B-21

[DaveBB]

From directly above, a stealth aircraft has a huge radar reflection.  The more perpendicular the aircraft is to the radar wave, the larger the reflection.  Some of it will be absorbed by the skin of the aircraft, and a bit will be reflected away from the radar receiver.  But it will still produce a very large signal.

But from my research, a geostationary orbit needs to be 22,000 miles above the Earth.  Explains why they haven't put a radar up there yet...

[Brooke]

It seems that low-frequency radar might pose the biggest future threat to stealth aircraft.  Stealth aircraft aren't so stealthy to low-frequency radar.

Historically LF radar has had problems with noise, size of the antenna, low specificity of location, etc.  However, technological advancement could mean overcoming some of these problems or using LF radar to rough in the detection then using other radar or other means to get more specific.

[Zimme83]

Geostationary orbit is 22,236 miles above the surface. The speed and orbit time for a satelite depends directly on what altitude its on so there is only one level were you can place a satelite if you want it to remain stationary over a fixed point on the Earth.

But sats in low Earth orbit could work, you just need a system of several satelites if you want to cover the entire globe.

[eagl]

Stealth aircraft need to be built with special materials that xxxxxx, shaping to help xxxx and xxxx, without xxxxx, and surface treatments that xxxx the xxxx to ensure xxxx while preventing xxxx and being easy to xxxxx.  All of these need to be balanced because the overall design and individual design details must be tuned to xxxx, leading to compromises in both xxxx and xxxx.  You can make a great all-around stealth shape with special materials, but it may not be flyable or useful due to payload, aero efficiency, and maintainability, and it still won't be perfectly "stealthy" against the entire EM, visual, or thermal spectrums.  So they do their best to match the stealthy characteristics against known and predicted threats in order to be "good enough" to get to the target and back both now and in the future, also generally assuming some level of cooperative support from other assets and capabilities in really high-threat scenarios.

So... its complicated and there will always be one or more current or future threat systems that will defeat any particular aircraft.  So what.  There's always a threat we can't defeat.  The question is if the weapon program will be good enough to fit within a system of systems to get the job done in scenarios we can anticipate, and hopefully have enough capability to be effective and survivable in those scenarios that surprise us.  This aircraft is no different from any other aircraft in the past or in the future, so don't get caught up in the rabble rousing on either side just because they can blabber on about what if this one specific highly technical situation where....

[eagl]

Geostationary orbit is 22,236 miles above the surface. The speed and orbit time for a satelite depends directly on what altitude its on so there is only one level were you can place a satelite if you want it to remain stationary over a fixed point on the Earth.

But sats in low Earth orbit could work, you just need a system of several satelites if you want to cover the entire globe.

Oh, that's all you need.  Easy. 

Seriously, I think the US put about a billion dollars into a space based radar system including some prototype experimental payloads, before trashing the envisioned system and starting over.  I think its just a bit harder than just tossing a few dozen radars into orbit.  A comm sat we tossed into the ocean a couple of years ago cost just over $500 million bucks, and that was just one satellite.  Just sayin...

[DaveBB]

Is there really any substitute for speed? If you were in a strike aircraft over enemy territory, would you rather be in a subsonic stealth aircraft, or a Mach 1+ B1b at 100 feet?

We are going to be fighting Isis and other extremist groups for a long time.  They don't treat downed pilots too well....

[Wolfala]

[Zacherof]

Its actually the B-2.1

thats what I said to myself lol

[Maverick]

Is there really any substitute for speed? If you were in a strike aircraft over enemy territory, would you rather be in a subsonic stealth aircraft, or a Mach 1+ B1b at 100 feet?

We are going to be fighting Isis and other extremist groups for a long time.  They don't treat downed pilots too well....

In a word, yes there is a potential solution. A slower aircraft and high alt can drop a glide style weapon from beyond return fire range and let the bomb fly itself to the target. Same goes for powered flight munitions.  The supersonic aircraft at very low alt will have to overfly the target directly.

[Sabre]

On the subject of stealth, wouldn't a satellite be able to use radar to detect stealth aircraft from above?  What is stopping a geo-synchronous satellite from using a large radar?

A number of technical problems. First, at Geo, you'd need both a huge antenna and gobs of power. The ground-based systems used to track objects in space have both; a geo-satellite to handle the same, but inverse, task would be prohibitively expensive to put into orbit. Then there's the issue of ground-clutter. Consider also: While the planeform view (the silhouette when viewed from directly above or below) presents a huge radar return from a specular perspective (i.e. with the radiating antenna viewing the planeform at zero aspect angle), the "spike" or lobe width of the return is very narrow. The larger the reflective surface, the narrower the angular cone where you get a return. In other words, the radar would only see it well when it was directly underneath the satellite...which is also the direction where ground clutter would be at its worst. So, in order to provide reasonably constant tracking, you'd need many satellites all linked together in a network, further compounding the cost and complexity. Lots more to it, of course, but that's this rocket scientist's view.

[Gman]

Geo synchronous is a lot lower alt than Geo stationary isn't it?  Couldn't enough lower earth orbiting geosync says be overlapped in various spots to use look down radar for detecting aircraft with reduced signature tech?

The Soviets loved their low earth orbit RORSATs, giant honking radiating everything in sight school bus sized things, which could spot ships easily enough...not sure about a/c, but since the 80s resolution and power must have improved a lot.  I wonder if the current stealthy high alt surveillance drones used by the USAF have the capability to track airborne aircraft with low observability tech.

Eagl, funny post.  Can't you USAF guys just ask the aliens at Area 51 you fly with to help speed along the development process, and eliminate most of those "xxxx"s?

[eagl]

I think the aliens are playing both sides of the fence and probably leaking stuff to commercial entities.   

[Zimme83]

Geo synchronous is a lot lower alt than Geo stationary isn't it?  Couldn't enough lower earth orbiting geosync says be overlapped in various spots to use look down radar for detecting aircraft with reduced signature tech?

The Soviets loved their low earth orbit RORSATs, giant honking radiating everything in sight school bus sized things, which could spot ships easily enough...not sure about a/c, but since the 80s resolution and power must have improved a lot.  I wonder if the current stealthy high alt surveillance drones used by the USAF have the capability to track airborne aircraft with low observability tech.

Eagl, funny post.  Can't you USAF guys just ask the aliens at Area 51 you fly with to help speed along the development process, and eliminate most of those "xxxx"s?

No, geosynchronous orbit has always the same radius. As i said. Orbit time is depending on the radius. If you want a satellite to have a certain orbit time you need to place it in an orbit with a certain radius.

Geosynchronous orbit has an orbit time of exactly one day (23 hours 56 minutes and 4 seconds), geostationary orbit is a geosynchronous orbit placed directly over the equator.

[Vraciu]

 

[Puma44]

 

Way funny and life like