a reply to: carewemust
If you are asking what the logical approach would be, then my recommendation would be as follows.
First, if communications attempts failed, one would assume that the military would set up some sort of cordon, a no fly zone around the city,
probably an evacuation of the area immediately beneath the craft (to reduce collateral damage in the event of it being shot down for some reason), and
begin laying down armour, artillery, and other mobile assets on the ground. Mobile infantry would probably be policing the streets from the suburbs
inward, to ensure that no visitors can gain the ground and pass through without being stopped. ICE would probably be there as well, since there would
have to be some immigration papers to go over, should any visitor eventually appear at ground level.
Alongside the security response, there would probably have to be a significant presence of the scientific community. You would have lab coats
swarming around the place, deploying sensors to check for electromagnetic anomalies, any energy signatures being output by the engines or whatever
mechanism holds the craft aloft. You would probably have some of them devoted to figuring out why there was no answer, probably an attempt at putting
together a mathematical communications tool, designed around certain numerical patterns common to physics for example, something that we can assume we
share a small amount of common ground with the visitor on.
I would imagine that use of small drones would become an increasingly acceptable option. Launched from a chopper or tall building, these drones would
be used to establish whether it is possible to actually touch the outer hull of the craft, or whether some energy field or other barrier exists,
between the visible outer skin of the craft, and the atmosphere around it. They would carry various sensory equipment, and operate on a partially
remote basis, but also in groups, using swarm AI which has come on a stretch over the last few years. They would be used to closely examine the hull
for imperfections which might suggest a hatch or door, to take close in readings from near any visible engines, or in the event where there is no
visible propulsion system, to rotate around the craft in intersecting patterns, to establish whether any energy that is being emitted from the craft,
has a singular origin, which might suggest the presence of a power source or propulsion system at that location within the craft. They would also be
on the look out for any protrusion which might represent a weapons system of some kind, although working with technology that allows anti-gravity
hovering for an extended period, might make a nonsense of that sort of thinking, since the craft may be so advanced that its pilots or controller can
simply funnel gouts of energy from any point on the hull, to any target in vicinity.
Eventually, I would have thought that paratroopers would be somehow landed on the craft, and attempt to gain some kind of access. At this point,
anything could happen. They could gain access, and find whatever is inside, but the lack of communication between craft and ground, would suggest that
any communications attempts made by paratroopers would not be effective either, since it is unlikely to have the sophistication necessary to achieve
what several well worked out science led approaches failed to achieve.
There is a good chance though, that no method applied to the task of breaking open the hull, would succeed, and those paratroopers would have to fall
back to ground. At the same time as all these things have been happening, the scientific and military thinkers of our time would be in communion with
one another, attempting to hash out what it all means, whether the craft represents a threat, and if so, what the best way to deal with it might be.
If it were decided that the craft posed a significant threat to national security, despite its stationary and neutral posture, the chances are that
the thing would get fired upon. The city would have to be fully evacuated, all essential infrastructure and data systems would have to be shut down
and/or relocated out of the city. All non-military personnel would be moved out of state too, and all military personnel would fall back to secure
locations, bunkers, and hardened locations throughout the city and state. Assuming entry methods deployed by the paratroopers included some sort of
breaching charge, and that the technique failed to leave a mark, deploying regular artillery HE or AP rounds would probably be pointless. Therefore,
it is probable that the military would draw on the most modern capabilities they have. I would have thought first strike would be lobbing a rail gun
round or two at it. After that, assuming failure, a MOAB detonated directly over the target. If both of those failed, a full evacuation of the state
and a warning to surrounding states and cities would have to go out, of the imminent deployment of a fairly high yield thermonuclear weapon.
I would not want it to go that way, but that is the most likely scenario, assuming all communications efforts and entry attempts were to fail. I
reason it would go this way, because regardless of the non threatening posture, the stationary position, the lack of any offensive action other than
its presence, the chances that the military would permit any foreign craft to maintain position over a major population and commercial center, for any
extended period are basically minimal, and since the military, not the scientists, would have the most guns, their word would be law in this