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Brian Weeden, Friday, 8-10-12 August 10, 2012

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Brian Weeden, Friday, 8-10-12


Guest:  Brian Weeden.  Topics:  Economics for LEO, GEO, space debris mitigation, & space sustainability.  You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, https://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We welcomed Brian Weeden back to the program to discuss space economics per his June 4, 2012 Space Review article, “The economics of space sustainability.”  You can read this article by visiting www.thespacereview.com/article/2093/1. I strongly recommend you read the article prior to listening to our discussion.  In our first segment, Brian spent time with us defining important terms including space as a global commons, space as a common-pool resource, GEO and LEO satellite usage, space debris regions, the Kessler Syndrome, good rivalrous, economic exclusion, economic non-exclusion, private goods, public goods and more.  Brian makes the valid point that in understanding how both GEO and LEO have been viewed and treated, we have a partial explanation of why it has been and still is so challenging to do something about the growing debris problem.  In Brian’s Space Review paper and in our discussion, he takes us to a point where we can view LEO and Geo differently than the more normal way of looking at space, economics, and debris issues. We came to view space not as a global commons but more as a common-pool resource.  From this vantage point, we can look at policy and programs that influence behavior toward a desired objective. He cited as an example the Chinese anti-satellite test that caused so much debris several years ago but told us that the test was repeated in 2010 without causing debris.  Listen to his explanation of this in the second part of our discussion.
     In the second segment, we talked about the value of both LEO and GEO.  All space is valued at $290 billion.  $110 billion is assigned to space services and related things.  The total insured value of GEO is around $20 billion but the insured value of LEO is only $1.4 billion.  He explained why this is so and the impact it has have on understanding the economics of space development and debris mitigation.  At one point in the discussion in response to a question, he talked about the pain threshold of the company or country.  Don’t miss this discussion.  Later in the segment, Brian introduced us to game theory and information economics as we continued to explore space economics.  Near the end of our program, we talked about the European Code of Conduct for Outer Space, how it might or might not become law in the U.S., and the realization that there must be more benefits flowing to the space companies and nations for dealing with debris than the costs, liabilities, and challenges.
     Please post your comments on the blog. If you want to email Brian Weeden, you can find his address on the SWF website or you can send it to me and I will forward it.


1. Dwayne Day - August 16, 2012

I listened to most of this interview and found it interesting, having just completed an NRC study of space object tracking that will be released next month.

However, I’m not sure that I buy the economic argument for the difference in debris populations for LEO and GEO. For starters, there are physics and operations issues that affect the two regions differently. As an example, sending satellites to GEO usually does not involve placing their discarded upper stage in the same orbit–the upper stage boosts the satellite to a transfer orbit, and then the satellite usually circularizes its orbit using onboard thrusters. This is not the same for LEO, where the upper stage usually ends up in nearly the same orbit as the satellite. Thus, keeping GEO clear of upper stage debris requires no extra effort, whereas keeping LEO clear of upper stage debris does require extra effort.

Although the economics issue is intriguing, I’m not sure that it can account for all, or even most, of the differences in debris populations.

brianweeden (@brianweeden) - August 16, 2012

Thanks for the comment Dwayne. I agree that the economics are unlikely to explain all of the differences, but I do think it plays a role. More research is definitely required.

As far as the differences between LEO and GEO, there actually are a lot of rocket bodies in or near the GEO belt. While modern GEO satellites are increasingly using their own thrusters, historically that was not the case and things like apogee kick motors were commonly used.

I sent you by email a copy of the 2012 edition of ESA’s Classification of Geosynchronous Objects which has details about the objects in and near GEO.

2. DougSpace - August 13, 2012

I just got done listening to the recording. I wish that there had been some discussion of a few issues.

The first big one that I don’t believe was ever addressed is, exactly how big of an issue is space debris anyhow? Specifically, what is the history of collisions? How many times/year is there a collision? If it is less than one, then just how urgent is this issue? He mentions that about 150 or so avoidance maneuvers are made, but I am imagining that if not moved, most would have been a near miss but not an impact. So is moving active assets an acceptable intermediate-term solution that we could afford to do for a couple of decades?

It wasn’t clear what the experts say about when space debris will become a rapidly accelerating threat. For example, I believe that China’s ASAT test increased the total debris by 30%. Yet has that resulted in any collision? Did it cause a crossing of the rapidly growing point of the curve within that orbital zone?

Also, is it possible that better practices such as self-removal from orbit in the time going forward will be all that’s necessary with old LEO debris clearing itself due to atmospheric drag thereby seeing a decrease in total debris using this approach alone?

Also, I thought he was heading there but is there a way of dividing up LEO orbits so that debris is less likely to impact anything else? Just think of all of the elevation and inclination combinations.

Thanks, Doug

brianweeden (@brianweeden) - August 16, 2012

Hi Doug. How important the space debris issue is depends on who you ask, and yes there are those who blow it way out of proportion. You are absolutely correct about the avoidance maneuvers – it is doubtful if any would have resulted in actual collisions, but we do not know. We do not have the technology to determine with 100% certainty if two objects will collide in space. All we can do is estimate the probability, and these satellite operators are maneuvering when the probability passes their risk threshold (typically 1 in 10,000 to 1 in 100,000).

Atmospheric drag does pull objects out of orbit, but only at very low orbits. At around 800 km altitude, where many remote sensing satellites are and the high concentrations of debris, it takes several decades or more for drag to pull debris out of orbit.

As far as dividing up LEO, it’s pretty much impossible. Within days after a collision, debris spreads around the Earth in a ring, and within a couple of years it spreads around the entire Earth because of perturbations.

A very good and reasoned overview of space debris can be found here:

DougSpace - August 19, 2012

A very helpful reply, Brian. Thanks, Doug

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