EOS SAT-1 / AgriSat-1

Quick facts

Overview

Summary

Mission Capabilities

The five pillars of EOS Sat-1’s mission are climate change, deforestation, soil degradation, food crisis, and water scarcity. All collected data feeds into solving these issues from an agriculture perspective. EOS Sat-1 features two multispectral DragonEye cameras each with a spatial resolution up to 1.4 m, making the data applicable for a wide variety of agricultural, environmental, and climate monitoring observations.

Performance Specifications

From a 540 km Low Earth Orbit (LEO), EOS Sat-1 operates at a 5-6 day revisit time on a data acquisition cycle of 2-3 hours. An orbital period of 94.75 min at an inclination of 97.43° places the satellite in a sun-synchronous orbit at 9:30 Local Time Descending Node.

The spacecraft’s two optical payloads are built with radiation-resistant parts and a Cassegrain optical system, minimising distortion in the high-resolution camera imagery. The DragonEye Cameras each have a mass of 18 kg and offer a swath width of 22.2 km from a 500 km orbit. The cameras capture images across 11 spectral bands in the visible and near-infrared (VNIR) ranges and deliver a resolution of 1.4 m for panchromatic imagery and 2.8 m for multispectral imagery. They are energy-efficient, consuming less than 45 W during imaging, and data is processed onboard and transmitted using a multigigabit interface.

Space and Hardware Components

The spacecraft is built on Dragonfly Aerospace’s in-house µDragonfly 100 kg class bus, which supplies up to 600 Wh (watt-hours) of energy storage. EOS Sat-1 has a total mass of 178 kg.

EOS Sat-1 payloads have implemented Neuraspace’s AI (Artificial Intelligence) Space Traffic Management system that delivers collision event analysis and suggestions to manoeuvre and avoid collisions with other space objects.  

Overview

EOS Sat-1, also known as AgriSat-1 or ZA-008, is an agriculture-focused satellite and the first of seven in a planned constellation built by Dragonfly Aerospace in Stellenbosch, South Africa. The SmallSat was commissioned by EOS Data Analytics (EOSDA), a company that employs AI-powered data analytics and satellite imagery for supporting sustainable agriculture and environmental monitoring purposes. The companies Space Electric Thruster Systems (SETS) and Flight Control Propulsion, who oversaw 3D printing of satellite parts were also part of delivering satellite capability. 1) 2) 3) 4)

Fitted with two ground imaging cameras, EOS Sat-1 will utilise optical and infrared imagery to deliver insights into soil moisture, yield expectation and biomass levels for harvesting, and support mapping, seasonal preparation, and infrastructure monitoring. This data will effectively aid farmers in preventing the use of excessive pesticides and fertilisers, reducing food wastage and developing more sustainable agriculture practices, overall working to mitigate food crises and water scarcity.

EOS Sat-1 is South Africa’s first commercial imaging satellite, and will aid in reducing deforestation and maintaining biome health and biodiversity by offering services to agricultural countries across the world. 5) 6) 7)

Spacecraft

EOS Sat-1 is based on Dragonfly Aerospace’s µDragonfly platform, with a mass of 178 kg and 600 Wh of energy storage. 8)

Electrical Power Subsystem

Dragonfly Aerospace’s EPS-LP-1k5 is a 28V Electrical Power System rated at TRL-9 (Technology Readiness Level-9), weighing 3.3 kg, and fitted with three power distribution modules: regulated mode outputs (60 W), low power mode (600 W) and high power mode (1500 W). The system contains multiple communication interfaces with Controller Area Network (CAN), Telemetry & Telecommands and DCL (Direct Command Line). It is fitted with the Dragonfly 28-300-BATTERY MODULE, a 28V scalable lithium battery for power storage and management. 9) 10)

Power may also be derived from an array of solar panels that peak at 220 W with an orbit average power (OAP) 140 W. 11)

Attitude and Orbit Control System (AOCS)

The bus’ fully automated attitude and orbit control system allows for satellite imaging capability to be delivered at high resolution. A pointing control stability of less than 0.0015°/sec (3-sigma) and accuracy less than 0.01° (3-sigma) is provided by a star tracker and RW-1 Nms reaction wheels by Dragonfly Aerospace. The high-fidelity reaction wheels deliver platform stability while minimising disturbances, providing a high torque output for slew manoeuvres at maximum momentum. The 1 kg device is also capable of regenerative braking and operates on 12–36 V with peak power at 108 W. Additionally, a fine sun sensor determines the position of the sun for steering control and orienting solar panels. 12)

For onboard computing, Dragonfly’s EuroCard 3U OBC-Q7S is integrated into the AOCS, consuming 5 W power and weighing 0.35 kg. The computer can operate independently or in tandem with orbit control for greater reliability, and is fitted with a microcontroller for magnetic control, allowing the satellite to perform detumbling and other simple control operations. 13)

A magnetometer conducts sensing of changes in the Earth’s magnetic field around the satellite’s orbit while a Xenon Electric Propulsion System provides 11mN thrust at 1400s specific impulse. 11)

Electrical interfaces

Telemetry and Telecommand (TMTC) are managed through a CANbus (Controller Area Network) unit using standard RS422/RS485 connections. Data is transmitted via Low Voltage Differential Signaling (LVDS) over the SpaceWire network, with a Serial Deserializer (SERDES) converting data between interfaces for high-speed communication. Collected data is stored on a High-Speed Data Recorder (HSDR) at 32 GB with Error Detection and Correction. 1) 11) 14)

Electric Propulsion System

Designed by Space Electric Thruster Systems (SETS), the SPS-25 SmallSat Propulsion System onboard EOS Sat-1 produces 5-11 mN (milli-Newtons) of thrust and a total impulse up to 115 kN∙s (kiloNewton-seconds) from 120-200 W of power. The Hall effect thruster uses Xenon or Krypton propellant and has a dry mass of 5kg. It is verified to TRL level 9. 15) 16)

Launch

EOS Sat-1 launched onboard the SpaceX Falcon 9 Transporter-6 mission from Cape Canaveral, Florida, on January 3 2023 at 09:56 local time. 2) 7) 8)

Orbit

EOS Sat-1 operates in a Sun-synchronous low Earth orbit (LEO) with an altitude of 540 km. The satellite has an orbital period of 94.75 minutes, a repeat cycle of 2-3 hours, an inclination of 97.43° and a 09:30 Local Time Descending Node (LTDN). 1) 5) 7) 17) 18)  

Mission Status

• May 23, 2023: The first light imagery captured by EOS Sat-1 is unveiled. 19)

• Jan 3, 2023: EOS Sat-1 was successfully launched by SpaceX from Cape Canaveral, Florida, onboard the Transporter-6 mission. 2) 7) 8)

Sensor Complement

DragonEye Imager

Onboard EOS Sat-1 are two in-house designed DragonEye Cameras, built with radiation-resistant parts with low thermal expansion. Implementing a Cassegrain optical system with a chromatic two-lens corrector, the camera has a large angular view without increasing aperture technology or loss of spatial resolution while reducing de-centering sensibility.

The DragonEye imagers have a 22.2 km swath width from a 500 km orbital altitude, a spatial resolution of 1.4 m for panchromatic bands, and 2.8 m for the multispectral bands. The imager's 11 spectral bands include RGB, NIR (Near Infrared) (two bands), red edge (three bands), water vapour, aerosol, and panchromatic. DragonEye imagery aligns with Sentinel-2 data, increasing the spatial resolution by seven times, enhancing support for applications including carbon sequestration modelling, greenhouse gas monitoring, vegetation tracking and environmental conservation efforts.

The imagers require 28 V DC power, consume less than 45 W during imaging, and less than 25 W during readout mode. Designed to last in temperamental conditions, the cameras can operate between 10°C - 30°C and can survive temperature extremes between -20°C - 55°C. Data read by the on-board data handling system are formatted as 10-bit or 12-bit, RAW, J2K lossless or lossy. For this, a data interface using a multigigabit transceiver communicates through LVDS.

The cameras are 320 mm x 930 mm in size, and have a mass of 18 kg. 20) 21) 22) 23)

Space Traffic Management Platform

EOS Sat-1 payloads have implemented Neuraspace’s AI (Artificial Intelligence) Space Traffic Management system, which provides collision event analysis and manoeuvre suggestions to avoid collisions with other space objects. 6)  

Ground Segment

Dragonfly Aerospace and EOSDA will obtain image datasets using four ground stations placed in different countries. The bus communicates telemetry and telecommand information using 400 kbps (kilobits per second) downlink in the S-band and 150kbps uplink. The bus can also accommodate 2.5 Gbps downlink in the X-band. The radios transmit real-time information of the satellite’s health, can receive commands for troubleshooting, and are used to transmit captured data in high resolution. 7) 11)  

Data is then stored using Amazon Cloud Services, and images are processed by the company Pinkmatter. Processed imagery then collected by EOSDA to provide services to global customers. 18) 24)

References

1. “Minister Blade Nzimande welcomes successful launch of EOS SAT-1 satellite,” South African Government, URL: https://www.gov.za/news/media-statements/minister-blade-nzimande-welcomes-successful-launch-eos-sat-1-satellite-09-jan
2. “EOSDA Launched Its First Agri-Oriented Satellite On January 3,” EOS Data Analytics, URL: https://eos.com/blog/eosda-sent-its-first-agro-satellite-on-jan-3-to-orbit/
3. “EOS Data Analytics and Space Electric Thruster Systems demonstrate technology in orbit,” SpaceNews, June 5 2023, URL: https://spacenews.com/eos-data-analytics-and-space-electric-thruster-systems-demonstrate-technology-in-orbit/
4. “Noosphere Ventures aims to build an integrated space powerhouse: Q&A with managing partner Max Polyakov,” SpaceNews, April 21 2021, URL: https://spacenews.com/noosphere-ventures-aims-to-build-an-integrated-space-powerhouse-qa-with-managing-partner-max-polyakov/
5. “EOS SAT Mission,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/eossat-1/
6. “Dragonfly Aerospace selects Neuraspace for enhanced space sustainability,” September 22 2023, URL: https://dragonflyaerospace.com/dragonfly-aerospace-neuraspace-partnership/
7. “World’s first agri-focused satellite launched from Cape Canaveral,” Dragonfly Aerospace, January 5 2023, URL: https://dragonflyaerospace.com/worlds-first-agri-focused-satellite-launched-from-cape-canaveral/
8. “EOS Data Analytics launched EOS SAT-1, the first satellite of its EOS SAT constellation,” Noosphere Ventures, January 5 2023, URL: https://noosphereventures.com/eos-data-analytics-launched-eos-sat-1-the-first-satellite-of-its-eos-sat-constellation/
9. “EPS-LP-1k5,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/components/electrical-power-system/
10. “28-300 Battery Module,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/components/battery-module/
11. “µDRAGONFLY BUS,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/satellite-buses/mdragonfly-bus/
12. “RW-1Nms,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/components/rw-1nms/
13. “OBC-Q7S,” Dragonfly Aerospace,” URL: https://dragonflyaerospace.com/components/obc/
14. “EOS-SAT 1 (EOS Agrisat-1),” Gunter’s Space Page, URL: https://space.skyrocket.de/doc_sdat/eos-sat-1.htm
15. “SPS-25 Propulsion System,” Space Electric Thruster Systems, URL: https://sets.space/sps25/
16. “SETS Successfully Completes Testing of its SPS-25 Propulsion System on EOS SAT-1 Satellite,” SatNow, URL: https://www.satnow.com/news/details/848-sets-successfully-completes-testing-of-its-sps-25-propulsion-system-on-eos-sat-1-satellite
17. “EOS SAT-1 White Paper Released By EOS Data Analytics,” EOS Data Analytics, February 28 2024, URL: https://eos.com/blog/eosda-releases-white-paper-on-eos-sat-1-satellite/
18. “Towards Sustainability - Evolving from Manufacturing Hardware to Providing Analytics Ready Data,” Dragonfly Aerospace, National Space Conference 2024, URL: https://www.spaceconference.co.za/wp-content/uploads/2024/09/NSC-2024-Plenary-1-6-EOS-SAT-1-Data-Christelis.pdf
19. “Images from EOS SAT-1,” Dragonfly Aerospace, May 23 2023, URL: https://dragonflyaerospace.com/dragonfly-aerospace-unveils-spectacular-first-images-from-eos-sat-1/
20. “DRAGONEYE,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/smallsat-cameras/dragoneye/
21. “EOS SAT DATA,” Dragonfly Aerospace, URL: https://dragonflyaerospace.com/eos-sat-data/
22. “EOS SAT-1 Satellite Building Process: From Design To Launch,” November 30 2022, URL: https://eos.com/eossat/launch-the-satellite/
23. “Technical Capabilities Of EOS SAT Agro-focused Constellation,” EOS Data Analytics, December 6 2022, URL: https://eos.com/blog/eos-sat-agro-focused-constellation-tech-overview/
24. “EOSDA Mission And Vision, Our Team, And Company History,” March 24 2017, URL: https://eos.com/company/