Where is the metallic hydrogen

[SSTO Crasher]

In the very first ksp2 feature video, we saw a focus on metallic hydrogen

Spoiler

 

But in a new SW Dennis video where he shows all the parts, metallic hydrogen engine like we saw them are not included, are they adding metallic hydrogen later?

[The Aziz]

Looks like it.

Next!

[Chilkoot]

There was unfortunately further research in 2022 showing meta-stable hydrogen my not be a thing.  Metallic hydrogen, yes, for sure, but stable in a way that it could ever be used as a propulsion... maybe not

I'll see if I can dig up the paper - I saw an abstract for it maybe 3 or 4 months ago but can't recall what university published it.

[Meecrob]

We only get the Kerbolar system so far in EA.  Let them get that system working before they give us essentially cheat code engines meant to go interstellar distances in the late game.

[Jarin]

Interstellar is step 3 on the roadmap. At best I wouldn't expect new uber-engines until we're moving heavy colony infrastructure in stage 2.

[Bej Kerman]

23 hours ago, SSTO Crasher said:

But in a new SW Dennis video where he shows all the parts, metallic hydrogen engine like we saw them are not included, are they adding metallic hydrogen later?

High-power engines are not coming until later on. The best you've got for EA release is the SWERV nuclear engine that outputs 700kn at 1450s, and uses hydrogen like the less efficient NERV. Until then, those and the ion thruster are your most efficient engines.

Please, temper your expectations. No-one said anything about releasing far future engines with EA - these things are coming later on the roadmap.

[Guest]

22 hours ago, Chilkoot said:

There was unfortunately further research in 2022 showing meta-stable hydrogen my not be a thing.  Metallic hydrogen, yes, for sure, but stable in a way that it could ever be used as a propulsion... maybe not

I'll see if I can dig up the paper - I saw an abstract for it maybe 3 or 4 months ago but can't recall what university published it.

No big loss tbh, the performance isn't exactly stellar and their previewed engine designs were some real head-scratchers.

[dansiegel30]

3 hours ago, Bej Kerman said:

High-power engines are not coming until later on. The best you've got for EA release is the SWERV nuclear engine that outputs 700kn at 1450s, and uses hydrogen like the less efficient NERV. Until then, those and the ion thruster are your most efficient engines.

Please, temper your expectations. No-one said anything about releasing far future engines with EA - these things are coming later on the roadmap.

Well, I think Ion and Nuke engines will be fine for any intra-Kerbol destination as long as the new timewarp under acceleration works as promised.  I dont recall anyone trying that during the ESA demo vids released in the last 48 hours.  If its a 300 minute burn that can be timewarped into 30 seconds, heh...no problem!!!

[Chilkoot]

3 hours ago, regex said:

No big loss tbh, the performance isn't exactly stellar and their previewed engine designs were some real head-scratchers.

The engine designs *were* odd... I could be wrong here, but my understanding is that the conversion from metallic back to molecular is where all the energy release happens, and that energy is harnessed to direct an expanding propellant out via the nozzle, a lot like any thermo-nuclear engine.  It sounded like the in-game implementation was just using high-density combustible hydrogen, but I could have misunderstood the dev description of the new fuel source.

Even under the best conditions, the projected ISP of a metallic hydrogen engine would be in the 1200 range for real-world, and maybe 1700 with some kind of magical materials breakthrough that could withstand contact with the 6000K reaction.  The new nuclear engines we saw in the ESA reveal were hitting 1200 ISP, so even though they have a crappy TWR , they're still looking great for interplanetary transfers.

[Guest]

Just now, Chilkoot said:

The new nuclear engines we saw in the ESA reveal were hitting 1200 ISP, so even though they have a crappy TWR , they're still looking great for interplanetary transfers.

Yo, that's nice, finally some realistic (theoretical) nuclear engine isps! I'd expect 1000s at the max but they're looking a bit further, and with the implied material science advance to enable metallic hydrogen engines we get better NTRs, maybe enriched fuel or a low pressure NTR.

[Drakenred65]

I think the main problem is they thought that you would get the metallic hydrogen somehow From Jool and store it. 

[mcwaffles2003]

On 2/20/2023 at 2:28 PM, SSTO Crasher said:

In the very first ksp2 feature video, we saw a focus on metallic hydrogen

  Reveal hidden contents

 

But in a new SW Dennis video where he shows all the parts, metallic hydrogen engine like we saw them are not included, are they adding metallic hydrogen later?

It's in the same place as the Orion drive, Daedalus, and all the other future tech... waiting for the interstellar update. Phase 1 isn't about giving us everything they've built so far, its about fixing the most fundamental bugs that all the later stuff will rely on to work. This will probably help prevent the spaghetti mess that was KSP 1's code as well as keep the devs focused on fewer specific bugs so we don't have 1000+ active bugs 10 yrs after launch.

[Bej Kerman]

15 hours ago, dansiegel30 said:

Well, I think Ion and Nuke engines will be fine for any intra-Kerbol destination as long as the new timewarp under acceleration works as promised.  I dont recall anyone trying that during the ESA demo vids released in the last 48 hours.  If its a 300 minute burn that can be timewarped into 30 seconds, heh...no problem!!!

Indeed

The NERV was going to be my go-to engine for interplanetary stuff, but when I saw the stats of the SWERV engine in @Space Scumbag's handy part overview video, my mind immediately changed. It's nice to see some love given to this engine niche.

10 hours ago, mcwaffles2003 said:

It's in the same place as the Orion drive, Daedalus, and all the other future tech... waiting for the interstellar update. Phase 1 isn't about giving us everything they've built so far, its about fixing the most fundamental bugs that all the later stuff will rely on to work. This will probably help prevent the spaghetti mess that was KSP 1's code as well as keep the devs focused on fewer specific bugs so we don't have 1000+ active bugs 10 yrs after launch.

Thank you for saying this

People are so used to Squad's atrocious management that we're already seeing expectations for new features right out the gate.

[magnemoe]

21 hours ago, Chilkoot said:

The engine designs *were* odd... I could be wrong here, but my understanding is that the conversion from metallic back to molecular is where all the energy release happens, and that energy is harnessed to direct an expanding propellant out via the nozzle, a lot like any thermo-nuclear engine.  It sounded like the in-game implementation was just using high-density combustible hydrogen, but I could have misunderstood the dev description of the new fuel source.

Even under the best conditions, the projected ISP of a metallic hydrogen engine would be in the 1200 range for real-world, and maybe 1700 with some kind of magical materials breakthrough that could withstand contact with the 6000K reaction.  The new nuclear engines we saw in the ESA reveal were hitting 1200 ISP, so even though they have a crappy TWR , they're still looking great for interplanetary transfers.

Hydrogen ISP is limited to the melting point of the engine material, this is that limits nuclear thermal engines unless you do crazy stuff like molten core, you let the reactor melt down this let you run it at higher temperature  
But metallic hydrogen after converted would be hydrogen ions who you could control with an magnetic nozzle. I say you could get ion engine ISP but high trust doing this. You could also inject normal hydrogen cooling the ions, this you an high trust and nuclear thermal ISP without radiation. To balance it I assume metalic hydrogen will be hard to produce in bulk. The factory shown was VAB sized, yes perhaps half the height but it was massive. But its the fuel you want on the landers you send over interstellar distances. 
 

[magnemoe]

16 hours ago, mcwaffles2003 said:

It's in the same place as the Orion drive, Daedalus, and all the other future tech... waiting for the interstellar update. Phase 1 isn't about giving us everything they've built so far, its about fixing the most fundamental bugs that all the later stuff will rely on to work. This will probably help prevent the spaghetti mess that was KSP 1's code as well as keep the devs focused on fewer specific bugs so we don't have 1000+ active bugs 10 yrs after launch.

I would expect some new tech like the dual mode nuclear thermal with an retractable vacuum nozzle with science.
I would expect Orion pulse nuclear with colonies as you need to move many hundreds of ton of cargo to other planets. Its not an interstellar engine, isp is ion engine level or a bit better for the larger one but it has trust to move thousands of ton and still having many thousands of dV.

Now metallic hydrogen engines is petty easy to implement in the game, its simply an better thermal nuclear engine. 
And that is the problem, Orion is an niche for massive ships as the engines will weight hundreds of ton and would nuke KSC if staged on the pad. Metallic hydrogen don't have many downsides if you get it free in the VAB. 

[Drakenred65]

I think the idea of a ground launch was to use a conventional explosive for the first pulse. Granted that was not going provide much thrust so each following pulse was going to be nuclear, which was why using Saturn's main stage as a booster/ First stage came in. 

 

Actually they had a lot of ideas for using Saturn's first stage , including launching NERV  based cargo tugs.

[mcwaffles2003]

6 hours ago, magnemoe said:

I would expect some new tech like the dual mode nuclear thermal with an retractable vacuum nozzle with science.
I would expect Orion pulse nuclear with colonies as you need to move many hundreds of ton of cargo to other planets. Its not an interstellar engine, isp is ion engine level or a bit better for the larger one but it has trust to move thousands of ton and still having many thousands of dV.

Now metallic hydrogen engines is petty easy to implement in the game, its simply an better thermal nuclear engine. 
And that is the problem, Orion is an niche for massive ships as the engines will weight hundreds of ton and would nuke KSC if staged on the pad. Metallic hydrogen don't have many downsides if you get it free in the VAB. 

Yeah, but they gotta drag us along and give us extra tidbits along the way. Also, they did throw us a bone and throw in a new nuclear engine with insane performance that is 10t. Personally I'm hoping to see some new ion type engines like in NFT as updates release

[magnemoe]

6 hours ago, Drakenred65 said:

I think the idea of a ground launch was to use a conventional explosive for the first pulse. Granted that was not going provide much thrust so each following pulse was going to be nuclear, which was why using Saturn's main stage as a booster/ First stage came in. 

Actually they had a lot of ideas for using Saturn's first stage , including launching NERV  based cargo tugs.

Yes, in real world they would used an Saturn 5, Nova or SRB clusters to push it into the stratosphere there you fire it up. 
But most players would not know / realize it, ship is fine but the KSC has lots of damages  

[Cailean_556]

While I can understand real-life studies debunking, or at least curbing our expectations of, metallic hydrogen-based fuels and engines...I don't see why they couldn't just add it anyway. Who's to say our little green friends didn't figure out a way to make metallic hydrogen work for them...or perhaps the Kerbal Workplace and Health and Safety authority are...less stringent...on occupational risks?

In the mean time, I'm looking forward to wrapping my head around the uprated ion engine and the 4-nozzle SWERV - right after I tinker with a few Mun landers.