AERO2705 Week 10CubesatsTuesday 10th OctoberThe University of Sydney
PresenterMr. Warwick HolmesExecutive Director Space Engineering
School of Aerospace, Mechanical and Mechatronic Engineering
https://sites.google.com/a/slu.edu/swartwout/home/cubesat-databaseSt. Louis University Cubesat database
Mission Status
St. Louis University Cubesat database
St. Louis University Cubesat databasehttps://sites.google.com/a/slu.edu/swartwout/home/cubesat-database
-- Update: 36 of 37 QB50 Cubesats have failed, solar flare missed!
Saint Louis University – Cubesat Database reports the following mission statistics up to Mon. 11th Sept 2017.https://sites.google.com/a/slu.edu/swartwout/home/cubesat-database#plots
Total Cubesat’s launched since Feb 2000 = 754
Cubesat Mission Success (5/5) (78/754) = 10%(Average life of Cubesat = 85days, NASA statistics)
Cubesat “Partial Success” (4/5) (316/754) = 42%
Commissioning only (3/5) (86/754) = 11%
Unreported status (failure) (2/5) (66/754) = 9%
Outright failure (1/5) (208/754) = 28%
Conclusions from St. Louis Database
• This St. Louis University Cubesat database is run by very strong proponents of Cubesats!
• The success status of each Cubesat is reported by the manufacturers only and is not verified.
• NO independent checks are made of the reported status and no independent verification.
• The success criteria is never defined, ratified or compared. On this basis the poor figure of 12% success is certainly a generous exaggeration!
Australian Cubesat’s in St. Louis Database
(1) UNSW-ECO (UNSW) is able to get to "science" mode but is unable to transmit any instrument data. Reported as (4/5)
(2) Inspire-2 (USYD) has remained in emergency "SAFE" mode since launch, cannot transmit science data from any of it's five instrument payloads. Reported as (4/5)
(3) SUSat1 (UniSA) has never transmitted any data since launch. Reported as (2/5)
(4) Biarra Point (UNSW) has never transmitted any data since launch. Reported as (1/5)
Summary:All 4 Australian cubesats have failed to deliver any payload data
Australian Cubesat’s in St. Louis Database
https://www.dst.defence.gov.au/news/2017/04/20/biarri-satellite-heads-space
Biarri Point – ADF Cubesat failure
http://www.acser.unsw.edu.au/biarri-gps-receiver-project
Inspire-2 launched on Atlas-5 18-April-2017 then deployed from the ISS by Nanoracks 26-May-2017.Inspire-2 has completed >2,000 orbits over three Aust. designated Earth stations, ANU, UNSW, UniSA.Ham radio enthusiasts in Europe have helped capture data from Australian Cubesats with 25m dish!Inspire-2 has been continuously in "SAFE" mode only transmitting 8 basic "House Keeping" TM data words.No data transmitted from any of the five instrument payloads, >100 Mbytes should have been received.
Payload problems for Inspire-2 and UNSW-ECO
http://sydney.edu.au/inspire-cubesat/payloads/index.shtml
Inspire-2 Instrument Payloads
Inspire-2 Instrument Payloads
All four Australian Cubesats have failed
INSPIRE - 2: No Instrument payload data, Beacon H/K data onlyUNSW_ECO: No Instrument payload data, Beacon H/K data onlyUni-SA QB50: No data of any kindUNSW Biarra Point: No data of any kind
http://sydney.edu.au/news/physics/1737.html?newsstoryid=16252
Professor Cairns said:"a project like this requires huge contributions from many people* including undergraduates and PHD students, plus many University and corporate staff members. We are also very grateful to Australia's Minister for Industry, Innovation and Science, the Honourable Greg Hunt, and his staff for awarding us an Overseas Launch Certificate. We are looking forward to INSPIRE-2's launch into space and to receiving its data."
* 20 team members listed
“The total cost of the INSPIRE-2 CubeSat was approximately $250k over a period of 10 months”
1000 x ≠
Cubesat: scales of economy
1000 x ≠
1000 x ≠
http://www.airspacemag.com/daily-planet/cubesats-are-great-even-if-they-die-you-180952745/?no-ist
CubeSat's have demonstrated very low reliability: small ≠ easy
Despite the long list of tests NASA has recommended for student-built satellites, basic failures appear to be common among Cubesat first-timers. Swartwout thinks it’s a combination of two factors:
(1) “Many universities jumping on the Cubesat bandwagon are bringing very little if any experience to the task, so there’s a steep learning curve.”
(2) “Sending a working spacecraft into orbit is harder than any newbie thinks it’s going to be, so students tend to run behind schedule and rush the critical tests that ensure their CubeSat's will work unattended in space. They do not test the elements working together as a system. Or skip the step testing the Cubesat running continuously for a week, powered only by a bright lamp to simulate sunlight, the way it would in orbit.”
http://www.airspacemag.com/daily-planet/cubesats-are-great-even-if-they-die-you-180952745/?no-ist
FLEET Space - Investor Analysishttp://www.fleet.space/
• 60 billion “devices” about to come online
• Provide “free” global Industrial IoT network
• 100’s of nano-satellites connecting billions of devices
• http://www.acser.unsw.edu.au/cubesat2017/proceedingsFleet presentation (day 2 session 3)
• 100 x 3U cubesats built by “Pumpkin” USA.http://www.pumpkinspace.com/about-us.html
• 20 orbital planes at 580 km altitude,
• No inter-satellite data links between cubesats.
• “low” data rate IP (store & foreword) IoT service
• Assume Rocket Labs launch?
FLEET Proposal ….. analysis:Would you invest $5mill? Is this a challenge for one-web?
Perform a FULL System engineering analysis. What is the best that FLEET could be offering based on purely technical facts and engineering reality only!
Examine the complete System: power, link, mass, data, RF, ground segment, launch, mission planning, budget.
Launch provider, orbits, cost, phasing, ground coverage, revisit rate, ground stations, terminals.
“Typical” Performance: Two-way data rate and capacity for how many customers simultaneously, how much latency
Max: 20 page report, 11 groups of 5 students, 12min presentation with 3mins question time
Spacecraft SubsystemsCommand and Data Handling SubsystemProcesses TC’s sent to TM sent from the S/C to/from the ground control system. Gathers S/C data (analogue & digital) TM and communicates with all the other spacecraft subsystems.
Avionics Subsystem & Flight Software SubsystemThe Avionics Subsystem is the “brains” controlling all electrical the hardware interfaces, effectively the PC of the S/C. Contains processors, flash memory, FPGAs, serial and parallel data-buses, mass memory storage, and communication interfaces.
Tracking, Telemetry, and Control Subsystem (Comms. Subsystem)Makes all comms. between spacecraft and ground. Includes antennas, TxRx-transponder, frame synchroniser all performing within constraints of the subsystem link budget (SNR) analysis.
Electrical Power Subsystem (Power Subsystem)Generates and delivers all power to spacecraft electrical units. Includes solar arrays, batteries, regulators and power distribution units within power budget (sunlight & eclipse).
Payload SubsystemThe Payload subsystem is why the mission exists! The Payload is often quite autonomous, in terms of avionics. Generally requires power and a comms interface to transmit mission data.
Thermal Subsystem (TCS)Maintaining the correct operating temperature of the spacecraft between predefined operational and non-operational temperature limits. Using passive and active heating and cooling systems to manage heat transfer.
Mechanical Subsystem and Harness SubsystemConsists of the fundamental structure supporting all units and stresses from static and dynamic mechanical loads. The harness subsystem is responsible for connecting all the different spacecraft components.
Propulsion Subsystem - Reaction Control System (RCS)Maintains S/C orbit, utilizing thrusters, propulsion fuels, valves, tanks, and heaters to ensure that the spacecraft is in the correct orbit and position. Including ability to perform ΔV manoeuvring and rendezvous operations.
Attitude Determination and Control Subsystem (ADCS)Implements control algorithms to determine and control the spacecraft attitude. Utilizing sensors and actuator hardware (GYR, GPS, star tracker, sun sensor with thrusters, reaction wheels) to maintain correct pointing.
Assembly Integration and Testing (AIT)All ground support, testing and launch equipment needed to test and operate the spacecraft. Responsible for all ground verification of the spacecraft functionality including full environmental test campaign. Responsible for all equipment for building, testing, moving, and launch of the spacecraft.
Spacecraft Subsystems
Spacecraft SubsystemsWhat are the requirements? What are the constraints?
Mission Constraints?• What is the mission’s prime objective:
Payload? Supported by service module (bus)• Mission resource constraints:
Money, time, staff, technology, facilities, political will, redundancies.
• Environmental constraints:Radiation, thermal, outgassing, shock, vibration, orbit, fov viewing.
• Launch vehicle constraints:Volume, vibration, acceleration, separation shock, thermal, deployment
• Payload constraints:Optical spatial & spectral resolution, power, data transfer, technology.RF beamwidth, antenna gain, antenna size, power, frequency, etc
• Risk constraints:Project commitment, funds, politics, technology, science, reliability
