Planet crackers done dirt cheap

[Le Blue Dude]

This is just basic physics here. In space, there is no little to no friction, therefore there no real max speed... You can keep speeding up until you run out of power. Using one of the near infinite energy sources, and the almost reactionless drives in Nepplisia and Yamata it is... easy... to built a planet cracker done cheap. Here's what you do. You take a small star-ship, and you figure out how fast it's gonna move. Then you aim it to hit a moving target several light years away.... You know where the target's going to be when it gets there though, because you have that calculated. You aim it, and release it. Even assuming the slow rate of acceleration of 10 meters per second squared (1G) it will be going around .8C or faster by the time it gets there if it is accelerating constantly. If it's a ship hull it's going to have some shields.




Sit back and enjoy the planet cracking as this monster plunges to the surface at between .8 and .999C

Please note: This does not work with inertialess drives because inertialess drives usually have a max speed. Inertial dampers will also reduce the effect. However without inertia-reducers once the vehicle in halfway there it can not be slowed before impact. It can still be destroyed or redirected.

 

[Wes]

 

[Le Blue Dude]

Fix'd

 

[Zack]

Sending ship on a mission like that would almost certainly see it be shot down.

Alternatively if you have a ship capable of such high speeds it is likely armed with weapons. If you can pull off a mission like this odds are you have control over the space around the planet. Logically it would be much more efficient to just blast away at the planet from orbit instead of waiting for the ship to accelerate for a long time as it makes its way from deep space to the planet. After all you can't use your FTL systems if you want to build inertia.


Though it is possible and gravity is 9.8m/s

 

[Doshii Jun]

Possible ... but yeah, strange use of resources.

You're not even really building a ship though, are you? You're essentially building a giant bullet or asteroid with engines and throwing it at a planet.

I don't think this even needs to be approved, honestly. It's a pretty straightforward concept.

What WOULD need to be approved is the "bullet" itself. Would you like to edit one in, or is a company interested in building one?

 

[Le Blue Dude]

Well the trick is making sure they don't know it's headed for you. By the time it is within the solar system it's too late.

Sure, I'll build a "robot ramship", should be fun.

 

[OsakanOne]

So basically you've dumped a concept as apposed to crafting a real submission.

While this is good and dandy, I hope you realize you are expected to produce a submission which follows the guidelines and terms of the site, right?

 

[Strangelove]

Actually, Relativistic Kill Vehicles are a relatively old sci-fi strategic weapons concept. Though having them in the SARP universe could almost certainly obsolete the whole idea of power armor, starships, and standard combat means. Especially if you throw in FTL technology.

 

[Le Blue Dude]

Yo-se. Yo-se. I'm working on it....

 

[Rabbit Eclair]

(This is what happens when an engineering student gets bored.)

Keep in mind, though, that any planet with a real atmosphere would probably shred most spaceships travelling that quickly. Most of the ships here are limited to speeds of several mach in atmosphere. The temperature that something encounters while entering atmosphere is proportional to the speed that it's going. For something going 7.8 km/s, a whole 0.0026% of light-speed, the re-entry temperature is hotter than the surface of the sun. Assuming that the rule of thumb in that article applies to extreme examples, your spaceship/bullet would be near 300,000,000 degrees Kelvin. That's as many as 300 millions. And that's terrible.

The point is, the ship would probably vaporize instantly unless it was made of zesuaium. Let's take, say, an Odori-class freighter. 90,000 tonnes, so 9x10^7 kg. Something's kinetic energy is (1/2)mv^2. In this case, m = 9x10^7 kg, and v = 299,792,458 m/s. So... approximately 4.04x10^24 Joules. Since 1 ton of TNT is 4.184 x 10^9 J, that comes out to equivalent to 9.67 x 10^14 tons of TNT. Which is a lot of boomski, assuming that it hits the ground.

But, wait, there's more! Some gentlemen have assembled a wonderful tool to tell the effects that an asteroid would have! I put in our frieghter friend as an iron asteroid (8000 kg/m^3 density, and the closest approximation of a spaceship material-wise) with a diameter of 27.8 m (the volume of a 13.9 meter radius sphere is 11249 m^3, which multiplied by the density gets us 89995956 kg, pretty close to the mass of the freighter). The velocity would be c, 299792 km/s.

And the survey says... it's just too small. Or, in their words, it shatters almost 10 km from the Earth's surface due to the atmospheric shockwave and extreme temperature. "Large fragments strike the surface and may create a crater strewn field. A more careful treatment of atmospheric entry is required to accurately estimate the size-frequency distribution of meteoroid fragments and predict the number and size of craters formed." It would have a lot of energy, yes, but that energy would probably rip it to shreds before it can hit the ground.

Of course, there were a lot of assumptions made here. The energy output of the projectile would be directly proportional to the mass, so something larger would work well- the bigger the 'bullet,' the more of its mass will survive to impact the crust. It'd also do way more damage to planets without atmospheres. I calculated this little puppy as having around 10 times the estimated energy of the impact believed to have caused the Cretaceous extinction, so if it could hit the dirt, it'd cause all manner of hell. Iron is also far less durable than most of the starship armors here- something made out of Zesuaium would be great for it. There's also the fact that it's not too hard to surpass light speed here... though what using a CDD to boost your speed would do to the resulting impact, I have no clue. Still, just strapping engines onto some junk freighter probably wouldn't do much for you as far as shattering planets goes.

It'd probably make a great tool to take out a city or something, assuming you could calculate its point of impact that far ahead of time. If you're going for planet-wide consequences, you'd probably get a lot more bang for your buck by launching a huge asteroid at a relatively low speed.

 

[Zack]

Actually, Relativistic Kill Vehicles are a relatively old sci-fi strategic weapons concept. Though having them in the SARP universe could almost certainly obsolete the whole idea of power armor, starships, and standard combat means. Especially if you throw in FTL technology.

RKVs are dangerous but I think you are overestimating their capabilities in this setting.

 

[Moon Doll's Twin]

Particularly when weighed against the compelling evidence posted by Kel.

 

[Le Blue Dude]

(This is what happens when an engineering student gets bored.)
And the survey says... it's just too small. Or, in their words, it shatters almost 10 km from the Earth's surface due to the atmospheric shockwave and extreme temperature. "Large fragments strike the surface and may create a crater strewn field. A more careful treatment of atmospheric entry is required to accurately estimate the size-frequency distribution of meteoroid fragments and predict the number and size of craters formed." It would have a lot of energy, yes, but that energy would probably rip it to shreds before it can hit the ground.

And at what point did you forget to factor in shields? Huh?

And you forgot about the distortion effects of going at a near relativistic speed... The distance between the upper bounds of the atmosphere and the surface is less then 1 mile from the point of view of something going at .9C

See there are these particles... sub-atomic ones that travel at very, very, fast speeds. They can only go about 10 feet through the air before they cease to exist, and yet they make it to our surface from outer space. They did the calculations with the distance distortion involved with going near the speed of light, and it turned out they were only going about a foot to get through our atmosphere

This is what the physics major responds with.

 

[Rabbit Eclair]

Ah, shields would change things. I got the impression that the ship was going to be just a big dumb chunk of metal with engines. If it's shielded, I know that the CFS shields could easily cope with atmospheric entry. Hell, a Sakura's shields could absorb the ship's entire kinetic energy in less than a second without collapsing... per square meter. Because of this, I guess you'd probably want to drop the shields an instant before impact, lest a lot of the energy be shunted off into them.

As for the effects of relativistic distance distortion, I don't know whether the program's estimates of the effects take it into account or not. Their documentation points out that they did intend the program for use with velocities up to the speed of light, but whether or not they fully adjust for it isn't mentioned.

But, assuming that it's shielded, it should have no problem impacting and raising some major hell, so that's moot. It's still likely not going to be rip-the-planet-in-half levels of destruction, but it could certainly make a lot of people very, very unhappy and/or dead.

 

[Moon Doll's Twin]

It also starts making things get more and more expensive, the more pretty tech you put into it to make it plausible. "Dirt cheap" vanishes.

Also: Interdiction fields, yo.

 

[Le Blue Dude]

Interdiction fields?

If this works total cost will only be around 2-3 hundred SP.....


1. About the Robot ramship

Prior paragraph

2. Dimensions and Crew Compliment
Type: Weapon/ship
Engine: Ion thrust
Manufacturer: Various militaries when they need one
Production: Limited production

Length: 50KM
Width: 50KM
Height: 50KM
Mass: 4,000 KG

3. Performance Statistics
Top Speed (STL): .999C
Acceleration (0-60mph): 20G

Range (Distance): 20-30 lightyears
Lifespan: 50 years

4. Vehicle Systems

Shields: Level 1 shields for impact

Armor: level 4 armour to help it hold together untill impact

Navigator A simple AI that keeps the ship moving towards it's target

Computer 100
Secondary gen 200
Sublight Engine 99.7
Shields 200
Armour 200

total cost 599.7


Please note: This is pretty cheap

 

[Doshii Jun]

Some planets, most notably Yamatai, can deploy interdiction fields. Those would eliminate FTL travel, but if the vessel never reaches FTL, there's no problem.

However, arguing it further is rather pointless. You need to stop replying here and actually submit a device or vessel that would be used for this purpose. The technology is sound enough; its success rate is another matter entirely.

 

[Doshii Jun]

(DP IS BAD)

Okay, so a giant ship that's probably hollow and has weak shields. You realize this is also pretty easy to destroy, right? Considering it's so slow? That's not to say it couldn't be approved, but who would built it and why would anyone bother if it could be so easily wasted?

 

[Le Blue Dude]

It's not hollow. It's solid.


You build it to crash it into planets

 

[Doshii Jun]

Then it should cost more than 600 -- that's a lot of material.