July 14, 2024

Military Spaceflight Part 10 - Modern ASAT

Work on anti-satellite weapons began almost as soon as it became apparent that satellites had military utility, although initial work was driven by fears that the Soviets would put nuclear weapons in orbit. For a variety of reasons, this wasn't particularly well-founded, and it meant that the initial American systems, which used nuclear warheads of their own, were retired relatively quickly. Focus instead shifted to non-nuclear systems. The Soviets had preferred these from the start, designing coorbital systems that would come alongside and blow the target up from close range, while the Americans preferred to go straight up and intercept the target at high speed. The Soviets also looked extensively at in-space weapons, to the point of unsuccessfully launching a laser battle station in the closing years of the Cold War.

A DF-21 launcher

With the end of the Cold War, ASAT development quieted down for about 15 years before things began to heat up in the mid-2000s. China, who had had a quiet ASAT program since the 60s, began live tests of a direct-ascent missile in 2005, said to be based on the DF-21 ballistic missile with a different kinetic kill vehicle. These culminated in a hit on a weather satellite in 2007, which caused more debris than any previous event in the history of satellite tracking. 3,438 pieces were eventually tracked, and because the satellite was in an 850 km orbit, decay is slow, and NASA has estimated that 30% of pieces larger than 10 cm would remain in orbit past 2035. There was global outrage, and while China has run several subsequent tests, these have been against ballistic targets, which don't produce orbital debris. There have also been reports of more powerful ASAT systems, some of which are credited with capability against targets in GEO. Read more...

July 07, 2024

Military Spaceflight Part 9 - Cold War ASAT

The military utility of satellites quickly set the US thinking about ways to counter Soviet space presence. Given that this started in the late 50s and early 60s, it should be no surprise that the initial efforts, Project Mudflap and Program 437, were nuclear-tipped. But these, based on small islands in the Pacific, had limited engagement windows and using them would require accepting the rather dramatic consequences of high-altitude nuclear weapons on satellites and those on the ground.

This had been justified by fears of the Soviets putting nuclear weapons in orbit, but in the early 70s, Project 437 was shut down as it became increasingly clear that the Soviets weren't going to do that. As for other Soviet satellites, their recon birds had to return their film for processing, limiting their utility during a war, while communications was done from orbits far too high for the Thor missiles used in Project 437 to reach. But things began to change in the late 70s, as the Soviet ocean surveillance program ramped up, exposing US forces to real-time space surveillance and producing a resurgence of interest in ASAT. The downsides of using nuclear weapons in space meant that this version would involve getting a direct hit on the target satellite. And because the target had to be killed quickly, the weapon would need to be far more mobile than the old Thor, resulting in a return of the air-launched concept that dated back to Bold Orion, although this time with the high-performance F-15 as a launch platform.1 Read more...

July 05, 2024

Open Thread 160

It's time once again for our regular open thread. Talk about whatever you want, so long as it isn't Culture War.

I'm going to do a virtual meetup next Saturday, 7/13, in the Naval Gazing Discord channel, at the usual time, 1 PM Central (GMT-6 or so). Should be fun if you want to talk about whatever happens to come up.

Overhauls are Rangefinding, Impressment, my pictures from Iowa's goat locker, The 3T Missiles - Launch Systems, Coastal Defenses Part 8, my review of the Jeremiah O'Brien and Pampanito and for 2023, Thoughts on the lost submersible, my review of the Kansas Aviation Museum, The German Navy in the Americas and my post thanking the base commander for the long lines at last year's Tinker Air Show.

June 30, 2024

Air Attack on Ships Part 5 - Early Dive Bombers

Throughout WWII, the single most effective way of delivering high explosives to ships was dive bombing. This is exactly what it sounds like, the aircraft diving towards the target before releasing the bomb, the performing a high-G pullout to avoid following the bomb into the target. It was originally developed during WWI to attack land targets, as pilots realized that it allowed them to place bombs far more accurately,2 although the fragile aircraft of the time were limited to fairly shallow dives.3

Curtiss F8Cs, the first US dive bomber

Dive bombing nearly died off in the years immediately after WWI, abandoned in the enthusiasm of airpower advocates for level bombing, but it was adopted by the US Marines and Navy in the late 20s, using fighters equipped with light bombs for support in ground fighting. Initially, they used fairly shallow dives, but the target had a tendency to disappear under the nose of the aircraft, and it was soon realized that steeper dives not only solved this problem and improved accuracy, but also were far harder to defend against. The plunging dive bombers were generally difficult to see before they began their dives, and once in a dive, the rapid change in range meant that heavy AA guns were ineffective, while lighter AA weapons had only a narrow window to work against the diving aircraft.4 The basic technique they used would remain standard throughout the dive bomber's life: approach at 10,000' or so, then push over into a steep dive, 70° or more. As he dove, he would aim at the target attempting to compensate for wind and the movement of the ship. The bomb would be dropped during the dive, and the pilot would then pull out and fly away at high speed and relatively low altitude. What altitude the pull-out was done at varied, with early tests taking place at 1000' or so, although later aircraft had to do so at greater altitude to avoid plowing into the ground.5 The pullout itself would often subject pilot and plane to 6G or more, enough to make the pilot's vision gray out, which generally limited the tactic to smaller aircraft.6 Read more...

June 23, 2024

Military Spaceflight Part 8 - Nuclear ASAT

Satellites have found a number of military uses: reconnaissance and intelligence, communications and navigation. But all of these require the satellites to be intact and functional, and that raises the possibility of denying the enemy these capabilities by degrading or destroying their satellites. That's right. It's finally time for ASAT.7

Bold Orion

First, a few words of definition. We can divide ASAT weapons into two fundamental categories: direct ascent and coorbital. Direct-ascent weapons, as the name suggests, ascend directly from the surface to intercept their target, while coorbital ASAT involves launching into the same plane as the target, then approaching and using some sort of warhead at close range. Direct-ascent is conceptually simpler and cheaper (as it can be executed by a fairly small missile if it's in the right place), and can use the target's own speed in place of a warhead if it can get a hit.8 The downside is that it requires incredibly precise guidance, with a typical launch window being a second or less, even if the system is fitted with a nuclear warhead. Coorbital ASAT, on the other hand, needs a full-size booster, but once the price for that has been paid, the guidance problem is greatly simplified, removing the need for a nuclear warhead even with 60s technology, and it is theoretically possible to leave the ASAT shadowing the target, then kill it at a moment's notice when war breaks out. The US has always preferred direct-ascent systems, while the Soviets and Russians often went for coorbital ones. Also worth noting early on is that not all satellites are created equal from the perspective of ASAT systems. An imagery satellite a couple hundred kilometers up is a far easier target than a GPS satellite or a comsat in GEO that are tens of thousands of kilometers up. This is more true for direct-ascent systems than for coorbital systems, but it affects both of them, and news stories about LEO systems that bring up the danger to GPS and the like should not be trusted. Read more...

June 21, 2024

Open Thread 159

It's time once again for our regular Open Thread. Talk about whatever you want, so long as it isn't Culture War.

First, long-time reader and commenter Cassander is looking for a managerial data science/product management role, preferably in aerospace. Email tint.michael@gmail if you have suggestions or leads.

Overhauls are Part 10 of the Aurora tutorial and for 2023, Warship Taxonomies and my writeup of the 2023 meetup in LA.

June 16, 2024

Military Spaceflight Part 7 - Space Surveillance

I've previously gone over the various capabilities that space systems bring to the military, ranging from reconnaissance to communications to navigation. But anything that provides such a capability is obviously going to turn the military mind to countermeasures.

At this point, it would be easy to immediately launch into a recounting of the various and delightful ways that people have come up with to blow up satellites, but that would be premature, because a great deal of the time and energy involved in counter-space work has been spent on keeping track of what is going on up in orbit. After all, it's rather difficult to blow up satellites if you don't know where they are, and very easy to blow up the wrong one if you don't know what they are, not to mention all of the other things you can do with this information. Read more...

June 09, 2024

Distributed Maritime Operations and the LUSV

The latest hotness in the USN is Distributed Maritime Operations (DMO), which is their strategy for dealing with the rise of Chinese maritime power. I'd love to give you the official definition here, but I can't, because despite talking about this for 6 years now, they have yet to give an official unclassified definition for it.9

Two USV prototypes

The best definition I've been able to find from DoD sources, and it took a bit of looking,10 is "An operations concept that leverages the principles of distribution, integration, and maneuver to mass overwhelming combat power and effects at the time and place of our choosing. This integration of distributed platforms, weapons, systems, and sensors via low probability of intercept and detection networks, improves our battlespace awareness while complicating the enemy’s own scouting efforts. Applying combat power through maneuver within and across all domains allows our forces to exploit uncertainty and achieve surprise." Translated out of five-sided thought,11 this is sort of a turbocharged version of network-centric warfare, seamlessly linking together all of the various sensors and weapons wherever they may be so we can face the PLAN with whatever assets are best-placed to destroy them while avoiding providing the enemy with juicy targets. Read more...

June 07, 2024

Open Thread 158

It's time once again for our regular Open Thread. Talk about whatever you want, so long as it isn't culture war.

First, apologies for not having a Jutland post this year. I didn't really have anything to cover, so I left that slot empty.

Second, I recently watched the Prime documentary on the Blue Angels, and very much enjoyed it. Would recommend.

Overhauls are Coastal Defenses Part 3 and for 2023, The East Asia Squadron Part 2, my review of Rules of the Game and RTW3 and Information.

June 02, 2024

Museum Reviews - 2024 New England Meetup

During the 2024 Naval Gazing Meetup, I got a chance to revisit several museums I'd been to years ago, and I thought I should take the chance to update my impressions based both on what has changed there and on the fact that I have spent the last few years thinking about how best to run a museum ship.

First was Battleship Cove, where the biggest change was the loss of Hiddensee, which had to be scrapped in 2023 because she was in bad shape and it would have been too expensive to keep her. This is an unfortunately common fate for Soviet-bloc museum ships, and I am aware of at least three others that were ultimately consigned to the scrapyard for similar reasons, but at least I got to see her before she went, unlike the others. This has had a knock-on effect, as previously visitors got onboard Lionfish via Hiddensee, so Lionfish is currently closed while they get alternate access set up. I believe they're hoping to get her open sometime this summer. Read more...