Engineers will calculate delta-V?

[Red Iron Crown]

In fact, I'll give all the people who think any old Kerbal should be able to work out delta-V an exercise:

A one-stage core masses 10 tons wet, 3 tons dry, and has an engine delivering 100 kN of thrust with an Isp of 400 s.

Attached to it are two solid boosters, each massing 4 tons wet and 0.5 tons dry, each delivering 300 kN of thrust with an Isp of 250 s.

All three engines ignite at launch and run at full throttle. The boosters are decoupled immediately after burnout.

Calculate the delta-V of this rocket.

For extra credit, assume the pilot throttles the core engine back to 2/3rds throttle when the boosters have used up half their fuel. Work out the new delta-v in less time than it takes the boosters to deplete their remaining fuel.

Does the fact that I, not a rocket scientist, physicist or engineer by training or profession, know how to do this calculation carry any weight?

Rather than just give the answer, I'll give the steps to calculate it:

From Thrust and Isp of both engine types, determine mass flow rate for each.

From mass flow rate and masses of solid boosters, determine burn time of SRBs.

Calculate mass of LFO burned by core in the same time.

Calculate net Isp for combined stage using a thrust weighted average.

Use that for calculating the first stage dV.

Then calculate the second stage dV with the remaining mass in the core and LFO engine Isp.

It really is not outside the grasp of anyone with a knowledge of algebra and a couple of basic rocketry equations.

(Note, I haven't taken into account changes due to varying atmospheric pressure; none of the dV calculator mods do so either, they just assume a constant.)

[Thomas988]

THIS IS THE GREATEST DAY OF MY LIFE! Duna, here I come!

[Liowen]

Being a game designer is not a prerequisite for useful criticism of a videogame. I don't have to be a chef to know when my steak is overdone.

Criticism is one thing, but anger and vileness is something completely different (IE calling a company stupid). Also if you go somewhere where the food was god awful would you go back repeatedly to complain about it? I know I wouldn't. Yet with videogames it is seemingly different for some reason, almost like they like to complain to complain. I honestly do not see the appeal of first person shooter games (to me they are all rewashes of the same design) yet I do not buy them and go to their forums to complain about it. Even when I played MMO's I would get annoyed with things I felt were wrong with it, however I knew where they were going was not something I would not enjoy so I left it to its own devices.

[Red Iron Crown]

^^ That's fair, there is a big difference between constructive criticism and just general complaining. The former is useful, the latter is not.

[Corw]

Criticism is one thing, but anger and vileness is something completely different (IE calling a company stupid). Also if you go somewhere where the food was god awful would you go back repeatedly to complain about it? I know I wouldn't. Yet with videogames it is seemingly different for some reason, almost like they like to complain to complain. I honestly do not see the appeal of first person shooter games (to me they are all rewashes of the same design) yet I do not buy them and go to their forums to complain about it. Even when I played MMO's I would get annoyed with things I felt were wrong with it, however I knew where they were going was not something I would not enjoy so I left it to its own devices.

Dude, but his stake is overdone...

[r4pt0r]

I'm somewhat disappointed they went back on their previous statement

In the end, it takes away a gameplay element because it takes some of the guesswork and some of the trial and error and figuring out for yourself what the delta-V is. It might take some of the magic away. One of the great things about KSP is doing just what Chad was doing just now [Editor's note: this was Thursday afternoon, and Chad Jenkins was in the process of livesteaming his creation of a flying rocket-powered surfboard, killing two-dozen Kerbals in the process] . That ridiculous contraption he was doing, just trying to see if he could make it to the water, just shooting it on a rocket. If you make it too technical, it's certainly possible to calculate it. But it's like giving the answer to a puzzle sometimes, and I don't know if we want that. The same applies to showing how much burn time you have remaining. I think there's always this element of tension of trying to calculate in your head how much fuel you have left and if you're going to make it. It's like filling out the crossword puzzle for you.

Source here, not that it matters

Personally my play style is to not really care about dV and just trial and error things. Thats fun for me. I got my first manned Duna lander to land and return in one shot just from guessing and not paying attention to launch windows.-snip

This quote mirrors completely my experience playing ksp. My first interplanetary mission was to Ike, and on the return i had less than 2 units of fuel left. That was exciting, nerve-wracking, great fun, and an overall blast. If I had some meter telling me "calm down you have __dv left, you will be fine no worries" I would not have had that experience.

But if it's coming it's coming. No sense fighting the tides of fate

Accept the things to which fate binds you, and love the people with whom fate brings you together, but do so with all your heart.

[Red Iron Crown]

So...don't look at the engineer readouts, and don't put engineers on your ships? Seat-of-the-pants is still possible.

[Robotengineer]

I expected something like this. It just couldn't be something as simple as having a readout. That might be useful. I suppose we will have to wait and see. On the Pilot thing, I hope it is not more automation. It will probably be an auto-dock type feature. Going to read through this thread...

[Alshain]

Criticism is one thing, but anger and vileness is something completely different (IE calling a company stupid). Also if you go somewhere where the food was god awful would you go back repeatedly to complain about it? I know I wouldn't. Yet with videogames it is seemingly different for some reason, almost like they like to complain to complain. I honestly do not see the appeal of first person shooter games (to me they are all rewashes of the same design) yet I do not buy them and go to their forums to complain about it. Even when I played MMO's I would get annoyed with things I felt were wrong with it, however I knew where they were going was not something I would not enjoy so I left it to its own devices.

Your comparison doesn't makes sense. You don't go back and re-buy the same game over and over again, it's not a consumable. Nor does your food suddenly change taste after the first bite. You are inappropriately drawing parallels between two different business models.

Also, did anyone actually call Squad stupid. The idea of tying Engineers to delta V certainly is stupid, and I gave several reasons why that is the case earlier in the thread, but I couldn't find where anyone simply said Squad was stupid (it is a long thread already though).

[NovaSilisko]

So...don't look at the engineer readouts, and don't put engineers on your ships? Seat-of-the-pants is still possible.

Exactly. I really never understood the idea that having information available somehow makes it impossible to improvise and do silly things...

[LethalDose]

Where's that dead horse so I can beat it again...and again...and again. Just remember, Squad loves their community!...on Reddit!

So, yeah, dv readouts. I'm not going to congratulate them for doing something they should have done when they added dv readouts to maneuvers. As far as it being tied to engineers. Well, it's a game mechanic.

Basically, this. The game has needed a stock dV display for years. Squad's "Numbers aren't fun' stance has been idiotic. They don't get a pat on the back for figuring out what the community has been telling them the whole time.

This is what I think about it. Probably going to get a reprimand for it (again), but it's worth it.

Also, parroting klg above, why is this all going through reddit instead of here on the their own freakin' forums?!

[Robotengineer]

--snip--

(Note, I haven't taken into account changes due to varying atmospheric pressure; none of the dV calculator mods do so either, they just assume a constant.)

KER does have an atmospheric adjustment option. With adjustments for speed and altitude for jet engines and other engines.

[RobotsAndSpaceships]

This is so stupid. You don't have to be an engineer to calculate dv. It's just an arcade game now. Thanks Squad.

And remember kids, those aren't bugs, those are "features"!

Edited February 10, 2015 by RobotsAndSpaceships

[Red Iron Crown]

KER does have an atmospheric adjustment option. With adjustments for speed and altitude for jet engines and other engines.

I knew I hadn't phrased that well enough. I mean it assumes a constant atmospheric pressure for its calculations, not modelling the change in pressure as a rocket ascends. Nor should it really, that's much more difficult to calculate and requires some foreknowledge of the ascent profile.

[cantab]

oh wait, someone already did... it's called Kerbal Engineer.

And it uses, by default, the same gosh darned approach Squad are advocating of requiring an Engineer kerbal.

(Or you can use the chip part, or turn off the requirement altogether. But nothing indicates Squad won't do both of those too.)

[r_rolo1]

Tz, tz ... dV on rockets as a function of the crew ? Really ? *insert facepalm pic*

Really, I could live with that being a function of the on ground crew ( the place where you need more to know the dV of a rocket is in conception, not in flight ) and thus at best being a function of the R&D or the Mission control upgrades ( "Now we have newfangled calculators with logarithms, so we can calculate how much whooph a rocket has !!!" ). But, of the crew? That makes as much sense as having the dV of a rocket being a function of the pilot skill, and no one would suggest anything so stupid as that, right ? ...

Oh, wait ... :/

[regex]

In fact, I'll give all the people who think any old Kerbal should be able to work out delta-V an exercise:

Why is the Kerbal doing this constantly while in flight? This is something the engineers on the ground should have calculated while designing the vehicle.

Criticism is one thing, but anger and vileness is something completely different (IE calling a company stupid)

No one called Squad "stupid". Their decisions on game design, OTOH, can be really dumb and intelligence-insulting sometimes.

And it uses, by default, the same gosh darned approach Squad are advocating of requiring an Engineer kerbal.

If they are, that's a dumb decision for the reason above.

Sometimes I feel like Squad hit it out of the ballpark with the basic idea of this game and then just forged ahead without a plan. All these features just seem like they've been randomly tacked together trying to build a cohesive whole, without direction, and now they've got to "balance" the entire thing. "Kerbals need to be useful", so now Kerbals are tied to basic spaceflight mechanics with a leveling system attached. so now we have this prospective system whereby you herp-derp around trying to get to space without your engineers being able to provide any useful information until they've got enough "experience" to do the basic freaking math that should have been done during the design stage of a vehicle. Also, pilots who can't seem to point in any of six directions until they've gained enough "experience" and astronauts who can't leave the capsule or pick up a rock until you've got the right building upgrades.

[Parkaboy]

I find terribly funny that people still wonder why the devs prefer to disclose new info anywhere but in this forum.

[regex]

I find terribly funny that people still wonder why the devs prefer to disclose new info anywhere but in this forum.

If you're alluding to criticism, they receive virtually the same pretty much everywhere.

[Alshain]

And it uses, by default, the same gosh darned approach Squad are advocating of requiring an Engineer kerbal.

(Or you can use the chip part, or turn off the requirement altogether. But nothing indicates Squad won't do both of those too.)

Not on my game, it doesn't. If you really think Squad is going to make it optional, let me direct your attention to pilots being required for SAS. Did they make that optional?

Edited February 10, 2015 by Alshain

[RobotsAndSpaceships]

Sometimes I feel like Squad hit it out of the ballpark with the basic idea of this game and then just forged ahead without a plan. All these features just seem like they've been randomly tacked together trying to build a cohesive whole, without direction, and now they've got to "balance" the entire thing. "Kerbals need to be useful", so now Kerbals are tied to basic spaceflight mechanics with a leveling system attached. so now we have this prospective system whereby you herp-derp around trying to get to space without your engineers being able to provide any useful information until they've got enough "experience" to do the basic freaking math that should have been done during the design stage of a vehicle. Also, pilots who can't seem to point in any of six directions until they've gained enough "experience" and astronauts who can't leave the capsule or pick up a rock until you've got the right building upgrades.

My thoughts exactly, it's a shame I can't throw any more forum rep at you, and why the hell aren't probes going to be able to have delta v readouts? Whats up with that? Even since before the start of our real life space program we've known how to calculate delta v. Theres no reason you should have to have an engineer on board to do it. I'm surprised we haven't had the backlash like we did when they announced more experienced kerbals could effect the vessels stats.

[Thnd3r]

Let's put it this way (I know I'm a noob, but still...) KSP doesn't tell you how much dV it takes to get anywhere. Just because it may tell you in the VAB or in mission shouldn't technically matter since you'll still have to go and look up how much dV it's going to take to go somewhere. For the people that have been playing forever you already know it takes x dV to go to y, but for new players they would have no clue without consulting the wiki or some other resource.

With the potential changes coming to the engineer's report in the VAB I'm hoping there's a mention of "your vessel will reach orbit" and let you know the dV, but it should be limited to difficulty levels. As difficulty increases you get less info. Easy - All info, dV, will it reach space, will it orbit... Medium - dV info only.... Hard - no info. We need to remember this is a game at its core and in order to attract players it will need be be accessible to a wide range of people. Let the flame war begin!

Edit: I also like the idea of this info being tied to building upgrades.

Edited February 10, 2015 by Thnd3r

[hoojiwana]

Tying dV readouts to one of the building upgrades (the same that gives you the manoeuvre nodes), and having them just be available at all times if the player wanted to use them makes far more sense, and doesn't block out probes from having access to the same simple maths. Trying to force engineers to be more useful by tacking this to them seems a cheap way out of finding actual engineering related things for them to do. A resource mechanic is being introduced, maybe tie them into the processing/drilling side of that somehow? Or have a few (certainly not all) of the current in-flight tweakables be only available if you've got an engineer aboard who knows how to do the tweaking. Expanding the tweakables to cover all the things that got missed in the initial implementation would go a long way to helping too.

If something like KAS were stock there would be no need to be scrabbling around looking for sensible engineering things for Kerbals to do.

[Robotengineer]

Pilot: "Hey engineer, we are going to land, can you run me the ∆v numbers again?"

Engineer: "We are short 10 m/s of ∆v to be able to land, why didn't the ground crew do this?"

Pilot: "How accurately are you approximating the natural log function?"

Engineer: "Only 2 steps, I can only do so much with a pencil and paper."

---

Alternate scenario.

Pilot: "Get me the ∆v stats engineer."

Engineer: "I can't, I haven't planted a flag on Minmus to get enough xp to do the calculation."

---

If these situations seem completely unreasonable, you are a hater of fun, and you need Squad logic.

On a less sarcastic note, why would you need to plant a flag on Minmus to learn the rocket equation? If they rebalance the way xp is earned, I won't be quite as dismayed by this turn of events, but with the current system it doesn't make any sense.

Edit: I agree with hoojiwana above, making it a mission control and/or tracking station upgrade makes some sense.

[metl]

I am thrilled to see this change. It makes damn good sense to have the engineers actually do something useful. Furthermore, calculating Dv of a moving vessel traveling through constantly a constantly changing atmosphere (or gravity source) is not only NOT basic math, it is also NOT going to be getting done by the pilot at the same time he is trying to fly the craft (but when in a safe spot, he could theoretically plot a maneuver node and figure out how long he needs to burn for.) Do you think NASA used three man capsules so they could just keep each other company? Every person in that capsule had different job assignments during flight.

As far as EVA, does anyone even remember how hard it was for NASA to train the guys to do an EVA? On thier first attempt, the dude barely managed to make it back into the capsule and was entirely wore out. EVA is NOTHING like getting out of a car in a parking lot. Having to have a proper facility to train for EVA makes sense (and yes, so would requiring training, but Squad is trying to avoid artificial time sinks as much as possible. Let's not start THAT conversation.)

yes, there are many things they could do differently, but the bottom line is they are purposely keeping things as simple as possible while trying to show just how involved space travel really is. The fact that they are finally including a Dv readout is freaking awesome!