Some Analyses

(And Articles I Have Written About Them)

I have several projects in work, these following pages are the part that I am ready to make public. I have been working with an international group of very accomplished astronomers, programmers, and others to contribute to their efforts and to use some of their results in novel ways. The following four pages are the results of combining efforts of the optical observers and the radio observers, along with my own analyses.

Satellites That Have Very Low Perigees

With many large satellites in orbit, there should be a way to warn people when any of those satellites is about to reenter, so that they are not alarmed. There are several professional and amateur groups that predict objects that may survive to hit the surface. But there are a class of satellites that are not going to show up on official U.S. government warnings (or warnings from other organizations) of satellite reentries - and there is no good reason for them to be left out of the warnings.

This is a silly omission and should be corrected. The "Low Perigees" page has more detail.

One of the most fascinating facets is that this involves a class of satellites who's perigees increase as well as decrease, and the change is significant. The page (linked below) has plots of apogee and perigee for several satellites.

Satellites That Have Very Low Perigees

Errors In The Default Official Satellite Catalog

By default, the US Air Force gives each new satellite a number and "International Designator" but they do an adequate job at best. A project I have is to compare the various satellite catalogs and try to eliminate errors.

The concern is mostly due to the fact that the U.S. government considers some satellites' missions and orbits classified at various levels. But there are other objects that are in one catalog but not another for other reasons. There are numerous omissions in the default official satellite catalog but there is not a good mechanism to point them out. See the "Errors" page for more detail.

Errors In The Default Official Satellite Catalog

Orbits That Are Getting Crowded

There is a group of orbits that are very critical to Earth observation and similar efforts, the Sun Synchronous orbits, that are rapidly getting crowded - this is an area where we all need action to take place but no one is seriously considering this. People in the satellite business should be taking action, some thoughts about that are here:

The Orbits That Are Getting Crowded story.

The promise of some work that we are doing is that we could prevent some breakups or prevent pieces from being scattered in orbit. There are also some orbits with high eccentricities where satellites have broken up and we should take some action there as well, of course there is far more volume for those pieces to disperse over.

Are There Actions Small Sat Developers Could Take To Improve?

First - I have never built a satellite! But I have tested LOTS of them and developed procedures and trained crew members and been in operations for a long time. Still I proceed cautiously when I begin to give advice to people who have built and flown satellites.

The latest article is about the "infant mortality" of satellites such as CubeSats, it turns out that a number of satellites have reached orbit but the developer was never able to communicate with it as designed. Some have never functioned after deployment (as intended) and some are considered "dead" even though that definition may be questioned on some.

It is even difficult to talk to the builders of these satellites perhaps because they do not want to be categorized as people who built satellites that failed. But we learn so much from each effort, they provide lessons learned that help make others succeed. One thing that would help enormously would be to have a way to find out if a satellite had deployed systems like solar panels and antennas.

CubeSats Are Challenging

Various Satellite Catalogs

One thing that I have found out is that many people think that they understand "Two Line Element Sets" or TLEs but they do not. As I mentioned in my Satellite Catalog article, there are several sources of orbital information but many people do not know where they come from. The main source of satellite orbits is the default international satellite catalog that is maintained by the US Air Force but they have a number of things that you have to live with. International Scientific Optical Network (ISON) has a catalog but it requires considerable knowledge to use. Many people use CelesTrak but do not know that TLEs on that site are from the US Air Force. There are a number of other sources for TLEs but you really have to dig to find them. I am slowly working away at a brief explanation of this.

I have (so far) written six articles for The Space Review, which come out of some of my analyses, to try to get some attention on these areas.

1. Acknowledging Some Overlooked Satellites

2. Time For Common Sense With The Satellite Catalog

3. When Is It Time To Turn Off A Satellite?

4. Satellite Breakups And Related Events

5. CubeSats Are Challenging

6. Why US Should Notify The Public Of All Satellites Reentries

If you read these, remember that they are all somewhat out of date - since I wrote them I have learned a lot. That was a part of the motivation for writing them.

The sixth one is about satellites that reenter but no one on the ground is warned. It combines two of my projects - reentering satellites and the situation of where the US keeps some satellites' orbital parameters out of the satellite catalog. This is not done out of malice but is almost certainly a legacy of some long ago decisions.

There are several other projects in process that hopefully will appear here when they are ready. One thing that I am looking at is "dead" satellites that apparently are not dead at all, there are dead CubeSats that people get telemetry from routinely.

Another project that I am trying to get to is a good comparison of the USAF satellite catalog and the International Scientific Optical Network (ISON) catalog. There are several satellites in the ISON catalog that are not in the USAF catalog for instance.

Other Professional Interests

Partners and I are submitting proposals to DARPA, to the Air Force Research Laboratory, and to NASA to do some innovative development of capabilities in space. I am currently working on a proposal (in the early stages) for the University Nanosat program run by the Air Force Research Laboratory. I analyze what is going on in space, what satellites are in what orbits and why they are there.

We have some innovative ideas for projects such as preventing certain orbits from being rendered less useful - these orbits are filling with debris. Eliminating that debris is one approach but we could also prevent the creation of debris from existing satellites. I use various software to analyze what is going on and to predict which satellites are good candidates to do things like break up in the future.

Looking at what satellites are doing in space - where they are and why they are in the orbits that they are in, has been interesting for a long time. I was an Orbital Analyst in what later became the Joint Space Operations Center (JSpOC) and worked there when the Air Force used the original 496L computer system in the Space Defense Center in the Cheyenne Mountain Complex. Later we transitioned to the Space Computational Center, using the problematic 427M computer system. Then I moved to Clear Air Force Station, Alaska where we ran the Ballistic Missile Early Warning System (BMEWS) radar, which was also in the middle of a very difficult computer transition. Were we upgrading to an IBM 7090? Being an Orbital Analyst was a neat job that I did not appreciate at the time. Later I got a Master's degree from the Air Force Institute of Technology, Wright-Patterson AFB, Dayton, Ohio in "Space Operations".

If you wonder how a person gets interested in odd projects like this, the US Air Force got me started.

This picture was taken in the Space Defense Center and you can tell that we were using pretty basic technology at that time. We had paper tape input and output, we used Hollerith cards and printers to communicate with the computer. We had people who drew the ground trace on our board - by hand. The Space Defense Center became the Space Computational Center (SCC) and is now the Joint Space Operations Center (JSpOC). The hardware and the software of all three of them started out as near state of the art but was very poorly maintained. Even today the JSpOC has ancient hardware and software.

as of: 6 August 2018

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