It's time for our regular open thread. Talk about whatever you want so long as it isn't culture war.
I will again remind people that Naval Gazing has a discord, and that we do things besides naval stuff there. General is often active with random stuff, and we have a dedicated Bulbasaur channel if anyone wants to talk about Pokemon.
Overhauls for 2022 are Speed and Range in Battleships and Southern Commerce Raiding Part 7.
The introduction of the Trident C4 still left the overall Trident program with an unresolved issue. The new Ohio class submarines were being built with much larger missile tubes than were required for the Poseidon/Trident I, and a new missile had been promised to fill them. What that missile would look like was an open question. Initially, the plan had been to increase range from the 4000 nm of the Trident I to as much as 6000 nm, allowing the missile to reach Moscow from a submarine off the coast of South Africa. But this seemed unnecessary, and a number of factions within the defense establishment instead began to push for better accuracy, giving the new missile a true hard-target capability that previous SLBMs, focused on retaliatory attacks on enemy cities, had lacked.
Much of this drive came from a shift in US nuclear strategy, which began to turn away from the all-out nuclear war in the early 70s. Secretary of Defense James Schlesinger wanted more options to attack Soviet nuclear forces, and pushed the SPO to improve the accuracy of their missiles, starting a program to better understand the sources of error in the existing missiles, with the hopes of improving not just the Trident I but also the Trident II. Several options came out of the program to reduce CEP,1 including fitting a receiver to use the new GPS satellites, a radar sensor that would look at the terrain as the warhead came in, and improvements to the stellar-inertia guidance system used on Trident C4. Eventually, the last option won out, due to concerns about the reliability of GPS during a nuclear war and a lack of confidence in the radar seeker, particularly due to issues with testing against inland targets. Read more...
In previous parts, we've discussed the basics of spaceflight, optical recon satellites and other types of recon satellites, but there has been one glaring omission. So far, all of these systems have been directed against land targets, but satellites could also help solve the problems of finding ships far out at sea.
The Soviets were the first to take a serious look at this problem, needing as they did some way to find the American carriers, armed with nuclear weapons, for their missile-armed bombers and submarines. Initially, they planned to get a rough fix using shore-based direction-finding apparatus, supplemented with long-range scout bombers. But as the Americans switched away from the use of HF radio, the DF system became less useful, and satellites were the obvious solution. Optical detection was clearly out, given its inability to see through weather and the problems of scanning the entire ocean, then processing and downlinking the data. A radar system would work much better, as it could penetrate clouds and automatically detect targets, greatly reducing the amount of data that needed to be sent to the ground station. Read more...
It's time once again for our regular Open Thread. Talk about whatever you want, so long as it isn't Culture War.
Overhauls are German Battleships in WWII and for 2022, NWAS Trident Part 1 and my take on the Light Amphibious Warship.
Although imaging satellites are the most prominent and best documented form of recon satellites, they are far from the only platforms to carry sensors into space for military purposes. The most common use is signals intelligence (SIGINT), taking advantage of the fact that radio waves generally travel in straight lines well past their target, and can be picked up by a passing satellite. Antennas also produce sidelobes that point in different directions from the main lobe, and satellites can often pick up signals in the lobes pointing up. Lastly, a snooping satellite can make use of the fact that radar signals have to be quite powerful to create a useful return, so even a simple receiver is usually enough to pick up a one-way signal.
In fact, the first plans to make use of these properties predate spaceflight itself. In the late 40s, engineers realized that they might be able to measure the signals of Soviet air-search radars by listening to signals reflected off the Moon. Initial tests found that the Moon was a surprisingly good reflector, but the cost of an operational program, and the development proper of SIGINT satellites, killed it off.
SIGINT satellites were planned from early on in the American space program, and a system known as GRAB (officially Galactic Radiation And Background, in fact simply for what it would do to Soviet electronic transmissions), was the world's first successful spy satellite. The satellite, with the cover name SOLRAD 1, was launched as a secondary payload with the Navy's Transit 2A navigation satellite (discussed in a later part) and despite weighing only 19 kg incorporated not only the SIGINT system but also a very real science capability, passing significant data on the Sun's X-ray signature. When in SIGINT mode, it was a simple transponder, relaying the signals it picked up to the ground station, where they were recorded for analysis. This gave not only the performance characteristics of the radars, but also their location, thanks to the use of doppler shift and a bunch of math. These were largely focused on Soviet air defense radars, vital information for both Navy and Air Force as they planned nuclear strikes on the USSR. Read more...
While in LA for the Naval Gazing Meetup (it was great, you should have come) I took the chance to visit the remnants of Fort MacArthur in San Pedro, not far from Iowa. I hadn't been interested in the field until a few years ago, and for various reasons hadn't been able to get there since.
Fort MacArthur was established in 1914 to protect the growing city of Los Angeles as part of the Taft board's expanded program of fortifications. Initially, it was equipped with a quartet of the standard 14" disappearing guns and eight 12" mortars, as well as mines and smaller guns to cover the entrance to the Port. These were supplemented in the interwar years by a pair of 14" railroad guns. The fort was not particularly popular with the neighbors, who complained of broken windows, and the railroad guns were often moved up and down the coast to allow the crews to train. After the outbreak of war, there were serious concerns that the Japanese would attack, and the existing defenses were bolstered by the addition of a pair of 16" guns in casemate mounts a little ways up the coast, and another battery was planned down the coast in Orange County. These were armed with the 16"/50 Mk 2 guns designed for the WWI-era South Dakota class, and while the Orange County battery was cancelled in 1944, the battery near MacArthur was among the last ever completed by the United States. Read more...
It's time once again for our regular open thread. Talk about whatever you want, so long as it isn't Culture War.
Since the last discord meetup worked quite well, I'm going to hold another one next weekend, 7/29, at 1 PM Central (GMT-6). Discord link is in the sidebar if you want to join, or if you just want to hang out in the regular channel.
Overhauls are Signalling Part 4 and for 2022, Corrosion at Sea and my review of Hornet.
Now that we have the basics of spaceflight out of the way, we can turn to the most obvious application of spaceflight for military purposes, putting up a fancy camera to see what the enemy is up to.
Reconnaissance satellites were an early priority for the US space program. The Soviets went to great lengths to limit the flow of information to the west, restricting travel in vast areas, falsifying maps and giving facilities the names of cities dozens of kilometers away. For many years, the best source of mapping data were captured German aerial photos taken during the war. In the early 50s, the lack of information had led to the "bomber gap", where the US erroneously believed that the Soviets had produced a massive fleet of intercontinental bombers. U-2 overflights proved that the actual numbers were barely into double digits, but only after a few years of frantic buildup left the US bomber force in the thousands. Worse, the U-2 was becoming increasingly vulnerable in the face of improved Soviet air defenses, and the diplomatic consequences of overflights were growing ever worse. Satellites could fill this role, and ensuring free overflight became the law was a major priority of Eisenhower's, to the point that he prioritized the civilian Vanguard rocket over the missile-derived Juno I to aid in making his case. Read more...
Space has been an important source of military capabilities for the last 60 years, and it is only growing more critical. I've touched on several aspects of military spaceflight in the my writing where they've interacted with other subjects, but it seems worth taking a look more specifically at the history and development of military spaceflight, and the various systems in use, both in the past and today.
But we need to start with a very brief introduction to spaceflight and orbits.3 Getting into space itself isn't that hard. It's 100 km straight up, which means that, neglecting air resistance, you need to be going about 1,400 m/s to get there, or about Mach 4. But you'll barely brush space, then come straight back down, which generally isn't what you want. And that brings us to orbits. The basic insight behind an orbit is that if you go sideways at the right speed, the Earth's surface will fall away below you at the same rate you're falling, allowing you to fall around it forever. If you're in Low Earth Orbit (LEO, altitude below 2,000 km or so) then this is around 7.5 km/s, and you can expect to go around Earth every 90 minutes-2 hours. At higher altitudes, gravity is lower, and you don't need to go as fast. For instance, at an altitude of 35,786 km, you only need to go about 3 km/s, and the orbital period is exactly one day. This is called Geostationary Orbit, because a satellite in this orbit stays stationary relative to the Earth's surface, an extremely useful property we will come back to later. Read more...
It's time once again for our regular open thread. Talk about whatever you want, so long as it isn't culture war.
Reminder that we're doing a virtual meetup in the discord (link in the sidebar) tomorrow at 1 PM Central (GMT-6).
Overhauls are Rangefinding, The Newport Conference and the US Dreadnought, Signalling Part 1, Coastal Defenses Part 8, and for 2022, Coastal Defenses Part 9 and my review of Jeremiah O'Brien and Pampanito.
Recent Comments