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8 hours ago, eskimo22 said:

I looked up the delta V on a BFS, a BFS will have just over 6 km/s of delta V with a 150t payload and 9 km/s without a payload

I can’t give the bfr that much delta v. If earths orbital velocity is 8500 ms and kerbins is 2400 than kerbins orbital requirement is apx. 28% of earths. So maybe the bfr should have 9km * .28= 2520ms with zero payload? Also, it seems this delta v number is only for the upper stage as 6km/s falls far short of orbital requirements (bare minimum u would need around 9.5km/s) this means if I make the bfr how you ask, when assuming how much fuel the bfr carries, you would likely have around 15km/s, which has no place in a stock herbal. I like playing rss because it bothers me how slow the orbital speeds are in stock. Literally in a to scale system you are traveling at 240% the speed of stock and hence need 240% the resources meaning a bfr in stock would have almost 2.5 x the delta v it would need.

Edited by harrisjosh2711

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43 minutes ago, harrisjosh2711 said:

I can’t give the bfr that much delta v. If earths orbital velocity is 8500 ms and kerbins is 2400 than kerbins orbital requirement is apx. 28% of earths. So maybe the bfr should have 9km * .28= 2520ms with zero payload? Also, it seems this delta v number is only for the upper stage as 6km/s falls far short of orbital requirements (bare minimum u would need around 9.5km/s) this means if I make the bfr how you ask, when assuming how much fuel the bfr carries, you would likely have around 15km/s, which has no place in a stock herbal. I like playing rss because it bothers me how slow the orbital speeds are in stock. Literally in a to scale system you are traveling at 240% the speed of stock and hence need 240% the resources meaning a bfr in stock would have almost 2.5 x the delta v it would need.

I agree, 9km/s is INSANELY OP in stock KSP. 

6.5-7 km/s is a better delta v for a BFS without a payload (that's what it currently has)

Edited by eskimo22
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@eskimo22 I fixed the color on that fuel tank. Also, just finished up making the wing for the BFR a bit smoother like you asked.

40930496831_c42365d48d_b.jpg

Edited by harrisjosh2711

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18 hours ago, harrisjosh2711 said:

@eskimo22 I fixed the color on that fuel tank. Also, just finished up making the wing for the BFR a bit smoother like you asked.

40930496831_c42365d48d_b.jpg

what part of the BFR is that? engine mount? any pics of the new wing?

Edited by eskimo22

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1 hour ago, eskimo22 said:

what part of the BFR is that? engine mount? any pics of the new wing?

Never mind, I see now. looks a lot better than the current one. It looked like a cone from this angle. also, the BFR's sea level engines will be flush with the vacuum engines, I think that the BFS's fuel lines should be mounted to the hull, instead of the SL engines (like Tundra Exploration's BFR SL engines).

Edited by eskimo22

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5 minutes ago, eskimo22 said:

Never mind, I see now. looks a lot better than the current one.

lol, yea its just disconnected from the ship. Are you playing in 1.4.1 right now by any chance? It seems all the RCS transforms have to be turned around, which I did, but now the RCS is firing the in the opposite way the ship is going, which really, really is confusing me. Like the RCS is rotating the ship clockwise, but according to the direction they are firing the ship should be spinning counter clockwise. I'm really not sure what is going on. I'm trying to get my hands on a new version of the parts tools If their is one to see if that fixes anything.

Just now, RaiderMan said:

@harrisjosh2711 did you grab the new ksp part tools yet?

No where are they I'm trying to find them now?

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1 minute ago, harrisjosh2711 said:

lol, yea its just disconnected from the ship. Are you playing in 1.4.1 right now by any chance? It seems all the RCS transforms have to be turned around, which I did, but now the RCS is firing the in the opposite way the ship is going, which really, really is confusing me. Like the RCS is rotating the ship clockwise, but according to the direction they are firing the ship should be spinning counter clockwise. I'm really not sure what is going on. I'm trying to get my hands on a new version of the parts tools If their is one to see if that fixes anything.

No where are they I'm trying to find them now?

I finally got 1.4.1 to work.

btw If you are re-texturing the BFR, plz put the RCS ports in the places that they will be on the real BFRdca8b5090827b96abff61020e48804e5_preview

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13 minutes ago, eskimo22 said:

I finally got 1.4.1 to work.

btw If you are re-texturing the BFR, plz put the RCS ports in the places that they will be on the real BFRdca8b5090827b96abff61020e48804e5_preview

I’m not re-texturing the bfr. If you can provide some sort of proof this came from spaceX and is not a mere artistic rendition than yes I will change them. Until then NO ONE has any clue besides the engineers directly designing the bfr. Not a single version I have seen from spaceX even has those outter flanges. So I don’t get where you are getting this is the real bfr from other than I found this on some website? I’m not saying it’s wrong but I can’t make changes every time some artist desires to make a different conception and everyone assumes this is right because some artist says so.

Edited by harrisjosh2711

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7 minutes ago, harrisjosh2711 said:

I’m not re-texturing the bfr. If you can provide some sort of proof this came from spaceX and is not a mere artistic rendition than yes I will change them. Until then NO ONE has any clue besides the engineers directly designing the bfr. Not a single version I have seen from spaceX even has those putter flanges. So I don’t get where you are getting this is the real bfr from other than I found this on some website?

I say that the BFR will have RCS ports in that location because almost every rendition I have seen has had RCS in those locations and because of these pictures, from the SpaceX IAC presentation in 2017. 

iss_bfr.jpg?w=730&crop=1 Spx18.jpgbfr-mars-iac2017-879x485.jpg

Edited by eskimo22

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22 minutes ago, eskimo22 said:

I say that the BFR will have RCS ports in that location because almost every rendition I have seen has had RCS in those locations and because of this picture, from the SpaceX IAC presentation in 2017.iss_bfr.jpg?w=730&crop=1 

Well I will look into that assuming this pic is truly from spaceX. It’s just my opinion that the those thrusters aren’t big enough. Since the bfr’s main control point in the Martian upper atmosphere, those thrusters don’t appear big enough to be moving around 100+ tons as quickly as it will need to be. I could be wrong. I almost question if it would need an entire set of Draco’s engines for this?

also, those thrusters will only give you full control on the x&y axis.This means translate sideways you would need to turn sideways. Are you ok with not having control in all directions, because you need a fifth thruster for that?

scratch that, looking at the pic there are only 3 thrusters. Up, down, and forward. So is this what u want to do? I’m ok with it. You originally asked for control on every axis. But wait that isn’t even possible because the BFR has to back against each other to re-fuel. See how these pictures are conflicting with its functionality? 

Edited by harrisjosh2711

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20 minutes ago, harrisjosh2711 said:

Well I will look into that assuming this pic is truly from spaceX. It’s just my opinion that the those thrusters aren’t big enough. Since the bfr’s main control point in the Martian upper atmosphere, those thrusters don’t appear big enough to be moving around 100+ tons as quickly as it will need to be. I could be wrong. I almost question if it would need an entire set of Draco’s engines for this?

also, those thrusters will only give you full control on the x&y axis.This means translate sideways you would need to turn sideways. Are you ok with not having control in all directions, because you need a fifth thruster for that?

scratch that, looking at the pic there are only 3 thrusters. Up, down, and forward. So is this what u want to do? I’m ok with it. You originally asked for control on every axis. But wait that isn’t even possible because the BFR has to back against each other to re-fuel. See how these pictures are conflicting with its functionality? 

You can see which way the thrusters fire by looking at the soot near the ports, from what I see, every axis of motion is covered. and these thrusters are likely to have 10 tons of thrust on the real BFR, that coupled with elevons, will be enough to control a BFR during EDL. These pictures were in the 2017 IAC presentation.

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9 minutes ago, eskimo22 said:

You can see which way the thrusters fire by looking at the soot near the ports, from what I see, every axis of motion is covered. and these thrusters are likely to have 10 tons of thrust on the real BFR, that coupled with elevons, will be enough to control a BFR during EDL. These pictures were in the 2017 IAC presentation.

Cold gas thrusters with 10 tons thrust. I’m going to need to research that. I looked at the soot, their are only three thrusters in those pictures and they only fire in three directions. When you say you see soot in every direction I’m not even sure what you talking about. Are we looking at the same pictures I only see soot in three places? It just so happens to be the three places those holes are.??????? 

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7 minutes ago, harrisjosh2711 said:

Cold gas thrusters with 10 tons thrust. I’m going to need to research that. I looked at the soot, their are only three thrusters in those pictures and they only fire in three directions. When you say you see soot in every direction I’m not even sure what you talking about. Are we looking at the same pictures I only see soot in three places? It just so happens to be the three places those holes are.??????? 

these won't be cold gas thrusters, they will be gaseous methane+oxygen thrusters (fuel+oxidizer+spark), cold gas thrusters don't leave soot behind. Thrusters firing perpendicular to the side of the BFS won't leave soot on the hull. you should copy the RCS arrangement that is on Tundra Exploration's BFR.

Edited by eskimo22

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32 minutes ago, eskimo22 said:

these won't be cold gas thrusters, they will be gaseous methane+oxygen thrusters (fuel+oxidizer+spark), cold gas thrusters don't leave soot behind. Thrusters firing perpendicular to the side of the BFS won't leave soot on the hull.

Dude, three holes, three nozzles, three directions. Unless there are more holes than I am seeing. You are making the assumption there are multiple points of thrust coming from those holes, which is not only purely an a assumption but more so wishful thinking.

So spaceX is developing another new engine? Whats this one called? Haven't heard about that, I'm going to need some info on that. Now we have the raptor, the merlin, the super dracos, and whatever engine you say they're making. Using liquid fueled thrusters(liquid oxidizer) in the fashion we would typically use cold gas is going to be interesting. There is a reason we decided long ago this was best to use cold gas in this situation. It just so happens fuel kind of likes to flow down not up, a problem you don't face with pressurized gas. This means extra fuel lines, pumps to help the fuel flow in the right direction, all of which carries with it extra weight along with a higher likely hood of failure, all of which are no-no's in the space game. What if one of those engines fuel pumps failed during re-entry(which happens so frequently, we now design rockets to fly when it has engines go out) ? Several hundred people are dead........ You can say engineering but engineering only goes so far..... 

Edited by harrisjosh2711

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5 minutes ago, harrisjosh2711 said:

Dude, three holes, three nozzles, three directions. Unless there are more holes than I am seeing. You are making the assumption there are multiple points of thrust coming from those holes, which is not only purely an a assumption but more so wishful thinking.

So spaceX is developing another new engine? Whats this one called? Haven't heard about that, I'm going to need some info on that. Now we have the raptor, the merlin, the super dracos, and whatever engine you say they're making. Using liquid fueled thrusters in the fashion we would typically use cold gas is going to be interesting. There is a reason we decided long ago this was best to use cold gas in this situation. It just so happens fuel kind of likes to flow down not up, a problem you don't face with pressurized gas. This means extra fuel lines, pumps to help the fuel flow in the right direction, all of which carries with it extra weight along with a higher likely hood of failure, all of which are no-no's in the space game. What if one of those engines fuel pumps failed during re-entry(which happens so frequently, we now design rockets to fly when it has engines go out) ? Several hundred people are dead........ You can say engineering but engineering only goes so far..... 

The engines will use gaseous fuel, no need for pumps. Thrusters can provide multiple axes of thrust if they are placed diagonally

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1 hour ago, eskimo22 said:

The engines will use gaseous fuel, no need for pumps. Thrusters can provide multiple axes of thrust if they are placed diagonally

Gaseous oxygen? Assuming this is correct, what about the new engines designed to run on these gaseous fuels? We certainly have never made a rocket engine to function off gaseous fuels(atleast since the beginning of rocketry), the only upside would be decreasing complication and likelihood of failure. What you are saying may be true but it complicates things big time. You certainly would not be using these things for docking. Monopropellant works because it ignites under a chemical reaction. Hence it can be turned on and off simply by closing the valves. A rocket engine does not work in such a fashion. You need a steady stream of fuel not just a quick spurt of gas. In fact, a rocket engine can only be throttled to a certain extent. If you need to stop thrust for even a second the entire engine must be cut off, re primed for ignition, and ignited. Lighting a rocket engine is also a tedious task. The fuel must be flowing completely through the engine before you attempt to light it- hence you must prime it. Many engines have been developed to ignite a finite number of times but none of those numbers were very high. A BFR would potentially need to do this hundred of times during a decent all after traveling through a rigorous 6 month journey in space. One way that you could account for this would be dependent on the throttling limitations of the engines. You could lower the thrust on the engines on the left and increase on the right assuming the difference provided adequate thrust for you maneuver. If it did not the engines on the left would need to be shut down until time the maneuver could be completed then they could be primed and shut back on. Picturing this in my mind these engines would be running the entire descent. You would only cut an engine off if you had to as re-starting the engine is never a guarantee. This is why we use monopropellant in space- we have no clue if and engine would fire up in ten years after being in space. It may, but it may not. May not doesn't cut it when there are billions of dollars or lives at stake. This isn't such a huge issue for the main engines as they only need to fire around 5-6 times in a round trip journey to mars.

 

My BFR is suppose to be using two different engines. The thrusters up front and on the tail are small weak thrusters for moving around in space. the thruster on the side are huge and produce much more thrust are for the atmospheric stuff. If you look they actually do produce a varying degree of thrust. You can cut one of them off.  

Edited by harrisjosh2711

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A self igniting blowtorch is a good analog to what I am talking about, just using methane and liquid oxygen instead of propane and air, and producing 5 to 10 tons of thrust. A self igniting blowtorch ignites 100% of the time with the press of a button and if fed with pure oxygen, could work as a thruster.

Edited by eskimo22

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22 hours ago, eskimo22 said:

A self igniting blowtorch is a good analog to what I am talking about, just using methane and liquid oxygen instead of propane and air, and producing 5 to 10 tons of thrust. A self igniting blowtorch ignites 100% of the time with the press of a button and if fed with pure oxygen, could work as a thruster.

lol, and how much thrust does a push button blowtorch produce? I have one, it doesn't produce any thrust. If you added a nozzle it would but then it would technically be a rocket engine and would suffer from the exact same downsides as one. Watch this video from Scott Manley he describes how difficult it really is to light a rocket engine and why hypergolic (self-igniting) fuels are a must use for reliable space engines. Igniting a rocket engine is not as simple as pushing a spark button like you imagine. Technically speaking, anything that throws matter out one side to produce thrust and momentum in the opposite direction is a rocket engine.

 

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16 minutes ago, harrisjosh2711 said:

lol, and how much thrust does a push button blowtorch produce? I have one, it doesn't produce any thrust. If you added a nozzle it would but then it would technically be a rocket engine and would suffer from the exact same downsides as one. Watch this video from Scott Manley he describes how difficult it really is to light a rocket engine and why hypergolic (self-igniting) fuels are a must use for reliable space engines. Igniting a rocket engine is not as simple as pushing a spark button like you imagine. Technically speaking, anything that throws matter out one side to produce thrust and momentum in the opposite direction is a rocket engine.

 

I don't mean a literal blowtorch, I mean spark ignition of a gas, which is how a blowtorch works. A blowtorch serves as an ANALOGY to the thruster I am talking about. Spark ignition of a gas is very reliable (ie, blowtorch) and rapid (milliseconds) and could ignite an RCS thruster.

16 minutes ago, harrisjosh2711 said:

lol, and how much thrust does a push button blowtorch produce? I have one, it doesn't produce any thrust. If you added a nozzle it would but then it would technically be a rocket engine and would suffer from the exact same downsides as one. Watch this video from Scott Manley he describes how difficult it really is to light a rocket engine and why hypergolic (self-igniting) fuels are a must use for reliable space engines. Igniting a rocket engine is not as simple as pushing a spark button like you imagine. Technically speaking, anything that throws matter out one side to produce thrust and momentum in the opposite direction is a rocket engine.

 

I've seen that video before, and spark igntion of a pressure fed oxy-gas thruster is much simpler than the ignition of a J-2 (like it would be in a supersized pushbutton blowtorch)

Edited by eskimo22

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14 minutes ago, eskimo22 said:

I don't mean a literal blowtorch, I mean spark ignition of a gas, which is how a blowtorch works. A blowtorch serves as an ANALOGY to the thruster I am talking about.

Yes, and if you watch that video you will see how un-reliable that is in igniting a rocket engine. Infact, according to the video, SpaceX doesn't light its merlin engines with flame. It carries a small amount of "starter fluid" that upon coming into contact with the fuel ignites. On the other hand, a recent Soyuz launch, who's engines can only be lit once, had to be aborted after one of the engines flames failed to ignite the engine- a catastrophic mistake had the rocket not been bolted to the ground. Plus you went back to liquid oxygen now which requires pumps again so what is the point in using gaseous methane since you will need a whole entire cumbersome tank for that considering the rocket Is already fitted with liquid methane and liquid oxygen?

Edited by harrisjosh2711

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3 minutes ago, harrisjosh2711 said:

Yes, and if you watch that video you will see how un-reliable that is in igniting a rocket engine. Infact, according to the video, SpaceX doesn't light its merlin engines with flame. It carries a small amount of "starter fluid" that upon coming into contact with the fuel ignites. On the other hand, a recent Soyuz launch, who's engines can only be lit once, had to be aborted after one of the engines flames failed to ignite the engine- a catastrophic mistake had the rocket not had been bolted to the ground. Plus you went back to liquid oxygen now which requires pumps again so what is the point in using gaseous methane since you will need a whole entire cumbersome tank for that considering the rocket Is already fitted with liquid methane and liquid oxygen?

The RCS will be connected to the raptor engine's gas generator (high pressure methane and oxygen gas) no need for pumps, and the Raptor engine will use SPARK IGNITION.

Edited by eskimo22

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30 minutes ago, eskimo22 said:

The RCS will be connected to the raptor engine's gas generator (high pressure methane and oxygen gas) no need for pumps, and the Raptor engine will use SPARK IGNITION.

Dude that is heresy. Where are you getting this info from some reddit board? Considering you build new technology off the technology you have already proven to work it is safe to say the Raptor engines will re-ignite just as the merlin's do because this would break the age old principle of "do not fix what isn't broken" SpaceX's merlin engine is the most reliable re-starting engine in existence, to hear someone say they are going to change it up is almost unfathomable. Also, US rockets haven't used torch light since before the Saturn V in the 70's. If you watch that video, these engines are referred to as old school rocket engines- made before the 70's, of which many are in use today because things went downhill after the 70's. You are in here claiming SpaceX is going to use archaic technology, that they themselves have never experimented with, as we can see no SpaceX engine currently in flight is lit by flame. I'm not even going to argue the fact that the engine would instantly destroy any said lighting source hundredths of seconds after the first ignition, just like the real ones that are lit this way destroy theirs. If someone had figured out some special place inside a rocket engine where this piece of technology could be safely stored from the intense heat and millions of pounds of pressure I'm sure we would do it this way. Unfortunately dealing with heats and pressure's like this even tungsten would melt. Also, as I mentioned before, sparks have were deemed in-reliable around fifty years ago. 

Notice how none of my claims are stated as facts but all yours are and you keep changing things up (gaseous oxy/lqd.oxy). I cant make a factual claim about the BFR as it doesn't exist and even if it did SpaceX isn't going to tell you all about it as they have competitors and they spent billion of dollars getting it to work.

Edited by harrisjosh2711

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49 minutes ago, harrisjosh2711 said:

Dude that is heresy. Where are you getting this info from some reddit board? Considering you build new technology off the technology you have already proven to work it is safe to say the Raptor engines will re-ignite just as the merlin's do because this would break the age old principle of "do not fix what isn't broken" SpaceX's merlin engine is the most reliable re-starting engine in existence, to hear someone say they are going to change it up is almost unfathomable. Also, US rockets haven't used torch light since before the Saturn V in the 70's. If you watch that video, these engines are referred to as old school rocket engines- made before the 70's, of which many are in use today because things went downhill after the 70's. You are in here claiming SpaceX is going to use archaic technology, that they themselves have never experimented with, as we can see no SpaceX engine currently in flight is lit by flame. I'm not even going to argue the fact that the engine would instantly destroy any said lighting source hundredths of seconds after the first ignition, just like the real ones that are lit this way destroy theirs. If someone had figured out some special place inside a rocket engine where this piece of technology could be safely stored from the intense heat and millions of pounds of pressure I'm sure we would do it this way. Unfortunately dealing with heats and pressure's like this even tungsten would melt. Also, as I mentioned before, sparks have were deemed in-reliable around fifty years ago. 

The Spark Ignition method had worked on a similar system, Nasa's Project Morpheus and was proven to be feasible, but not the best way to do things, so SpaceX probably wouldn't change things if it already works, as you said "do not fix what isn't broken". 

Edited by ChickenBot448
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