Realism Overhaul Discussion Thread

[PLAD]

I'm curious as to what others use for a re-entry procedure from the moon. .

With the Mk1-2 pod: I set a vacuum periapsis of between 56 and 65km before hitting the atmosphere. I then use descent mode as needed to get an actual first periapsis of 58.5 to 59.9 km. I then try to not skip back up higher than 65km (rotate to the maximum sink position if you have to). After I start back down from 65km I keep the pod rotated for maximum lift until the flames stop. This keeps the g-max to about 4-5. As you found, if you bounce up too high after the first pass you might come down the second time too steeply to survive. Good luck!

[ninjaweasel]

With the Mk1-2 pod: I set a vacuum periapsis of between 56 and 65km before hitting the atmosphere. I then use descent mode as needed to get an actual first periapsis of 58.5 to 59.9 km. I then try to not skip back up higher than 65km (rotate to the maximum sink position if you have to). After I start back down from 65km I keep the pod rotated for maximum lift until the flames stop. This keeps the g-max to about 4-5. As you found, if you bounce up too high after the first pass you might come down the second time too steeply to survive. Good luck!

After reading this, it is clear that my problem is that I don't know the first thing about how to fly the Mk1-2 pod. My procedure has been:

1. Set periapsis

2. Turn on decent mode. Because I'm descending, right?

3. Cross fingers, hope I got step 1 right.

Where can the instructions for flying that pod be found?

[NathanKell]

Here's a nice tutorial (I believe it's linked in the RO OP...)

https://www.youtube.com/watch?v=gLnoKRuIdBMT

Note that that's from back when pods were always in descent mode (i.e. the CoM was just plain shifted, no plugin toggle), so the zeroeth step for the tutorial, these days, is turning descent mode on.

[Keudn]

Does anyone know how to get my service module's RCS to fire? Since my command pod is separated by a heatshield only the RCS on the pod itself fires, the RCS on the fuel tank won't

http://gyazo.com/3139cf08f44a5e237b9f8ff3ec939d89

[RobotsAndSpaceships]

How can I get hotrockets and smokescreen working with RO?

[NathanKell]

If you install RO manually, it comes with RealPlume; if you install via CKAN, it suggests it.

RealPlume is the equivalent of HotRockets for RO. It's a WIP (obviously) but most Squad and FASA engines are currently well-supported.

[RobotsAndSpaceships]

If you install RO manually, it comes with RealPlume; if you install via CKAN, it suggests it.

RealPlume is the equivalent of HotRockets for RO. It's a WIP (obviously) but most Squad and FASA engines are currently well-supported.

That's weird, since I installed it without CKAN, and still get the stock effects. Is it integrated into the realismoverhaul.dll, or is it a separate package?

[NathanKell]

Make sure you have Smokescreen installed and that there are Smokescreen_* folders inside RealismOverhaul...

[RobotsAndSpaceships]

Make sure you have Smokescreen installed and that there are Smokescreen_* folders inside RealismOverhaul...

Will having hotrockets installed at the same time somehow conflict with it? I see SmokeScreen_EffectCfgs, SmokeScreen_MP_Nazari_FX, and SmokeScreen_RE_Sounds in the realismoverhaul folder right now.

[RobotsAndSpaceships]

Alright, I figured it out, but some engines still seem to be missing configs.

[frsd]

So what's up with the part rescales, the Mk3 cockpit, cargo bays, fuesalages/tanks are all rescaled but the adapters are not?

[chrisl]

I'm not sure if this is the right place for this post or not. Please point me in the right direction if necessary.

Anyway, I'm still very early in my RO/RP-0/10x career (with RemoteTech). Just got the research that includes the DTS-M1 directional antenna so I decided that I'd try putting up my first communication satelites but I keep running into issues. I've put together an Atlas-Agena rocket using the "Atlas SLV-3" tank, LR-105 & LR-89 engines (on the Atlas stage), the Agena-D Guidance Unit and antenna, Bell 8247 engine and a procedural tank setup to give the Agena stage the 265s burn time it's supposed to have. Historically this setup should be able to put a .7t satelite into GEO orbit. The satellite itself weighs in at 0.843t with it's own Bell 8247 engine and 16s worth of fuel. It also has a Communotron 16, two DTS-M1 and some solar panels.

After launch, I remain vertical until reaching 150m/s which puts this rocket at around 2500m asl. This happens at about t+36s, at which point I lean the rocket to around 65 degrees as part of my gravity turn. I stay at 65 degrees and monitor the temperature of the SLV-3 tank until it's at just about 670C, at which point I jettison the boosters. This happens at about t+1:43 at which point I'm traveling at about 1km/s, am just over 30km and have an anticipated Apoapsis of over 65km. Once the boosters clear the remaining engine, I pitch over to 50 degrees which is where I stay for the next couple minutes. At about 90km asl, I activate the Agena antenna which should let me remain in contact with KSC to around 3.75Mm. At this point I pay close attention to my Apoapsis and vertical speed. Vertical speed has been dropping basically ever since I jettisoned the boosters but eventually it'll start climbing again as my horizontal speed picks up. Once my Apoapsis is around 120km (or if my vertical speed starts climbing), I'll start pitching over further. Usually I go in 5 degree increments every time my vertical speed starts climbing.

At somewhere over 150km, at t+7:44, the Atlas SLV-3 tank will finally run dry at which point I stage to the Agena. Just before staging, I'm on a suborbital trajectory with an Apoapsis a bit above 160km, a Periapsis showing as below -4Mm, a surface speed of around 4.5km/s and an orbital speed showing just over 5km/s. My Agena stage says its got 3835m/s dv available which should be enough to at least get me into orbit. Normally right after staging to the Agena, I'll also jettison the fairings I've had covering my payload and will activate the antenna on it. I'll point one DTS at Kerbin and the other at Mission Control for now. Also, because of the pitching I've been doing up till now, I'm usually at around 10 degrees above the horizon which is pretty much were I leave the rocket pointed while the Agena stage burns through it's fuel. Only instead of running out of fuel, I encounter my first issue.

At around t+10:22 with the Agena antenna, Communotron16 and two DTS-M1 antenna all running, I suddenly lose my connection with mission control which shuts the Bell 8247 engine down. According to Mechjeb, I'm about 1.5Mm from the runway and I'm still just over 160km asl. Both of my omni antenna should still be well within range of mission control, plus I've got a DTS pointing right at mission control. I suppose I could simply be out of LOS of mission control because of the curvature of the planet but if that's the case, how else am I supposed to get a comm satelite into orbit?

My second problem is that when the Bell 8247 engine shuts down, Mechjeb reports that I have no more delta-v available in this stage even though I still have about half a tank of fuel. I'm under the impression that the Bell 8247 can be restarted a few times but when I right click on the now shutdown engine, it say "Ignitions: Hypergolic - 0/1". Am I doing something wrong that's not allowing me the ability to restart this engine? I do have little rcs thrusters on the actual satellite which I should be able to use to settle the fuel.

Finally, just before the Agena stage shut off from lack of communication, I had something like 2000m/s dv still remaining on it. After the shut off I'm still in a sub-orbital trjectory with Apoapsis of just over 161km, Periapsis below -2Mm, surface speed of over 6km/s and orbital speed of around 6.6km/s. Supposedly the Atlas-Agena could put a 0.7t payload into GEO orbit and while my payload is actually 0.843t, 2000dv doesn't seem like nearly enough to get me near a circulized GEO orbit. If my comms weren't failing, would the 2000 dv from the Agena, plus the 1900dv from the satelite itself really be enough to not only finish putting me into orbit, but also to adjust my orbit up to around 36Mm?

[Felger]

I'm not sure if this is the right place for this post or not. Please point me in the right direction if necessary.

Anyway, I'm still very early in my RO/RP-0/10x career (with RemoteTech). Just got the research that includes the DTS-M1 directional antenna so I decided that I'd try putting up my first communication satelites but I keep running into issues. I've put together an Atlas-Agena rocket using the "Atlas SLV-3" tank, LR-105 & LR-89 engines (on the Atlas stage), the Agena-D Guidance Unit and antenna, Bell 8247 engine and a procedural tank setup to give the Agena stage the 265s burn time it's supposed to have. Historically this setup should be able to put a .7t satelite into GEO orbit. The satellite itself weighs in at 0.843t with it's own Bell 8247 engine and 16s worth of fuel. It also has a Communotron 16, two DTS-M1 and some solar panels.

After launch, I remain vertical until reaching 150m/s which puts this rocket at around 2500m asl. This happens at about t+36s, at which point I lean the rocket to around 65 degrees as part of my gravity turn. I stay at 65 degrees and monitor the temperature of the SLV-3 tank until it's at just about 670C, at which point I jettison the boosters. This happens at about t+1:43 at which point I'm traveling at about 1km/s, am just over 30km and have an anticipated Apoapsis of over 65km. Once the boosters clear the remaining engine, I pitch over to 50 degrees which is where I stay for the next couple minutes. At about 90km asl, I activate the Agena antenna which should let me remain in contact with KSC to around 3.75Mm. At this point I pay close attention to my Apoapsis and vertical speed. Vertical speed has been dropping basically ever since I jettisoned the boosters but eventually it'll start climbing again as my horizontal speed picks up. Once my Apoapsis is around 120km (or if my vertical speed starts climbing), I'll start pitching over further. Usually I go in 5 degree increments every time my vertical speed starts climbing.

At somewhere over 150km, at t+7:44, the Atlas SLV-3 tank will finally run dry at which point I stage to the Agena. Just before staging, I'm on a suborbital trajectory with an Apoapsis a bit above 160km, a Periapsis showing as below -4Mm, a surface speed of around 4.5km/s and an orbital speed showing just over 5km/s. My Agena stage says its got 3835m/s dv available which should be enough to at least get me into orbit. Normally right after staging to the Agena, I'll also jettison the fairings I've had covering my payload and will activate the antenna on it. I'll point one DTS at Kerbin and the other at Mission Control for now. Also, because of the pitching I've been doing up till now, I'm usually at around 10 degrees above the horizon which is pretty much were I leave the rocket pointed while the Agena stage burns through it's fuel. Only instead of running out of fuel, I encounter my first issue.

At around t+10:22 with the Agena antenna, Communotron16 and two DTS-M1 antenna all running, I suddenly lose my connection with mission control which shuts the Bell 8247 engine down. According to Mechjeb, I'm about 1.5Mm from the runway and I'm still just over 160km asl. Both of my omni antenna should still be well within range of mission control, plus I've got a DTS pointing right at mission control. I suppose I could simply be out of LOS of mission control because of the curvature of the planet but if that's the case, how else am I supposed to get a comm satelite into orbit?

My second problem is that when the Bell 8247 engine shuts down, Mechjeb reports that I have no more delta-v available in this stage even though I still have about half a tank of fuel. I'm under the impression that the Bell 8247 can be restarted a few times but when I right click on the now shutdown engine, it say "Ignitions: Hypergolic - 0/1". Am I doing something wrong that's not allowing me the ability to restart this engine? I do have little rcs thrusters on the actual satellite which I should be able to use to settle the fuel.

Finally, just before the Agena stage shut off from lack of communication, I had something like 2000m/s dv still remaining on it. After the shut off I'm still in a sub-orbital trjectory with Apoapsis of just over 161km, Periapsis below -2Mm, surface speed of over 6km/s and orbital speed of around 6.6km/s. Supposedly the Atlas-Agena could put a 0.7t payload into GEO orbit and while my payload is actually 0.843t, 2000dv doesn't seem like nearly enough to get me near a circulized GEO orbit. If my comms weren't failing, would the 2000 dv from the Agena, plus the 1900dv from the satelite itself really be enough to not only finish putting me into orbit, but also to adjust my orbit up to around 36Mm?

Holy wall of text batman!

On communications:

Depending on how far downrange you've got, you might have fallen behind the earth's curvature. Radio signals don't travel so good through rock. There's a few ways to accomplish an insertion this way:

• Use the flight computer to pre-program the rest of your ascent.
  
• Launch some commsats using manned missions to give coverage
  
• Launch from a launch site with ground stations downrange (make sure you have the up-to-date RSS RemoteTech config file, it has a few more comm stations)
  
• Write a config file to remove the signal processors from probes (probes without a signal processor won't require a link for control, but still have to have a link for data transmission.)
  

On Delta-V

Have a look at this:

In general, it's about 2.45km/s to GTO, and another 1.5km/s to circularize at GEO (the chart linked has slightly better numbers) depending on your starting orbit. So no, I don't think you could have circularized. Not to mention the cost to drop your inclination to zero degrees (Want to do that at apoapsis, much lower DV cost) if desired.

[NathanKell]

Also, 65 degrees!? Well, that would explain things. You are kicking over quite late (150m/s) and to a KSP-level degree. Please see the Guides here, especially the False KSP Lessons one and Ferram's ascent / TWR tutorial. That should help you out. The key is smooth.

Also, Atlas generally dropped boosters at 2min 15s in. You might well want to wait a bit extra.

Suggestion: Put a small satellite in orbit first (something like a 300x2000km orbit), and launch your geosat while that one is overhead, to act as a relay.

[chrisl]

@Fledger: Yeah, sorry about the wall of text. I figured at least part of my problem was likely the ascent profile I was using so figured I should describe it. Anyway, I'm playing with 10x Kerbal, not stock RSS, so there are only 4 receivers on the planet. Didn't realize that stock RSS had more.

Also, if what you're saying is correct about the delta-v, I'm missing something. My satellite is only 20% heavier then what the real Atlas-Agena was supposed to be able to put into GEO orbit (according to the wiki, anyway) and most of that weight is the fuel it has so I could do some orbital maneuvers (I'm trying to fill a contract as well as put up a geo comm sat). I'm not sure why I'm so far off if I need nearly another 2km/s.

@NathanKell: I've been droping the boosters when I do because the fuel tank has reached 670C. I know the specs in game say it should go up to 800C but what I've been seeing is that shortly after 700C the thing explodes. I ran a number of test flights and learned that 670C was about as hot as I could let the tanks get because even after the boosters drop, there's still a second or two before the tank starts to cool back down.

EDIT: I had reveiwed several of the guides but I'll do so again to try and see what I've missed. Thanks.

EDIT: Did a test flight. Pitch to 85 degrees as 100m/s then follow prograde, all the while monitoring the temperature of my atlas fuel tank. At t+1:49 I've slowly pitched over to around 65 degrees, I'm at just around 39km with a surface speed of 1.1km/s and the Atlas SLV-3 says it's at 692C. At t+1:51 I'm just a tick beyond 65degrees at over 41km doing 1.15km/s and the Atlas SLV-3 has just hit 720C and exploded. I'm using Deadly Reentry 6.4.0 set to normal mode.

EDIT: Downloaded Deadly Reentry 6.5.2 Beta and reran my flight. Normal and "Alternate Heading Model" selected (those are the defaults). Again, at 100m/s I pitch to 85 and then follow surface prograde. This time I was able to fly to t+2:15 before jettisoning the boosters and even then, my tank is only at 264C which is much better. I'm also at about 62 degree, 73km and doing about 1.9km/s. However, I only have about 3:10 of fuel left in the tank according to MechJeb. According to the wiki I'm reading, the "first stage" of the atlas-agena should be able to run for 5 minutes. I assumed that was 5 minutes after jettisoning the booster which means I've lost 2 minutes somewhere. Is it actually saying 5 minutes from activation (which happens with the booster)?

Also, at this point my Apoapsis is showing 230km which is higher then I think I want. Presumably it's okay to pitch over once my Apoapsis is about where I want it? Or should I be pitching a bit faster then I did for this set of tests?

UPDATE: One last update. Went back to the VAB and reworked my payload so that it's 0.703t so it's only 0.4% above what the Atlas-Agena could put into GEO orbit. Figured I should rule out my payload weight being the issue. Still need at least 1000dV more then I have to reach GEO. So I went back into VAB and pulled the entire payload section. According to the wiki I've been using, the Atlas-Agena weighs in at 155t. It's Booster stage should run for 134s, stage 1 should run for 5 minutes and stage 2 should run for 265s. I noticed that my 2nd stage can run 272s so it's a bit larger then it should be but my complete launch vehicle is only 128.4t. So I have to wonder, if I had another 26.6t of fuel in the Atlas stage, would that give me the dV I expect based on the wiki?

Edited February 13, 2015 by chrisl

[Hattivat]

I'm pretty sure these figures on Wikipedia are wrong, it says 1000 kg for LEO and 700 kg for GEO. The only way such a mass fraction could be possible is if Agena used a nuclear rocket or an ion engine. Normally for rockets PayloadToGEO <= 1/2*PayloadToGTO <= 1/4*PayloadtoLEO, and that's with hydrogen stages with Isp in excess of 400, with Agena's poor Isp it's bound to be even worse. Assuming it can lift 1000 kg to LEO, my guesstimate would be 300 kg to GTO and 100 kg to GEO, and I'm probably being optimistic here.

See here: http://en.wikipedia.org/wiki/Comparison_of_orbital_launch_systems

For example: Atlas V 501 lifts 8250 kg to LEO, 3970 kg to GTO, and 1500 kg to GEO

As for Deadly Reentry, it's not very realistic, especially not in simulating ascent heating, but it's the best we have for now. So when it makes your reasonably-piloted rockets blow up on ascent, it a reason to adjust DRE's settings, not to adapt your ascent path to its unrealistic behavior

[NathanKell]

chrisl: Yes, as you saw, DRE is kinda screwy, but much better behaved in beta.

As to turns, if you're only at 65 degrees by nearly two minutes (and 40km) in, you're turning a bit slow. Try a sharper kick, or adding a bit more down-pitch during the turn (rather than flying a zero-lift ascent). You should aim to hit 45 degrees at 1km/sec. In particular, it sounds like you *stop* pitching at 65 degrees for some reason...you're supposed to keep pitching smoothly all the time, and only stay "above" the prograde indicator if for some reason your time-to-apoapsis is getting too small.

Yes, 5 minutes is the total burn time (basically you jettison boosters at ~2m15s, then stop sustainer at ~5 minutes in, then burn on verniers until desired velocity reached).

230km is a fine first apoapsis; most LVs, after all, circularize after apogee (so you'd be burning all the way to, and past, 230km, and finish circularizing about 180km on the way back down).

[chrisl]

Well, I figured part of the problem was I used the Atlas SLV-3 tank which is listed as one of the more used tanks on the wiki. But when I finally took a look at the Atlas SLV-3A tank, I managed to get a vehicle weight that matched the wiki. So I'm guessing that the wiki is based on values from all of the Atlas launch vehicles that are mentioned (LV-3, SLV-3, SLV-3A, SLV-3B and E/F) which explains some of the odd results. And probably explains why the wiki says 1000kg to LEO and 700kg to GEO.

As for my pitch rate, I have to run with SAS on so it's constantly trying to stop me from pitching over. I tried one flight without SAS going but it starts pitching AND yawing which results in my having to make constant corrections. Figure if I have to do that already, I might as well just control the pitching myself. I'll work on leading prograde a bit more. And not really sure why it stopped pitching during that first flight other than by that point I was out of the atmosphere by quite a ways. I did finally manage a couple of test flights with 180km periapsis (apoapsis anywhere between 2Mm-26Mm based on various factors in the flights) but I end up pitching pretty hard (40 degrees or so) just after I jettison the boosters to manage that. Just need more work on my gravity turn.

Wait. I'm supposed to shut the sustainer engine down? I've been burning that till I'm out of fuel and even then I have yet to actually manage to get into GTO, let alone GEO. I figured you burned the sustainer until the Atlas tank was dry, at which point you stage to the Agena. Keep in mind, I'm not even making it to LEO on just the Atlas tank. I'm running dry probably 1km/s shy of what I'd need for LEO. If I shut the sustainer down and run just on the verneirs, I don't see how I'll do any better since the verneirs won't have enough thrust on their own.

Maybe the circulization is also part of my issue. The few times I've managed it to 180km periapsis, I've basically burned the described gravity turn until my apoapsis is just above 180km, then I pitch over to 0 until I reach apoapsis. Once I hit apoapsis, I pitch back up just enough to keep my vertical speed near 0. I'll slowly pitch down again as I speed up, always trying to keep vertical speed at 0. When I finally run out of fuel on the Atlas and stage to the Agena, I continue that process but the Agena's lower thrust means I pitch up quite a bit (back to around 40). That'll slowly lower back down to 0 as I speed up, but maybe I'm losing too much dV fighting gravity that way? I'm guessing I'd still have to fight gravity a bit if I initially aimed for 230km and let myself fall back to 180km while finishing the circulization process, but maybe less them I'm doing now?

I find it so weird, though. I managed to put a Mercury/Atlas into actual orbit on nothing more then that "Mercury-Atlas Launch Vehicle" and that's less fuel than the SLV-3A tank. It wasn't a great orbit (something like 140km x 1.8Mm) but still. I figured the more powerful Atlas-Agena would put my little satellite up without much issue.

[BevoLJ]

On the last point there, I always use the smaller Atlas tanks. In my experience the larger tanks are super heavy. I always get better results on the smaller Atlases.

[Astrofox]

I have an issue with the engines, the engine plumes are not showing up when they are firing, even when in midair.

here's the issue:

or if the pic doesn't work, here: pic

thanks.

[Felger]

I have an issue with the engines, the engine plumes are not showing up when they are firing, even when in midair.

here's the issue:

https://www.dropbox.com/s/xtgxn518lu5u8xp/Screenshot%20of%20engine%20not%20producing%20plume.png?dl=0

or if the pic doesn't work, here: pic

thanks.

That's weird, do you have SmokeScreen installed?

[Astrofox]

No, I checked thoroughly, but no I don't have smokescreen.

[Felger]

No, I checked thoroughly, but no I don't have smokescreen.

It's sort of a bug in the way we built the SmokeScreen configs. I'll fix it in the next release, but basically you either need to install SmokeScreen, or remove the RealismOverhaul/SmokeScreen_~~~/ folders from your installation.

[chrisl]

Finally managed to get my GEO/contract satellite into orbit. It took using the large Atlas SLV-3A tank plus upgrading the two boosters to their best option and even then I only had about 50dV remaining once I got it into a stable 29Mm orbit. But at least it's up and the contract is finished. Now I can try setting up closer range (thinking 10Mm orbit) comm relays.

[chrisl]

Likely, this is the wrong thread for this but since one of the "read me" files for RO talks about "MechJeb Ascents", I figured I'd try here first. Now that I've put a satellite up using a proper gravity turn (more or less), I wanted to try using MechJeb. I setup my ascent path as described in the MechJeb Ascents document (start 1km, end 150km, turn shape 50) and for the most part this seems to work, but I am ecountering two issues.

First, once I've reached about 100m/s, the Ascent Guidance window says it's starting the Gravity turn, but if I leave it to MechJeb, the rocket continues to climb straight up. In fact, it doesn't seem to actually start the gravity turn until it's doing closer to 300m/s. I can't figure out what might be causing this, though. Hopefully someone has a suggestion.

Second, by default, MechJeb will fire the engines until the Apoapsis matches the Orbit Altitude you've set on the Ascent Guidance window. Then it cuts the engines and sets up for a circulization burn. In RO this is a problem since your main engine likely can't be ignited again. Is there a way to tell MechJeb to not shut the engine down? Or at least not shut the engine down until you've actually achieved the orbit you've requested?