On Sunday, August 30 at 23:18 UTC, SpaceX launched a Falcon 9 carrying three satellites to a polar orbit from Cape Canaveral — this is the first East coast polar orbit launch for SpaceX.

The main passenger for this flight was Argentina’s SAOCOM 1B with rideshare payloads Tyvak-1072 and GNOMES-1.

The Earth observation satellite SAOCOM 1B weighs in at about 1600 kilograms. It’s the second in a two-satellite constellation; the first was also launched into space aboard a Falcon 9 rocket back in October of 2018. Developed by Argentina’s space agency CONAE, it will image the Earth’s surface using an L-band synthetic aperture radar, allowing detailed images to be taken day or night and in all weather conditions.

Not much is known about Tyvak-1072 except that it was built by, well, Tyvak. It’s definitely a microsatellite, as that’s what the company specializes in.

GNOMES-1, or GNSS Navigation and Occultation Measurement Satellite, is owned by PlanetiQ. It’s the first of a planned twenty-satellite constellation that, according to the company, will collect radio occultation data for weather forecasting, climate research, and space weather monitoring.  What that means is that the satellites will measure signal strength coming from global navigation system satellites.

Even though all of these satellites are in space, their signals can still be partially blocked by the atmosphere. GNOMES-1 will literally measure how much the atmosphere is blocking the signals. This is most effective when the signals received from satellites are at a low look angle and have passed through the bulk of the atmosphere. Changes in the signal strength can indicate cloud and storm formation. The biggest change between the newer GNOMES constellation and older radio occult weather satellites is that the newer satellites are capable of receiving signals from the US’s GPS, Russia’s GLONASS, Europe’s Galileo, and China’s Beidou global navigation satellite systems (or GNSS).

The launch of SAOCOM 1B and company itself was significant in terms of the track that it followed. Since the payloads were destined for Sun-synchronous orbit (SSO) that meant the rocket needed to turn due south from the launch site, taking it over Cuba among other places. This is the first time this has been done from the Cape since a launch in 1960 caused debris to land on the island nation, killing a cow in the process, and prompting protests in front of the US Embassy there. 

The FAA and range safety officials approved this launch profile for SpaceX for two reasons: first, the Falcon 9 uses an automatic flight termination system that can activate without outside radio signals in case of an emergency. This is useful since ground-based signals would have to be received through the rocket trail left behind during the launch. Second, since the first stage was able to land back at the launch site, there was no debris that was likely to fall on places downrange in the first place.

For those of you keeping score at home: this was the fourth flight for this first stage. In a press release, SpaceX shared that it had “previously launched Dragon to the International Space Station for SpaceX’s 19th and 20th commercial resupply missions, and it also supported the launch of SpaceX’s ninth Starlink mission.” 

As far as the fairings go, no catch was planned but Ms. Chief did successfully retrieve both fairing halves from the ocean.

More Information

SpaceX mission update 

CONAE press release 

Spaceflight Now article 

SAOCOM info page (Gunter’s Space Page)

GNOMES info page (GSP)