U.S. military said moving ahead on new bomber

correct me if i am wrong, but wouldn't bombs launched from space burn up in the atmosphere? _javascript:icon('')
_javascript:icon('')

You aren't bombing from space. By going into space you cut your transit time down from hours to minutes. You launch, enter orbit, drop down and hit your target, then climb back to orbit. Where a B-2 would fly a 40+ hour mission from Whiteman to Afghanistan and back if you could climb to orbit it might take 4-5 hours.

Spurri,

>>
Correct me if i am wrong, but wouldn't bombs launched from space burn up in the atmosphere?
>>

Yes, if you envision bombs as looking like those dropped on Berlin out of a B-17.

OTOH, particularly 'Rods From God' will likely be dense metal penetrators in a conical or wedge shaped ablative skirt, designed to skip several times over atmosphere to gain range and slow down before tipping over to stoop down onto a target which they impact with 100X the Megajoule energy of a tank main gun at point blank range. Energy which they transfer to the target either by pushing through as deep as possible behind a pneumatic 'air blast' or by destablizing to shatter at Mach 8-10 or more. If you've seen pictures of the Tunguskan forest, you get an idea of what the latter at least is apt to do to most above surface buildings.

i.e. A MIRV without the nuke, remains a MIRV.

I don't know if the orbital drop out and reclimb approach actually works or not. IMO, the problem with this is the MASSIVE amount of energy required to get back up to space, even absent the warload. It _might_ be possible if you had the system already orbited and simply did an unpowered reentry, followed by a burnback profile similar to the Spaceship One's.

The problem then being that this is a lifting body with a leading edge shaped like a rolling pin and next to no wingspan. Which means that 'just loitering about' will not be practical for an aircraft whose targeting is not provided directly.

At which point, (persistent ISR as a precursor effect) the big question becomes, 'why not MIRVS From Space' and avoiding the bus platform altogether. I have to assume that there are some fractional adjustments of orbital mechanic which would be harder to achieve from a given constellational/ground track placement of a limited (covert because it's illegal as hell and LEO is hardly 'unobserved') satellite network. Without an intermediate transfer/retro grade burn option.

But even here (burning up the bus vehicle), reloading and fueling whatever satellite you launched from gets to be iffy.

In the end, it may well be that the best which can be said (or sent) is something in the intermediate hypersonic class (7-12) with just enough payload:fuel fraction to make the complexities of SCRAM or PDWE workable while retaining 'call back' on a platform that is functionally a ballistic trajectory weapon but not one irretrievably targeted as much as lost once launched.

Again, if you take a globe and quarter it up relative to the known Commands, you can just about show the relevant reach vs. basing point problems necessary for U.S. to 'have leverage' if or once our presence as a naval patrol or air expeditionary force is no longer welcome.

Diego Garcia to Northern Pakistan. Central Australia or Alaska to Korea with enough 'skid' vector control to avoid overflying China or Russia and recover back at a U.S. territorial or _close_ ally, half a world away.


KPl.

Originally posted by ch1466
The notion of flying 'anywhere in the world in 2-3 hours' is beyond laughable. Look at the XB-70 or the B-58 and note how much of their flight profiles were _subsonic_ in similar strategic range missions lasting upwards of half a day. Now halve the speed (1-1.5 as the best we can sustain with today's affordable materials and engines) and look at a Globe.

Uh, the XB-70 cruised at Mach 3 (targeted, it usually went at around Mach 2.7). The engineers figured out that just as much fuel would be used by cruising subsonically and then doing a Mach 3 'dash' as would be used by cruising at Mach 3 the entire time.

I think that the U.S. could get into a lot of trouble with this trying to make a plane that's more capable then they really need most of the time but so expenseive that they can only afford a handful. The plane most in need of replacement seems to be the B-52, however the design approach they seem to be taking makes it a more suitable replacement for the B-2.... which they could probably hold onto for a while more. The main difference here is the price for fielding a B-2 is catastrofically more then a B-52 and as such will lack the numbers to give the air force a bomber option with most every deployment. If that's the case you'll still have fighter aircraft or cruise missles doing the grunt work in bombing in most cases which is even more money wasted.

XB70,

>>
Uh, the XB-70 cruised at Mach 3 (targeted, it usually went at around Mach 2.7). The engineers figured out that just as much fuel would be used by cruising subsonically and then doing a Mach 3 'dash' as would be used by cruising at Mach 3 the entire time.
>>

First off, the original 6,500-7,500nm range quote was based on the WS-110 with ethyl borane 'zip' fuel in a 3/4 million pound airframe. It never flew.

REAL range of the XB-70 was between 3,500 and 4,300nm. That's less than half what you need for a survivable SIOP mission into the central Russian missile fields or Far Easterm command complexes.

Second, the XB-70 flew at Mach 3.1 or so for all of about 20 minutes on AV-2 and less than 5 on AV-1. During it's test program it suffered ALL KINDS of hydraulics and skin delamination and structural breakup and stability problems. Most of which were only partially overcome (quick fixed) before testing for the SST program ended (itself long after Daddy Mac had cancelled the XB and RS-70 programs along about 1960).

The phenomena of compression lift and particular adjustments in trim and wave drag relative to optimized shock formation and the drooping tips (and fuel transfer for CG) is _highly_ dependent on achieving an optimum speed range and the combinaton of the canard interaction with flow over the inner roots and the basic deltoid shape problems with L/D were far from optimum for this, given the power available.

I don't recall whether it was the inlet system or the J93's themselves but the total thrust curve was also disappointing with about a .5G acceleration (similar to Concorde but with a cruise height almost 20,000ft higher) which meant that the jet spent about an hour in climbout sucking gas like a drunk in a wine cellar.

The first jet had terrifying high speed altitude:pitch and directional control issues and the second (with the dihedral'd wing) only marginally improved on this at the cost of massive increases in roll and wallow below the Mach.

As I recall there were also specific operational weight (runway length) and climbout issues with relative to fuel and payload fractions which required a sub optimal fuel load just to get in the air and up to refueling height (away from the base) on an Alert Status.

The truth of the matter being that the XB-70 had half the payload:range of the B-52 and NONE of it's 'outsize' carriage options (Skybolt and Hounddog among others). It preferred to cruise around Mach 1.4 and AV-1 was specifically limited to Mach 2.5, even Av-2 was only about a 2.7 bird. Neither of which was sufficient for the 'travel faster than you burn JP' argument for compression lift.

While you could probably hookup with a tanker and make radius, the problems with the aircraft's structural capabilities and profile Mach point:climb factor would have not made it a returnable flight, even into Turkey, IMO.

As the jet most assuredly would have done a critical portion of it's flight subsonic or low supersonic which is exactly where the benefits of the exotic aerodynamics _did not work_.

I can't say it enough folks. CompLift be hanged, nothing comes for free and unless you have _Thrust Minus Drag_ to get to height quickly, you are gonna be penalized for all the time you spend in a series of Rutowski curves making altitude in stair steps.

The XB-70 failed for a reason.


KPl.

dumb and strange because they allready have some of those newer and unknown to us.

www.janes.com...

maybe they are those spoken of in the link pasted above.

I appologize for my absence - first a mission trip, then internet troubles. Although I doubt it's the forefront of anyone's concerns.

The problem with ICBMs being used as offensive weapons is a simple one - they are easily tracked and intercepted. Northrop-Grumman has a proposed missile defense grid that is nearly impermiable. It also dual-functions well to fend off against aircraft coming in over seas or plains. Better still, the entire defense grid can be set up in 48 hours or less, with the first Kinetic Energy Interceptors being deployed anywhere in the world in 24 hours.

The grid is effective against just about everything that flies and can be tracked by radar.

More primitive systems could be used to defend against ICBMs by other countries - rather easily. Unlike an aircraft - a ballistic missile has a predictable course and several key points that are very opportune for an interception.

Cruise missiles are harder to defend against, however they are very limited in range and are not effective against targets en mass or highly mobile targets. When most cruise missiles have to strike at targets deep within enemy territory - they must be launched by aircraft to begin with. Land-locked countries are barely within range of ship-launched missiles, and ground based launchers are restricted to friendly territory - as a battery of Tomahawks falling into the hands of hostile forces would NOT be very good tactics, much less publicity.

A highly maneuverable, mobile, and stealthy fighter-bomber would offer a wide range of flexibility, as well as additional functions such as recon, interception, search and destroy, CAP, CAS, and JSOW weapons delivery.

ICBMs are also not practical for an extended engagement. Sure - they're intimidating. But they are more effective at delivering fission or fusion warheads - weapons that do massive amounts of damage. They would work okay in the precision-strike role, however, you would have to erect massive missile bases around the U.S. to be able to handle an extended engagement.

In short - they would work nice as a supplement - but, alone, are not and cannot be the answer. They are too ineficient, vulnerable, and very costly to field or base. The price margin is, in total, about the same as running a bomber fleet.

I know that this response reaks with the scent of typical response of a conspiracy theorist, but this is one more piece of evidence that the Aurora is real and will be put into service.

Well pointed out.

This is just a set up for the eventual public appearance of whatever version of the Aurora project.

The decision to go ahead with the project is simply a way to correct the accounting books.

Personally, I hope its not unmanned bomber. I would like to see the yokes being controlled by good ol' humans hands and heart to fight and win with determination. I sure believe it can be supercruise around Mach 2 due with their maybe being powered by four ramjet or design new engines to make it far more effective than ramjet and scramjet itselfs. I don't give in trust to unmanned jets yet.