Myth #1: Nanosatellites ReliabilityMyth: Nanosatellites are not reliable, Their success rateis less than 50%Fact: Success rate of Nanosatellite projects for the lastfive years are stable and are about 80%• Nanosatellite Industry is complex and incorporates industrial, research and academic institues• Discussing “Nanosatellite Reliability” without taking into account who manufactured the satellites is like discussing “automobile reliability” while comparing BMW to TATA
Are COTS Reliable enough ? • הגרף הבא מציג סטטיסטיקה(*) של נאנולווינים CubeSat מבוססי• source: Wikipedia Cubesat page
Myth #2: Components ReliabilityMyth: Components are not reliable, They are the cause forfailuresFact: Components are very reliable, the problem isworkmanship• Two thirds of the projects are done by amateurs with no experience in space standards AIT• Technical analysis presented at 2011 small sat conference showed most failures are related to workmanship• Components are getting better all the time – This is a competitive market with several leading manufacturers pushing for constant quality improvement of products
Most satellites are being built by amateurs•Attack of the CubeSats: A Statistical Look: Michael Swartwout – Saint Louis University
Subsystems Failure analysis• Keeping space industry standards during AIT prevent failures Source: SPACECIALIST research
Myth #3: Nanosatellites don’t last long in spaceMyth: Nanosatellites that reach space last for severalmonths and than dieFact: There are nanosatellites that launched almost adecade ago and are still operational• Manny of current components are RAD tolerant up to 20 Krad• Computers are Latchup and SEU protected• The low cost allow redundancy – Several items in a satellite – Several satellites (mission redundancy)
Mission Lifetime for Nanosatellites• Satellites active since 2003 – Cute-1 – CubeSat XI-IV – RS-22• Satellites active since 2005 – Cubesat XI-V• Satellites active since 2006 – GeneSat-1• Satellites active since 2008 – Cute-1.7 + APD II – Delfi-C3 – SEEDS II• Satellites active since 2009 – PRISM – SwissCube – BEESAT – ITUpSAT1• Average mission lifetime = 40 months source of data: Cubesat page at the AMSAT web page
Summary• About 65% of nanosatellites projects are being built by amateurs “responsible” for most of the failures – “Flagships” launching more than one satellites have a success rate of 52 out of 59• Workmanship is the main cause for failures – Communication system failures are often due to bad wiring and not transmitter or receiver failures – Power system failures mostly occur due to connection loss between solar panels and batteries• Quality of subsystem is constantly improving – Number of manufacturers is rising, especially in Europe – Economical constraints derived meticulous QA – Competitiveness in the market manifests in the form of better quality products• Size doesn’t matter – Use of proven methodologies especially during AIT is a MUST
Sources of Information• 25 Years of Small Satellites – Siegfried Janson – The Aerospace Corporation• Attack of the CubeSats: A Statistical Look – Michael Swartwout – Saint Louis University• Recent CubeSat Launch Experiences on U.S. Launch Vehicles – Jordi Puig-Suari, Roland Coelho – California Polytechnic State University; Scott Williams, Victor Aguero, Kyle Leveque, Bryan Klofas – SRI International• Distant Horizons: Smallsat Evolution in the Mid-to-Far Term – Matt Bille, Paul Kolodziejski, Tom Hunsaker – Booz Allen Hamilton• Nine Years and Counting – A Nanosatellite Designers Perspective – Andrew E. Kalman , President & CTO, Pumpkin, Inc. Director, SSDL, Stanford University• Propulsion Solutions for CubeSats – W. Dan Williams, Busek Co. Inc• Beyond CubeSats: Operational, Responsive, Nanosatellite Missions – Jeroen Rotteveel, ISIS- Innovative Solutions in Space11
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