I hope it works.
This press release describes the new 500-mile range variant which compares it to the 200-mile range original variant.
JASSM is sub-sonic and since there aren't any videos of it doing nap-of-the-earth flight profiles, it is possible that it depends only on stealth to survive.
That could be challenging. First day of duck season.
Also mentioned by the USAF is its over-optimism with GPS assistance to the inertial navigation (INS) in the missile. GPS is great for the JDAM which has a short flight time (around 1 minute). If the jet dropping JDAM already has a tight INS fix (better if enhanced by a radar update), the JDAM's INS is going to hit--GPS or no.
The longer range you shoot the more updates you need. GPS degradation is mentioned by the USAF but if it is a long range shot and GPS is denied, good luck hitting much. This comment doesn't hold water:
"Even without GPS, the JASSM can find its target due to its internal sensor."
Also, if they are depending on net-enabled updates, that can be geo-located and/or denied.
What would help? Celestial navigation. The B-2 has a very accurate celestial navigation unit in its left wing. Some old Cold War ideas had an analog ones...but accuracy only needed to be good enough for nukes.
How did pre-GPS cruise missiles like ALCM off of the B-52 do it? With a terrain contour-matching guidance system (SAC SIOP=highly scripted missions) and again nukes needing less accuracy. Survivablity was based on flying nap-of-the-earth around known threats.
Bomb damage assessment (BDA) of Desert Storm targets hit with ALCM's converted from nuke to conventional warheads, with this technology of the day was mixed; and, over-hyped. Or as General Powell put it: something about bouncing rubble with million-dollar missiles; for those those that made it near the proper target.
Post-Desert Storm, ALCMs were upgraded with GPS assist.
How the JASSM acts in real combat against high-end threats will be interesting. I hope we never have to find out. Scripted range events and all that. It beats the over-sell by the F-35 Joint Strike Fighter crowd claiming high-end IADS survival which doesn't exist.
The F-35 problem is that it is too weak to take on high end-IADS and too expensive to operate for any other kind of lesser threat. Unusable for the Pacific. Current legacy aircraft that can carry JASSM have a better shot at taking care of high and low threats.
JASSM was supposed to be an "affordable" cruise missile in the $400,000 each region. What the U.S. pays for each weapon these days isn't anywhere close to that.
So, cruise missiles are it. We are out of money and any real air power advocates are retired, dead, or doing anything else.
And, I wonder, why the USAF thinks 1763 F-35 Joint Strike Fighters, still makes any sense.
7 comments:
INS can be pretty accurate, compact and cheap nowadays. much better than 0.1% error.
Add a laser altimeter and a run-of-the-mill passive thermal sensor with a pattern detection algorithm that allows for pinpoint targeting of structures and you're fine for static targets unless OPFOR does a really fine job.
Static and some semi-mobile targets have little chance of survival when facing Western air power, maybe even when facing Russian air power (then up to ~400 km depth).
The real reasons for concerns are about the ability to match expectations in regard to air supremacy in face of gazillions of small drones and in regard to offensive action against camouflaged mobile targets driven by competent and careful drivers.
The most damning thing to any INS is time. If it goes a log ways over time without updates, you still get drift. If the terminal sensors in the JASSM can't acquire the imagery expected near the target, you risk a miss. So much money has been invested in JASSM now that it would be nice to see an automated celestial nav device in it as a backup to GPS and network denial. It would probably work very well.
You'd be restricted to clear sky night missions, probably even to nights without full moon.
the B-2 flies high, JASSMs likely not.
European and East Asian weather isn't reliably clear enough for what you wish.
It is a potential backup. What you just described also applies to GPS and networking. When the enemy jams it out, it is unavailable.
Celestial navigation is fine for wide-area navigation, not for precision attack stuff. And down low even with modern IR/near IR trackers the star sight propability is less than 50%. And then in something small like a cruise missile it's really hard to get a precise vertical.
INS coupled with an internal terrain model can help, actually should be in there anyway to check GPS plausibility.
And for the end game a LIDAR is probably the way to go, as it at least to a degree enables attacks against masked (semi-)mobile targets.
You're talking a lot of ifs.
If GPS jamming is present.
If GPS jamming EP is ineffective
If GPS jamming is effective over entire time of flight
If if the INS drifts enough (200nm at subsonic fighter speeds is around 20min?)
If the sensor then can't acquire in the uncertainty volume
Etc etc
The world according to "Flasheart"
If it is American it always works perfectly, and if it comes from China or Russia it does not.
This bloke is a genius, however if all you do is read comic books and visit kiddies sites the world is different.
Flasheart suggest you read some history.
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