Tom Clark, W3IWI DC AMSAT Group April 1 st , 2001

1. Clark's Scaling Laws: A.C.V.O.W.I.T.T. Build a Satellite in Your Basementa.k.a. AMSAT and SmallerCheaperFasterBetter Tom Clark, W3IWI DC AMSAT Group April 1st, 2001

2. A.C.V.O.W.I.T.T. . . . . .ACurmudgeon’s View of what it takes to Build a Satellite in your Basementa.k.a. AMSAT and SmallerCheaperFasterBetter____________ • Curmudgeon: • “… crusty, ill-tempered, or difficult and often elderly person…” [Webster’s 3rd Int’l Dictionary] • “COF” • “geezer”

3. My views are based on 25+ years of observing the “AMSAT Process”______________ • AO-8 • “ORBIT” Software • PSK Modem • AO-7 • P3A • AO-10 • AO-13 • SAREX Packet Hardware (Robot”) • The Microsats: -16, -17, -18, -19, -26, -30 • AO-40 • AMSAT’s BoD, ExVP & President

4. Some Caveats and Disclaimers …( Truth in Advertising ) • My comments are based solely on my own ideas. They do not represent any official opinion of AMSAT-NA, its Officers or its Board of Directors. • Although I work for NASA, the concepts I will discuss are definitely not NASA policy. • Some of these ideas may disturb you and you may disbelieve. That’s Fine! • Please feel free to try to disprove some of my more pessimistic views. I’d be happy to be proven wrong.

5. AMSAT is Two (Several?) Different Organizations • A membership organization composed of ~6000 users and supporters in USA and Canada (AMSAT-NA) • A group of a few hundred tekkies that build satellites • A similar similar distribution of like-minded folks elsewhere in the world (AMSAT-DL, AMSAT-UK etcetera) • Some folks who get their jollies from running organizations (“I gave up amateur radio to take up amateur bookkeeping!) I’m mainly a tekkie, so my comments are biased!

6. How many times have you heard: Dear Mr. AMSAT: For your next satellite, you guys should ,,, - or - Hey AMSAT: You Guys are Idiots to use a French Rocket ... - or - Hey AMSAT: Here are some new laws of physics (or communi-cation link budgets, or …) you need to use ...

7. AMSAT is US and not “You Guys” Dear Mr. AMSAT: For your next satellite, you guys should ,,, • Every AMSAT project (at least that I can remember) happened because of a few factors: • A few members decided that something needed to be done, • They made sure that the mission was practical and technically feasible, • They identified the critical resources that would be needed: • Launch • Community Support • Funding • Then they came to AMSAT (meaning the members, the Board and the Officers) for support.

8. There’s No Such Thing as a Free Launch ! • Of all these factors, two have proven to be the most critical: • Technical Feasibility of the Concept • - and - • Availability of a suitable launch. • In the “early” days, NASA was a dependable source for LEO launches. • Recently, Arianne has had more available space, both to LEO and GTO. • More people (Commercial Users, Educators & Government) now want “niche” launches. • Launches have become a commercial commodity.

9. A Big Surprise: • Only ~10% of the content of an Amateur Satellite is what people would call “Amateur Radio” ! • So what’s the other 90% ? • Mechanical, Thermal, Power, Computers, etc. • AstroGeoOrnithology (Political Birdwatching): • Launch vehicle interfaces (The cost of doing no harm) • Export permits (You mean my satellite is a munition?) • Fund Raising (OSIF: everything costs more than you planned) • Frequency Coordination (i.e. learning international politics) • Publicity (i.e. answering stupid questions kindly) • Soothing over bent egos(i.e. conflicts between prima donnas) • Worrying about all the things you probably forgot. • Etcetera (including imminent divorce) . . . . .

10. Scaling Laws (1)Complexity: Experience has shown that Complexity (= C) increases as the number of subsystems N like C = [ N  a ] + [ N  (N-1)/2  b ] - or - C = [A  N] + [B  N2]

11. Scaling Laws (2)Time: Experience has also shown that increasing the Complexity C increases the length of time T that it takes to do a project. T = K1 • C [ where my experience says  1 ]  T = K1•[A  N + B  N2]

12. Scaling Laws (3)Cost: The cost of a project $ increases with both Complexity and Time: $ = K2 • C • T but we already saw that C = A  N + B  N2 and T = K1•[A  N + B  N2] with  &  both  1  $ = K1K2  [AN + BN2]•[A  N + B  N2]

13. Scaling Laws (4)Cost -- The law of “Feature Creep” ( It’s VooDoo Math Time! ): $ = K1K2  [AN + BN2]•[A  N + B  N2] Assume for simplicity that ,  and  all  1  CO$Tscales as[AN + BN2]• [A  N + B  N2] with terms proportional to N, N2 , N3 and N 4 Or, in short, complexity, duration and cost all grow astronomically as more and more systems are added! Don’t try to fly the kitchen sink. The “optimum “N” may very well be  1

14. AMSAT’s Secret of SmallerCheaperFasterBetter All these factors optimize for a small number N of systems. Prudence Dictates the KISS Principle -- KEEP IT SIMPLE, STUPID And (IMHO) NASA still doesn’t understand why their satellites cost so much ! They never have paid heed to AMSAT’s experiences!

15. Some Other Topics Too Mentionable to be Numerous ( at least not today ): • AMSAT’s experience and philosophy on reliability • How do we encourage volunteers? • How do we keep it fun? • What should AMSAT do next? • Who are the next generation of leaders? • Where are the launches coming from? • AMSAT’s relations with the educational community (both K-12 and universities). • Whither Amateur Radio? • ... 73 de Tom Clark W3IWI