Qfyilyi

My Dino theme park business didn't end well and I reluctantly fall into depression and decided to go into suspended animation to seek a cure. 200 years later, a lady claims she works with the military woke me up and wants to award a contract of constructing 1000 space ready battleships within 5 years. My depression was instantly cured and promptly agreed to take the offer, after learning everything about spaceship building from many social media I need to look for a suitable site for the construction.

Would it be much faster and economical to do shipbuilding in low gravity region such as orbit compared to on the surface? The contract states that I must deliver the fleet battle ready on Mars surface within 10 years, propulsion engines to be provided by a sub contractor appointed by the client and the only details I received regarding the engine is that it has a specific impulse of 3 million Newton Seconds/Kg. If the economy has remain stagnant ever since fall of 2018, should I put my factories into orbit?

There are several important factors here, like whether or not your space fleet has been designed to also operate in a gravity well, and whether or not you have access to a space elevator.

In general terms, if the answer to the first question is yes, and the second no, then you're far better building on the ground, so as to save the energy cost of getting construction tools and people into orbit. The amount of mass you have to lift is the key factor here and lifting the ship (as opposed to the mass of the ship AND the mass of the construction tools and people) is obviously smaller).

In almost every other scenario, you're better off building in orbit, especially if you have access to raw materials from low gravity locations like (say) the asteroid belt. Being able to build the ship in space is actually essential if it's not designed to lift off a planet, and if you have a space elevator, it's easier and cheaper to lift the mass of the ship components up into space for assembly and launch.

Space is dangerous of course, and building in space means many different things can go wrong, so this may well be the most efficient solution in terms of energy cost, but your staff safety costs are likely to go through the roof, and the pool of people actually rated to build in space is much lower, meaning they'll demand much higher salaries.

In short, there are many considerations, energy cost being only one. I'd factor in (at a minimum) design constraints of the ships, raw material sourcing, availability of space elevators and the like, and whether or not your contract requires you to pay for the energy cost in the first place or fuel etc. is supplied.

The only advantage of building in orbit is that, if you lack the capacity of lifting a huge load, you can send many small loads in space and create the huge there. Moreover if your assembly doesn't have to fly through the high Q region of atmosphere, you have more versatility with the design.

That is basically what has been done with the ISS.

For all the rest building in space with present level of technology is a real pain in the back: it is expensive, it's hard to hide, it's highly risky.