Vignette: US Space Force - Dominance in Space since 1964

It has been written that US Space Force was built to make the US Air Force powerless. While some sources attribute the creation of US Space Force to handling of Cuban Crisis, when the reckless attitude of USAF generals irritated the Kennedy brothers, it was also a nod to the futuristic look of early 1960's. Also, creation of US Space Force ensured the USAF would be fully concentrated on various limited war tasks instead of solely focusing on general, ie. nuclear, war like it had in 1950's. But it was not only McNamara's folly, but rather a honest effort to grasp the significance of new technologies of hydrogen bombs, satellites and intercontinental missiles without traditional military mindset which might well lead into a global nuclear holocaust.

The US Space Force was formed around core of various US military space programs and most significantly, the newly constructed ICBM capabilities built by USAF. In an effort to make the force truly independent and not a subsidiary of US Air Force, it was recruited from all traditional branches of US military. In a nod for science fiction tradition, the rank structure was adopted from the US Navy.

President Kennedy inaugurated the new Force in 1964. Like all branches of the military, it immediately began lobbying for more resources and it was the favourite of both President Kennedy and SecDef McNamara. The influential STRAT-X -study mapped the development of US strategic capabilities for the rest of the Cold War and it might be said that it was rigged in USSF's favour. The final implementation, however, did bring significant advantages for USN too.

The initial goal of USSF was to lobby for an Outer Space Treaty which would allow basing nuclear weapons in space. This goal was abandoned by US adminstration, however. What USSF did get was a primary position in US strategic deterrence using dual systems of "Golden Arrow" BGM-175 ICBM's situated in superhardened rock silos and MGM-134 Midgetman mobile single-warhead ballistic missiles. Both of these systems would ultimately enter service in early 1980's, touted as achievements of President Reagan.

The US Navy's Polaris program was heavily criticized in the report for the heavy cost, low accuracy and low reliability of the missiles. Thus a major decision was made not to develop a successor SLBM system, instead a distributed "cruise missile" system was to be developed to ensure second strike capabilities. These cruise missiles would be deployed on board attack submarines of the future "Los Angeles" class and also on board future cruisers and destroyers. Finally, during 1980's, these would also be deployed from land bases in NATO countries. These "Hurlbat" missiles had range of some 3500km's.

The decision was loathed upon by USN but really proved to be a blessing in disguise in post-Cold war era when USN did not have to spend a large number of resources on SSBN's.

The USAF was to abandon it's heavy bombers but the US Air Force managed to secure use for it's B-52 bombers with their modification.

STRAT-X also secured funding for MOL manned orbital surveillance station and a lot of less visible satellite systems.

While McNamara was no fan of ABM systems, the incoming Republican Rockefeller adminstration was more favourable toward it's development. Ultimately, though, the coming detente and various treaties with with Soviet Union as well as budgetary reasons made the "Safeguard" program very limited, protecting just two missile fields in Colorado and Wyoming.

Rockefeller adminstration also granted funding for new joint NASA/USSF space transport system, "The Space Shuttle", which in retrospect has been thought as a failure. The six shuttles procured, three for NASA and three for USSF, ultimately could not achieve the planned operational rate and two were lost in accidents. The decision to cut MOL lead into cartoons on USSF being a space navy without any spacemen. The Space Shuttle program led into early retirement of Titan and Minutemen systems as the USSF could not fund both.

The renewed Cold War in 1980's under Carter and Reagan adminstrations was perhaps the heyday of USSF. Golden Arrow, Midgetman and Safeguard were all operational and highly visible. It was also the most dangerous phase of the Cold War, as USSF brought it's ASAT capabilities visibly into public which made USSR counterreact.

Thus, when Reagan and Gorbachev signed the treaty on peaceful use of outer space in 1988 this was seen as a sign of Cold War finally coming to an end.

End of the Cold War brought heavy lobbying from other branches as well as many peace activists to dismantle USSF, but the force survived although it's capabilites were rather just kept online rather than renewed. Now, with coming ascent of China and new commercial space renaissance the USSF seems to have found a new meaning.
 
Space Force!
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ProjectOrionBattleshipIllustration.jpg
Orion.png

Hell Yeah.

one of the most radical, but little known USAF Project Orion proposals was the nuclear-powered orbital battleship that was proposed in the late-1950’s.
While this system seems like something out of a science fiction novel or a movie, the massive nuclear-powered armed spaceship would orbit high above
the Earth and if needed be, unleashes it nuclear payload on multiple targets.

The Orion orbital battleship was post to use a massive nuclear pulse rocket engine that used fission material bombs to power the giant spacecraft.
Original plan was to launch the spacecraft to orbit using its nuclear-powered rocket from bases in Southwestern United States or from special launch
platforms in the ocean like aircraft carriers or modified ships. However, due to safety reasons and nuclear fallout, they’ve decided to launch it instead
using chemical rockets to Earth’s orbit. Orion was a giant massive spacecraft which was 286ft which was taller than most skyscrapers in that era and
164ft in diameter. It would had a crew of close to thirty people onboard that would have operated the orbital battleship. The spacecraft would use a
special damper or shock absorbers and shielding to protect the crew from radiation from the ship’s engines and space.

Nevertheless a unmanned variant of the Orion orbital battleship was planned too Furthermore, Orion also carried five smaller spaceplanes for resupplies,
crew replacements, and emergency life boat in case the Orion was having problems or was getting attacked. It was also quite possible that those small
spacecraft were used in defensive and offensive roles including protecting the Orion from Soviet spaceplanes and satellites along with providing
reconnaissance and strike roles if necessary

Nevertheless though, the main mission for the Orion battleship would be nuclear deterrence against nations like the Soviet Union, China, and Warsaw Pact
nations. The orbital battleship would carry up to 500 20MT nuclear warheads in the frontal part of the spaceship which can be fired downwards while orbiting
above a target. Along with its nuclear warheads, the Orion orbital battleship carried massive array of defensive weapon systems like direct-energy weapons,
five Mark 42 127mm naval guns, and ten, but mysterious Casaba howitzer which fired a special shaped rounds. The Orion battleship would have lived up to
its name since it was armed like a naval battleship on the high seas.


Nonetheless, even despite all these features and equipment for the Orion orbital battleship, there were still a lot problems the design. One of the issues which
faced the whole Project Orion program was the issue over the damper and shock absorbers to protect the ship and crew from the nuclear blast form the engines.
Nevertheless, the engineers were on ways fixing the shock absorber and damper issue along with improving the shielding protection for the crewmembers
would be operating the battleship. Another problem was the cost since the whole Project Orion program would cost over billions of dollars to manufacture and
build despite these giants. Furthermore, there were fears from meteorites and other space debris along with accidental or glitch that can send warheads or the
battleship into de-orbit mode which wouldn’t be pretty either. But the biggest issue was political since the U.S and the Soviets sign the Partial Test Ban Treaty in
1963 which banned testing nuclear weapons or any other nuclear devices in the high atmosphere which would later prove to be a final death nail for the Orion
nuclear-powered battleship along with whole Project Orion program. Nonetheless, there is a story that USAF officials showed a model and told him details about
the Orion orbital battleship to then President John F. Kennedy in which he got “freaked out” over the proposal that he canceled the project the second he hearing
about it! While the project has been officially canceled in the early-1960’s, very little is known about the Orion orbital battleship proposal and a lot of details are still
very much classified too this day including its nuclear weapons system and Casaba Howitzer.
https://www.defenceaviation.com/2013/04/usaf-nuclear-powered-doomsday-machines.html

Now that weapon

The Casaba Howitzer is the result of research into reducing the spread of the particles produced by a nuclear pulse unit. Make the cone narrow enough
and it becomes a destructive beam.
Casaba_Howitzer_Concept.jpg


Concept design by Scott Lowther
The original nuclear shaped charge design called for the use of a tungsten plate. The particles that resulted from the detonation of a pulse unit
would fit inside a cone with a spread of 22.5°. The particles would be relatively slow (between 10 and 100km/s depending on thrust requirements)
and rather cool (14000°C in transit, 67000°C after hitting the plate).

As noted before, using lighter elements, such as plastics or even hydrogen, in a thick and narrow instead of wide and flat shape, you can achieve a
very narrow cone and very high particle velocities. A Science & Global Security report from 1990 used polystyrene as the propellant material to
produce a particle beam with a spread of 5.7° and a velocity of 1000km/s.


In a propulsion pulse unit, it is not known how efficiently a nuclear shaped charge is able to heat the propellant. Most sources cite a 85% of the
device's energy being sent in the desired direction. It is unknown also whether this is before or after some of the propellant is accelerated in the
wrong direction, and whether larger pulse units are more efficient (higher propellant mass fraction). This is important as it would allow a
thermodynamic estimation of the particle velocity.

It would be reasonable to use a lower figure when calculating the amount of energy delivered to the propellant. Scott Lowther gave a 50% figure
for small fission charges. An SDI nuclear weapons study, project Prometheus, experimentally tested Casaba Howitzer weapons using plastic propellants.
It achieved 10% efficiency. A Princeton University study from 1990 on third-generation nuclear weapons cited 5% instead, but for fusion devices with
ten times better beam focus.

Effectiveness

Despite the reduction in cone spread, the stream of particles produced by by Casaba Howitzer dissipates much more quickly than an electro-magnetically
accelerated particle beam or a laser.

It is possible to reduce the beam angle to 0.006 degrees in width, as reported by the third-generation nuclear weapons study. 0.057 degrees has been
experimentally achieved by project Prometheus. The trade-off is much lower efficiency than propulsive units (5-10% vs 80-85%).

The theoretical maximal performance of a thermonuclear device is 25TJ/kg. Modern weapons are able to achieve 2.5TJ/kg, but this figure is for large
weapons that have better scaling. Smaller warheads such as those tested for project Prometheus are likely to be in the kiloton range, and mass about 100kg.
Better understanding of fission ignition has reduced the nuclear material requirement down to a kilogram or less.


Let us calculate some examples:

Small Casaba Howitzer (50kg)
0.01 radian directivity (0.057 degrees)
5kt yield, 10% efficiency: 2.09TJ
Distance 1km: Irradiance = 673GJ/m^2
Distance 10km: Irradiance = 6.7GJ/m^2
Distance 100km: Irradiance = 67.2MJ/m^2
Distance 1000km: Irradiance = 672kJ/m^2

Large Casaba Howitzer (1000kg)
0.001 radian directivity (0.0057 degrees)
1Mt yield, 5% efficiency: 209TJ
Distance 1km: Irradiance = 6728TJ/m^2
Distance 10km: Irradiance = 67.3GJ/m^2
Distance 100km: Irradiance = 672MJ/m^2
Distance 1000km: Irradiance = 6.7MJ/m^2

Futuristic Megaton Nuclear lance
0.0001 radian directivity (0.00057 degrees)
1Mt yield, 20% efficiency: 836TJ
Distance 1000km: Irradiance = 2691GJ/m^2
Distance 100000 km: Irradiance = 269MJ/m^2

To determine destructive capability, we can model the Casaba Howitzer as a direct energy weapon. We can recreate the particle strike as a laser
weapon firing a single pulse with equal properties.

We will describe the strike as a laser pulse of duration 1 microsecond, containing X energy and with Y spot radius. A 1.63 micrometer wavelength
laser focused by a 2cm diameter mirror consistently produces the same spot sizes as a 0.01 radian beam. A 20cm mirror is used for 0.001 radian
beams, and 200cm for 0.0001. We test penetration against Aluminium.

Small Casaba Howitzer:
X = 2.09TJ
1km, Y = 0.994m: 734mm penetration
10km, Y = 9.94m: 0.73mm penetration

Large Casaba Howitzer:
X = 209TJ
50km, Y = 4.97m: 586mm penetration
500km, Y = 49.7m: 0.59mm penetration

Futuristic Megaton Nuclear lance:
X = 836TJ
1000km, Y = 9.94m: 293mm penetration
5000km, Y = 49.7m: 2.35mm penetration

The results reveal that the Casaba Howitzer is an extremely destructive weapon, with the larger models able to strike at distances usually
reserved for lasers. Even a small Casaba Howitzer is effective at up to several kilometers, using technology tested in the 80s. Larger, more
modern devices can strike at greater distances. Futuristic devices will reach particle velocities of about 10000km/s, so time to target is negligible.

However, these distances are lower than those of powerful lasers, so the Casaba Howitzer will need a delivery system such as missile, or be used in defensive roles.

http://toughsf.blogspot.com/2016/06/the-nuclear-spear-casaba-howitzer.html
 
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