Military Embedded Systems

Satellites and the kill web


November 25, 2019

Ray Alderman

VITA Standards Organization

WARFARE EVOLUTION BLOG. In August 1990, Saddam Hussein invaded Kuwait. At that time, the US. .Defense Satellite Communications System (DSCS) had one communications satellite in geostationary orbit (GEO) operating over the Indian Ocean, covering the Middle East. Within the next few weeks, a satellite over the Atlantic Ocean was tilted to access the Persian Gulf. Another satellite in polar orbit was moved to 65 degrees East, and a reserve satellite over the Indian Ocean was activated. Some British satellites were linked-in, and these measures created the first space-based military communications network in history.

Meanwhile, imaging satellites (IMINT) in low-earth orbit (LEO) maneuvered over Kuwait and Iraq, taking pictures. SIGINT and ELINT satellites in geostationary orbit (GEO) started vacuuming-up all the communications and radar signals coming out of Iraq and Kuwait.

In January 1991, U.S. and coalition forces invaded Iraq, with all that satellite intelligence factored into the attack plan. GPS-guided cruise missiles and bombs hit identified targets in Baghdad. Ground combat units, coordinating through the new satellite communications network, flanked Iraqi forces in Kuwait and drove them down Highway 80 (the Highway of Death) back into Iraqi territory by the end of February. Allied forces killed about 1,000 soldiers and destroyed more than 2,000 vehicles and artillery pieces on that road, based on the SIGINT/ELINT/IMINT intercepts. The ground war took only 100 hours to defeat the world’s 4th largest army, astonishing our enemies. What happened in that campaign demands that we examine how satellites fit into the kill web.

In order to make this article both entertaining and informative, I need to answer some questions. How many satellites are in space? Where are they relative to the earth? What do they do? How fast are they moving? Consider the numbers used in the answers here as good approximations, not absolute values.

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How many

The best place for us to start on this mission is the publicly available information at the Union of Concerned Scientist’s website. They track all satellites in space, their orbits, their positions, who owns them, and their functions. New satellites are going into orbit all the time, so they update the database 3 times per year (last update was March 2019). This is some of the best data out there on satellites. Download their Excel spreadsheet if you doubt me. Second, I used a nifty aerospace calculator on the web. You enter the altitude of a satellite, and it will calculate the speed for you. Just do a web search on “satellite altitude speed calculator casio” and it should pop-up for you.

There are about 5,000 satellites in orbit as of March 2019, but only 2,062 are operational. Eleven countries have satellites in space. Of those that are functional, 1,338 satellites are in low earth orbit (LEO), 125 in medium earth orbit (MEO), 45 in elliptical earth orbit (EEO), and 554 are in geostationary orbit (GEO). The U.S. operates a total of 901 satellites. The U.S. military controls 176 of them for secure communications, optical and infrared imaging intelligence (IMINT), geospatial intelligence and mapping (GEOINT), identification and direction-finding of enemy radar systems (ELINT), tracking and copying enemy RF communications (SIGINT), and the navigation, positioning, and timing signals for weapons. The remaining U.S. satellites are commercial (communications, satellite TV/radio, and observation satellites like Google Earth) or government operated (weather, deep space telescopes, and scientific experiment satellites).

Where are they

Now is probably a good time to make you aware of Kepler’s laws. The plane of all satellite orbits must go through the center of the earth: satellites cannot just spin over certain hemispheres. All satellite orbits are elliptical, to a greater or lesser degree. They are not perfectly circular because the earth is not a perfect sphere. Satellites do not travel at the same speed. They travel faster when closer to the earth, and slower when further out. The time it takes a satellite to circle the earth (the orbital period) is determined by its distance from the earth. And finally, satellites can fly north to south, or south to north in a polar orbit. But, they only fly west to east laterally, to take advantage of the earth’s rotation. Now, let’s look at where the satellites are located, how fast they go, and what they do.

The first place we find satellites is in low earth orbit (LEO). That zone is 100 to 1,240 miles above sea level. Some satellites in this zone have highly elliptical orbits: they dip down to 70 miles at the low point (perigee), and then go back out to 500 miles (apogee) at the high point. They can’t spend much time at lower altitudes because of atmospheric drag. These satellites have an orbital period of 89 to 128 minutes, and travel at about 4.7 miles per second (MPS) or 17,000 MPH. Satellites in polar orbit fly at these altitudes and speeds too. This is the region where the International Space Station, electro-optical (IMINT) satellites, weather satellites, and some communications satellites live. IMINT satellites can get much better image resolution of enemy tanks, ships, missiles, and troop formations on earth at LEO altitudes than at higher orbits. If these satellites orbit the planet every 90 minutes, it’s obvious that they can only spend a few minutes over each target area on earth. That’s why the terrorist in the Middle East go into their caves for 10-15 minutes when our IMINT satellites fly over them. Additionally, EEO is a LEO orbit where satellites sit before they move into MEO or GEO orbits.

The next zone is the inner Van Allen radiation belt at 620 miles to 7,500 miles high, give to take a gap here and there. You need to be careful where you put satellites in this region or they will be destroyed by radiation.

Medium earth orbits (MEO) range from 1,240 miles up to about 12,800 miles. Satellites at this altitude have an orbital period of about 12 hours and fly at 16,000 MPH (4.4 MPS) at the lower altitude, and 10,000 MPH (2.78 MPS) at the higher altitude. At about 11,000 miles up, we find the navigation, position, timing, GPS, and some communications satellites. This is also where scientific research satellites operate.

The second Van Allen radiation belt curves down between 8,100 and 37,000 miles in altitude. The toroidal shape of the belt suggests that the safest place to put satellites is 10,000 to 12,000 miles high. Anything flying on either side of those altitudes will be fried by the radiation.

Geostationary orbits (GEO) are at 22,236 miles above the earth. That’s where the speed of the satellite (6,876 MPH or 1.91 MPS) matches the speed of the rotation of the earth, so they are stationary above some point on the earth. In this zone, we find ELINT (enemy radar intercept) and SIGINT (enemy communications intercept) satellites. They share this region with TV and radio satellites, long-range weather satellites, and military communications satellites. Since they are geosynchronous, you don’t need to move your antenna to track them.

High earth orbit (HEO) is beyond 22,300 miles, and that’s the satellite graveyard. Before a satellite dies, the thrusters onboard push it out of the GEO zone so it doesn’t become a hazard to navigation for other satellites.

According to web information, the heaviest satellite in orbit is one of the U.S. military KH-11 imaging (IMINT) satellites. It flies in LEO and weighs about 43,200 pounds. The lightest is an Indian satellite (Kalamsat) that weighs 64 grams (2.25 ounces). The largest satellite in orbit is a U.S. military SIGINT satellite (LR-32) in GEO. The signal intercept antenna is over 300 feet in diameter and it looks like a giant umbrella.

Space Command

So, where does the new U.S. Space Command (activated in August 2019) fit into the kill web? They recently established their headquarters in Colorado. Their first mission, as you have seen, is to position satellite assets where they are needed. Second, they will defend America’s satellites from enemy attack by moving them around in their orbits. Our enemies know how critical satellites are to America’s military capabilities. In the 1970s and 1980s, the Soviets were temporarily blinding American intelligence satellites with lasers to irritate our military people. Over the past few years, Russian satellites have sidled up to American and European satellites in orbit. They may have been intercepting the data being sent and received, looking at how the satellites were assembled, or practicing to become a Russian kamikaze satellite. In January 2007, China shot-down an old weather satellite with a missile fired from earth. In February 2008, the U.S. shot down a malfunctioning spy satellite with a missile. In March 2019, India shot-down one of their satellites in orbit with a missile. The official government position is that we don’t have any laser or kinetic weapons on our satellites in orbit today. All we can do right now is play dodgeball with our enemy’s anti-satellite weapons.

Space Command will eventually have a maintenance function with the RSGS space vehicle (Robotic Servicing of Geosynchronous Satellites). DARPA is working on this concept. That’s a satellite than can maneuver close to another satellite in orbit, inspect it with cameras, replace broken parts, refuel the satellite’s thrusters (like we refuel aircraft in flight), add or remove certain mission packages using its robotic arms, and move the satellite back into proper orbit (stationkeeping). When a satellite dies, the RSGS can grab it, attach a propulsion package, and send it off to HEO (the graveyard). This scenario suggests that we can do the same to enemy satellites in orbit. And, that implies a space-based offensive capability for RSGS.

Finally, Space Command will have a combat mission at some point, to disable or destroy enemy satellites. They can do this with direct ascent weapons (missiles fired from earth), cyber weapons, electromagnetic and laser weapons, or co-orbital weapons (kamikaze satellites). G. Harry Stein, the father of model rocketry, says there's a better way to kill satellites. Take a small cheap rocket, load it with 200 lbs of nails from the hardware store, launch it into the LEO orbit of the enemy satellite, and dump-out the nails. Within 90 minutes, that satellite will slam into those nails at about 17,000 MPH and be shredded into pieces. What we have here is the space-domain equivalent of the primitive IED’s (improvised explosive devices) being used by terrorists against our ground combat vehicles in the Middle East. Kinetic anti-satellite weapons create a lot of debris making that orbit unusable, so non-kinetic weapons make more sense than nails in a space war.

Eventually, Space Command must move from Colorado to a base on the moon. From there, they can view the surface of the earth every 24 hours, they can radar-detect all satellites in earth orbit, they can detect missile launches on the planet, and they can launch weapons from the moon against enemy satellites in space and their satellite ground stations on earth. The moon is the high ground in space warfare. If you control the moon, you also control space and the earth. Go read about two military programs: Brilliant Eyes (intensive reconnaissance of space) and Brilliant Pebbles (space-based weapons). Better yet, get a copy of “The Future Of War” by George and Meredith Friedman and read it. They have several excellent chapters on satellites, the importance of the moon, and space warfare.

Finally, to get an idea of war in space and what Space Command might be doing in the distant future, take a look at this animated video.

Animated Rendering of Space Battles With Nuclear Orion Spaceships –

You will see another version of Stein’s nails used as a space weapon. The nuclear-powered Orion spaceships in the video were actually a U.S. military project from 1957 to 1965, They were designed in detail but they never got built. You can read about the history of Orion propulsion and see the design drawings in George Dyson’s book, “Project Orion.”

Space congestion

Looking at the information above, space is becoming congested in LEO. Have two satellites ever collided in that zone? Yes, in February 2009. A non-functioning 2,100 pound Russian communications satellite (Kosmos-2251) collided with a perfectly functioning 1,200 pound Iridium communications satellite (Iridium-33) at 26,000 MPH, 490 miles above Siberia. About 1,500 pieces of debris are still floating around in that orbit today. In March 2012, one of those chunks passed within 400 feet of the International Space Station as six crew members scrambled to get into their original launch capsules (escape pods). Satellites flying in LEO come within a few miles of each other several times per day. The Iridium people say that other satellites come within 3 miles of their 75 orbiting satellites about 400 times per week. That’s a lot of close calls.

In the future, it looks like LEO congestion is going to get much worse. As of May 2019, SpaceX has launched 62 satellites for their Starlink internet access constellation. Starting in November 2019, they plan to launch 60 more every two weeks or so, until they have 1,600 at 340 miles altitude, 2,800 at 710 miles, and 7,500 at 210 miles. That’s 11,900 satellites being added to LEO. After that constellation is complete, they plan to launch another 30,000 satellites when the orbits are approved. That's 41,900 satellites being added to the LEO zone by SpaceX alone. The U.S. Air Force just contracted with SpaceX to connect their satellite communication links to military platforms. The Europeans, Chinese, Russians, and India all have plans to launch thousands of satellites into LEO.

In September 2019, the people at the U.S. Space Surveillance and Tracking System (SSTS) told the people at the European Space Agency (ESA) that their Aeolus Earth Observation satellite was on a collision course with SpaceX’s Starlink-44 satellite at an altitude of 198 miles. So, the ESA folks called-up SpaceX folks and asked them to move their satellite out of the way. The SpaceX folks declined. Fuel for thrusters is a precious commodity in space, so SpaceX told ESA to use their fuel and go around Starlink-44, instead of SpaceX using their fuel to move. The Aeolis satellite had been using that orbit since its launch in August 2018. Starlink-44 went into that orbit in May 2019. ESA fired the thrusters on Aeolis and altered its orbit, avoiding a collision. Apparently, prior occupation of an orbit in space does not establish ownership of that orbit.

Consider a similar confrontation between an American military satellite and a Russian military satellite. U.S. Air Force Space Command in Colorado calls-up the Russian Air Force Space Command near Moscow and asks them to move their satellite out of the way, and they refuse. We could see a shooting war in space much sooner than you think. There’s a NATO meeting in Europe in December. Look for them to declare space as a new warfare domain at that meeting.

By now, you probably realize that satellites are the backbone of the kill web on earth. The primary functions in the kill web (find, identify, fix, track, fire, finish, and feedback), along with battlefield communications, don’t work without them. Russia and China know this, so they are developing anti-satellite weapons and strategies. North Korea could put Stein's cloud of nails in LEO orbits and destroy some of our satellite assets. Iran might be able to do the same in a few years. Obviously, space will be contested territory in the future. That’s why the new Space Command was activated in August, to protect and defend our military satellite resources. Their motto is “In your face from outer space”, so don’t expect them to be passive.

In our next exploration, we’ll take a look at all the new 6G fighter jets on the drawing boards. There are seven countries developing these new aircraft, so we’ll take a look at their ideas and their timetables. However, by the time these planes fly, the new satellites going into LEO will be blocking most of the sunlight on earth.