PC/WI: All US ICBM/SLBM's missiles put on land mobile launchers?

This is not correct. SSBNs use internal position keeping. They get updates from GPS when they can. The missile takes a reference picture of stars when out of the atmosphere. This corrects for any mistakes.

https://en.m.wikipedia.org/wiki/UGM-133_Trident_II

I did mention astro-inertial guidance form SLBMs. However, sea floor topography is also surveyed for guidance purpose:

http://discovermagazine.com/1996/mar/theseafloorfroms713

Late in the cold war, the United States Navy decided it would be a good idea to survey the altitude of the ocean surface, all over the world, to within a few inches. The point was not to measure waves. The ocean is not flat even where it is calm: it has hills and valleys that depart by as much as a few hundred feet from what we think of as sea level. The slopes of these features are so gentle--they extend over tens or even hundreds of miles--that no ship ever feels them. Yet the Navy decided that submarine commanders, of all people, would benefit from precise measurements of this imperceptible topography.

Why? Because the study of bumps on the ocean surface is a reliable kind of phrenology: it reveals deeper truths about the ocean. Small, shifting bumps are created by the shifting fronts between water masses--between the warm Gulf Stream and the cold Atlantic, say--and those same fronts scatter sound, thus creating sonar shadows that can hide a Red October. The larger and more permanent hills and valleys are created by something else entirely: by Earth’s gravity field, which varies slightly from place to place. Knowing those variations helps a submarine stay on course when it is underwater and sailing blind. And when the time comes to launch a missile at Minsk, knowing the precise direction of gravity at the launch site--it does not always point straight toward the center of Earth-- is essential. If the missile starts out on a slightly wrong heading, it will miss its target, thousands of miles away.

So in 1985 the Navy launched Geosat, a satellite that measured the height of the sea surface by bouncing a radar beam off it. In a near- polar orbit, 500 miles high, Geosat circled the spinning Earth, painting it with a tight mesh of densely packed radar tracks. The satellite worked flawlessly, and it yielded the most comprehensive set of gravity measurements ever. For the Navy, the payoff was a substantial reduction in a missile’s margin of error--which meant a better chance of hitting Minsk. The Navy was not very interested in making a beautiful map of Earth’s gravity field; and even less was it interested in using such a map to chart Earth’s most remote frontier--the unseen topography of the seafloor. But David Sandwell and Walter Smith were interested in precisely that. And when the Navy finally declassified the Geosat data last summer, Sandwell and Smith wasted no time in creating the map you see here.

Let us be perfectly clear about one thing: this is a map of gravity, not of seafloor topography. Where the map is blue-green, the rate at which Earth’s gravity accelerates a falling object (little g in the equations of physics) has more or less its average value of 9.8 meters per second squared--or 980 gals, as physicists say, in honor of Galileo, who first measured the acceleration. In the bright orange areas of the map, gravity is at least 60 milligals--about 60 parts per million--stronger than average. In the darkest purple areas it is at least 60 milligals weaker.

The map shows tiny variations in gravity, then--and yet to anyone who has ever seen a map of seafloor topography, its broad outlines will look familiar. That shouldn’t be surprising: insofar as mountains tend to have more mass than valleys, topography generates gravity. And insofar as one person can be said to have invented the idea that small bulges detected on the sea surface by a satellite could reveal the presence of large mountains on the seafloor, the credit should probably go to a geophysicist named William Haxby of the Lamont-Doherty Earth Observatory. In the early 1980s Haxby took data from a NASA predecessor of Geosat, called Seasat, and made a much cruder version of the map shown here. People looked at the data, Sandwell recalls, and said, ‘Oh wow, we can see seamounts and fracture zones and all types of features on the seafloor.’ That was when people really woke up to this idea.
(emphasis added by me)

A journal paper:

http://topex.ucsd.edu/marine_grav/white_paper.pdf

Table 1. Applications of High Spatial Resolution Satellite Altimetry Topography Applications: • fiber optic cable route planning (http://oe.saic.com) • tsunami models (Yeh, 1998) • hydrodynamic tide models, tidal friction, and stirring of the oceans [Jayne & St. Laurent, 2001] • improvement of coastal tide models [Shum et al., 1997; 2000] • ocean circulation models [Smith et al., 2000; R. Tokmakian, pers. commun.] • understanding seafloor spreading ridges [Small, 1998] • identification of linear volcanic chains [Wessel and Lyons, 1997] • education and outreach (i.e. geography of the ocean basins) • law of the sea [Monahan et al., 1999] Gravity Applications: • inertial guidance of ships, submarines, aircraft, and missiles • planning shipboard surveys • mapping seafloor spreading ridges and microplates (http://ridge.oce.orst.edu) • establishing the structure of continental margins (http://www.ldeo.columbia.edu/margins/Home.html) • petroleum exploration (Section 2.4) • plate tectonics [Cazenave and Royer, 2001] • strength of the lithosphere [Cazenave and Royer, 2001] • search for meteorite impacts on the ocean floor [Dressler and Sharpton, 1999]
 
I did mention astro-inertial guidance form SLBMs. However, sea floor topography is also surveyed for guidance purpose:

http://discovermagazine.com/1996/mar/theseafloorfroms713

(emphasis added by me)

A journal paper:

http://topex.ucsd.edu/marine_grav/white_paper.pdf

That is pretty cool. Unless it was built in and not known or talked about, I never saw it in any SSBN I was on. Before GPS we used SINS only and after would take GPS position when we could to check SINS. SSNs are always checking temperature, so the part about Red October not much use either.
 
One slightly OT idea for a network of mobile ballistic missile launchers was the US Army's Project Iceworm in the '60s. This was intended to turn 130,000 km2 of Greenland into a space enclosing 4,000km of tunnels for around six hundred mobile IRBM systems plus a network of supporting bases and other infrastructure. All nuclear powered of course.
The reason for this grandiose lunacy was the huge problem with Atlas, Titan and their other IBCMs; they were operated by the US Air Force...

One can imagine in a world several points to peppermint where sanity and common sense didn't win out and this project was implemented, twelve thousand of soldiers living under the ice (inclose proximity to nuclear warheads and reactors) to operate this network. Plus the anti-aircraft missiles to stop Soviet bombers (200 Nike-Hercules were planned for).

Possibly also dring giant (nuclear powered of course) vehicles based on the Antarctic Snow Crawler, but carrying IRBMs. Matches of course by clandestine Soviet espionage, infiltration and sabotage efforts.
A world were the triad became a quadriad.

The Doctor Who scenario practically writes itself.
 
The midgetman ICBMs were intended to be based in remote areas, their hardned mobile launcher could go over 100 mph off road.
That scared the crap out of the Soviets.
 
Well this source seems to have a different view of the likely speed of the midgetman mobile launcher

https://books.google.ca/books?id=1smvCwAAQBAJ&pg=PA7&lpg=PA7&dq=midgetman+off+road+speed&source=bl&ots=CSIp3BFiW-&sig=p-aY3TK0W4uIApyjknRU2-Hd2Wk&hl=en&sa=X&ved=2ahUKEwi9rJi9857bAhVyLH0KHcF4BBsQ6AEwDHoECAYQAQ#v=onepage&q=midgetman off road speed&f=false

I doubt a midegetman deployment would have been much scarier (if any) to the Soviets than Trident 2.
Especially given a slant launched D5 would give a very short warning time.
 
Especially given a slant launched D5 would give a very short warning time.
Does any one know if so called "depressed trajectory" launches were ever tested at all (or perhaps fully tested ?) with the D5. Back when I was used follow these matters there was some talk that actually testing (or perhaps further testing ? sorry my memory is a bit hazy re this) this capability with the D5 might cause further issues with the Soviets. I stopped following these matters after the early 90's (and never looked deeply into the depressed trajectory testing issue.)
 
Why not base them like these babies where at RAF Greenham Common & RAF Molesworth in the UK when operating the Tomohawk GLCM?

View attachment 388497

Speaking of which, did anybody else recognise that site in The Force Awakens?

800
 
Does any one know if so called "depressed trajectory" launches were ever tested at all (or perhaps fully tested ?) with the D5. Back when I was used follow these matters there was some talk that actually testing (or perhaps further testing ? sorry my memory is a bit hazy re this) this capability with the D5 might cause further issues with the Soviets. I stopped following these matters after the early 90's (and never looked deeply into the depressed trajectory testing issue.)
DT testing was prohibited by the US HoR in MAY1988 as part of the defense spending bill for FY1989 but vetoed by Reagan. However there were no flight tests and significant attempts to ban the modifications necessary.
However technical evaluations and paper studies suggested that, even without additional stressing of the missile body and further heating shielding the D5 was capable of striking to ~2,000km with apogee of ~90km and a sub-7 minute flight time.
There were proposals for a new booster, better heat shielded RVs and streamlined MARV to handling a 50% increase in burnout velocity.

The best reference on STOF SLBMs from the late Cold War era is Medalia's Fast-Trajectory Strategic Ballistic Missiles.
 
DT testing was prohibited by the US HoR in MAY1988 as part of the defense spending bill for FY1989 but vetoed by Reagan. However there were no flight tests and significant attempts to ban the modifications necessary.
However technical evaluations and paper studies suggested that, even without additional stressing of the missile body and further heating shielding the D5 was capable of striking to ~2,000km with apogee of ~90km and a sub-7 minute flight time.
There were proposals for a new booster, better heat shielded RVs and streamlined MARV to handling a 50% increase in burnout velocity.

The best reference on STOF SLBMs from the late Cold War era is Medalia's Fast-Trajectory Strategic Ballistic Missiles.
Thanks. Much appreciated.
 
Interesting topic. The Soviet response to SLBMs was what they referred to as "Boil the ocean" In response to their inability to match anticipated US ABM technology as well as a similar inability to precisely locate the Boomers, ultra high megatonage area weapons were developed and (the de-rated to 56 MT "Tsar Bomba") demonstrated. Mobile US ICBMs, which would also be imprecisely located (despite undoubted overt and covert sighting information), would invite application of a similar Soviet strategy to the continental US.

Depressed trajectory firing of ballistic missiles was considered an aspect of Fractional Orbital Bombardment, and therefore off limits to the US. The world loves a good loser.

Dynasoar
 
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