January 3, 2018

BAHFest London 2017 – Louie Terrill: Why the Kessler Syndrome is key to humanity’s future

Filed under: Humour, Space — Tags: , , , , — Nicholas @ 02:00

Published on Dec 11, 2017

Watch Louie Terrill at BAHFest London 2017 present his theory, “Making sure we’re all in this together: Why the Kessler Syndrome is key to humanity’s future.”

BAHFest is the Festival of Bad Ad Hoc Hypotheses, a celebration of well-researched, logically explained, and clearly wrong scientific theory. Additional information is available at http://bahfest.com/

October 18, 2017

Are There Parts of German WW1 Warships in Space?

Filed under: Germany, History, Military, Space, Technology, USA, WW1 — Tags: , , , — Nicholas @ 02:00

Real Engineering
Published on 19 Jul 2017

October 2, 2015

Something to worry about – chances of a Kessler cascade

Filed under: Space — Tags: , , , — Nicholas @ 04:00

If you’re the worrying type, Charles Stross has a bit more for you to fit into your nightmares:

Today, the commercial exploitation of outer space appears to be a growth area. Barely a week goes by without a satellite launch somewhere on the planet. SpaceX has a gigantic order book and a contract to ferry astronauts to the ISS, probably starting in 2018; United Launch Alliance have a similar manned space taxi under development, and there are multiple competing projects under way to fill low earth orbit with constellations of hundreds of small data relay satellites to bring internet connectivity to the entire planet. For the first time since the 1960s it’s beginning to look as if human activity beyond low earth orbit is a distinct possibility within the next decade.

But there’s a fly in the ointment.

Kessler Syndrome, or collisional cascading, is a nightmare scenario for space activity. Proposed by NASA scientist Donald Kessler in 1978, it proposes that at a certain critical density, orbiting debris shed by satellites and launch vehicles will begin to impact on and shatter other satellites, producing a cascade of more debris, so that the probability of any given satellite being hit rises, leading to a chain reaction that effectively renders access to low earth orbit unacceptably hazardous.

This isn’t just fantasy. There are an estimated 300,000 pieces of debris already in orbit; a satellite is destroyed every year by an impact event. Even a fleck of shed paint a tenth of a millimeter across carries as much kinetic energy as a rifle bullet when it’s traveling at orbital velocity, and the majority of this crud is clustered in low orbit, with a secondary belt of bits in geosychronous orbit as well. The ISS carries patch kits in case of a micro-particle impact and periodically has to expend fuel to dodge dead satellites drifting into its orbit; on occasion the US space shuttles suffered windscreen impacts that necessitated ground repairs.

If a Kessler cascade erupts in low earth orbit, launching new satellites or manned spacecraft will become very hazardous, equivalent to running across a field under beaten fire from a machine gun with an infinite ammunition supply. Sooner or later you’ll be hit. And the debris stays in orbit for a very long time, typically years to decades (centuries or millennia for the particles in higher orbits).

How about a kickstarter campaign for laser-equipped orbit-cleaning satellites? Sweep up our orbital trash before it becomes a huge problem. If you’ve read Neal Stephenson’s Seveneves, you’ve already got the image of a really extreme result of too much space junk (in the case of the novel, it was shattered pieces of the moon creating the Kessler cascade).

September 27, 2013

The day World War III didn’t happen

Filed under: History, Military — Tags: , , , , , — Nicholas @ 08:59

In The Register, Iain Thomson takes us back to the depth of the Cold War, when it nearly turned very hot indeed:

Computer problems are an annoyance for us all, but thirty years ago a fault in the Soviet Union’s ballistic missile early warning system very nearly caused nuclear war, if not for the actions of Lieutenant Colonel Stanislav Petrov of the Soviet Air Defense Forces.


in the early hours of the morning on the September 26, there was panic when the Soviet early warning system Oko, a monitoring system of geostationary satellites and ground stations designed to spot ballistic missile launches, reported that the US had fired off a missile against the Soviet Union. Then four more launches were reported by the system in quick succession.

“An alarm at the command and control post went off with red lights blinking on the terminal. It was a nasty shock,” Petrov told Moscow News in 2004. “Everyone jumped from their seats, looking at me. What could I do? There was an operations procedure that I had written myself. We did what we had to do. We checked the operation of all systems — on 30 levels, one after another. Reports kept coming in: All is correct.”

Petrov, then the officer in command of the Oko system at a bunker near Moscow, had the responsibility of informing the Soviet high command in the event of a US missile launch. Although he didn’t have launch control of the USSR’s huge nuclear arsenal, he was the first responder, and given the scant minutes available in the event of a surprise attack, his word would most likely have been accepted by the Soviet leadership.

But Petrov didn’t make the call. He knew that the Oko system, which had only gone live the year before, was buggy. He also later described how logically such a move made no sense. While a first strike by the US wasn’t out of the question, if the capitalists were to do so they’d launch everything they had, not a few missiles at a time, he reasoned.

January 4, 2013

North Korea adopts maskirovka to conceal rocket preparations

Filed under: Asia, Military, Pacific — Tags: , , , , — Nicholas @ 10:09

Strategy Page on the most recent North Korean hoodwinking of western intelligence agencies:

Western intelligence agencies are a bit embarrassed that they were not able to predict the exact day that North Korea recently launched a long-range rocket. Even though North Korean announced the two week period during which the launch would take place last December, and several nations had photo satellites flying over the launch site regularly, the actual launch came as a surprise. The North Koreans apparently took advantage of the regular schedules of these spy satellites to move equipment around the launch site at the right time to conceal just how close the rocket was to takeoff. Many intel analysts had not seen this sort of thing at all (if they were young) and the older ones had not seen it done to this degree since the 1980s, when the Soviet Union was still around and using their maskirovka (“masking”) agency to carry out large scale deceptions of photo satellites. The Russians taught the North Koreans many things, and maskirovka was apparently part of the curriculum.

In addition to concealing weapons, their performance and movements, the Soviets also used satellite deception to mislead the west on how their troops would operate in the field. Several times a year, the Soviets would hold large scale maneuvers. Each of these exercises would involve many divisions, plus hundreds of aircraft and helicopters. Satellite photos of these maneuvers were thought to reveal tactics the Soviets were going to use in future wars. But the Soviets knew when American satellites were coming over and sometimes arranged displays of tactics they had no intention of using. Naturally, this made it more difficult for the Western intelligence analysts to figure out exactly what the Soviets were planning. This, of course, was the sort of confusion the Soviets wanted to create with these little deceptions.

November 19, 2012

Space-Age technology on Earth, but not so much in space

Filed under: Science, Space, Technology — Tags: , , , , — Nicholas @ 09:33

In The Register, Shaun Dormon explains why almost all the electronic components used on modern spacecraft, satellites, and the International Space Station (ISS) are actually not cutting-edge, top-of-the-line items:

I hate to say it, but most of what you think about space-age technology is a total fabrication. It’s the stuff of sci-fi.

Perhaps the biggest misconception of all is that spacecraft are equipped with cutting-edge computing platforms that any self-respecting technophile would commit unspeakable acts to get their mitts on.

If only. The fact of the matter is that even the most advanced chips up there were considered obsolete ten years ago down here. Although it’s true that in space no one can hear you scream, outer space is actually a very noisy place, electromagnetically speaking.

The computer on your desk is very unlikely to experience much in the way of EM radiation unless someone cuts a hole in the side of the kitchen microwave. Out in orbit, though, there are many sources of radiation, ranging from the relatively mundane stuff pouring out of the Sun and collecting in the Van-Allen radiation belts to more exotic things such as cosmic rays and other high-energy particles that cause so-called “single-event effects”.

[. . .]

The damage is cumulative. Individually, an impact causes the ionisation of a single oxide molecule present in the semiconductor. It’s not enough to cause instant failure, but as more and more impacts take place, the effects combine to significantly alter the electrical properties of the circuit until it can no longer function correctly.

More exciting dangers arise from exposure to gamma or cosmic rays. These ultra-high energy impacts cause localised ionisation which results in an unexpected flow of current. In the case of a lower energy event, this may result in a “single event upset” or “bit-flip”, and data corruption can ensue. These are not usually fatal to the system. No so the worst case “single event burnout”, which creates such high currents that the very circuitry itself is burned out almost instantaneously.

October 9, 2012

Falcon 9 loses an engine, able to partially complete mission

Filed under: Space, Technology — Tags: , , , , — Nicholas @ 07:40

Lewis Page at The Register, with a well-timed reminder that work in space is still not routine or ordinary:

The Falcon 9 rocket from upstart rocket firm SpaceX, which lifted off yesterday with supplies for the International Space Station, will deliver those supplies successfully following loss of an engine during launch. However a commercial satellite which was also aboard the rocket has been placed into a lower orbit than planned as a result of the mishap.

As we previously reported, the nine-engined Falcon first stage suffered an engine failure as it climbed towards space, with launch video giving the impression that one of the Merlin rockets had lost its nozzle. The Falcon is designed to carry out its mission even having lost an engine, and the flight path was duly adjusted. The Dragon capsule with supplies for the International Space Station was successfully sent on its way and is expected to reach the ISS without trouble.

[. . .]

Orbcomm says it is investigating the possibility of getting its satellite into the right place using its own onboard propulsion. Even if this can be achieved, however, it will be unsatisfactory as a satellite’s own fuel must be sparingly eked out over its operational lifespan to maintain it in orbit. Using up a lot of it before even beginning operations is liable to mean a short working life for the Orbcomm bird.

September 30, 2012

Tracking (smaller) space junk in orbit

Filed under: Space, Technology, USA — Tags: , , , — Nicholas @ 11:04

Strategy Page on the latest developments in tracking even smaller pieces of space junk in orbit around the Earth:

The U.S. Air Force is spending nearly $4 billion to build a S-Band radar on Kwajalein Island in the Pacific. This will make it easier and cheaper to find and track small (down to 10mm/.4 inch) objects in orbit around the planet. Such small objects are a growing threat and Space Fence will make it possible to track some 300,000 10mm and larger objects in orbit.

Getting hit by an object 100mm (4 inch wide), if it’s coming from the opposite direction in orbit, results in an explosion equivalent to 20 kg (66 pounds) of TNT. That’s all because of the high speed (7 kilometers a second, versus one kilometers a second for high-powered rifles) of objects in orbit. Even a 10mm object hits with the impact of 50-60 g (2 ounces) of explosives. In the last 16 years eight space satellites have been destroyed by collisions with one of the 300,000 lethal (10mm or larger) bits of space junk that are in orbit. As more satellites are launched more bits of space junk are left in orbit. Based on that, and past experience, it’s predicted that ten more satellites will be destroyed by space junk in the next five years. Manned space missions are at risk as well. Three years ago a U.S. Space Shuttle mission to fix the Hubble space telescope faced a one in 229 chance of getting hit with space junk (that would have likely damaged the shuttle and required a backup shuttle be sent up to rescue the crew). Smaller, more numerous, bits of space junk are more of a danger to astronauts (in space suits) working outside. The shuttle crew working outside to repair the Hubble satellite had a much lower chance of being killed by space junk because a man in a space suit is much smaller and the space suits are designed to help the person inside survive a strike by a microscopic piece of space junk.

July 10, 2012

Telstar’s 50th anniversary

Filed under: History, Space, Technology, USA — Tags: , , — Nicholas @ 09:47

Scott Van Wynsberghe in the National Post:

What followed Echo 1 was a space race within a space race, this one determining whether government or industry would send up the first active non-military communications satellite. In 1961, NASA awarded a contract for such a satellite to the company RCA, but Pierce and Bell Labs were undeterred. According to Calvin Tomkins, Bell Labs spent US$50-million (at early-1960s rates) for research and development and devoted about 700 of its personnel to the project.

The baby that was born of it all was a sphere weighing 170 pounds (77 kilograms), called Telstar 1. Going by specifications collected by Bill Yenne, an authority on U.S. spacecraft, Telstar 1 received signals at 6,390 megacycles, re-transmitted them at 4,170, and boasted of 600 voice channels and one channel for television.

Perched atop a Thor-Delta booster — paid for by Bell Labs but launched by NASA — Telstar 1 ascended on July 10, 1962. It did not go far, parking itself in an elliptical orbit less than 2,000 miles (3,220 kilometers) away. Within hours, Bell Labs arranged what was previously impossible — transatlantic television. As described by T.A. Heppenheimer, the ensuing video exchange humorously followed national stereotypes. The United States sent France and the U.K. taped material heavy on patriotic themes, the French responded with footage of actor Yves Montand and other cultural figures, and the British muddled about for a few days before getting things straight.

Humour aside, the achievement left the world stunned. In just the month of the launching of Telstar 1, the New York Times ran almost 100 articles related to the satellite. Joe Meek’s Telstar composition stormed the pop charts later in the year, and that 1963 New Yorker profile of Pierce ran for 29 pages. Telstar 1 did not outlast some of this acclaim, as it ceased transmission in early 1963, but it had blazed a path. Today, anyone using satellite TV or radio is honouring that decades-old triumph of engineering.

Update: Bill Ray has more at The Register:

Arthur C Clarke is often credited with inventing the idea of satellite communications, though in fact his contribution was to point out that three birds in geostationary orbit could provide global coverage. Geostationary orbit is more than 35,000km up, beyond the reach of radios in 1962, so Telstar’s orbit peaked at less than 6,000km up and dipped down to less than 1,000km during its two-and-a-half-hour circumnavigation.

That dip is also what caused Telstar’s downfall. Its repeated drops into the Van Allen radiation belt did allow the satellite to gather information about the belt (which was part of the plan) but the information it gathered was largely the havoc such radiation plays with electronic circuits. If Wikipedia is to be believed then US nuclear tests at the time had left the Van Allen particularly charged, but either way the satellite failed intermittently for a few months and finally stopped relaying signals entirely in February 1963. However, it remains in orbit to this day, faithfully tracked by the US government as required by international treaties.

Telstar was solar powered, with 3,600 solar cells feeding 19 nickel-cadmium batteries which received a 6GHz signal and retransmitted it with 2.25w of power at 4GHz. The electrics necessary were all suspended by shock-absorbent nylon cords in the middle of the spherical body, which had to spin at 180 rpm for stabilisation (gyroscopes perform the same function on modern satellites, but weren’t reliable enough back then).

April 13, 2012

Filling in for Envisat: “the CSA’s Radarsats 1 and 2 will try to fill some of the gaps”

Filed under: Cancon, Europe, Science, Space — Tags: , — Nicholas @ 08:43

The European Space Agency is still at a loss on why their flagship Envisat satellite suddenly went silent, but while they’re trying to diagnose and hopefully fix the problem, the Canadian Space Agency is helping to cover some of the gaps:

Controllers say the eight-tonne spacecraft appears to be in a stable condition, but they are not receiving any data at all from it.

Contact was lost with Envisat at the weekend shortly after it downloaded pictures of Spain’s Canary Islands.

A recovery team, which includes experts from industry, is now trying to re-establish contact with the craft.

Mission managers said on Friday that they were working through a number of possible fault scenarios but conceded they had little to go on.

[. . .]

Of more immediate concern are the operational and scientific projects that rely on Envisat data.

The satellite’s information is used daily to monitor for oil spills at sea, to check on iceberg hazards, and to provide information for meteorological forecasts, among a wide range of services.

All this had now been disrupted, said Prof Liebig.

“What we have done is [activate] the contingency agreement we have with the Canadian Space Agency (CSA) which we have had for many, many years. Canada has responded very positively. So, for a certain time, the CSA’s Radarsats 1 and 2 will try to fill some of the gaps.”

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