Question on orbital surveillance and patrolling

[ar81]

I came to think about something.
If you launch 2 shuttles at once, intercepting is very hard.

Now imagine a criminal on earth escaping to Mars where his crimes are not crimes.
Or how about space pirates assaulting orbital freighters...

I wondered what should be the best orbital patrol pattern.
I came to think that 4 space stations in prograde orbits aligned with the rest of the solar system could prevent most of
those piracy attacks.

Escaping craft should still be hard to intercept, mostly if they have non solar system aligned orbits, but they would also
need more fuel.  And if all refuelling stations are in those police space stations, and launchers that allow surface to space
and planetary transfers should be forbidden. Then you could prevent criminals from escaping.

I came to think about this after I read an article in La Nacion, the most reputable newspaper in Costa Rica, about pirates in
Somalia hijacking UN food supply freighters.

[Urwumpe]

important is geometry: transfer ellipses have a very accurate geometry, which you can exploit. You can eg place your patrol
craft at a point behind earth to intercept a vehicle coming from mars. you wouldn't have a easy prey because of the still
large distance, but you would be able to detect and plot their course long before long range radar on earth would detect
them. When you have two crafts or more, i think you could even make them close the corridor for a mars transfer of the
incoming crafts by follow a accurate orbit and formation.

When you know where they are going, you can launch interceptors from earth - thats more effective as letting the crafts you
use for long range detection intercept them. the detecting crafts only have to stay relatively close to track the incoming
vehicles - depending on the capabilities of their radar.

If you eg look at a Draco vehicle from World of 2001, you can assume that it can detect and track large targets already from
about 500,000 km distance (with a very very bad update rate). For actual combat, this distance would drop to about 3000 km,
if it can afford combining all antennas on a target. More likely would be 500 - 1000 km, if it has to detect also minor ship
activities: Launching of weapons, incoming missiles, decoys and other events.

With a typical radar, the problem is: Each radar system can only detect either larger long-distance targets or small
short-range targets, but not both at a time. When you look for a 50m craft in 1 AU distance, you won't notice a 500m station
5 km away from your radar while you fry the station. your radar might filter strange echos, but won't display a contact.
Maybe it will even assume a jammer some 50 km away.

[Schimz]

"amagad, someone launched us a missile two weeks ago, we're doomed"





Message modifié ( 27-03-2007 20:37 )

[Schimz]

Urwumpe a écrit:
Plein de trucs

   
Which is most advantageous, radar or optic ?



Message modifié ( 27-03-2007 20:45 )

[Urwumpe]

Schimz a écrit:

Urwumpe a écrit:
Plein de trucs

   
Which is most advantageous, radar or optic ?

Depends - if it comes to range, no radar can beat passive radar or optical sensors, as active radar looses power at r^-4
compared to r^-2 for optics or passive radar.

But both optics and passive radar can't do reliable doppler measurements, or determine the range instantly. Also you can't
make some special tricks like using the resonance of the signal to analyze the object.

Also, optical sensors are slower in their movement as phased array radars - maybe we will see phased array optics one day.

[DocHoliday]

Agree about detection.

As for interception: I'd go with a (Reagan's) star-wars type laser thingies and knock out whatever is needed to strand the
"offender" in the orbit and intercept them at will, later on.

You just can't beat speed of light at planetary distances.

[Urwumpe]

DocHoliday a �crit:
As for interception: I'd go with a (Reagan's) star-wars type laser thingies and knock out whatever is needed to strand the
"offender" in the orbit and intercept them at will, later on.

You just can't beat speed of light at planetary distances.

You can't, but why bother... the power and range of a laser is limited by its optics. Unless you built a HUGE laser system,
it will be nothing else but a large flashlight.

http://projectrho.com/rocket/rocket3x.html

[reekchaa]

Yeah, Reagan's brilliant leanings would have been about as successful as Japan's research for the Death Ray.

[scinrd]

or Tesla's, but who knows? mabye he really had something?

[sunshine135]

reekchaa wrote:
Yeah, Reagan's brilliant leanings would have been about as successful as Japan's research for the Death Ray.

http://www.boeing.com/defense-space/military/abl/doc_src/ABL_overview.pdf

Reagan had it right just like Kennedy did in the early 1960's about going to the moon.
Star Wars- coming to a theatre near you

[Urwumpe]

Well, you can imagine Reagans (or some current advisors) Starwars like stopping a rioting mob with dozens of toy water guns.

The same effect. It will not help you much, but you only make the mob more aggressive. Technology is not ready for starting a
arms race against MIRVS and decoys. Maybe in some years, it will change. But currently, the advantage for the MIRVs is too high.