Author Contributions
Conceptualization (D.B., C.B. (Catherine Billard)), LATMOS (M.M., P.K., A.S., T.B., S.B., L.D., P.G. (Patrick Galopeau), A.H. (Alain Hauchecorne), C.D. (Christophe Dufour), A.F., A.-J.V., E.B., P.G. (Pierre Gilbert), N.C., C.D. (Clément Dias), J.-L.E., P.L.), ONERA (F.B., K.G., V.R., S.S.), ACRI-ST (V.S., A.M.), Adrelys (Y.A.), Oledcomm (B.A., C.B. (Cyril Brand), C.D. (Carlos Dominguez)), ISIS (A.H. (Akos Haasz), A.P., K.S.), PIT (P.M., S.A.), AMSAT-Francophone (C.M.); science (climate studies, solar physics, ionosphere), LATMOS (M.M., P.K., A.S., S.B., L.D., P.G. (Patrick Galopeau), A.H. (Alain Hauchecorne)), ONERA (F.B., K.G., V.R., S.S.); hardware and engineering, LATMOS (M.M., A.-J.V., E.B., P.G. (Pierre Gilbert), N.C., C.D. (Clément Dias), J.-L.E., P.L.), ONERA (F.B., K.G., V.R., S.S.), Adrelys (Y.A.), Oledcomm (C.B. (Cyril Brand), C.D. (Carlos Dominguez)), ISIS (A.H. (Akos Haasz), A.P., K.S.); methodology, LATMOS (M.M.); software, LATMOS (M.M., P.K., A.S., T.B., S.B., L.D., P.G. (Patrick Galopeau), A.H. (Alain Hauchecorne), C.D. (Christophe Dufour), A.F.); formal analysis, LATMOS (M.M., P.K., A.S., T.B., S.B., L.D., P.G. (Patrick Galopeau), A.H. (Alain Hauchecorne), C.D. (Christophe Dufour), A.F.); resources, LATMOS (M.M., P.K., A.S., T.B., S.B., L.D., P.G. (Patrick Galopeau), A.H. (Alain Hauchecorne), C.D. (Christophe Dufour), A.F., A.-J.V., E.B., P.G. (Pierre Gilbert), N.C., C.D. (Clément Dias), J.-L.E., P.L.), ONERA (F.B., K.G., V.R., S.S.), ACRI-ST (V.S., A.M.), Adrelys (Y.A.), Oledcomm (B.A., C.B. (Cyril Brand), C.D. (Carlos Dominguez)), ISIS (A.H. (Akos Haasz), A.P., K.S.), PIT (P.M., S.A.), AMSAT-Francophone (C.M.); writing—original draft preparation, LATMOS (M.M., P.K., A.S., T.B., S.B., L.D., P.G. (Patrick Galopeau), A.H. (Alain Hauchecorne), C.D. (Christophe Dufour), A.F., A.-J.V., E.B., P.G. (Pierre Gilbert), N.C., C.D. (Clément Dias), J.-L.E., P.L.), ONERA (F.B., K.G., V.R., S.S.), ACRI-ST (V.S., A.M.), Adrelys (Y.A.), Oledcomm (B.A., C.B. (Cyril Brand), C.D. (Carlos Dominguez)), ISIS (A.H. (Akos Haasz), A.P., K.S.), PIT (P.M., S.A.), AMSAT-Francophone (C.M.); writing—review and editing, LATMOS (M.M., P.K., A.S., T.B., S.B., L.D., A.F.), and ONERA (F.B., K.G., V.R., S.S.); project administration, LATMOS (M.M.); funding acquisition, LATMOS (M.M.), ONERA (F.B.), ACRI-ST (A.M.), Adrelys (Y.A.), Oledcomm (B.A.). All authors have read and agreed to the published version of the manuscript.
Figure 1.
Computer-aided design of the INSPIRE-SAT 7 CubeSat with all printed circuit boards (PCBs) and payload instruments (ERS, TSIS sensors, UV sensors (standard and new generation), Li-Fi payload, CUIONO1 payload, SPINO payload, IMU).
Figure 1.
Computer-aided design of the INSPIRE-SAT 7 CubeSat with all printed circuit boards (PCBs) and payload instruments (ERS, TSIS sensors, UV sensors (standard and new generation), Li-Fi payload, CUIONO1 payload, SPINO payload, IMU).
Figure 2.
INSPIRE-SAT 7 during integration phase in November 2021. View of ERS location.
Figure 2.
INSPIRE-SAT 7 during integration phase in November 2021. View of ERS location.
Figure 3.
Design of the TSIS and standard UVS sensors (UVS and UVS).
Figure 3.
Design of the TSIS and standard UVS sensors (UVS and UVS).
Figure 4.
Principle of the measurement along the CubeSat orbit. During the time where the satellite is direct line of sight, the incidence varies and hence the cutoff frequency.
Figure 4.
Principle of the measurement along the CubeSat orbit. During the time where the satellite is direct line of sight, the incidence varies and hence the cutoff frequency.
Figure 5.
INSPIRE-SAT 7 downlink configuration.
Figure 5.
INSPIRE-SAT 7 downlink configuration.
Figure 6.
INSPIRE-SAT 7 uplink configuration.
Figure 6.
INSPIRE-SAT 7 uplink configuration.
Figure 7.
(a) TOA outgoing shortwave radiation from ERA 5 model. 1° × 1° latitude by longitude. Monthly averaged. (b) TOA outgoing shortwave radiation from ERA 5 model with UVSQ-SAT data time acquisition. (c) TOA outgoing shortwave radiation from UVSQ-SAT observations in August 2021. (d) TOA outgoing longwave radiation from ERA 5 model. 1° × 1° latitude by longitude. Monthly averaged. (e) TOA outgoing longwave radiation from ERA 5 model with UVSQ-SAT data time acquisition (eclipse period). (f) TOA outgoing longwave radiation from UVSQ-SAT observations in August 2021 (eclipse period).
Figure 7.
(a) TOA outgoing shortwave radiation from ERA 5 model. 1° × 1° latitude by longitude. Monthly averaged. (b) TOA outgoing shortwave radiation from ERA 5 model with UVSQ-SAT data time acquisition. (c) TOA outgoing shortwave radiation from UVSQ-SAT observations in August 2021. (d) TOA outgoing longwave radiation from ERA 5 model. 1° × 1° latitude by longitude. Monthly averaged. (e) TOA outgoing longwave radiation from ERA 5 model with UVSQ-SAT data time acquisition (eclipse period). (f) TOA outgoing longwave radiation from UVSQ-SAT observations in August 2021 (eclipse period).
Figure 8.
(left) Monthly time series of the TOA outgoing shortwave radiation of ERA 5, ERA 5 model with UVSQ-SAT data time acquisition, UVSQ-SAT (data in orbit), and INSPIRE-SAT 7 (simulation). (right) Monthly time series of the TOA outgoing longwave radiation of ERA 5, ERA 5 model with UVSQ-SAT data time acquisition, UVSQ-SAT (data in orbit), and INSPIRE-SAT 7 (simulation).
Figure 8.
(left) Monthly time series of the TOA outgoing shortwave radiation of ERA 5, ERA 5 model with UVSQ-SAT data time acquisition, UVSQ-SAT (data in orbit), and INSPIRE-SAT 7 (simulation). (right) Monthly time series of the TOA outgoing longwave radiation of ERA 5, ERA 5 model with UVSQ-SAT data time acquisition, UVSQ-SAT (data in orbit), and INSPIRE-SAT 7 (simulation).
Figure 9.
First steps of the simulation of two satellites in orbit (UVSQ-SAT and INSPIRE-SAT 7) to restore the flux of the Earth at the top-of-the-atmosphere.
Figure 9.
First steps of the simulation of two satellites in orbit (UVSQ-SAT and INSPIRE-SAT 7) to restore the flux of the Earth at the top-of-the-atmosphere.
Figure 10.
(left) Estimation of the number of satellites (constellation) according to the temporal resolution. (right) Influence of field of view (FOV) on spatial resolution for three CubeSats altitude.
Figure 10.
(left) Estimation of the number of satellites (constellation) according to the temporal resolution. (right) Influence of field of view (FOV) on spatial resolution for three CubeSats altitude.
Figure 11.
Terra-F constellation of 32 satellites that evolve on 8 orbital planes.
Figure 11.
Terra-F constellation of 32 satellites that evolve on 8 orbital planes.
Table 1.
Scientific requirements (UVSQ-SAT, INSPIRE-SAT 7, and future Terra-F constellation).
Table 1.
Scientific requirements (UVSQ-SAT, INSPIRE-SAT 7, and future Terra-F constellation).
Requirements | UVSQ-SAT | | | |
Parameter | Absolute accuracy | Stability per year | Spatial resolution | Temporal resolution |
OSR | ±10.00 Wm | ±5.00 Wm | 2500 km | 30 days |
OLR | ±10.00 Wm | ±1.00 Wm | 2500 km | 30 days |
Requirements | INSPIRE-SAT 7 | | | |
Parameter | Absolute accuracy | Stability per year | Spatial resolution | Temporal resolution |
OSR | ±5.00 Wm | ±1.00 Wm | 2500 km | 10 days with 2 CubeSats |
OLR | ±5.00 Wm | ±1.00 Wm | 2500 km | 10 days with 2 CubeSats |
Requirements | Terra-F | | | |
Parameter | Absolute accuracy | Stability per decade | Spatial resolution | Temporal resolution |
TSI | ±0.54 Wm | ±0.14 Wm | – | 24 h |
OSR | ±1.00 Wm | ±0.10 Wm | 10–100 km | Diurnal cycle (3 h) |
OLR | ±1.00 Wm | ±0.10 Wm | 10–100 km | Diurnal cycle (3 h) |
EEI | ±1.00 Wm | ±0.10 Wm | – | – |
Table 2.
INSPIRE-SAT 7 CubeSat properties.
Table 2.
INSPIRE-SAT 7 CubeSat properties.
Properties | Value | Comments |
---|
Orbit | Sun-synchronous orbit | Maximum altitude of 600 km, LTDN of 09:30 |
Design life time | 2 years for LEO | 3 years desired |
Launch date | Q1 2023 | Launch vehicle: Falcon 9 |
Size | 2 U | 11.5 cm (X) × 11.5 cm (Y) × 22.7 cm (Z) |
Mass | 3.0 kg | Maximum with margins |
Solar cells | 20 | 3G30A solar cells provided by Azurspace |
Batteries | 45 Wh@16 V | 4 Panasonic batteries (NCR18650B) with heaters |
Power generated | 3.8 W | OAP in LEO |
Power consumption | 3.2 W | Maximum orbit average with margins |
ADCS | 3-axis magnetometer | Measurements of the local Earth magnetic field |
| 3-axis magnetorquer | 0.2 Am magnetic dipole |
| 6 SLCD-61N8 photodiodes | Coarse estimation of the Sun’s direction () |
CDHS and OBC | 400 MHz, 32-bit ARM9 | Processor |
| 32 MB SDRAM | Synchronous Dynamic Random Access Memory |
| 2 × 2 GB SD-cards | Non-volatile data storage (SD card redundancy) |
| 1 MB NOR flash | Code storage |
| IC, SPI, UARTs | UART is only used for debugging iOBC |
Data downlink | 1.2/9.6 kbps | UHF BPSK (437.410 MHz) communication |
Data uplink | 9.6 kbps | VHF FSK (145.970 MHz) communication |
Ground contact station | Less than 1 h per day | LATMOS station |
Redundancy stations | LATMOS | Other stations: amateur radio partners |
Downlink UVSQ-SAT data | 1.8 Mbyte per day | Maximum during a day |
Uplink UVSQ-SAT data | 0.3 Mbyte per day | Maximum during a day |
Payload | 12 ERS | ERB measurements |
| 4 TSIS | TSI measurements |
| 10 UVS | UV SSI and ozone measurements |
| 1 CUIONO1 payload | Ionospheric measurements |
| 1 Li-Fi payload | Wireless communication system |
| 1 SPINO payload | Functions for amateur radio community |
| Audio transponder | FM live retransmission (amateur radio) |
| 1 IMU | 3-axis accelerometer/gyroscope/compass |
Launch adapter | ISIPOD or Quad-pack | CubeSat deployer with a satellite mass up to 3 kg |
Table 3.
ERS and temperature sensors technical requirements. N is the number of parts.
Table 3.
ERS and temperature sensors technical requirements. N is the number of parts.
Type | Location | N | Sensitivity | Range | Resolution | Noise |
---|
ERS | +X, −X, +Y, −Y | 4 | 1.5 V/Wm | [−4500 … 4500 V] | 34.3 nV/bit | 150 nV rms |
ERS | +X, −X, +Y, −Y | 4 | 1.5 V/Wm | [−4500 … 4500 V] | 34.3 nV/bit | 150 nV rms |
ERS | +Z, −Z | 2 | 0.2 V/Wm | [−750 … 750 V] | 5.7 nV/bit | 25 nV rms |
ERS | +Z, −Z | 2 | 0.2 V/Wm | [−750 … 750 V] | 5.7 nV/bit | 25 nV rms |
T | 2 per side | 12 | 1.0 A K | [−70 … 70 A] | 0.5 nA/bit | 100 nA rms |
Table 4.
UVS and TSIS sensors technical requirements with their photoresponsivity (P).
Table 4.
UVS and TSIS sensors technical requirements with their photoresponsivity (P).
Sensor | N | Aperture | | P | Range | Resolution | Noise |
---|
TSIS | 4 | ∅ 1 mm | 0–1100 nm | ∼0.21 AW | [0 … 250 nA] | 9.5 × 10 nA/bit | <0.1 nA rms |
UVS | 4 | 500 × 800 m | 215 nm | ∼0.01 AW | [0 … 250 nA] | 9.5 × 10 nA/bit | <0.1 nA rms |
UVS | 3 | ∅ 3 mm | 308 nm | ∼0.14 AW | [0 … 3000 nA] | 11.4 pA/bit | <0.1 nA rms |
UVS | 3 | ∅ 3 mm | 340 nm | ∼0.15 AW | [0 … 3000 nA] | 11.4 pA/bit | <0.1 nA rms |
Table 5.
Li-Fi payload characteristics.
Table 5.
Li-Fi payload characteristics.
Parameters | Li-Fi Payload Performances |
---|
Parameters | Li-Fi payload characteristics |
Protocol of communication | I2C |
Data Rate | 5 Mbps |
Distance of communication | 1 to 2 cm |
Field of view | 10° |
Wavelength | 940 nm |
PCB dimensions | 90 × 95 × 8 mm |
Weight | 70 g |
Consumption | 1 W peak |
Power Supply | 5 V |
Telemetry | Data rate, latency, jitter |
Telemetry | <200 Bytes per communication with the OBC |
Table 6.
INSPIRE-SAT 7 IMU technical requirements.
Table 6.
INSPIRE-SAT 7 IMU technical requirements.
Parameter | Requirements |
---|
IMU signal range | Accelerometer: ±2.0 g |
| Gyroscope: ±250.0 deg |
| Compass: ±491.2 T |
IMU resolution | 16 bits |
IMU noise detection | Accelerometer: <250 g/ |
| Gyroscope: <0.02 deg/s/ |
IMU time response | <20 ms |
Acquisition integration time | <10 s |