The Spox and the Supersonic Combustion Ramjet

16 May, 2020

Hypersonic vehicles typically consist of a Supersonic Combustion Ramjet, or Scramjet propulsion system to enable such high speeds. A Scramjet engine is an engine that uses “air breathing” technology.[iii] This means that the engine collects oxygen from the atmosphere as it is traveling and mixes the oxygen with its hydrogen fuel, creating the combustion needed for hypersonic travel.[iv] This is different than a traditional ramjet, which is used on space shuttles and satellite launches.[v] The traditional ramjet engine carries liquid oxygen, and hydrogen together, adding a tremendous amount of weight to the vessel.[vi] Most of the added weight comes from the liquid oxygen (the oxidizer), which is nearly 70% of the fuel used in space launches.[vii]

Hypersonic Weapon Basics

[February 19 2020 1,000 low-yield U.S. nuclear bombs and cruise missiles ]

The U.S. already has about 1,000 low-yield nuclear bombs and cruise missiles, which could be dropped or fired from F-15, F-16, B-1, and B-2 aircraft. Advocates of the low-yield Trident missile W76-2 warhead argue that those planes might be shot down by Russian air defenses, whereas the Trident missiles—launched from undetectable submarines—would definitely get through Russian defenses.
50 warheads would be modified to the low-yield version, at a cost of $65 million, less than 0.1 percent of the entire defense budget.

[Febtuary 24 2020 Some W76 thermonuclear warheads to be modified to low-yield ]

The deployment of the “low-yield” warhead W76-2 was reported last week by the Federation of American Scientists, citing anonymous sources and reporting that it was believed to have begun in the final weeks of 2019 with an Atlantic deployment of the USS Tennessee. The National Nuclear Security Administration (NNSA) has said the low-yield version, the W76-2, would be configured “for primary-only detonation.” This could mean a yield of less than 10 kilotons. It is the first major addition to the strategic nuclear arsenal in recent decades and is a departure from the Obama administration’s policy of lessening dependence on nuclear weapons
The W76 is a United States thermonuclear warhead. The first variant was manufactured from 1978 to 1987, and is still in service as of 2020. Trident II D-5 submarine-launched missiles, each carrying 4-5 W76 or W-88 warheads. Each W76 warhead has an explosive yield of 90 kilotons, or 90,000 tons of TNT. That’s enough to flatten a city or industrial target: by comparison, the atomic bomb dropped on Hiroshima was just 16 kilotons. Others D-5s carry the more powerful 455 kiloton W-88 warhead. In 2018 a new low-yield variant was announced which was expected to gain initial operating capability in 2019. The W-76 is carried inside a Mk-4 re-entry vehicle. The National Nuclear Security Administration announced in January 2019 that production of the first W76-2 had begun. The requirement calls for only a small number of warheads to be modified to the low-yield configuration.

The first test of a thermonuclear weapon, or hydrogen bomb, in the United States in November 1952 yielded an explosion on the order of 10,000 kilotons of TNT. Thermonuclear bombs start with the same fission reaction that powers atomic bombs — but the majority of the uranium or plutonium in atomic bombs actually goes unused. In a thermonuclear bomb, an additional step means that more of the bomb’s explosive power becomes available.

First, an igniting explosion compresses a sphere of plutonium-239, the material that will then undergo fission. Inside this pit of plutonium-239 is a chamber of hydrogen gas. The high temperatures and pressures created by the plutonium-239 fission cause the hydrogen atoms to fuse. This fusion process releases neutrons, which feed back into the plutonium-239, splitting more atoms and boosting the fission chain reaction

“John Rood, the Under Secretary of Defense for Policy. said the need for the new low-yield weapons came from intelligence reports of Russian emphasis on the use of nuclear weapons earlier in a conflict, “and the mistaken belief that they have the ability to use a low-yield nuclear weapon earlier in the conflict in a way to deter response.” He cited Russian President Vladimir Putin’s public statements advocating the early use of low-yield nuclear weapons “as a way of deterring an adversary.”

[July 17 2018 United States allows Japan to reprocess plutonium ]

On Tuesday (Jul 17), a decades-old deal with the United States which allows Japan to reprocess plutonium was renewed, but the pact can be terminated by either side with just six months’ notice.

Spent fuel from nuclear reactors is reprocessed to extract uranium and plutonium, which is then recycled into fuel called mixed oxide, or MOX, for use in both conventional nuclear reactors and fast-breeder reactors.Most reprocessing is currently done overseas, mainly in France, and Japan has struggled with technical problems at the new facility.
The country’s Atomic Energy Commission reportedly plans a self-imposed cap on the reserve, which now stands at 10 tonnes inside the country, with another 37 tonnes in Britain and France for reprocessing.
“Japan appears be caught up in the idea that in an emergency it can produce nuclear weapons with its reprocessing technology,” said Hideyuji Ban, co-director of the Citizens’ Nuclear Information Centre, an anti-nuclear NGO.


Rokkasho plant in Aomori Prefecture, a key pillar of the country’s nuclear fuel recycling policy

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: