Investigation into Interstellar Flight
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Power Generation
Electrical Power Conversion
Power Storage
Power Systems for Interstellar Missions
1Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Photovoltaics
2Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
I
I
Solar Flux
IEarth=1358 W/m2
α≅1.5
3Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
4
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Mercury Venus Earth Mars Jupiter Saturn
Relative Power Generated
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Frfefefe12
5
Si amorph Si GaAs InP GaInP/GaAs
Theoretical efficiency
20.8% 12% 23.5% 22.8% 25.8%
Lab efficiency
20.8% 10% 21.8% 19.9% 25.7%
Survivability* 4 yr 4 yr 6 yr 89 yr 6 yr
* : time for 15% degradation, while in GSO (high radiation levels - 10 MeV electrons)
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Si processing refinement Thin-Film processing (flexible low cost cells) Metamorphic multijunction solar cells (NRAL, 40% efficiency) Conductive Organic Polymers Nanoparticle Processing (carbon nanotubes, quantum dots) IR Solar Cells (plastic sheets with nano-antennas) UV Solar Cells (permit optical wavelengths to pass) Antireflective, All-Angle coatings Metamaterials (absorb EM radiation)
6Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Tentative interest has been maintained in this technology.
7
Appropriate for station keeping and supplementary power systems, for atmosphericmining platforms (Icarus).
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
A fuel cell is an electrochemical conversion device.
8
Fuel Oxidant
Catalyst
Load
Reaction is reversible, which allows for regenerative cells.
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
9
Mining gas planets gives easy access to large, renewable quantities of Hydrogen.
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
RadioIsotope Thermoelectric Generators
10Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
RadioIsotope/Heat Sources
11
Isotope Half Life in years Thermal Radiationper gram
Radiation level (Curie/W)
Curium-242 0.45 100 27
Strontium-90 28 0.25 153
Plutonium-238 86 0.55 30
A glowing red hot pellet of plutonium-238 dioxide.
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
12
478436
398370
344 327
0
100
200
300
400
500
600
Date 0 3 8 13 18
Voyager II RTG Power Output
68% of initial power generation after 21 yearsDr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
13
Advantages Disadvantages
•Long Lifetime•Invulnerable to high radiation fields•Long Mission lifetimes•Mature technology•Lightweight and Compact•High KW/Kg ratio•No moving parts•No maintenance
•Cannot be turned off•Must be continuously cooled•Spacecraft components must be shielded from radiation•Instruments must be shielded from IR interference•Low efficiency ~5%•Radioisotopes are very expensive
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
14
Energy Source
Heat Receiver and
Storage
Thermodynamic Engine
Waste Heat Collector
Systems Heating
Heat Rejection to
Space
Electrical Alternator
Power/Frequency Regulator
Main Bus
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
15
The proposed ISS Solar Dynamic Power SystemDr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Stirling Brayton Rankin
16
A liquid-metal potassium power conversion system has been outlined for use in space vehicles for human exploration of outer planets, by Adams et al, NASA (2003)
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Thermoelectric Effect
17
Add power to cool the plate (Peltier effect)
Add heat to get a voltage(Seebeck effect)
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
18
Deep cycle discharging can recondition batteries
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Flywheels store KE and angular momentum.
19
NASA’s G2 Flywheel Module
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Supercapacitors and Ultracapacitors have capacities of 5-5000 Farad.
20
Maxwell Technologies new line of supercapacitors have up to 3 KF
capacity and exhibit thermal stability.
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
21
Availability | Applicability | Resourcefulness | Invention | Adaptation
Concerning Icarus
•A little bit of everything•You don’t have to take it all•Fuel cells are great backup systems•Flywheels keep what you would have wasted•Wireless transmitters within S/C?•Pulsed Fusion MicroexplosionEngine with Thermocouples have the least moving parts.
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
22Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Nominal Operation Science Data Reduction/Storage Navigation/Attitude Control Communications Fault Control/Repair
23Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Very Long Flight Times Open Mission Profile Advanced Decision Tree Unmanned\Unserviceable
24Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
No single point failure No single point repair Fault isolation/containment
25Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Artificial BiologicalSelf Repairing Survival Instinct
Autonomous Design Independence\Individuality
Vary Operational Goals Choices\Curiosity
Online\Offline Processing Conscious\Subconscious
Operational Overview of Subsystems\Probes Maternal Instinct
26Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Deep space processing only possible with rudimentary machine intelligence.
Fault Tolerance from System Integrity Uninterrupted Operation, even during rewrites\repairs Secure database of Mission profiles (constants\prime
objectives)
Double/Triple Modular Redundancy Rollback/Roll forward Conditioning
27
But how do these safety precautions affect the mission objectives?
Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Speed Memory Storage Redundancy Data Rate Failure Rate Power Usage
28Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Improve programming reliability by simplifying code Sacrifice speed for reliability when necessary (i.e. TCP) Software design for asynchronous processing
Continuous monitoring Performance evaluation Seamless decision making \ protocol rewrites
N-model redundancy M out of N model redundancy
Model architecture performance by statistical methods.
29Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Distributive processing Identical computer subsystems All subsystems are full processing nodes All subsystems are interconnected All interconnects and switchable On failure, dormant systems take over Each system is capable of error checking, auditing and
replacing each other
Simplicity above all
30Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
31Dr. Andreas C. Tziolas | Project Icarus Wednesday, September 30th, 2009 BIS Symposium | Daedalus: 30 Years Later
Top Related