AMSAT CubeSatSim — CubeSat Simulator (hardware v2.1.0)
The AMSAT CubeSatSim is an educational satellite simulator that allows students to explore the subsystems and operation of a functional CubeSat. Students assemble a modular system comprising a main controller board based on the Raspberry Pi Pico or Zero, a battery management board, and a multi-channel solar power monitoring board. Through this hands-on project, learners investigate aerospace concepts including telemetry transmission via UHF radio, power budget analysis using digital current sensors, and environmental data collection through inertial and atmospheric sensors. The lab covers electronics fabrication, RF filtering design, and the software integration required to operate a simulated orbital platform and ground station.
Uploaded by demo on 2026-07-19 · ready · Electronics · Original source ↗
Files: CubeSatSim Main v2.1.0 BOM.xls · cubesatsim-main-v2.1.0_bom.csv.txt · cubesatsim-solar-v2.1.0_bom.csv.txt · cubesatsim-battery-v2.1.0_bom.csv.txt · cubesatsim-main-v2.1.0_schematic.pdf · cubesatsim-solar-v2.1.0_schematic.pdf · cubesatsim-battery-v2.1.0_schematic.pdf · NSF_ATE_provenance.txt
Readiness checks
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complete 2026-09-02 22:50 🛡 Cybersecurity: Do not place on an open network · 3 findings 31 searches · 8 pagesview · PDF
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complete 2026-09-02 19:07 🛡 Cybersecurity: Do not place on an open network · 2 findings 34 searches · 7 pages · $0.37view · PDF
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complete 2026-07-19 15:55 🛡 Cybersecurity: not checked 31 searches · 0 pagesview · PDF
Latest report — 2026-09-02 22:50
Readiness: AMSAT CubeSatSim — CubeSat Simulator (hardware v2.1.0)
Verdict: Ready with caveats · 2026-09-02 · est. parts cost insufficient pricing Cybersecurity — software & network: Do not place on an open network
Verdict unchanged from this morning's report. Every part carried by authorized catalog distributors is Active with healthy stock and identical pricing, and the retail breakout modules remain widely listed. The caveats are unchanged too: the two RF transceiver modules — SR105U (U6) and the Dorji DRA818V alternative (U7) — are absent from every ECIA-authorized distributor and can only be bought through maker marketplaces and direct vendor storefronts. Today none of those retail product pages could be fetched for confirmation, so their listings are reported from search results and should be verified manually before ordering. The exact Seeed ferrite part number is likewise not distributor-stocked, but a fully verified Murata drop-in is plentiful.
Action required
| Part | Problem | Recommended action |
|---|---|---|
| SR105U (U6 - Main Board) | Not stocked by any authorized distributor; specialty sourcing only. Retail listings could not be re-verified today (product-page fetches returned no content). | Order via the odlstore listing or the earlier-revision SR-FRS-0W5U at dwmzone; verify the live listing and footprint before purchase. |
| Dorji DRA818V (U7 - Main Board) | Not stocked by any authorized distributor; maker/hobbyist channels only. Tindie and dorji.com pages could not be fetched today. | If building the VHF configuration, order via Tindie (DORJI store), uputronics or eBay; verify the live listing first. |
| 303030001 ferrite (L1, L2 - Main Board) | Seeed part number not carried by DigiKey or any ECIA distributor. | Use the verified substitute BLM18AG121SN1D (Murata, $0.10, 706,396 in stock). |
Parts
1. Integrated Circuits and Proprietary Modules
| Part | Spec/Package | Status | Stock | Price | Source | Drift |
|---|---|---|---|---|---|---|
| Raspberry Pi Pico (U1) | Microcontroller board, 3.3V logic | Readily available | In stock | $3.95 | PiShop USA | prev. $2.99 (Micro Center); comparable |
| SR105U (U6) | 0.5W UHF FM module, footprint SR_FRS_0W5 | Hard to obtain | Listed | listing | odlstore (unverified today) | prev. $22.50; unconfirmed |
| Dorji DRA818V (U7) | VHF FM module, footprint DORJI_DRA818V | Hard to obtain | Listed | listing | Tindie DORJI store (unverified today) | prev. $8.98; unconfirmed |
| INA219AIDR (U2, U10–U14 Solar; U2 Battery) | Digital current/power monitor, SOIC-8 | Readily available | 29,736 | $2.12 | DigiKey | none |
| INA219 "Purple Board" (U1 Battery; U3–U8 Solar) | Sensor breakout module | Readily available | In stock | $9.95 | Adafruit (generics from $1.25) | prev. $6.90; comparable |
| MPU6050 Module (J4) | 6-DOF IMU breakout | Readily available | In stock | $12.99 | Micro Center (Adafruit) | none |
| BME280 Module (J5) | Environmental sensor breakout | Readily available | In stock | $9.98 | ShillehTek | prev. $9.00; comparable |
2. Diodes and Protection
| Part | Spec/Package | Status | Stock | Price | Source | Drift |
|---|---|---|---|---|---|---|
| BYW27-400 (D1) | Avalanche rectifier, 400V 1A, DO-41 axial | Readily available | 4,834 | $0.43 | DigiKey | stock −1 |
| 1N5817 (D2, D10 Main; D1–D6 Solar) | Schottky, 20V 1A, DO-41 axial | Readily available | 8,866 | $0.29 | DigiKey (MCC 1N5817-TP; exact-suffix 1N5817 $0.34) | none |
| 1N4148 (D3) | Small-signal diode, 100V 200mA, DO-35 axial | Readily available | 763,524 | $0.10 | DigiKey (onsemi) | none |
| BAT20J (D7–D12 Solar) | Schottky, 23V 1A 620mV, SOD-323 | Available (shallow at DigiKey; deep at Arrow 63,000 / Newark 8,773) | 39 | $0.62 | DigiKey (BAT20JFILM) | none |
| RHEF100-2 (F1 Main) | PTC resettable fuse, 30V 1A | Readily available | 11,411 | $0.84 | DigiKey (Littelfuse) | stock −1 |
| MF-R010 (F1 Battery, representative) | PTC resettable fuse | Readily available | 12,053 | $0.40 | DigiKey (Bourns) | none |
3. Passive Components
| Part | Spec/Package | Status | Stock | Price | Source | Drift |
|---|---|---|---|---|---|---|
| 1 kΩ (R1, R3, R7, R30 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 100 Ω (R8, R19 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 220 Ω (R9, R20, R29 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 68 Ω (R13, R15 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 180 Ω (R14 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 4.7 kΩ (R23, R24 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 10 kΩ (R27 Main) | Axial 0.1 inch | not checked | — | — | — | — |
| 10 kΩ (R2, R3 Battery) | 0603 SMD | not checked | — | — | — | — |
| 0.1 Ω shunt (R1, R2, R5, R6, R9, R10 Solar) | 0805 SMD, 1% | not checked | — | — | — | — |
| 4.7 kΩ (R3, R4 Solar) | Axial 0.1 inch | not checked | — | — | — | — |
| 18 pF (C1, C3 Main) | 0603 SMD | not checked | — | — | — | — |
| 16 pF (C2, C4 Main) | 0603 SMD | not checked | — | — | — | — |
| 100 nF (C6, C9 Main; C2–C7 Solar) | 0603 SMD or PTH small | not checked | — | — | — | — |
| 47 µF (C5 Main) | PTH small electrolytic/tantalum | not checked | — | — | — | — |
| Ferrite 120 Ω L0603 (L1, L2 Main), snapshot PN 303030001 | Chip ferrite bead, 120 Ω @ 100 MHz, 0603 | Exact PN hard to obtain; verified substitute available | 706,396 (substitute) | $0.10 | DigiKey (Murata BLM18AG121SN1D) | substitute stock −55 |
4. Connectors and Electromechanical
| Part | Spec/Package | Status | Stock | Price | Source | Drift |
|---|---|---|---|---|---|---|
| Stacking header 20x2 (J1, all boards) | 40-pin female stacking, 0.1 inch pitch | Readily available | In stock | $2.95 | PiShop USA / Adafruit | none |
| ANT-916-CHP-T (E1, E2 Main) | 916 MHz chip antenna, SMD | Readily available | 2,656 | $3.61 | DigiKey (TE/Linx) | none |
| SMA vertical female PTH (X2, X3 Main) | SMA jack, PCB mount vertical | Readily available | In stock | $4.49 | Vetco Electronics | none |
| SJ1-2503A (J13, J14 Main) | 3.5mm stereo jack, PTH | Readily available | 24,759 | $0.75 | DigiKey (Same Sky) | stock −1 |
| SparkFun USB-C breakout (J8 Main) | USB-C receptacle breakout | Readily available | In stock | $4.95 | SparkFun | none |
| Micro JST 2-pin (J6, J7 Main; JP1–JP26) | JST-PH 2-pin vertical PTH | Readily available | In stock | $0.50 | SparkFun | none |
| Keystone 1024 (BT1 Battery) | Single AA clip/holder, SMD | Readily available | 1,675 | $4.92 | DigiKey | stock −1 |
| Keystone 1012 (BT2 Battery) | Dual AA clip/holder, SMD | Readily available | 12,275 | $8.02 | DigiKey | stock −1 |
| RA-SPST switch (S1 Main) | Right-angle SPST slide, PTH | Readily available | In stock | $0.15 | Jameco | none |
| 5mm LEDs (LED1–LED5 Main) | 5mm T1-3/4, five colors | Readily available | In stock | $13.48 kit | DigiKey (assorted kit) | none |
Substitutes
| For part | Substitute | Differences | Verified | Judgment |
|---|---|---|---|---|
| 303030001 ferrite (L1, L2) | BLM18AG121SN1D (Murata) | 120 Ω @ 100 MHz matches spec; 0603 (1608 metric) matches L0603; 800 mA rating; −55 to +125 °C. | Verified: impedance and package from DigiKey parametrics. | Acceptable drop-in. |
| BAT20J / BAT20JFILM (D7–D12) | SBA130CS_R1_00001 (Panjit, DigiKey-suggested) | Vr 30V exceeds the 23V requirement (acceptable); Io 1A matches; Vf 470 mV @ 1A is lower than 620 mV (acceptable). Package listed as SC-90/SOD-323F (flat-lead) vs the original's SC-76/SOD-323, though both carry supplier package "SOD-323". Stock: DigiKey 21, Mouser 910 @ $0.21. | Verified: Vr/Io/Vf ratings from DigiKey parametrics. Not fully verified: footprint — SOD-323F vs SOD-323 lead-form difference; confirm land-pattern fit before ordering. | Electrically acceptable; confirm footprint manually. |
| BAT20J / BAT20JFILM (D7–D12) | 1SS404,H3F (Toshiba, DigiKey-suggested) | 20V Vr and 300 mA Io both fall short of the 23V / 1A requirement. | Verified: ratings from DigiKey substitute data. | Rejected — under-rated on both counts. |
| SR105U (U6) | SR-FRS-0W5U (earlier revision, dwmzone / AliExpress) | Same manufacturer family, 0.5W UHF 400–480 MHz per listing titles; snapshot names the U6 footprint SR_FRS_0W5, matching this family's naming. | Not verified: every product-page fetch this run returned no content — revision equivalence and footprint rest on listing titles and the snapshot only. | Plausible, unverified — confirm the live listing and footprint before ordering. |
| SR105U (U6) | Dorji DRA818V on footprint U7 | VHF (134–174 MHz) instead of UHF; uses the board's dedicated U7 footprint — physically incompatible with the U6 pads (hard stop as a direct swap; supported as an alternative build by the PCB per the snapshot). | Verified: board-supported alternative per snapshot; module listing unverified today. | Alternative build option, not a U6 drop-in. |
Always verify pinouts, footprint dimensions, and electrical ratings against component datasheets before ordering substitutes.
Cybersecurity — software & network
Do not place on an open network — The required OS (Debian 11) is past the end of all security support with no fix short of platform migration, and the lab enables an SSH service that may carry default credentials.
Since the previous report: No change in the software itself since this morning's report: same end-of-life Debian 11 requirement, same unpinned installs, verdict unchanged. The SSH default-credential exposure, previously described only in the exposure statement, is now recorded as its own posture finding.
| Component | Version | How known | Support status |
|---|---|---|---|
| Debian | 11 | read from project (fetched/01-install refuses to proceed unless /etc/debian_version is 11 and /etc/os-release says bullseye) | unsupported since 2024-08-14 |
| CubeSatSim software suite | not determined | unpinned (fetched/01-install installs from git master; no tag or commit pinned) | — |
| Bundled radio/telemetry tools (direwolf, WiringPi, pi-power-button, ssdv, fcdctl, PiSSTVpp, rpitx, MPU6050 and BME280 libraries) | not determined | unpinned (nine git clones in fetched/01-install, none pinned to a tag or commit) | — |
| Python packages (adafruit-blinka, RPI.GPIO, adafruit-extended-bus, adafruit-circuitpython-ina219) | not determined | unpinned (pip3 install with no version constraints in fetched/01-install) | — |
| Raspberry Pi Pico SDK / firmware | not determined | not determined | — |
| Component | Finding | Severity | Fix available? |
|---|---|---|---|
| CubeSatSim software suite | Dependencies unpinned: 4 pip packages and 9 git clones in fetched/01-install install whatever is current, so the software the students run has no checkable security state. (new) | posture | Mitigation only — pin versions / use the lockfile |
| Debian | The install script requires Debian 11 (Bullseye), whose standard support ended 2024-08-14 and whose extended LTS security updates ended 2026-08-31, so the operating system the lab runs on no longer receives any security fixes. (new) | posture | No — requires platform migration |
| Raspberry Pi OS (SSH service) | The lab's documentation instructs students to enable SSH, and standard Raspberry Pi OS images may retain the published default credentials if they are not changed during setup. (new) | posture | Mitigation only — change default credentials and keep the simulator off open networks |
What this means for your lab
This simulator is built on an operating system that stopped receiving security fixes on August 31, 2026, and its setup instructions have students turn on SSH remote access. If it is placed on a shared or campus network, anyone on that network could try the well-known default Raspberry Pi login, and if it was never changed they could sign in, change the simulator's configuration, trigger radio transmissions, or read its files — and future OS flaws will never be patched. Keep the simulator on an isolated bench network or its own network segment, change the default password the day it is set up, and talk to campus IT before ever connecting it to a wider network. The application software itself installs at whatever version is current on install day, so its security state cannot be assessed in advance.
Not checked
- CubeSatSim software suite: unpinned; installed from git master, no version to check and no advisory database for the project
- Bundled radio/telemetry tools: unpinned git clones of source-only projects; no advisory database covers them
- Python packages (4): unpinned; no exact versions exist to check against OSV
- Raspberry Pi Pico SDK / firmware: version not determined; vendor firmware with no advisory database
- Raspberry Pi OS: endoflife.date has no raspberry-pi-os product entry; assessed via its Debian 11 base instead
- raspberry-pi-os 11: support status: endoflife.date has no such product
Other dependencies
- PCB fabrication (Main, Battery, Solar boards): 2-layer, ~10 cm × 10 cm CubeSat form factor — not checked.
- Primary project site
https://cubesatsim.org— not checked. - Hardware design files
https://github.com/alanbjohnston/CubeSatSim/tree/master/hardware/v2.1— not checked. - Audio PWM tutorial (hackster.io) — not checked.
- RF attenuator calculator (chemandy.com) — not checked.
- Adafruit INA219 Current Sensor PCB repository — not checked.
Watch list
- SR105U / SR-FRS-0W5U (U6): specialty walkie-talkie modules sold only through niche storefronts; every product page also resisted automated fetching today, so listings can vanish without this check noticing. Verify before each build cycle.
- Dorji DRA818V (U7): same specialty-channel exposure; Tindie/dorji.com/uputronics are the only channels seen.
- BAT20JFILM (D7–D12): DigiKey stock is 39 units; deep stock currently at Arrow (63,000) and Newark (8,773), but the DigiKey-suggested substitute has a footprint caveat, so a broader shortage would hurt.
- ANT-916-CHP-T (E1, E2): single-source chip antenna with modest stock (2,656).
Snapshot What the lab depended on when it was uploaded — the baseline the readiness checks research against.
This snapshot captures the temporal dependencies of the AMSAT CubeSatSim (hardware version 2.1.0), a satellite simulator platform designed for educational use. The system is distributed across three primary boards: a Main Board, a Battery Board, and a Solar Board. The simulator is designed around the Raspberry Pi Pico (microcontroller) or Raspberry Pi Zero (SBC), utilizing a 3.3V logic rail for sensors and control, with a 5V (VBUS) rail for USB/charging and a battery rail (approximately 3.6V to 4.8V for NiMH cells). RF transmission occurs in the UHF band (approx. 430-440 MHz or 915 MHz depending on the antenna/module choice).
Bill of Materials
The system uses a hybrid of through-hole (PTH) and surface-mount (SMD) components. Several parts are marked "DNI" (Do Not Install) in the documentation to allow for configuration between different RF modules or power schemes.
1. Integrated Circuits and Proprietary Modules
- Microcontroller (U1 - Main Board): Raspberry Pi Pico. Supply: 3.3V. Sourcing: retail shopping search: Raspberry Pi Pico.
- UHF FM Transceiver (U6 - Main Board): SR105U (0.5W UHF FM module). Must be exactly this module for PCB footprint compatibility (SR_FRS_0W5). Sourcing: retail shopping search: SR105U UHF module.
- VHF/UHF Transceiver (U7 - Main Board): Dorji DRA818V. Alternative to U6; high-power module. Must be exactly this part for the DORJI_DRA818V footprint. Sourcing: distributor lookup: Dorji DRA818V.
- Current/Voltage Monitor (U2, U10-U14 - Solar; U2 - Battery): INA219AIDR. Package: SOIC-8 (D0008A_N). Digital current/power monitor. Sourcing: distributor lookup: INA219AIDR.
- Current/Voltage Monitor Breakout (U1 - Battery; U3-U8 - Solar): INA219 "Purple Board" (generic Adafruit-style breakout). Used as an alternative to the discrete IC. Actuator: none (static module). Sourcing: retail shopping search: INA219 module.
- Inertial Measurement Unit (J4 - Main Board): MPU6050 (Header for module). Sourcing: retail shopping search: MPU6050 module 6-DOF.
- Environmental Sensor (J5 - Main Board): BME280 (Header for module). Sourcing: retail shopping search: BME280 module.
2. Diodes and Protection
- Avalanche Diode (D1 - Main Board): BYW27-400. Standard silicon rectifier, 400V, 1A. Sourcing: distributor lookup: BYW27-400.
- Schottky Rectifiers (D2, D10 - Main Board; D1-D6 - Solar): 1N5817. Package: DO-41 or axial 2.5mm. Sourcing: distributor lookup: 1N5817.
- Small Signal Diode (D3 - Main Board): 1N4148. Package: DO-35 or axial 2.5mm. Sourcing: distributor lookup: 1N4148.
- Schottky Diodes (D7-D12 - Solar Board): 1A/23V/620mV. Specified as BAT20J or equivalent. Package: SOD-323. Sourcing: distributor lookup: BAT20J.
- Resettable Fuse (F1 - Main Board): RHEF100-2 (1A, 30V PTC). Sourcing: distributor lookup: RHEF100-2.
- Resettable Fuse (F1 - Battery Board): PTC (specified generally as resettable fuse). Sourcing: distributor lookup (representative example): MF-R010.
3. Passive Components
- Resistors (Main Board):
- 1 kΩ (R1, R3, R7, R30). Axial 0.1 inch.
- 100 Ω (R8, R19). Axial 0.1 inch.
- 220 Ω (R9, R20, R29). Axial 0.1 inch.
- 68 Ω (R13, R15). Axial 0.1 inch.
- 180 Ω (R14). Axial 0.1 inch.
- 4.7 kΩ (R23, R24). Axial 0.1 inch.
- 10 kΩ (R27). Axial 0.1 inch.
- Resistors (Battery/Solar Boards):
- 10 kΩ (R2, R3 - Battery). 0603 SMD.
- 0.1 Ω Shunt (R1, R2, R5, R6, R9, R10 - Solar). 0805 SMD. Must be 1% or better for measurement accuracy.
- 4.7 kΩ (R3, R4 - Solar). Axial 0.1 inch.
- Capacitors:
- 18 pF (C1, C3 - Main). 0603 SMD.
- 16 pF (C2, C4 - Main). 0603 SMD.
- 100 nF (C6, C9 - Main; C2-C7 - Solar). 0603 SMD or PTH Small.
- 47 µF (C5 - Main). PTH Small Electrolytic/Tantalum.
- Inductors/Ferrites (L1, L2 - Main Board): 13 nH. Specified as 120-ohm chip ferrites (L0603). Used for RF filtering. Sourcing: distributor lookup: 303030001 (Seeed/Generic).
4. Connectors and Electromechanical
- Stacking Header (J1 - All Boards): 20x2 (40-pin) female stacking header. 0.1 inch pitch. Sourcing: retail shopping search: 2x20 stacking header Raspberry Pi.
- Antenna (E1, E2 - Main Board): Linx ANT-916-CHP-T (916 MHz chip antenna). Sourcing: distributor lookup: ANT-916-CHP-T.
- RF Connectors (X2, X3 - Main Board): SMA Vertical Female PTH. Sourcing: retail shopping search: SMA-VERT female PCB mount.
- Audio Jacks (J13, J14 - Main Board): SJ1-2503A (3.5mm stereo jack). Sourcing: distributor lookup: SJ1-2503A.
- USB Connector (J8 - Main Board): Sparkfun USB-C Breakout (Header for module). Sourcing: retail shopping search: Sparkfun USB-C Breakout.
- Power/Solar Connectors (J6, J7 - Main; JP1-JP26 - Solar/Battery): Micro JST (2-pin, 0.1 inch pitch, vertical PTH). Sourcing: retail shopping search: JST-PH 2-pin vertical connector.
- Battery Holders (BT1, BT2 - Battery Board): Keystone 1024 (Single AA) and Keystone 1012 (Dual AA) battery clips/holders for NiMH cells. Sourcing: distributor lookup: Keystone 1024, Keystone 1012.
- Switch (S1 - Main Board): RA-SPST (Right-angle Single Pole Single Throw). Sourcing: retail shopping search: right-angle SPST slide switch.
- Status LEDs (LED1-LED5 - Main Board): 5mm T1-3/4 (White, Yellow, Green, Blue, Red). Standard 20mA. Sourcing: retail shopping search: 5mm LED kit.
Software and Network Dependencies
The system functions as a satellite simulator and telemetry ground station.
- Software Components:
- Main Application: CubeSatSim software suite. Stated in documentation (GitHub
alanbjohnston/CubeSatSim). - Operating System: Raspberry Pi OS (formerly Raspbian). Version not stated; typically uses Lite versions for the Pi Zero.
- Firmware: Raspberry Pi Pico C/C++ SDK or MicroPython.
- Main Application: CubeSatSim software suite. Stated in documentation (GitHub
- Manifest Location: Not stated in the hardware-focused sources provided.
- Network Exposure:
- Interface: The Raspberry Pi Zero (if used) typically connects via Wi-Fi or USB Gadget mode (Ethernet over USB).
- Services: The simulator typically listens on SSH (port 22) for configuration. Documentation instructs students to enable SSH. Default credentials (pi/raspberry) may exist if standard Raspberry Pi OS images are used.
- Check Plan:
- Vulnerability lookup: Raspberry Pi OS / Debian / Version not stated.
- Support-status lookup: Raspberry Pi Pico SDK / Not checkable (vendor firmware).
- Vulnerability lookup: CubeSatSim application / GitHub / master branch (unpinned).
Fabrication and URLs
- Board Dimensions: Not explicitly stated, but designed to fit the CubeSat standard form factor (approx. 10cm x 10cm).
- Layer Count: 2 layers (standard).
- Primary Source:
https://cubesatsim.org - Design Files:
https://github.com/alanbjohnston/CubeSatSim/tree/master/hardware/v2.1(Retrieved 2026-07-19). - RF Filter Design: Reference design by Randy Standke, KQ6RS. Uses a specific LPF (Low Pass Filter) for UHF.
- External References:
- Audio signal generation PWM tutorial:
https://www.hackster.io/news/learn-how-to-use-pwm-to-generate-an-audio-signal-from-your-raspberry-pi-pico-00347dece8b8 - RF Attenuator calculator:
https://chemandy.com/calculators/matching-pi-attenuator-calculator.htm - Current Sensor Library:
https://github.com/adafruit/Adafruit-INA219-Current-Sensor-PCB
- Audio signal generation PWM tutorial: