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On the 14th of June as part of the spacekeet programme researcher Dave Young will give a talk on the history satellite based weather forecasting in the Department Of Search Forum. The talk starts at 15:00.

multiple-satellite-orbits

Weaponising Weather: Satellite Experiments in Forecasting and Control during the Cold War

In the mid-20th century, the practices involved in the task of weather forecasting were undergoing a transformation. This transformation–surmised as a shift from the “art of forecasting” to the “science of meteorology”–is bound with the broader turn towards rationalism, systems-thinking, and digital technology in American post-war science. In the context of the tense geopolitical order of the Cold War, the capacity to accurately forecast the weather offered the possibility to perhaps control it, raising the question: would it be possible to employ it as a weapon in war? For some, the answer to this question lay in the new technology of the satellite.

Drawing on declassified administrative documents, operations reports, and technical manuals, this talk will provide an account of experiments in satellite technology and weather control research in the United States during the early decades of the Cold War. In doing so, I ask: What interests were involved? What were the political connotations of the satellite during this era? And what was the legacy of this research?

Dave Young is an M3C/AHRC funded doctoral researcher based at the Centre for Critical Theory at Nottingham University. His current work explores the crossovers between bureaucratic media, network technologies, and systems of command and control in the US military during the Cold War. His practice takes the form of workshops, talks, texts, and website development, and he has presented work for organisations such as the Disruption Network Lab, Transmediale, Servus, and Furtherfield. An archive of past/ongoing work can be found at dvyng.com.


Within the werkgroep there is currently a lot of discussion on the best way to build (and control) dish rotors. During the last meeting of the werkgroep kunstmanen the members brought along their dish rotors to have a diversity of approaches to discuss and show. From the fully self-built designs, to designs which are clever hacks based on commercial products to more modern 3d-printed designs. The design and building of the rotors is relatively involved, especially for the members who are not inclined to spend hours in a workshop (or that don't have a workshop). Currently there is no 'recommended design', it is all relative to the amount of skills/time/money/patience one has.

Collection of all the rotors brought to the meeting A collection of all the rotors that where brought to the meeting.

X/Y Diseqc

Closeup X/Y Diseqc

An X/Y Rotor can be constructed by using two commercially available rotors and mounting one on the axis of the other. A downside every X/Y motor has is that one motor will carry the weight of both. Additionally it is difficult or impossible to install a counter-weight for the dish itself which requires additional carrying capacity for your motors. The advantage of an X/Y model over an Az/El design is that it can track any point in the sky in a single fluid motion. An Az/El design is limited by the requirement that at some point it crosses through its origin, meaning the whole system needs to be flipped to track something from horizon to horizon. This could lead to losing track of your signal in the mean time.

A video of a Azimuth/Elevation design.

90s design by Peter Smits

Closup of the design by Peter Smits Design by Peter Smits that was built in the 90s and worked until it was hit by a heavy storm. The design is based on stepper motors. Very robust but requires a lot of resources and skills to build.

Miniature rotor by Peter Smits Very small Az/El design.

Hendrik Jalving's clever hack based on two commercial DiSeQ rotors Hendrik Jalving made a very clever design based off two commercially available DiSEqC rotors that can be purchased in any satellite tv shop. They are modified so that the axis extends through the head of the rotor. That way two identical rotors can be mounted on top of each other. The compact design means there is also a bit of space for counter-weights.

Close up of Hendrik's design

Job de Haas built a design based on 3d printed parts

Close up of Job's design Job de Haas built a design based on the SatNOGs project that can be largely 3D printed. The design requires to build two identical sets, one for the X-axis and one for the Y-axis which are then mounted on each other. The advantage of this design is that it is well documented and, because it is based on standard components mixed with 3d printed parts, relatively reproducible.


The Spacekeet will be able to track satellites as they fly across the sky. One of the parts required for this is a large dish. The main dish will be a do-it-yourself 120cm wire dish. It is based on a design by the Werkgroep Kunstmanen and drawn by Harry Arends. That design uses an F/D ratio of 0.5, the one I've been building has a ratio of 0.6, which leads to better magnification.

The changes in F/D ratio mean that the curvature of the center radials is altered and this the lengths for those are different than the original plans.

Transporting the 4m long aluminum pieces Together with Job de Haas we ordered all the materials at a bulk aluminum merchant and transported the materials on the roof of his car.

The raw materials that will make up both dishes We had most of the materials cut to 4m by for transport. We drove them to Peter Smits, a long time member of the Werkgroep, who would help us with the processing of the pieces.

Peter's 1.20m dish from the 90s Peter had already built multiple dishes, this 1.20m dish he built in the 90s. It was a useful example on how to do some of the assembly.

Example dish, radials connection Closeup of the assembly of the cross-sections that the wire-mesh can be attached to in order to maintain the parabolic curve.

Backside mounting disk The radials are placed onto a disk and assembled with nuts and bolts.

Center front mounting disk The front side mounting disk.

Bending the tube to become the outer frame of the dish We started off using his self-built roller to bend the 8mm tubing into circles that would form the outer frame of the dish. The total length for this tubing is the diameter of the dish multiplied by pi.

description Both the front and back mounting disks where built from sheet material.

description They where rough-cut with a plate shear and in the case of the front disk later made fully circular on a lathe.

Cutting the rods to length Afterwards we cut the u-channel aluminum rods that would make the radials to size.

description 12 pieces for Job's 1m dish and 12 for the spacekeet's 1.2m dish.

description Arguably the most difficult part of building the dish is curving the radials. The radials are almost straight towards the center of the dish and then curve outwards. Job had plotted the curvature using * for windows.

description The plot was turned into a line graph on which we could compare our results.

description Bending happened using the same roller we used to bend the outside frame.

description Since it is a manual process we approximated the curvature as much as possible based on the plot

description Between the individual radials there are still some that bend back out of shape, these need to be individually hammered into shape.

description Perforating the back-side mounting disk with 4mm holes.

description Same goes for the front side.

description Making a template for the curvature and checking every radial and bending to size

description The radials are perforated on two points so they can be attached to the mounting disks

description Drilling holes in the radials.

See part two for futher construction details


Before. The keet as it was before march

After. frontside of the keet

Built a roof mounting system to hold various antennas and dishes. Added a small dash of green.