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Adiós, Space Fence

While most news outlets were freaking out about killer pythons, the Japanese helo carrier, or the 68th anniversary of the bombing of Hiroshima, the US Air Force was quietly preparing to shut down Space Fence, one of the oldest but most productive parts of its space surveillance network.

It’s also one of the few facilities that can provide 24/7 “uncued detection” capability… which is nerd-speak for the ability to find things in orbit that nobody expected to be there (ie. space junk).  Contrary to what Hollywood likes to show you, it’s impossible to track every single object of space debris.  There are over half a million distinct objects, some smaller than a penny, and no one nation (or even group of nations) has enough radar or visual coverage to follow them all.  In fact, the US Space Surveillance Network has only 6 facilities worldwide dedicated to on-orbit detection and tracking; Space Fence was the largest and most effective of them, spanning the continent at the 33rd parallel.


Space Fence is the red line stretching across North America

Why is the closure of this capability important, you ask?  It might be easier to have some visual reinforcement.


STS-7 window impact

This is what a mere fleck of paint did to a cockpit window on OV-099 Challenger during the STS-7 mission, back in June of 1983.  The pit you see there is only 1mm in diameter, but remember that paint is probably the most innocuous bit of debris one can run into when travelling 17,580 miles an hour.   During STS-59, OV-105 Endeavour experienced similar window damage, and the object actually penetrated half of the window’s total depth.  That’s kind of a big deal.  Other STS missions have seen micro-collisions where objects have punched right through the orbiter’s silvery radiator panels.  Objects like this paint fleck are too small for Space Fence to detect and track, but there are literally hundreds of thousands of larger objects.

Despite being several decades old, Space Fence is still relevant today because it has a longer reach than most other sensors, and because it can do its work un-cued.  In other words, it detects without being specifically tasked to look for a known or unknown object in a given region of orbital space.  It is responsible for around 40% of the observations on the 23,000 objects the Department of Defense currently tracks.

Though part of a broader surveillance network, the VHF Space Fence is crucial because it can track objects up to 24,000 kilometers away. Other sensors in the network generally track objects at altitudes lower than a few thousand kilometers, [Brian Weeden, technical adviser at the Secure World Foundation, a nonprofit organization dedicated to space sustainability] said.

“The Space Fence is very important as it gives an ‘uncued tracking’ capability,” Weeden said. “Because it’s constantly transmitting, it can detect objects without being tasked to do so. There are some other sensors in the network that can do uncued tracking to some degree, but the Space Fence is rather unique in the sheer size of the detection coverage it has.”

Gruss, Mike.  Shelton Orders Shutdown of Space Fence.  SpaceNews, 6 August 2013.

Granted, the current Space Fence is a little long in the tooth and suffers the additional handicap of being based on 1960s technology.  Thanks to sequestration, not only is the current capability being forced to close, but its future replacement is also stuck in limbo—waiting for the Pentagon to decide what projects it can reasonably afford.  Meanwhile, there are about 500,000 debris objects too small (from 1-10cm in diameter) for the current space surveillance network to keep tabs on.  And their numbers will only increase.


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Physics and geography

A good understanding of both is helpful, if you are 1) an astrophysicist trying to raise money for a private space launch facility, or 2) the wire services reporter assigned to cover the story.

MONTREAL—The head of the Muhammad Institute for Space Science wants to build a space-launch facility in Canada.

Redouane Al Fakir’s goal is putting the Islamic world back at the forefront of scientific discovery.

But the Vancouver astrophysicist wants all Canadians to be involved in his project.

His proposed commercial space port in British Columbia would be the first of its kind in this country — and Al Fakir says it’s about time.

The way he sees it, if countries like India, China and Japan can launch satellites into space, why not Canada?

The UBC astronomer is out raising money, especially in the Middle East, but he faces a big challenge: Al Fakir estimates that it would take $100 million to build a facility, and $500 million to send up a rocket.

— Canadian Press. “Man raising money in Middle East for Canadian space launch site“. Toronto Star, 5 December 2010.

Let me say first of all that I would welcome the development of a commercial space launch facility, but the choice of Vancouver (and well, Canada in general) presents some significant challenges.

When our American neighbours selected Cape Canaveral as their launch facility, it wasn’t just because of readily available land, and an affinity for alligators. Florida is a lot closer to the Earth’s equator than any other continental American state, and that proximity translates into increased speed for the boosting platform. (Wired magazine’s Rhett Allain has penned a good summary of the physics and constraints of geography.)

To get that speed boost you also need to launch in the direction of the Earth’s rotation (which is from west to east). A booster leaving Florida on an easterly heading takes it out over the Atlantic, which is handy if you have to drop stages or debris and want to avoid killing people on the ground in the process. Launching from Vancouver means the ascent path would take a booster over populated areas of British Columbia and Alberta. Not so good if you have to abort/destroy the booster, or drop stages on the way to orbit.

Then there’s the more prosaic concerns about communications and telemetry, having appropriate tracking resources on orbit so that you don’t have to build an array of expensive ground tracking stations. And making sure the launch facility is sturdy enough to endure our wintry climate, and so on.

Building a launch centre here is certainly not impossible, but it will always be more expensive in fuel and hardware than launching the same booster and payload from somewhere further south. Countries such as India, China and Japan are a whole lot closer to the equator than Canada, and as such will always enjoy an energy (and financial) advantage over something launched from a higher latitude.

These are not insurmountable obstacles, but they’re worth keeping in mind when you’re trying to make money from such a venture.

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You’re doing it wrong

If you ever wanted to see your wife or girlfriend as imagined in a particularly boring James Bond title sequence, here’s your chance.

A Scottish company trialling “intimate communication over a distance” is seeking couples interested in drawing lines of light on each other’s bodies rather than the more-traditional teledildonics hardware.

The technology comes from Forres-based Distance Labs, who are looking for three couples in which one partner is based near Edinburgh, and the other more than 250km away, to see if drawing lines of light on each other’s bodies can replicate some of the ambiance involved in relationships.

The drawing is done with a ring, which glows red, and so can be easily detected by an overhead camera. Special bedroom electronics project lines drawn by the distant partner, as well as those traced out locally, enabling the couple to “communicate through the language of touch as expressed on the canvas of the human body”.

— Bill Ray.  “Scots to pioneer remote sex via glowing ring“, The Register, April 22nd, 2009.

Sorry fellas, but where I come from sex is not playing with light pens over a network connection.  That sounds suspiciously like “Microsoft Live Meeting with Whiteboard”, which is something I won’t voluntarily play.  No matter how you spin it, teleconferencing never gets exciting.  Anybody who has ever worked in an office should know this already.

Right then.  Those of you not interested in playing remote Spirograph on your spouse can get back to the old-fashioned method of teledildonics; phone sex.  Or as we do it in the 18th century, long, windy letters professing undying devotion via ink pens.

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