On Thursday, February 20 at 08:25 UTC, the Russian Military launched a Soyuz-2 with the Meridian-M 19L satellite.

At first glance, it looks like this mission went completely nominally.  THAT’S NOT THE CASE! This launch was originally scheduled for January 24th, but during pre-flight checks it was discovered that the Soyuz third stage — the upper of the two center core stages — had an electrical problem. After inspection, technicians decided to replace the third stage ENTIRELY rather than try to repair the one in place. That meant rolling the rocket back to its assembly building, UNSTACKING ALL OF THE PARTS, then bringing the new third stage in, and putting it all back together again!

This combined with the launch windows available for the spacecraft’s intended orbit delayed launch by almost a month. The Soyuz 2.1a rocket with a Fregat upper stage and the new third stage finally took off from the Russian military’s Plesetsk Cosmodrome, located about 800 km / 550 mi north of Moscow. The launch successfully put the spacecraft into a highly elliptical, highly inclined orbit. I’ll talk more about that orbit in a second.

The satellite launched last Thursday was the second of an upgraded batch of Meridian Ms, the 1st of which was launched back in 2018. They are designed to work within the Russian military’s Integrated Satellite Communications System (ISCS), which provides uplink and downlink support for services and satellite tracking and control via Raduga and Globus satellites in geosynchronous orbit. A total of nine Meridian satellites have been launched since 2006; seven have apparently been successful, while one was deployed into the wrong orbit in 2009, and another was lost during a launch failure in 2011. 

Space is hard, people: space is hard.

In any case, the new satellite is part of a system that will help allow, among other things, broad, persistent coverage of high Arctic areas. The Russian military suggested that among other possible missions, Arctic ice reconnaissance planes communicating voice and survey data back to distant ground stations could be done via this satellite network.

Okay, on to that odd orbit:

Normally when we cover satellite launches, the satellites involved are put into mostly circular orbits. The ISS, Starlink, and GPS satellites are all placed in circular or near-circular orbits to accomplish their missions. However, the Meridian satellites are placed in a Molniya orbit, which is highly elliptical and highly inclined.

And here, when we say elliptical we don’t mean a tiny bit egg-shaped: we’re straight into “severely stretched” territory, with altitudes ranging from 600 to nearly 40,000 km above Earth!  Take that long oval of an orbit and place it at a 63 degree angle relative to Earth’s equator, and you get the highly inclined orbit. But why would you even do this to a satellite?

Thanks to orbital mechanics, a Molniya orbit is uniquely suited to providing useful satellite coverage for Earth observation and communications services needed by ground terminals operating in high northern latitudes. Those areas are not easily serviceable from satellites in the typical geosynchronous orbits over the equator because any antenna you’re using would be pointing at such a low angle that a small hill could easily block the path of the signal. And even though polar orbiting satellites can see these same latitudes, they only have coverage of any given spot for several minutes at a time. The Molniya orbit is inclined in such a way that the desired areas are not only clearly visible, the satellite is able to “pause” for a time at its highest point thanks to orbital mechanics, which provides several hours of uninterrupted coverage that LEO and GEO satellites simply can’t match.

More info on this:

• Meridian-M 19L (Rocket Launch Live) https://www.rocketlaunch.live/launch/meridian-m-19l
• Soyuz launches Meridian satellite (Russian Space Web) http://www.russianspaceweb.com/meridian9.html
• Communication satellite launch (ISS-Reshetnev, in Russian) https://www.iss-reshetnev.ru/media/news/news-210220
• A source spoke about the threat of an accident at the launch of Soyuz-2 (RIA, in Russian) https://ria.ru/20200220/1565031246.html
• Russia delivers Meridian-M military communications satellite into orbit (TASS) https://tass.com/science/1122373
• Russia launches Soyuz rocket with Meridian-M military satellite from Plesetsk spaceport (TASS) https://tass.com/science/1122299
• Successful launch from the Plesetsk Cosmodrome (Roscosmos, in Russian) https://www.roscosmos.ru/28067/
• Overall launch coverage: https://spaceflightnow.com/2020/02/20/soyuz-rocket-launches-russian-military-satellite-after-one-month-delay/