Defcon Alerts Threat Monitor: Space/Nuclear

SpaceX Applied Speed Limits on Starlink and Starshield in Ukraine for 10 Days Before Restoring Service

Defcon Level — Sat, 24 Oct 2026 23:46:18 GMT

UKRAINE — Ukraine’s Ministry of Defense stated on October 24 that its monitoring systems recorded the restoration of Starlink and Starshield operating speeds, with connectivity remaining stable at mo…

Space Systems Command: China Is Pacing Threat and Russia Acute Threat to U.S. Space Superiority

Defcon Level — Thu, 15 Oct 2026 18:36:43 GMT

SPACE — On October 13, Space Systems Command stated that the United States holds space superiority but that Russia and China seek to surpass it after fielding terrestrial and orbital counter-space capabilities for years.

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Capt. Amy R. Padilla, branch chief for Intelligence Plans and Programs in the command’s Intelligence Directorate, said China is the pacing threat while Russia is the acute threat, adding that if either achieved space superiority or supremacy it would severely limit U.S. capabilities in space.

The command described space as a war-fighting domain and listed specific historical tests by both countries along with launch and satellite figures.

Locations Affected

North Korea Fires Two East-Coast Ballistic Missiles Into the Sea of Japan

Defcon Level — Sun, 20 Sep 2026 11:50:26 GMT

KOREAN PENINSULA — On September 20 at about 8:54 AM UTC (5:54 PM Japan time), North Korea launched at least one ballistic missile from the vicinity of its east coast toward the northeast, the Japanese Defense Ministry and Cabinet Secretariat said.

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The ministry estimated that missile reached a peak altitude of about 43 miles (70 km), flew about 367 miles (590 km), and fell in the Sea of Japan outside Japan’s exclusive economic zone, the maritime belt extending up to 200 nautical miles from the coast in which a coastal state holds resource rights. Government notices to nearby aircraft and ships had produced no damage reports at the time of the release.

In a separate launch the same afternoon, at about 6:00 AM UTC (3:00 PM Japan time), North Korea fired at least one ballistic missile from near its east coast toward the northeast, the Japanese Defense Ministry said.

That earlier missile reached about 37 miles (60 km), flew about 273 miles (440 km), and was also estimated to have fallen in the Sea of Japan outside Japan’s exclusive economic zone.

South Korea’s Joint Chiefs of Staff identified the first firing as a short-range ballistic missile from the Wonsan area that flew about 280 miles (450 km) toward the East Sea, the name Seoul uses for the same body of water.

Japanese Prime Minister Sanae Takaichi issued the same three instructions after each launch: gather and analyze information and brief the public, confirm the safety of aircraft and ships, and hold a full readiness posture.

Japan Protests Missile Launches As Violations Of UN Security Council Resolutions

IAEA: Drone Hits Kursk Reactor Cooling Tower, Tusk Warns of Hybrid Strikes On NATO Countries

Defcon Level — Fri, 18 Sep 2026 18:35:16 GMT

EUROPE — The International Atomic Energy Agency said on September 18 that it had been informed a drone struck the cooling tower of a reactor unit at the Kursk Nuclear Power Plant in Russia early on Thursday.

Credits: Donald Standeford, Open Street Map, Modified Copernicus Sentinel data.

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The agency said the unit was operating at the time, that its operating mode did not change, and that there was no fire.

IAEA Director General Rafael Mariano Grossi said all attacks on nuclear facilities are unacceptable because they could endanger nuclear safety and security wherever they occur, and he repeated a call for maximum military restraint to prevent a nuclear accident.

Credits: Donald Standeford, Open Street Map, Modified Copernicus Sentinel data.

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On the same day as the first notice, the 70th IAEA General Conference in Vienna adopted a resolution titled “Nuclear Safety, Nuclear Security, and Safeguards in Ukraine.”

Ukraine’s Ministry of Foreign Affairs said the text received 63 votes in favor, 6 against, and 46 abstentions.

The ministry’s comment on September 18, welcomed the vote, said Zaporizhzhya remains a Ukrainian plant that must return to Ukrainian control, and did not mention the Thursday Kursk cooling-tower event.

Polish Prime Minister: Intelligence Assessments Indicate Russia Plans Hybrid Drone, Missile Strikes On Countries Supporting Ukraine, Including Poland

China Conducts Submarine-Launched Strategic Missile Test into Pacific Ocean

Defcon Level — Mon, 06 Jul 2026 16:44:14 GMT

SOUTH PACIFIC — The People’s Liberation Army Navy (PLAN) launched a strategic missile carrying a dummy warhead from one of its nuclear-powered submarines on July 6 at 12:01 p.m. Beijing time.

Footage of Missile Strategic Missile Test. Credit: Xinhua, Chinese Military

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The missile flew toward designated high-seas waters in the Pacific Ocean and landed precisely in the target area, according to Chinese Navy and Foreign Ministry.

Map credits: Open Street Map, Modified Copernicus Sentinel data.

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Chinese government statements described the event as a routine element of annual training. Beijing stated that relevant countries received advance notification and that the launch complied with international law and practice. The action was not directed against any specific country or target.

Ukraine's Zaporizhzhya Nuclear Power Plant Loses Off-Site Power Connection for the 21st Time

Defcon Level — Fri, 03 Jul 2026 18:26:32 GMT

UKRAINE — The International Atomic Energy Agency reported on July 3 that the Zaporizhzhya Nuclear Power Plant lost its connection to the 330 kV Ferosplavna-1 line, the 21st such loss during the military conflict.

Map credits: Open Street Map, Modified Copernicus Sentinel data.

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The IAEA team on site was informed of and could hear military activity that caused the actuation of electrical protections on lines connecting the plant to the Ferosplavna-1 line, including one recently repaired during June’s ceasefire.

Map credits: Open Street Map, Modified Copernicus Sentinel data.

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Emergency diesel generators started operating to supply power for reactor cooling and other essential nuclear safety functions. Power has been recovered, but one line connecting the site to the power line remains unavailable.

Details of the July 3 Power Loss

NASA Directs ISS Astronauts to Shelter in Crew Dragon as Roscosmos Addresses Worsening Air Leak in Zvezda PrK Tunnel

Defcon Level — Fri, 05 Jun 2026 17:18:59 GMT

INTERNATIONAL SPACE STATION — NASA mission control ordered five astronauts to enter their docked SpaceX Crew Dragon spacecraft and assume an elevated safety posture on June 5 after an air leak in the Russian-operated Zvezda service module’s PrK transfer tunnel worsened.

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The directive at 9:04 a.m. ET followed confirmation that the leak rate had doubled to roughly two pounds of air per day. The five crew members donned spacesuits inside the spacecraft as a precaution while Russian cosmonauts worked on the Russian segment.

Russian-operated Zvezda service module

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Approximately two hours later, after Roscosmos paused structural repairs for additional measurements, NASA lifted the safe-haven order and directed the crew to resume normal station operations.

The leaks originate from microscopic cracks in the PrK transfer tunnel, a component of the Zvezda service module that has experienced air leaks since 2019.

Roscosmos detected two leaks during the June 5 inspection of the transfer chamber while pressurizing the Zvezda module’s transfer chamber to the International Space Station’s pressure. The first was sealed quickly, and preparations began for the second while station pressure stayed stable.

Crew Dragon Spacecraft

Routine Unarmed Minuteman III ICBM Operational Test Launch GT 256 Scheduled at Vandenberg Space Force Base

Defcon Level — Tue, 19 May 2026 01:13:48 GMT

CALIFORNIA — An operational test launch of an Air Force Global Strike Command unarmed Minuteman III intercontinental ballistic missile (ICBM) is scheduled between 12:01 and 6:01 a.m. Pacific Time on May 20 from the northern portion of Vandenberg Space Force Base.

File photo: Previous unarmed Minuteman III ICBM test

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This launch, designated GT 256, was scheduled years ago and is not in response to world events. The purpose of the ICBM test launch program is to confirm the effectiveness, readiness and accuracy of the weapon system, according to the May 18 announcement from Air Force Global Strike Command and Space Launch Delta 30.

Launch Schedule Details

Zaporizhzhya Nuclear Plant Loses All Off-Site Power for 13th Time

Defcon Level — Tue, 14 Apr 2026 15:51:17 GMT

UKRAINE — The International Atomic Energy Agency (IAEA) reported on April 14 that Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP) “lost all off site power this morning after the disconnection of its last remaining external power line.”

Zaporizhzhya Nuclear Power Plant (ZNPP) . Credit: Energoatom

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The IAEA stated this is the 13th time the plant has lost all off-site power during the military conflict. “The plant’s emergency diesel generators immediately started operating to provide the power needed for essential safety functions,” the IAEA announced. The agency’s on-site team is monitoring the situation.

In a follow-up statement on April 14, the IAEA announced that “Power has been successfully restored to the ZNPP through the Ferosplavna-1 330 kV power line, bringing an end to the loss of offsite power after approximately 90 minutes.”

“The plant’s emergency diesel generators have since been safely shut down,” the IAEA added.

Diesel Generator Dependence and Power Restoration

North Korea Fires Short-Range Ballistic Missiles in Back-to-Back Launches as Pyongyang Issues Threatening Statement Toward Seoul

Defcon Level — Wed, 08 Apr 2026 06:09:57 GMT

KOREAN PENINSULA — North Korea fired multiple short-range ballistic missiles toward the East Sea on Wednesday, April 8, South Korea’s Joint Chiefs of Staff (JCS) reported, marking the second launch in two days after an apparent failed attempt on Tuesday.

North Korean 600mm multiple rocket launcher system during a prior test firing. (Photo: KCNA, file)

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U.S. Indo-Pacific Command (INDOPACOM) stated the launches “do not pose an immediate threat to U.S. personnel or territory, or to our allies.”

The launches came as North Korea’s Foreign Ministry issued a statement calling South Korea “the most hostile enemy state” and stating “you will have to pay dearly if you persist in rash acts before us,” according to the Korean Central News Agency (KCNA), North Korea’s state-run media.

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The back-to-back firings followed South Korean President Lee’s expression of regret over drone flights by unidentified drones into North Korean territory.

Launch Details

U.S. Air Force Prepares for Minuteman III ICBM Test Launch from Vandenberg Space Force Base

Defcon Level — Sat, 28 Feb 2026 00:51:23 GMT

WEST COAST — An operational test launch of an unarmed Minuteman III intercontinental ballistic missile is set for a designated window from Vandenberg Space Force Base.

Photos of previous Minuteman III ICBM launches

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This event, managed by Space Launch Delta 30, focuses on validating the weapon system’s effectiveness, readiness, and accuracy. The test forms part of routine evaluations scheduled years ahead, according to the U.S. Space Force.

Launch Schedule and Objectives

U.S. Declassifies Seismic Evidence Confirming Lop Nur Nuclear Explosion In 2020

Defcon Level — Fri, 27 Feb 2026 03:23:16 GMT

GLOBAL — U.S. officials have publicly detailed intelligence assessing a seismic event near China’s Lop Nur nuclear test site on June 22, 2020, as a low-yield nuclear explosion.

photo for illustration purposes only

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The assessment relies on waveform data from Primary Seismic Station 23 (PS-23) at Makanchi, Kazakhstan, part of the International Monitoring System, a global network of sensors designed to detect nuclear tests.

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A magnitude 2.75 event was recorded at 09:18 Greenwich Mean Time. Seismic signals showed a short, sharp pressure wave (Pn) — the kind produced by a sudden energy release like an explosion — and no side-to-side shaking energy (Lg) that natural earthquakes normally produce at the expected time.

Historical Lop Nur earthquakes exhibit long, emergent Pn waves and clear Lg shear phases. The 2020 event’s waveform matched explosion signatures in official U.S. comparisons.

U.S. analysts estimate a yield of approximately 10 tons nuclear (or 5 tons conventional equivalent), assuming the blast was fully contained in solid rock — meaning all energy transferred into the ground rather than being absorbed by softer material.

If the test was conducted in a way that dampened the seismic signal (decoupling), the actual yield would be higher than the estimate.

Seismic Waveform Comparison

Sentinel ICBM Restructure on Track for Completion by End of 2026 with Initial Capability Targeted for Early 2030s

Defcon Level — Wed, 18 Feb 2026 19:52:29 GMT

WASHINGTON — The U.S. Air Force announced on February 17 that the LGM-35A Sentinel intercontinental ballistic missile program restructure remains on track for completion by the end of the year, with Milestone B certification targeted for the same period and initial operational capability planned for the early 2030s.

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The announcement from Secretary of the Air Force Public Affairs directly supports the 2026 National Defense Strategy’s emphasis on accelerating modernization of the land-based leg of the nuclear triad. Officials described the restructured acquisition strategy as a deliberate, data-driven effort to deliver credible, long-term deterrence through a consolidated management structure.

The Sentinel program replaces the Minuteman III system, which has been in service since 1970, along with its associated launch facilities, command centers, and supporting infrastructure. Recent technical milestones and fielding preparations at multiple bases demonstrate measurable progress following the program’s earlier restructure.

Program Timeline and Acquisition Strategy

U.S. Department of War Airlifts Next-Generation Ward 250 Nuclear Reactor as Trump Administration Secures Central Europe Nuclear Partnerships

Defcon Level — Mon, 16 Feb 2026 16:58:43 GMT

WASHINGTON — On February 16, the U.S. Department of War announced the airlift of a next-generation nuclear reactor aboard a C-17 Globemaster III from March Air Reserve Base, California, to Hill Air Force Base, Utah, for eventual testing at the Utah San Rafael Energy Lab.

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This operation advances President Trump’s May 23, 2025, executive orders on nuclear energy. At the same time, Secretary of State Marco Rubio finalized civil nuclear agreements in Slovakia and Hungary during visits on February 15-16, strengthening U.S. national security through enhanced energy cooperation in Central Europe.

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Key Developments The Department of War transported the Ward 250, a 5-megawatt nuclear reactor designed to fit inside a C-17 aircraft and theoretically power approximately 5,000 homes.

Officials described this portable system as a step toward greater military base energy security by reducing dependence on vulnerable civilian power grids and enabling independent operations overseas.

The move directly supports President Trump’s directives to modernize America’s nuclear capabilities for both military and civilian use.

In Central Europe, Secretary Rubio signed the U.S.-Hungary Civil Nuclear Intergovernmental Agreement in Budapest. The agreement establishes decades of cooperation on nuclear energy and positions Hungary as a hub for regional small modular reactor development.

In Slovakia, U.S. funding will support the Front-End Engineering and Design study for a new Westinghouse large reactor under the Department of State’s FIRST Program.

These steps aim to bolster regional energy security, industrial growth, and technology competitiveness—including powering artificial intelligence applications—while generating over $15 billion in opportunities for U.S. vendors and thousands of American jobs.

Micro-reactor and Small Modular Reactor Overview

Former IRGC Commander's Unsubstantiated Allegation of Saudi Nuclear Weapon Amid Saudi Plans To Build Nuclear Power Plant In Duwayhin

Defcon Level — Wed, 11 Feb 2026 07:21:39 GMT

MIDDLE EAST — Former Islamic Revolutionary Guard Corps commander Hussein Kanani Moghadam asserted in a February 9 interview that Saudi Arabia possesses a nuclear weapon, with the United States and Israel aware.

Satellite imagery of Saudi nuclear reactor work in 2019. Credit: Google Earth.

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This assertion emerges during U.S.-Iran indirect negotiations on Tehran’s nuclear activities, where Iran has enriched uranium to 60 percent purity. Assessments from governments and international agencies indicate Saudi Arabia maintains civilian nuclear infrastructure without weapons.

Saudi leaders have stated intentions to match Iranian capabilities if Tehran acquires weapons, but programs focus on energy under safeguards. U.S.-Saudi cooperation emphasizes nonproliferation.

Details of the Claim, Analysis:

The Next Era of Nuclear Arms Control: U.S. Advocacy for Multilateral Framework Amid Russian Rejection and China's Rapid Expansion

Defcon Level — Fri, 06 Feb 2026 14:24:42 GMT

WASHINGTON, D.C. — The New Strategic Arms Reduction Treaty (New START) expired on February 5, 2026, removing verifiable limits on U.S. and Russian strategic nuclear arsenals for the first time since 1972, with each previously capped at 1,550 deployed warheads and 700 delivery systems.

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This development, alongside Russia’s 2023 suspension of implementation and China’s accelerated nuclear buildup from over 200 warheads in 2020 to more than 600 in 2026, has prompted the United States to advocate for a new multilateral arms control structure involving multiple nuclear peers.

Concurrently, Iran has prioritized the restoration of ballistic missile facilities damaged during the June 2025 12-Day War, with reconstruction at sites such as Parchin and Shahroud progressing more rapidly than efforts at nuclear facilities like Natanz and Fordow.

Key Developments in Arms Control Landscape

IAEA Reports Reduced Capacity at Ukrainian Nuclear Power Plants Following Military Attacks on Electrical Infrastructure

Defcon Level — Mon, 17 Nov 2025 20:32:27 GMT

EUROPE — The International Atomic Energy Agency (IAEA) has reported that two Ukrainian nuclear power plants have operated at reduced capacity since November 8 due to military strikes on critical electrical substations.

Rivne nuclear power plant. Credit: Victor Korniyenko, CC BY 3.0, via Wikimedia

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The attacks disconnected the Khmelnitskyy and Rivne facilities from key 750 kilovolt power lines, prompting grid operators to limit output from several reactors to maintain stability. One damaged line has been restored, while others remain offline, highlighting ongoing vulnerabilities in Ukraine’s energy grid amid the conflict.

IAEA Director General Rafael Mariano Grossi emphasized the critical role of reliable off-site power for nuclear safety systems and cooling functions, noting that dedicated expert missions will assess the affected substations. The agency continues to provide assistance, including equipment deliveries to support Ukraine’s nuclear infrastructure.

Details of the Strikes

The strikes targeted substations serving as nodes in the country’s electrical grid, which are essential for voltage transformation and ensuring stable power supply to nuclear facilities.

Following the incident during the night of November 7, both plants lost connection to one of their two high-voltage lines each. In response, operators reduced electricity generation from some reactors at the request of the national grid authority.

Although one line has returned to service, the ongoing outage of the other has sustained limited operations at three reactors.

This situation underscores the interdependence between Ukraine’s nuclear sector and its broader energy network, which has faced repeated disruptions since the conflict began.

IAEA Efforts and Deliveries

IAEA efforts include implementing a comprehensive assistance program, with recent deliveries of electrical components to regional energy firms and radiation monitoring equipment to the South Ukraine Nuclear Power Plant.

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These actions, supported by multiple European nations and the European Union, aim to bolster the reliability of power supplies critical for nuclear operations.

Additionally, radiation monitoring capabilities have been enhanced at the South Ukraine facility, contributing to international data sharing through the agency’s monitoring system.

Ukraine’s central radioactive waste management enterprise and the Chernobyl Nuclear Power Plant have also received specialized equipment to strengthen security measures.

Restoration at Zaporizhzhya Nuclear Power Plant

Iran Denies Any Uranium Enrichment Since June Strikes as IAEA Unable to Verify Stockpile Amid Recent Tanker Seizure

Defcon Level — Mon, 17 Nov 2025 15:46:18 GMT

MIDDLE EAST — The International Atomic Energy Agency reports an inability to verify Iran’s near-weapons-grade uranium stockpile since U.S. and Israeli strikes in June, raising proliferation concerns.

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Iranian officials deny any ongoing enrichment activities across nuclear facilities. U.S. intelligence maintains no active nuclear weapon decision by Tehran, despite retained capabilities.

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US, Israeli Strikes On Iran’s Nuclear Facilities In June

Iran’s nuclear infrastructure faced significant disruptions from Israeli and U.S. strikes in June, targeting key enrichment and missile sites. Post-strike analyses from arms control organizations note that Iran retains capabilities to reconstitute elements of its program, including missile delivery systems.

U.S. intelligence assessments as of mid-2025 maintain that Tehran has not decided to develop nuclear weapons, despite possessing enriched uranium near weapons-grade levels. The Arms Control Association reported that critical materials for rebuilding remain available, potentially allowing Iran to regain threshold status rapidly.

Iran Denies Efforts To Enrich Uranium At Targeted Sites

North Korea Launches Short-Range Ballistic Missile Toward East Sea

Defcon Level — Fri, 07 Nov 2025 07:36:48 GMT

EAST ASIA — North Korea launched a suspected short-range ballistic missile from near Taegwan County in North Phyongan Province at 12:35 p.m. local time (3:35 a.m. UTC).

The projectile traveled approximately 435 miles (700 kilometers) before falling into the East Sea. Japanese authorities confirmed the launch and noted it landed outside Japan’s exclusive economic zone with no reported damage.

This marks North Korea’s fifth ballistic missile launch since January. The event follows U.S. sanctions on North Korean entities for laundering funds.

Intelligence from South Korea and the United States detected preparations in advance, enabling real-time tracking. No immediate North Korean state media response detailed the launch purpose.

Regional partners continue heightened monitoring amid ongoing tensions. The incident comes after North Korea’s denunciation of U.S. sanctions and announcements of countermeasures. Diplomatic efforts persist to promote de-escalation.

Previous launches occurred on October 22 and October 31. No casualties or infrastructure damage resulted from the recent event.

Coordinated monitoring among allied forces remains in place. The launch site’s proximity to the border introduces additional security factors. Assessments indicate the action aligns with patterns of diplomatic signaling.

Launch Details and Trajectory:

Russia Considers Resuming Nuclear Weapons Tests in Response to U.S. Statements On Resumption

Defcon Level — Wed, 05 Nov 2025 16:31:49 GMT

EUROPE — Russian President Vladimir Putin directed officials to prepare proposals for potential nuclear weapons tests following announcements from U.S. President Donald Trump regarding the resumption of U.S. nuclear testing activities.

Soviet OTR-21 Tochka missile. Capable of firing a 100-kiloton nuclear warhead a distance of 185 km. Credit: Mil.ru, CC BY 4.0, via Wikimedia

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This development stems from a Security Council meeting where concerns over international nuclear policies were discussed. Russian authorities emphasized the importance of monitoring actions by other nations to maintain strategic balance.

Meeting with permanent members of the Russian Security Council. kremlin.ru

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The directive involves multiple ministries and security services in analyzing information and formulating recommendations. Such measures reflect ongoing efforts to ensure nuclear capabilities amid global changes.