Project Hius Interstellar craft for 2010P1 development

[Artlav]

(Latest is 110118, info in post #27)
Latest link: http://orbides.1gb.ru/orbf/hius-110118.zip
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Hius is an interstellar ship that sucks the medium between the stars and fuses it into a beam of thrusting light.
Basically a Bussard ramjet, capable of reaching about 70% lightspeed.
Includes a (partly-done) full ship systems simulation - power, air, gravity, interiors, etc. UMMU compatible.

The thing was in development for the last many years, and seeing a lack of a good vessel of that class combined with looming interstellar Orbiter galaxy add-on, i thought it would be good to revive the old Hius.

If you tried the older version back in 2007, then there are not so many obvious differences.
This version was widely debugged and adapted for the more recent Orbiter version, but not yet noticeably moved ahead on the monstrous planned feature list.

Now, what i'm interested in at this stage is performance and ideas.
Older ideas thread is gone with the old M6, so what would you like to see in such a vessel?

For performance - it's a big mesh. Does it run with any sort of acceptable FPS?
Then, the MFDs are made in a peculiar way. If you go to Navigation->NAV, you'll see what i mean. Does the FPS appear acceptable there?

For testing and getting ideas, there is a manual included as readme.txt.
You should be able to easily reach cruising speed, but steering this monster is not easy.

Also, be prepared that it works on a scale of months - it would take one to reach 1.5% lightspeed on DHD boosters that is needed to start the ramjet in the first place, then it's a year till full speed.

Camera might (and will, 2005 code don't mix with 2010 Orbiter well) turn upside-down or point in a wrong direction. Just press Home to fix that.

Here is the current build:
http://orbides.1gb.ru/orbf/hius-110115.zip
(Asks for weird dlls? My trademark screw-up is posting debug versions instead of release ones. Fixed, just re-download.)

What does it look like:

The observation deck:

Oxygen garden:

At the airlock:

The entire thing:

Controls:

And in better light.
The airlock is the white pixel in the middle of the thing inside the shield of the upper booster.

One monstrous engine:

Two smaller boosters:

Enjoy!

 

[T.Neo]

Hius has a few problems. Starting with the fact that the main exhaust velocity is- if my number are correct- 25 times the speed of light. The auxilliary engines on the other hand have an exhaust velocity of between 0.1-0.26 c, more plausible for a fusion to an antimatter drive- in essence, what the main engine's thrust should be.

Furthermore the density of the vehicle is 0.85 ton/m^3- almost comparable to a modern submarine. The ISS, for comparison, has a density of around 0.074 ton/m^3, and the shuttle orbiter a density of 0.088 ton/m^3. While things like radiation shielding push up the mass, and thus the density, this figure is definitely anomalous especially considering the advanced materials and construction techniques that would go into the design of such a futuristic vehicle.

Exhaust streams shouldn't be wildly over or underestimated, though a 0.12 c Bussard fusion drive with a thrust of 50 meganewton would have a thrust power of around 900 terawatts (0.9 petawatts). This would undoubtedly be quite destructive; although the exhaust stream would spread out rapidly and have short range as an effective weapon, it will still be extremely damaging- a single deuteron going at that velocity, would have an energy of over 13 MeV. Perhaps it would be best to light the main drive up far away from any planets, satellites/stations or magnetospheres...

In addition such a drive would produce absolutely monumental amounts of waste heat. This would undoubtedly require extensive, futuristic and likely implausible waste heat mitigation methods.

The backup/aux boosters would need to be tuned down a good deal... they could become high performance fission (exhaust velocity 98 000 m/s maybe) and fusion (10 600 000 m/s) designs.

With a more realistic revised mass, the vehicle no longer needs such an enormous thrust to accelerate at a set acceleration, thus the thrust can be reduced and the overall power will drop.

 

[Arrowstar]

...the main exhaust velocity is- if my number are correct- 25 times the speed of light.

LOL! That's not an engine, it's the Death Star's main energy beam weapon. :lol:

 

[Carmen A]

Wow, it reminds me of the colony ships in the old Master of Orion game. The little ship icons are shaped like that

 

[Wishbone]

The ship is quite fun to handle, apart from two (possibly related) bugs:

a) When I enter the bridge (Alt-1) the RCS rotational directions are reversed
b) When I press F8 for the bare-bones, the bridge goes upside down.

Reactor and navigation views are interdependent meaning I always have to switch between the two after boosting up. Think scope state, acceleration and drag and other relevant params should be on the same screen.

Another gripe. The crew is entirely all-male. The trip is too long for them to go without spouses.

 

[T.Neo]

Another gripe. The crew is entirely all-male. The trip is too long for them to go without spouses.

Maybe they're not interested in women?

Either way, I agree, it isn't very gender neutral...

 

[Wishbone]

Having just returned from skiing:

a) They may be not interested in anything after a heavy gamma dose... That's why some kind of dosimetric control (even bogus at first) should be part and parcel of the Life support screen.

b) Isn't the "scope", in fact, a _scoop_?

 

[Artlav]

Hius has a few problems.

Here's the current math:
empty mass - 3830000 tonnes;

Fuel:
Boosters - 100 tonnes of rocket fuel
Fusion accelerators (DHD pods) - 10000 tonnes of hydrogen/whatever fuel
RCS fuel - 10 tonnes.

Booster thrust - full_mass*18.3/8 each of 8.
DHD thrust - full_mass*5.6/2 for each of 2.

booster ISP - (8* 2.1e3*MAX_BST_THRUST)/(MAX_BST_FUEL*18.3) = 80642310.0
DHD ISP - (2*24000e3*MAX_HYD_THRUST)/(MAX_HYD_FUEL*5.6) = 9216264000.0
RCS ISP - 50e9 (supposed to be flywheels with rockets for residual elimination)

max PHT thrust - full_mass*21.7
No ISP defined for PHT.


Yeah, too much handwavium.
What would be an adequate mass for a vessel of such proportions?

If i get it down to 28000 (full mass 38000) tonnes, then the numbers become more realistic:
DHD ISP of 92184000, good fusion/antimatter engine
BST ISP of 806610, nice NSWR fission rocket
But is 28000000 kg enough for such a ship?
I can't judge masses of this scale easily.

a) When I enter the bridge (Alt-1) the RCS rotational directions are reversed

Huh? You did take into account different perspective? How to reproduce?

b) When I press F8 for the bare-bones, the bridge goes upside down.

Known bug, pressing Home/moving camera a little should fix it.

Reactor and navigation views are interdependent meaning I always have to switch between the two after boosting up. Think scope state, acceleration and drag and other relevant params should be on the same screen.

Maybe. All that empty space is reserved for a lot of controls for reactor, scoope, etc. Also, MFDs are kinda slow (are they?), so i keep them separately.

Another gripe. The crew is entirely all-male. The trip is too long for them to go without spouses.

That's just the commite that looks over the vessel, not the trip crew .

 

[Spacethingy]

Stupid question #1405 here, but, what's the giant... err... NET at the front for?

Edit: I've just looked up the Bussard Ramjet! This thing is cooooool!

Nice to see Hius back with a vengeance, good job!

 

[Wishbone]

Re: bridge and rotation. I press Numpad 2, it pitches up, Numpad 8 - down. Same story for 1 and 3 (yaw).

Re: RCS - you could actually switch to CMGs only in a later version since the craft has excess energy.

Re: committee. I suppose at least one woman should be in it; this said, harbour reservations that a ship may be ruled by a committee (all previous attempts failed utterly). Also there's a great idea to put interlocks that don't allow EVA while any of the engines is on.

Lastly, the tapestry on the wall. Any chance of changing them during the flight? A selection of historical (Bayeux, New World, etc.) and folk/ornamental ones would do finely

 

[Pyromaniac605]

Re: bridge and rotation. I press Numpad 2, it pitches up, Numpad 8 - down. Same story for 1 and 3 (yaw).

Umm that's how it should be...

 

[T.Neo]

In regard to masses, a simplistic method is to multiply the vessel volume (you can get it from the mesh in ShipEdit) by the average density. A list of spacecraft densities obtained using Orbiter meshes can be found here. I originally got the idea from Atomic Rockets.

Currently Hius is denser than a warship. WIth a more plausible density of 0.15 ton/m^3 to 0.2 ton/m^3, you have a mass of 675 890 to 901 180 tons.

DHD ISP of 92184000, good fusion/antimatter engine
BST ISP of 806610, nice NSWR fission rocket

An antimatter beam core drive has an exhaust velocity of 33% c, or about 100 000 000 m/s.

The exhaust velocity of fusion really depends on what drive you're using. The Atomic Rocket Engine List lists;

IC Fusion MAX: 10 000 000 m/s (3.3% c) - similar to Daedalus exhaust velocity (10 600 000 m/s)

H-He Fusion MAX (Helium 3-Deutarium fusion?): 30 000 000 m/s (10% c) - similar to 12% c exhaust velocity for a bussard ramjet.

F-He Fusion MAX: 50 000 000 m/s (16.67% c)

I'm unsure of the last one, especially since fusing stuff with iron isn't supposed to yield much, if anything (as far as I can tell). But the others look relatively sound.

Thing is, if you have an antimatter drive, the question is: why do you need a Bussard ramjet anyway? The minimum speed for a bussard ramjet to be feasible is (AFAIK) something like 1% c, and the Daedalus-grade 10 600 000 m/s drive should do that with a minimal amount of fuel.

That drive then essentially makes a lower performance drive unecessary... unless for some reason you want a lower power drive, for travel within a star system. That could be a fusion drive with an exhaust velocity of 100-300 km/s, or even maximum-ISP gas core fission drive (98 000 m/s)

RCS ISP is tricky, you can't really dedicate fusion or fission engines as RCS thrusters in a normal case, but since this vehicle is so large and heavy, it might be required. Since you know the RCS thruster positions and their thrust, you'd be the best person to decide which drive type would be optimum for RCS thrusters. Go through the Atomic Rockets list and different drive types you think might be plausible.

But is 28000000 kg enough for such a ship?

I'm not sure. The best easy bet is the density method, if you want to calculate the mass of each major component and assembly things would be more accurate, but also require what is essentially the design process of a whole spacecraft.

The "not defining ISP" for the main engine make sme uneasy, it'd be better to full the tanks up as the vehicle is at speed, it might be harder but at least it doesn't badly confuse armchair rocket scientists when they look into the attributes of the vessel.

That's just the commite that looks over the vessel, not the trip crew .

I don't know, I agree with Wishbone, there should be more gender equality there as well...

Stupid question #1405 here, but, what's the giant... err... NET at the front for?

Edit: I've just looked up the Bussard Ramjet! This thing is cooooool!

Yeah, the net is the coil for the magnetic scoop that acquires propellant/fuel for the vehicle.

Lastly, the tapestry on the wall. Any chance of changing them during the flight? A selection of historical (Bayeux, New World, etc.) and folk/ornamental ones would do finely

This. The tapestry is probably my favourite part of the whole ship. :thumbup:

 

[Artlav]

Re: bridge and rotation. I press Numpad 2, it pitches up, Numpad 8 - down. Same story for 1 and 3 (yaw).

Seems about right, you're looking sideways after all. The proper orientation is at scoop camera.

Re: RCS - you could actually switch to CMGs only in a later version since the craft has excess energy.

Sorry? What was that about again?

Re: committee. I suppose at least one woman should be in it; this said, harbour reservations that a ship may be ruled by a committee (all previous attempts failed utterly).

Meaning no meaningful crew was defined yet.

Also there's a great idea to put interlocks that don't allow EVA while any of the engines is on.

I suppose. The thing is designed for EVA at thrust, but Orbiter is not designed for collision detection.

In regard to masses, a simplistic method is to multiply the vessel volume (you can get it from the mesh in ShipEdit) by the average density.

Well, nothing more than 40000 tonnes works with non-handwaved engines, so something would have to be handwaved, or the mass turn out to be plausible.

which drive type would be optimum for RCS thrusters.

Flywheels. And steam puffers for residuals elimination.
Hm, won't work - the wheels should be quite massive.
I guess something small and nuclear then.

The "not defining ISP" for the main engine make sme uneasy, it'd be better to full the tanks up as the vehicle is at speed

Won't work, Orbiter don't like it at all.

 

[T.Neo]

Well, nothing more than 40000 tonnes works with non-handwaved engines, so something would have to be handwaved, or the mass turn out to be plausible.

What makes a handwaved engine... handwaved? As opposed to a non-handwaved engine?

The output power? In that case you'll at the very least need to twitch your fingers vigorously, regardless of the vessel mass...

I guess something small and nuclear then.

Don't forget the adequate shielding, though considering the size of the vessel distance is probably your best shielding.

Won't work, Orbiter don't like it at all.

Are you sure? Have you tried giving the ramjet a somehow unlimited propellant resource?

I've never tried it, but didn't the Vespucci use some sort of ramscoop? How did that work?

 

[jedidia]

Re: committee. I suppose at least one woman should be in it; this said, harbour reservations that a ship may be ruled by a committee (all previous attempts failed utterly).

One of the problems here will always be that UMMU doesn't let you define gender. The only thing gender related are the meshes, which is a different one for any "profession", so gender ultimately depends on the profession. Docs and Scientists are female meshes, for example, so any doc or scientist will always be "female". UMMU is a bit unflexible in these terms, unless you do your own meshes.

RCS ISP is tricky, you can't really dedicate fusion or fission engines as RCS thrusters in a normal case

For RCS you'd probably want good thrust rather than high ISP, though. Any chemical thruster that can at least use partly hydrogen should do fine (since Hydrogen in this case is replenishable). For small course corrections during flight a center of gravity shift might make sense, but I can't see it quite working with the whole thing under rotation...

 

[Wishbone]

CMGs - what you call flywheels - control moment gyros ("гиродины") - are not currently modelled by Orbiter, but are the best bet for spacecraft with abundant electricity aboard (RCS or whatever used for detorquing). A handwavium solution has been to change rotation matrix directly, explaining it away as action of CMGs without concurrently counting the power budget. I'll be re-reading Wertz again in maybe a fortnight and will want to model CMGs; your interstellar behemoth has got power budget all right, so it's going to be an interesting challenge (wonder if there is any way to store anything in the wheels to save mass)

Another attitude control note: with the scoop open and some initial speed (200 km/s?), there will be significant forces that could be harnessed to provide stabilisation by "slightly" (I don't know if it's an applicable word) changing the configuration of the scoop .

Turning the beauty around is going to be a problem anyway, and the default orbiter attitude AP doesn't help it...

EDIT: A still more significant yet related problem: at default integration settings, and high time compressions the craft tumbles disastrously. Space-fixed orientation should be maintained by default (given by a Euler triple or a quaternion).

Re: communications. Not being a physicist, cannot answer a simple dumb question - can the Hius send messages to Earth by modulating the main engine?

EDIT #2: EVA under thrust is going to be a problem. I also somehow shudder at the thought of an EVA at 0.7c beyond the shielded volume.

 

[Sky Captain]

Since this thing likely has plenty of electrical power RCS could be using arcjets. They recquire only electricity and H2 - both of those are replenishable resources aboard this ship. When main drive is running you could vector thrust slightly to keep desired attitude. RCS would be needed only when main drive is off or when quick change of attitude is recquired.

 

[Izack]

RCS would be needed only when main drive is off or when quick change of attitude is recquired.

What exactly would warrant a quick change of attitude when the main engine is running? Planetesimals? Klingons?

 

[T.Neo]

You don't want to change attitude when you're at speed, you want to keep the craft pointed in the direction of travel, because the magnetic scoop and associated equipment are not only to present to drive the ship, but to protect the ship from interstellar gas and debris (though getting rid of solid debris will be a bit tougher... they would require ionisation, somehow).

In addition, the coil/scoop can be turned into a parachute; with the fusion drive shut off (or dedicated solely to power generation), the magnetic field of the coil can be extended to create drag from the interstellar medium, slowing the spacecraft without propellant, and maintaining the same attitude.

 

[Wishbone]

Can we deform the coil/scoop somehow? This could give pitch and yaw control, not sure about roll.