# UVsq-Sat NG, a New CubeSat Pathfinder for Monitoring Earth Outgoing Energy and Greenhouse Gases
## 3 Description of the Uvsq-Sat NG Space-Based Mission
### Description of the Uvsq-Sat NG Satellite and Its Payloads
\begin{table}
\begin{tabular}{l l l} \hline \hline
**Properties** & **Value** & **Comments** \\ \hline Orbit & Sun-Synchronous Orbit (SSO) & Maximum altitude of 600 km, LTAN of 06:30 \\ Design life time & Minimum of 2 years in LEO & 3 years desired \\ Launch date & Between Q2 2025 and Q1 2026 & Launch vehicle: Falcon 9, Vega-C or Zephyr \\ Launch adapter & QuadPack or EXOpod deployer & Payload mass up to 12 kg \\ \hline CubeSat type & 6 UXL & Easy-to-assemble modular design \\ Launch mass & 10.0 kg 1  & Maximum with margins \\ Dimensions & 10.0 cm \(\times\) 36.6 cm \(\times\) 22.6 cm & Stowed along X, Y, and Z axes \\  & 111.3 cm \(\times\) 36.6 cm \(\times\) 38.8 cm & Unstowed including all deployable elements \\ \hline Payloads & Two Earth Radiative Sensors (ERSs) & Outgoing terrestrial radiation measurements \\  & Six Uvsq-Sat NG photodiodes & Outgoing shortwave radiation \\  & One Uvsq-Sat NG Spectrometer & Greenhouse gases monitoring \\  & One Uvsq-Sat NG NanoCam & Imaging and geolocation \\  & One Audio transponder & FM live retransmission (amateur radio) \\  & One LATMOS IMU & Three-axis accelerometer/gyroscope/compass \\ \hline Power & Up to 35 W generation at 1 AU 2  & Two deployable solar panels on the Z\(-\) side \\  & 52 solar cells on multiple sides & 3G30A solar cells provided by Azur Space \\  & Batteries of 90 Wh @16 V & 8 Panasonic batteries (NCR18650B) with heaters \\  & Power of 15.0 W generated & OAP in LEO with LTAN of 09:00 \\  & Power of 10.0 W consumed & Day average—nominal operations \\ \hline CDHS and OBC & CubeSat OnBoard Computer & Isispace \\  & 400 MHz, 32-bit ARM9 & Processor \\  & 64 GByte & Storage \\  & I2C/CAN/SPI/USART/UART & Data bus \\ \hline Thermal control system & Passive design & Coatings \\  & 120 Ohms at 16 V & Heaters for batteries protection \\ \hline Communication & Uplink of 9.6 kbps & VHF (G3 RUH FSK, AX25) — 148.0 MHz 3  \\  & Uplink data of 0.3 Mbytes & Maximum during a day \\  & Downlink of 9.6 kbps/4.3 Mbps & UHF (BPSK) — 401.0 MHz 3  \(\mid\) S-band — 2245 MHz 3  \\  & Downlink data of 150.0 Mbyte & Maximum during a day with the S-band \\  & Contact station of \(\sim\)1 h per day & LATMOS and ACRI-ST ground stations \\ \hline Electric propulsion & 10 to 350 uN of thrust & Emulsion, Exotrail, or no subsystem \\ \hline Pointing and ADCS & ADCS OnBoard Computer & Isispace, Cortex-M7 ARM micro-processor \\  & Magnetorquer board (iMTQ) & Isispace \\  & Deployable magnetometer & iMTM from Isispace \\  & Fine Sun Sensor & Lens R\&D \\  & Reaction Wheels & Astrofein \\  & Star Tracker and its OBC & Sodern (including Isispace processing unit) \\  & Three-axis magnetometer & Measurements of the local Earth magnetic field \\  & Three-axis magnetorquer & 0.2 Am 2 magnetic dipole (per actuator) \\  & Six SLCD-61N8 photodiodes & Coarse estimation of the Sun’s direction (\(\theta\)) \\  & \(<\) 0.10 degree for all three axes & Absolute Performance Error (Roll, Pitch, Yaw) \\  & \(<\) 0.02 degree for all three axes & Performance Drift Error (Roll, Pitch, Yaw) \\ \hline Time and position & GNSS receiver & Novatel \\  & GNSS patch antenna & Isispace \\  & \(\sim\)20 ns rms & Timing accuracy \\  & \(<\)2 m rms & Orbit position determination accuracy \\  & \(<\)0.03 ms\({}^{-1}\) rms & Orbit velocity determination accuracy \\  & Maximum slew rate of 10 \({}^{\circ}\)s\({}^{-1}\) & Depending on CubeSat moment of inertia \\ \hline Modes & B-dot mode & Detumbling phase \\  & Scientific modes & Nadir, zenith, Earth’s limb, Sun, deep space \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Characteristics of the Uvsq-Sat NG spacecraft. Numerous ADCS modes are available (including Initial Mode, Safe Mode, Detumbling Mode, Rate Estimation Mode, Attitude Determination Mode, Nadir Pointing Mode, Ground Point Tracking Mode, and Sun Tracking Mode) to ensure that the Uvsq-Sat NG satellite will maintain its desired orientation in orbit, tailored to the specific operational demands.