Japan's Type-25 HVGP & HCM Hypersonic Weapons: Japan hypersonics in Australia

Japan’s new Type 25 hypersonic missile family are changing the operational picture in the region from the 25SSM hypersonic cruise missile to the 25HGP hypersonic glide variant.

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Comments by wispywood2344 from Japan on August 29, 2026 and September 1, 2026, August prompted me to conclude Japan is rapidly maturing hypersonic weapons. 

I then researched this subject using AI Google analysis on September 3, 2026. Using and presenting AI effectively and critically takes experience:

Japan has begun deploying its first stand-off hypervelocity weapons while actively developing advanced hypersonic glide and cruise missile technologies.

Key Weapon Systems

• Type-25 HVGP (Block 1)[aka 25HGP ] : Japan deployed this hypervelocity gliding projectile for island defense, featuring a range of several hundred kilometers. [1, 2]
• HVGP Block 2: An advanced variant with an extended range targeting roughly 2,000 kilometers, scheduled for deployment in the 2030s. [1]
• Scramjet Hypersonic Cruise Missile (HCM) [aka 25SSM ] : Japan is researching scramjet-powered engines for future compact, high-speed cruise missiles, including potential underwater launch applications. [1]

Strategic & Technological Developments

• Underwater Launch Plans: Japan's FY2027 defense budget request includes unpriced funding to research submarine- or modular unmanned underwater vehicle (UUV)-launched long-range strike and hypersonic capabilities. [1, 2]
• Testing in Australia: Japan and Australia announced a [new hyperlink bilateral agreement ] allowing the Japan Self-Defense Forces to test [see 5(d)] long-range stand-off and hypersonic missiles on Australian military ranges over the coming decade. [1, 2]
• Space-Based Tracking: Japan is developing low Earth orbit (LEO) infrared sensor payloads (such as pathfinder experiments aboard JAXA's HTVX1 spacecraft) to continuously detect and track manoeuvring hypersonic threats. [1]

The specific strategic implications for regional security

1. Complicating PLA Operations in the First Island Chain

• Targeting Amphibious Fleets: Japan’s hypersonic weapons are optimised for anti-ship strikes. This directly threatens China’s People's Liberation Army (PLA) surface combatants and amphibious assault groups. [1, 2]
• Disrupting Taiwan Conflict Planning: In a potential Taiwan Strait conflict, Japan could hold PLA naval forces at risk from a distance, restricting their freedom of movement within the critical First Island Chain and the Miyako Strait. [1, 2]
• Mitigating Airbase Vulnerability: Japan faces a severe shortage of hardened aircraft shelters, making its air forces vulnerable to pre-emptive strikes. Deploying mobile, ground-launched HVGPs to areas like Kyūshū, alongside stealthy underwater-launched hypersonic variants from submarines or unmanned underwater vehicles (UUVs), ensures a highly survivable strike capability that China cannot easily suppress. [1, 2, 4, 5, 6]

2. Shifting the Interconnected Threat Dynamics (China, Russia, North Korea)

• Breaking the "Shield Only" Posture: For decades, regional adversaries operated under the assumption that Japan would act only as a "shield" while the United States acted as the "spear". Japan’s ability to conduct independent, high-speed, precision strikes against launch sites or command nodes fundamentally alters adversary risk calculations. [1, 2]
• Countering Coordinated Pressure: Tokyo views the military activities of China, Russia, and North Korea as an interconnected security challenge (such as joint Sino-Russian strategic bomber patrols and North Korean missile tests). Hypersonic weapons provide a flexible, rapid-response option to counter multi-front intimidation. [1]

3. Escalation Risks and Compressed Decision Windows

• Incentives for Pre-emption: Because hypersonic missiles travel at speeds exceeding Mach 5 and follow unpredictable, maneuvering flight paths, they leave adversaries with virtually zero reaction time. This compresses the decision-making windows for all regional actors, which analysts warn could increase the risk of miscalculation or spark pre-emptive strikes during a crisis.
• Intelligence Dependency: For the immediate future, Japan remains heavily reliant on US intelligence, surveillance, and reconnaissance (ISR) for mid-flight targeting coordination in access-denied areas. This deepens bilateral operational integration but anchors Japan firmly within the US-led alliance's escalatory ladder. [1, 2, 3, 4]

4. Anchoring Multi-National Mini-Lateral Alliances

• The Australia-Japan Defense Axis: Japan’s decision to test its long-range stand-off and hypersonic missiles at remote military ranges in Australia marks an unprecedented expansion of security ties. This shifts their relationship from diplomatic alignment into an integrated, practical defense partnership.
• [new hyperlink] AUKUS Pillar II Integration: Japan's rapid domestic hypersonic advancements reinforce the momentum to formally integrate Tokyo into AUKUS Pillar II. This collaboration accelerates the co-development of advanced underwater capabilities, artificial intelligence, and next-generation hypersonic technologies among Australia, the US, the UK, and Japan. [1, 2]

Hypersonic Missile Research and Doctrine

Artist's conception of HyStrike in flight and internally. This is one hoped for practical product of hypersonic missile research.

On July 11, 2007 I commented on progress of Australia-DARPA "HyCause" hypersonic ramjet research. Something that may now be using results from that research (or working in parallel) is the "HyFly" test series.

From Defence Talk.com, October 6, 2008 came the following:

ST. LOUIS: Boeing has been awarded an $18.3 million follow-on contract from the U.S. Defense Advanced Research Projects Agency (DARPA) to conduct a third powered flight of the HyFly hypersonic missile. HyFly is powered by a Dual Combustion Ramjet (DCR) engine.

"The DCR engine is designed to accelerate HyFly and sustain flight at Mach 6," said Carl Avila, director of Advanced Weapons and Missile Systems for Boeing. "This will be a major step in the development of a weapon system that could revolutionize the military's ability to respond rapidly to time-critical threats hundreds of miles away. It will demonstrate that hypersonic weapons are viable and will put us one step closer to making a high-speed strike weapon available to the warfighter."

This third HyFly test follows two initial flights that, while partially successful, yielded significant data that will be useful in completing a successful test flight. The first flight in September 2007 successfully tested stage separation, inlet cover ejection, and DCR engine ignition. A software error prevented missile acceleration, ending the test.

For the second test in January 2008, HyFly successfully boosted to Mach 3.5. The missile achieved stage separation and inlet cover ejection, but the DCR engine failed to light due to a malfunction in the fuel system unrelated to the engine. HyFly remained under control during the flight and successfully completed a demonstration of terminal guidance accuracy.

Both flights were launched from a Boeing-operated F-15E aircraft over the sea range at the Naval Air Warfare Center Weapons Division, Point Mugu, Calif.

Comments

The HyFly project may well by ahead of any hypersonic research being conducted by Russia or France or ahead of any Russian-Indian hypersonic "BrahMos-2" research. 

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My estimation is that proponents of hypersonic missiles see them (in mainly classified specs) as being used for extremely rapid reaction and short to intermediate range. An early US goal was 700 nautical miles (1,300kms). Further than that ballistic missiles may have the edge.

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Unlike ballistic missiles hypersonic could be guided by an operator right onto target or (unlike ballistic) exploded or disarmed midair if a decision is made not to hit the target. Alternatively (unlike ballistic but like subsonic) they could be redirected mid flight to different targets.

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All launch modes, fixed and static, land, sea and air are possible. Of this subs operating close to enemy coasts may be a particularly suitable scenario.

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For Australia I think hypersonic cruise missiles fired from a future conventional "baby Virginia" sub may be what we'll have by 2030. Australia probably won't be realistic enough to go to nuclear powered subs with small ballistic missiles - but hopefully the upward firing cruise missile launch tubes could be reconfigured to ballistic (like the Indian ATV plans).

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So in that sense hypersonic may partly be seen as a compromise by "peaceful nations" short of (or before) going ballistic.

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Unlike ballistic (assumed nuclear if sent by a nuclear power) there is no such assumption that a hypersonic missile will be armed with a nuclear warhead.
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Just like subsonic cruise missile doctrine shifted from purely nuclear to mixed warhead uses hypersonic may be mixed - although the expectation might lean towards nuclear till experience proves otherwise.

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The technical difficulties of long distance hypersonic flight are still extreme. They centre on the missile overheating through friction in the dense lower atmosphere. Something for the aerodynamicists and metallurgists to nail by 2012 or so.

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Pete

Hypersonic Medium Range Boost-Glide Vehicles

A clear (July 3, 2018) discussion of hypersonic cruise missiles and boosted hypersonic glide vehicles. Will the physics of speed and the atmosphere causing overheating forever be an obstacle?
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Drawing from KQN's 30 January 2019 comment below this Submarine Matters' article of 29 January 2019:

The French Armed Forces Minister, Florence Parly, on January 21, 2019 announced France will be developing a missile boosted, then hypersonic (Mach 5+), glide vehicle by 2021. The glide vehicle is designated the Vehicule Manoeuvrant eXperimental (V-MaX) or experimental manoeuvring vehicle in English.

There might possibly be a proliferation of 1,000-3,000 km range missiles (MRBM)
 (eg. China's DF-21)(see below) as the launch platform for hypersonic gliders.

Even though Australia has been experimenting with hypersonic flight since 2007 (if not earlier) any Australian project would need to be a joint program (with the US, UK or France) on an unknown time-frame. A launch platform might conceivably be torpedo tubes in Australia's future submarines, modified F-35As, vertical launch systems in existing Hobart class destroyers or future Hunter class frigates.

At a minimum, the modified ballistic (glide) trajectory may point to a conventional warhead, rather than a nuclear warhead (with nuclear ambiguity inviting a nuclear response (eg. from China). China is developing the hypersonic DF-ZF (previously called "WU-14" by the US).

BACKGROUND

Courtesy wiki: Boost-glide trajectories in the military sense are reentry trajectories extending the range of reentry vehicles by employing aerodynamic lift in the high upper atmosphere. 

In most examples, boost-glide roughly doubles the range over the purely ballistic trajectory. In others, a series of skips allows range to be further extended, and leads to the alternate terms skip-glide and skip reentry.

The concept was first seriously studied as a way to extend the range of ballistic missiles, but has not been used operationally in this form. The underlying aerodynamic concepts have been used to produce maneuverable reentry vehicles (MARV) to increase the accuracy of some missiles.

More recently the traditional form with an extended gliding phase has been considered as a way to reach targets while flying below their radar coverage.

"...research was eventually put to use in the Pershing II's MARV reentry vehicle. In this case, there is no extended gliding phase; the warhead uses lift only for short periods to adjust its trajectory. This is used late in the reentry process, combining data from an inertial navigation system with and Goodyear Aerospaceactive radar seeker.^[17] Similar concepts have been developed for most nuclear-armed nation's theatre ballistic missiles.

In contrast to these maneuvering warhead concepts, there has been growing interest in the traditional boost-glide concept not to extend range per se, but to allow it to reach a given range while flying at a much lower altitude. The goal, in this case, is to keep the reentry vehicle below radar coverage until it enters the terminal phase.

Such a system is assumed to be used on the Chinese DF-21D anti-ship ballistic missile, which is also believed to maneuver during the terminal phase to make interception more difficult. 

China's later DF-26, a development of the DP-21, may be armed with the WU-14 later named DF-ZF, a hypersonic glide vehicle that has been successfully tested six times by the Chinese.^[18] Similar efforts by Russia led to the Kholod and Igla hypersonic test projects, and more recently the Yu-71 hypersonic glide vehicle which can be carried by RS-28 Sarmat.^[19][20]

Hypersonic Glide Vehicles could be used for delivering quick nuclear decapitating strikes.^[22]

In March 2018, Russia unveiled hypersonic glide vehicle Avangard.

COUNTER-MEASURES

While flying below the operational envelope of Exoatmospheric Kill Vehicles, the tradeoff with HGVs in comparison to conventional MIRVs are many-fold, including no needle in a haystack protection from missile decoys and both less speed and altitude as they near the target, all of these characteristics result in HGVs having poorer survivability odds when placed against lower-tier interceptors.^[24] 

Some examples of which include the high thrust mach-10 Sprint missile, its US derivatives and the still operational mach-17 Russian 53T6, ABM-3 Gazelle. Moreover, the possible re-emergence of nuclear or hit-to-kill stratosphere reaching guns, guided and triggered by forward operating flight-path sensors (such as the 2016 Hypervelocity Projectile (HVP) in development for the M109 howitzer) also will decrease HGV survivability odds.

Other more speculative counter-hypersonic vehicle measures may involve laser or rail gun technologies.^[25]

KQN, Wiki and Pete

Hypersonic Missiles for US, Australian & Even Israeli? Subs

Some interesting hypersonic snippets on US led hypersonic missile developments.

Under AUKUS Pillar 2

“The AUKUS partners will work together to accelerate development of advanced hypersonic and counter-hypersonic capabilities.” [Official AUKUS Fact Sheet, April 5, 2022].  Also see Wiki.

Australia and the US have been cooperating on the development of hypersonic missiles since 2020 after signing an agreement to "flight test full-size prototype hypersonic cruise missiles" under the [Boeing and Lockheed Martin preliminary designed Southern Cross Integrated Flight Research Experiment (SCIFiRE). contract] ^[97][98][99]

Lockheed Martin Awarded $1.1 Billion Initial Contract To Provide Nation's First Sea-Based Hypersonic [Conventional Prompt] Strike Capability: February 17, 2023 … [Conventional Prompt Strike] CPS shares a common [integrated support system] AUR with the Army LRHW and can be launched from multiple platforms including surface ships, submarines, and land-based mobile launchers.

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“Leading Hypersonic Solutions"

"Lockheed Martin is partnering with DARPA, the U.S. Air Force, the U.S. Army, and the U.S. Navy to transition hypersonic concepts to operational reality. Discover why hypersonics are a key to battlefield supremacy and an essential element in national defense."

[In the Youtube, uploaded by LM in 2022, here and above] 

"Lockheed Martin’s Chief Technology Officer and VP Steve Walker and VP, Advanced Program Development, Space Eric Scherff explain the advantages of hypersonic systems and Lockheed Martin's expertise in scaling complex weapon systems and leadership in hypersonics.”

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Tomorrow we'll take a look at the US (Boeing)-Israeli Arrow 3 Hypersonic missile. "The missile's reported flight range is up to 2,400 km"  and

"Another advantage mentioned was the ability to launch the Arrow 3 from advanced missile boats." 

Submarine Hypersonic Missile Idea Gains Traction

Andrew Greene, Defence Correspondent for Australia’s ABC News has written the excellent article below. It includes a major section on Hypersonic missiles for future Australian SSNs.

PETE COMMENT

I have written extensively about hypersonic missiles for the last 13 years https://gentleseas.blogspot.com/search?q=hypersonic in connection with future Australian Virginia SSNs.

See my “Comments” here https://gentleseas.blogspot.com/2008/10/hypersonic-missile-research-and.html

Preferably Australia's future hypersonic missiles should be nuclear tipped when the threat from China warrants it - say in the 2040s.

See my discussion of Australian Virginia or UK-AUKUS SSHNs (H for Hypersonic missiles) instead of the terms SSGNs or SSNs for Australia. See my articles https://gentleseas.blogspot.com/2023/07/sshns-or-xluuvs-are-australias.html and https://gentleseas.blogspot.com/2024/05/australias-nuclear-weapon-sshns-2030s.html .

Our Hypersonic missile warheads might need to be developed by Australia or preferably sourced from the US under yet another US-Ally nuclear sharing agreement. 

The US shares nuclear weapons with five NATO countries: Belgium, Germany, Italy, the Netherlands not to mention dangerously with NATO country  Turkey https://en.wikipedia.org/wiki/Nuclear_sharing. This is separate from the 1958  US-UK  nuclear weapon sharing arrangement.

ARTICLE

By defence correspondent Andrew Greene wrote at Australia’s ABC News on January 17, 2025 and at https://www.abc.net.au/news/2025-01-17/us-congressional-analysis-blunt-on-aukus-difficulties/104826856

"Congressional analysis lays bare AUKUS challenges as Australia looks to arm future submarines with hypersonics"

• Vice Admiral Jonathan Mead (left) insists [on the political mantra
   not shared by submarine professionals in the USN and RAN that]
   “strong and tangible” progress is being made on AUKUS [Virginia acquisition]. 
  ([Photo Supplied by]: Department of Defence)
  
  In short:
  
  Details of the problems being faced by US shipyards to speed up submarine
   production for AUKUS have been detailed in a new report to Congress.
  
  [see [US] Congressional Budget Office January 2025 [Report] 
  An Analysis of the Navy’s 2025 Shipbuilding Plan

   https://www.cbo.gov/publication/61155#_idTextAnchor054 
  -> Plans for Specific Ship Programs -> Submarines.]

  Budgetary analysis warns delays on new Columbia-class ballistic missile
   submarines could hamper transfer of Virginia-class boats for Australia
  
  What's next?

Senior military figures insist "strong and tangible" progress being made on AUKUS and future Australian submarines are "highly likely" to carry hypersonic missiles. 

New budgetary analysis for the US Congress has outlined the difficulties America's shipyards face to increase nuclear-powered submarine production so that Virginia-class boats can eventually be sold to Australia under the $368 billion AUKUS program.

The blunt assessment of US industrial challenges has been published as senior military figures express confidence that the ambitious AUKUS endeavour will succeed and predict future Australian submarines are “highly likely” to carry hypersonic missiles.

Under the AUKUS plan Australia is expecting to receive at least three second-hand Virginia-class boats from the US beginning in the early 2030s, before eventually building a new class of boat with the United Kingdom known as SSN-AUKUS.

Trump administration will back AUKUS submarines deal, says Rubio

Photo shows Two men with their arms around each other

Donald Trump's pick for secretary of state appears to have ended months of speculation on whether the incoming administration would back the AUKUS submarine deal, saying it will have Trump's strong support.

Before Australia receives its first Virginia-class boat in 2032, the US government must increase its current annual SSN production rate from roughly 1.2 boats to 2.3, so that it can maintain its overall submarine force numbers while transferring others.

However, in its latest analysis, the Congressional Budget Office (CBO) details how the US Navy's "priority" program to build new larger Columbia-class ballistic missile submarines (SSBNs) is behind schedule and could further delay Virginia-class (SSN) production.

"It would be very difficult and expensive for the U.S submarine industry to increase production of attack submarines while also building 1 Columbia class ship per year," the CBO document published in January states.

"Columbia class SSBNs are two and one-half times the size of Virginia class SSNs, and the amount of work required to produce ships scales roughly with ship size."

"Moreover, SSBNs are the Navy's highest acquisition priority. As a result, the sale of SSNs to Australia could reduce the number of attack submarines available to the Navy."

The CBO report titled An Analysis of the Navy’s 2025 Shipbuilding Plan'also discusses the potential strategic advantages and disadvantages to the US for giving up some of its submarine capability to its alliance partner Australia under AUKUS.

"That loss might even be more than offset because the Australian submarines would be based in the Western Pacific region and therefor could respond more quickly to any conflict with China over Taiwan or other issues in the South China Sea.

"However, Australia would control its own submarines, and their participation in any particular conflict would not be guaranteed," the report warns, citing comments made by Defence Minister Richard Marles in 2023.

AUKUS unravelling: Greens

Greens Senator and outspoken AUKUS critic David Shoebridge described the report as "damning", claiming it is further proof that Australia's nuclear-submarine endeavour is unravelling.

"This congressional budget office report states a hard truth, that any submarines the US sells Australia under AUKUS must come from a seriously limited supply needed by the US Navy.

"Despite the billions invested, including from Australia, the US shipbuilding industry is nowhere near producing enough nuclear submarines for their needs with no credible way to fix that.

"In fact, the US submarine shipbuilding troubles will only grow in the next decade as it has to produce a whole new class of extra large Columbia class nuclear missile submarines as its first priority."

Hypersonic missiles 'highly likely'

Ahead of the publication of the CBO analysis in Washington, the head of the Australian Submarine Agency (ASA), Vice-Admiral Jonathan Mead, said he was confident the AUKUS nuclear submarine endeavour was progressing well.

"There is a lot of work that happens behind the scenes, some of it is sensitive work but we are making strong and tangible progress in delivering this capability," Vice-Admiral Mead said.

Speaking to ABC Radio National’s Global Roaming podcast late last year, the ASA director said it was "highly likely" that the new SSN-AUKUS submarines being designed with the UK would have the capability to launch hypersonic missiles.

"I think it gives you greater capability, many countries are embarking upon hypersonic missiles, there's a lot of work being done around the world on hypersonic technology.

"Hypersonic missiles are really just a variation of some current class of missiles except that they have far greater speed and manoeuvrability and are harder to intercept."

Late last year the ABC revealed former defence secretary Dennis Richardson had been asked by Mr Marles to examine the operations of the ASA amid concerns raised from within and outside the organisation."