the early days of KSP, before maneuver nodes existed. There was always a hubbub over getting to the Mun, until one person revealed the trick of merely aiming for the navball horizon, and then starting your burn once the Mun appeared over the Kerbin horizon. I used the map from then, waiting until my orbit got just beyond the Mun's orbit, which would actually give you a free-return trajectory unless you burned to establish orbit around the Mun. However, anybody paying attention from there would see the approximate speed necessary from there to shoot for, allowing for just an IVA-only flight. Anybody with the resources and their tracking station still at its Level 1 build should do a bit of experimenting and see what they can discover.

[Frostiken]

What has always amazed me is that the computers on board the Apollo missions were about as high tech as a hand held calculator, it is kind of frightening knowing that it was more of a fly by your seat than what we have today.

Because the only thing you need IS a calculator. You don't need two GTX 870s, 16 gigs of RAM, and an 8-core processor.

NASA essentially calculated the transfer orbit Dv, and them they calculated the orbital period, and figured out where the moon needs to be so they could hit it. I believe they also assumed that only the gravity of one body acts on you at a time... Patched conic essentially.

That, and there was an allowable window for uncertainty. The Apollo flights had lots of burns, and I imagine their solution to the n-body problem was to assume only one body acted at a time, and to just burn to correct any deviations when they got close enough to the moon.

Hell, Apollo 13 corrected their reentry trajectory manually.

Edited December 21, 2014 by Frostiken

[Bill Phil]

Yeah. They used patched conics. And there were a lot of margins. The CSM had a large amount of Dv. So the margins were pretty big.

[Kesa]

Seriously, how NASA got to the moon and back without patched conics and a map view is amazing

But they upgraded their launchpad. Twice. And the R&D center. Reguarding the relative costs, I think they'd better have done some more surveys contracts and go for a better tracking station and map view, but I'm not playing RO, so I don't know if the pricse were the same for them.