Spaceflight Insider

EKS marks the spot: Russia set to launch 2nd of 6 early-warning satellites

A file photo of a Soyuz-2.1b on the pad at the Plesetsk Cosmodrome. Photo credit: Roscosmos

Russia looks to enhance its missile detection system with the launch of the second in a series of six early-warning satellites. The EKS-2 satellite, alternately classed as a member of the ‘Tundra’ family of launch detection spacecraft, is designed to replace Russia’s aging early-warning infrastructure and is targeting a launch at 2:33 a.m. EDT (06:33 GMT) on May 25, 2017, from the Plesetsk Cosmodrome.

Early detection

Although ground-based radar systems may be adequate to spot a missile already in flight, it may not provide the high-fidelity information needed to detect the vehicle “below” the horizon. This lack of certainty can significantly reduce the warning time a defender may have should it come under attack.

A small-scale model of the EKS series of early-warning satellites. Photo credit: The Moscow Times

Understanding this limitation and needing as much warning as possible, both the United States and Russia (and its predecessor, the Soviet Union) needed a launch warning as close to liftoff as possible. To accomplish this, both nations developed a series of satellites tasked with detecting the telltale infrared and optical signatures of intercontinental ballistic missiles during its boost phase of flight.

While the Cold War spurred the development of these systems, Russia’s early-warning infrastructure didn’t keep pace with those of the United States after the dissolution of the Soviet Union. Indeed, Russia lost nearly all of its early-warning satellites in the Spring of 2014.

The United States launched the third of its current-generation launch detection spacecraft, SBIRS GEO-3, in January 2017.

The EKS/Tundra system is an attempt by Russia at modernizing its military’s ability to detect incoming threats on the 21st-century battlefield.

Military satellite in an uncommon orbit

With it being a Russian military satellite, there are few concrete details available about EKS-2. However, with it being the second of a family of six, some inferences can be made from the first launch in the series.

The EKS-2 spacecraft is likely built by RKK Energia on the USP satellite bus. Tipping the scales at about 2,600 pounds (1,200 kilograms), the military satellite is likely outfitted with instruments capable of detecting both ground- and sea-launched ballistic missiles, as well as some types of cruise missiles.

The satellite will be able to calculate the projectile’s flight path, which can be relayed to ground stations for more accurate tracking.

It is also highly probable the spacecraft will have military communications capabilities should more traditional systems be destroyed in the event of war.

A Soyuz-2.1b rocket on the launch pad at the Plesetsk Cosmodrome waiting for the launch on Nov. 17, 2015.

A file photo of a Soyuz-2.1b rocket on the launch pad at the Plesetsk Cosmodrome waiting for the Nov. 17, 2015, launch of EKS-1. Photo Credit: Russian Ministry of Defence

EKS-2 will likely join its EKS-1 sibling in a highly elliptical Tundra orbit. The orbit, which has an orbital period of one sidereal day (approximately 4 minutes shorter than a standard solar day) and is inclined 63.4 degrees, provides extended loiter capabilities at apogee over a chosen area of Earth.

Currently, the only known user of a Tundra orbit is Russia with its EKS system, although Japan plans to launch three Quasi-Zenith Satellite System (QZSS) GPS-augmentation satellites into Tundra orbits in 2017 and 2018

Reliable rocket

While the EKS spacecraft may represent a thoroughly modern replacement to an aging fleet of early-warning satellites, its ride to orbit is the very definition of the “if it isn’t broken, don’t fix it” mantra. In fact, the Soyuz-2.1b launch vehicle is a modern evolution of the venerable R-7 family of launchers, dating back to 1957.

While the outward appearance of the Soyuz is a classic design, it sports upgraded hardware, electronics, and avionics under the skin. Coupled with line’s enviable overall 97.25 percent success rate, the Soyuz-2.1b is an eminently capable launch vehicle.

The rocket’s iconic design marries four tapered side-mounted boosters to a central core stage. Each of the boosters is powered by a single RD-107A, burning a mixture of liquid oxygen (LOX) and a highly refined kerosene named RG-1, which produces 188,720 pounds-force (∼840 kN) of sea-level thrust.

The four boosters, burning simultaneously with the core stage’s single RD-108A engine, provide a combined 933,020 pounds-force (4,150 kilonewtons) of sea-level thrust. Each of the five engines is largely similar in design – propellant is fed from a single shaft-driven turbopump into four separate combustion chambers – although they differ in the number of vernier control engines, leading to the distinct model number for each.

The boosters, considered to be the first stage on the flight profile, only provide assistance during the first two minutes of flight while the core (second) stage operates for nearly three minutes longer.

The Soyuz’s third stage is powered by a lone RD-0124 engine. Like its first and second stage cousins, the RD-0124 burns a mixture of LOX and RG-1, producing 66,200 pounds-force (∼290 kilonewtons) of vacuum thrust.

The fourth stage comprises the Fregat-M upper stage to place the satellite into its final orbit. The stage, outfitted with an S5.95 engine, provides 4,460 pounds-force (∼20 kilonewtons) of vacuum thrust, burning a mixture of unsymmetrical dimethylhydrazine (UDMH) and dinitrogen tetroxide.

Launch of the first EKS satellite, EKS-1. Video courtesy of the Russian Ministry of Defence



Curt Godwin has been a fan of space exploration for as long as he can remember, keeping his eyes to the skies from an early age. Initially majoring in Nuclear Engineering, Curt later decided that computers would be a more interesting - and safer - career field. He's worked in education technology for more than 20 years, and has been published in industry and peer journals, and is a respected authority on wireless network engineering. Throughout this period of his life, he maintained his love for all things space and has written about his experiences at a variety of NASA events, both on his personal blog and as a freelance media representative.

Reader Comments

Have the Russian Early Warnings Satellites detected the UFO Phenomena as did the United States Early Warning Defense Support Program (DSP) Satellite, Flight 7 on 5 May 1984

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