If We Ever Get Heavy Scifi SSTOs We Would Probably Launch And Land From The Ocean...

[Spacescifi]

Scenario: You are running off a fuel with the energy density of antimatter... mixed with less energetic propellant... so as to give the propellant waaay more thrust than it would achieve off mere chemical reactions. Thus you are able to SSTO heavy spaceships on par with naval sea vessels for wet mass with fuel/propellant to spare.

Thankfully the fuel is easier to work with than antimatter.... but like antimatter it emits gamma rays when burned out as exhaust mixed with chemical propellant.

 

Thus the thermal combustion chambers are lined with super dense gamma reflective material.

 

Why the ocean:  Launch is easy... even with a belly lander, flipping a ship vertical in the ocean is as easy as filling the rear end up with water so it sinks and raises up the nose.

Also water works fine as propellant.

 

And it is safer for gamma exhaust to occur on the ocean instead of land.

 

In space... where radiation is common... blasting gamma exhaust when landing on moons without atmosphere matters less given there is no habital environment to pollute.

 

 

[farmerben]

Corn based ethanol is the perfect additive.  If your seals are all rated for antimatter, you don't have to worry about the ethanol gumming things up.  

[kerbiloid]

56 minutes ago, farmerben said:

Corn based ethanol is the perfect additive. 

with caffeine and taurine.

Because

1 hour ago, Spacescifi said:

energetic propellant

[KSK]

14 hours ago, kerbiloid said:

with caffeine and taurine.

Because

It also improves spacecraft aerodynamics whilst reducing structural complexity and mass. After all, there's no need to equip your vessel with aero-control surfaces when Red Bull gives you wings. 

Ahem.

Back to OP.  The thread title is a bit of an overgeneralization but for this design of science-fiction SSTO, water landings probably do make sense.

[Spacescifi]

3 hours ago, KSK said:

It also improves spacecraft aerodynamics whilst reducing structural complexity and mass. After all, there's no need to equip your vessel with aero-control surfaces when Red Bull gives you wings. 

Ahem.

Back to OP.  The thread title is a bit of an overgeneralization but for this design of science-fiction SSTO, water landings probably do make sense.

Realistically we cannot do it because we do not have good antimatter storage or generation.

 

Significantly I learned that gamma rays and antimatter are very much related.

 

This from google:

When gamma rays made by electrons interact, they can create matter-antimatter pairs—an electron and a positron. Now, scientists have developed a new trick to create these matter-antimatter pairs even more efficiently.

https://www.laserfocusworld.com/test-measurement/research/article/16571409/laser-pulses-make-electrons-produce-gamma-rays-then-matterantimatter-pairs-of-particles

It's from 2018 though.

But it stands to reason that if mass can generate radiation... radiation can be used to generate mass.

Just like water when broken down becomes separate elements but can be combined to make water.

I only thought of antimatter or something like it because Scott Manley fusion rockets are a no go even if we had them due to the neutron radiation being even worse than nuclear fission.

 

Gamma ray exhaust from rockets the atmosphere can readily absorb though... so is a less polluting choice mankind would be more willing to use.

 

My point was more or less if we get SSTOs... especially heavy ones we have no way of lifting now... as far as we know cannot pull that off without significant radiation exhaust.

 

Thus the ocean. Crew can use inflateable speed boats to reach the shore while the SSTO anchors at sea.

 

 

Edited January 22, 2023 by Spacescifi

[Gargamel]

On 1/21/2023 at 11:51 AM, Spacescifi said:

You are running off a fuel with the energy density of antimatter

That could be anything.    Dirt.   Water.   A pile of chairs.    Anti matter is the same thing as matter, but…. The opposite.    The majority of antimatter will only release energy when it meets matter.    Of course stuff like anti-dynamite will still explode if you light the anti fuse, but anti matter has no more energy density than matter does.   The energy released by matter/antimatter interactions is purely dictated by E=mc^2.    You take an anti-pencil and tap it with a pencil it will release the same amount of energy if you hit an anti rock and rock together if they have same mass as the pencils.   
Therefore, a fuel with the energy density of antimatter is simply…. Matter.   Of any type.  

[kerbiloid]

Antimatter doesn't matter.

[Spacescifi]

8 hours ago, Gargamel said:

That could be anything.    Dirt.   Water.   A pile of chairs.    Anti matter is the same thing as matter, but…. The opposite.    The majority of antimatter will only release energy when it meets matter.    Of course stuff like anti-dynamite will still explode if you light the anti fuse, but anti matter has no more energy density than matter does.   The energy released by matter/antimatter interactions is purely dictated by E=mc^2.    You take an anti-pencil and tap it with a pencil it will release the same amount of energy if you hit an anti rock and rock together if they have same mass as the pencils.   
Therefore, a fuel with the energy density of antimatter is simply…. Matter.   Of any type.  

 

You know what I'm trying to say.... a fuel with the energy density of a reaction between antimatter/matter of it's mass.

 

For example 8 kilograms antimatter reacting gradually with whatever amount you are willing to spare of propellant over time.

Truth be told you do of not need a lot of antimatter... just a lot of propellant to mix with small amounts of antimatter.

 

I suspect antimatter storage may be harder than generating it.

 

Perhaps we may find ways of generating useful amounts of antimatter but will use it immediately in a flash of antimatter/matter reaction?

 

What would be really cool is a fuel that could generate antimatter from laser pulses... meaning the laser pulse would generate pulsed uber thrust from the midst of the reaction chamber everytime.

Essentially turning a bit of propellant into antimatter while surrounded in a pool of normal propellant.

 

Via I dunno... laser pulses and a forcefield, maybe manipulating the weak force with a forcefield while laser pulsing?

Edited January 23, 2023 by Spacescifi

[Gargamel]

35 minutes ago, Spacescifi said:

 

Truth be told you do of not need a lot of antimatter... just a lot of propellant to mix with small amounts of antimatter.

 

Then you get exactly the amount of energy as converting that small amount of antimatter.     
 

You can’t mix antimatter and matter without getting a complete 100% conversion of mass  to energy.  
 

It’s not an octane booster.   It’s not some chemical or element you can mix with anything.   It’s antimatter.   It’s the opposite of matter.   There’s nothing special about antimatter.    It’s not magic.   It’s just stuff, but different.  
 

You are basically saying you want to take anti-basketballs and throw them into a big tank of gasoline to make the gasoline have more oomph.   But it doesn’t work like that.  
 

And you can’t have a substance that has the same energy density as antimatter, because that’s just antimatter.  It’s 100% efficient.   Anything that would be the same would have to also be 100% Efficient.   And that _only_ comes from an anti matter / matter reaction.
 

And all of this is completely ignoring your misuse (And my subsequent misuse) of the term energy density.     Anti matter doesn’t have energy density.   Matter doesn’t have energy density.   It has mass.     Materials undergoing a process have energy density.   A material doing XYZ will yield so many joules per kilogram.     A lump of uranium on my coffee table isn’t doing anything except for losing my security deposit.     A lump of uranium on my coffee table undergoing fission is making the news.   It’s how the energy is extracted is what gives a material its energy density.  

[Spacescifi]

1 hour ago, Gargamel said:

Then you get exactly the amount of energy as converting that small amount of antimatter.     
 

You can’t mix antimatter and matter without getting a complete 100% conversion of mass  to energy.  
 

It’s not an octane booster.   It’s not some chemical or element you can mix with anything.   It’s antimatter.   It’s the opposite of matter.   There’s nothing special about antimatter.    It’s not magic.   It’s just stuff, but different.  
 

You are basically saying you want to take anti-basketballs and throw them into a big tank of gasoline to make the gasoline have more oomph.   But it doesn’t work like that.  
 

And you can’t have a substance that has the same energy density as antimatter, because that’s just antimatter.  It’s 100% efficient.   Anything that would be the same would have to also be 100% Efficient.   And that _only_ comes from an anti matter / matter reaction.
 

And all of this is completely ignoring your misuse (And my subsequent misuse) of the term energy density.     Anti matter doesn’t have energy density.   Matter doesn’t have energy density.   It has mass.     Materials undergoing a process have energy density.   A material doing XYZ will yield so many joules per kilogram.     A lump of uranium on my coffee table isn’t doing anything except for losing my security deposit.     A lump of uranium on my coffee table undergoing fission is making the news.   It’s how the energy is extracted is what gives a material its energy density.  

 

Yes I realize this.

 

Basketballs worth of AM conversion in the fuel tank may be a bit much though.

 

Still you get more energy produced from matter/antimatter annihilation and thus in layman's terms... more bang for your mass (better efficiency).

 

In general using AM means you can get by using less propellant but that depends on how energetic the reaction is.

 

The greater AM/matter reaction the more propellant is required to be exhausted to avoid destroying the engine from the extreme heat.

Edit: I get it. You will exhaust whatever is in the fuel tank if I tried that.

 

Oh well... I tried lol.

[Shpaget]

15 minutes ago, Spacescifi said:

Still you get more energy produced from matter/antimatter annihilation

No. You most certainly do not. Producing antimatter is not making an energy source; it is storage, of poor efficieny. Making antimatter on the fly just to anihilate it immediately is wasteful.

[Terwin]

46 minutes ago, Shpaget said:

No. You most certainly do not. Producing antimatter is not making an energy source; it is storage, of poor efficieny. Making antimatter on the fly just to anihilate it immediately is wasteful.

In theory, if you could somehow produce pure antimatter(not matter+antimatter like we do now, but just antimatter) with a high enough efficiency (more mass produced than energy wasted, so > 50% efficient)

You could potentially end up with more energy from the matter+antimatter reaction than you put into producing the antimatter, because you get the full energy bound in both the matter and the antimatter, giving the reaction a 200% 'efficiency' compared to the mass of the antimatter.  (you would also need to capture nearly 100% of the energy released and convert it into a more useable form, including the gamma rays and other forms of radiation that we cannot currently capture)

Of course both the matter+antimatter and the energy-> antimatter reactions would both need to be highly efficient to give more energy than just using the energy you started with.  I think star-trek does something like that, using dilithium crystals to control the reaction and convert some of the energy into thrust.  I have difficulty seeing a society without similar levels of 'space magic' being able to pull this off however.

 

[kerbiloid]

1. Make a blackhole of reasonable size.

2. Put a magnet in close orbit.

3. On the antiparticle-particle pair birth, by the magnetic field, the antiproton is deflected outside, while the proton is deflected inside.
Thus you will get antiprotons and scoop them.

[farmerben]

Take a ball of metallic anti-deuterium.   Fuse it and pump the antineutrons and antihelium into the hot zone of a nuclear thermal rocket.

[Spacescifi]

3 hours ago, kerbiloid said:

1. Make a blackhole of reasonable size.

2. Put a magnet in close orbit.

3. On the antiparticle-particle pair birth, by the magnetic field, the antiproton is deflected outside, while the proton is deflected inside.
Thus you will get antiprotons and scoop them.

 

Or use one of those scifi conceit gravity generators all scifi starships seem to have. Combine that with the fact that generating radiation and magnetic fields is easy by comparision and that should be enough to pull off a miracle or two.

 

Don't ask me why gravity generators don't drag anything in their wake....

Edited January 23, 2023 by Spacescifi

[Terwin]

Probably the best reason for sea-launch of a SSTO, would be that it would need to be so massive that only specially made barges and super-freighters could handle the masses involved.

You would probably need multiple super-tankers just to fill the fuel tanks.

The rocket equation is so harsh for SSTO from earth, that a sea-based launch is probably the only real option(like sea-dragon, but with hundreds of large engines instead of one huge engine/bomb).

Of course even if you had a SSTO heavy lift vehicle, fuel costs alone would probably make it less cost-effective than the current falcon 9 which discards the second stage.

(and dumping that amount of energy into a chunk of ocean would no doubt do bad things to any local or down-stream life)

[Spacescifi]

6 hours ago, Terwin said:

Probably the best reason for sea-launch of a SSTO, would be that it would need to be so massive that only specially made barges and super-freighters could handle the masses involved.

You would probably need multiple super-tankers just to fill the fuel tanks.

The rocket equation is so harsh for SSTO from earth, that a sea-based launch is probably the only real option(like sea-dragon, but with hundreds of large engines instead of one huge engine/bomb).

Of course even if you had a SSTO heavy lift vehicle, fuel costs alone would probably make it less cost-effective than the current falcon 9 which discards the second stage.

(and dumping that amount of energy into a chunk of ocean would no doubt do bad things to any local or down-stream life)

 

There is only one type of payload that really desires SSTO, and that's people.

 

SSTOs are ideal for space imports... but export are better two staged.

[Terwin]

16 hours ago, Spacescifi said:

There is only one type of payload that really desires SSTO, and that's people.

SSTOs are ideal for space imports... but export are better two staged.

Why would you use a heavy launch vehicle for people?  (this topic is about a heavy SSTO)

Unless and until you are sending thousands to mars in a single launch, there is not really any call for it, and it would probably be better to send a larger number of smaller vehicles(like SS) which can be proven reliable with non-human payloads(and thus not SSTO).

 

In my opinion, unless you get some sort of space-magic that would let the family van go sub-orbital as a short-cut to visit a distant country, a fully reusable TSTO heavy-lift vehicle that can be refueled in orbit  makes SSTOs obsolete.(for earth at least)

Edited January 25, 2023 by Terwin