1. EnerGY: SPACECRAFT ENGINEERING & SCIENCE
Kelly L. Perry
NASA Jet Propulsion Laboratory
University of Southern California

2. ENGINEERING ENERGY MISSION PHASES SPACECRAFT POWER INSTRUMENTATION
LAUNCH
CRUISE
TOUR
SPACECRAFT POWER
INSTRUMENTATION
SCIENCE

3. Cassini Spacecraft Cassini is 22 ft tall and 13 ft wide
Weighs more than 10,000 pounds
12 Science Instruments
Scientists and engineers from 17 different countries worked together to build Cassini
Launched in 1997 and began to orbit Saturn in July 2004
2 million mile journey
Spacecraft travels at speeds between 2-12 miles per second
Around the Rose Bowl Loop in 1-4 times per second

4. LAUNCH
Energy for launch was obtained by combustion of chemical propellants
Used Titan IVB/Centaur
2.2 million pounds at launch
2 solid-propellant stage-zero motors, a liquid propellant 2-stage core and a 16.7ft diameter payload fairing
Cassini required upgraded solid rocket boosters and a Centaur high-energy stage
Launched from Cape Canaveral on Oct 15, 1997
If Cassini were launched from the equator, would it have required more or less energy?

5. CRUISE Rocket was most powerful available, but it wasn’t good enough
GRAVITY ASSISTS were needed
Used since the 1970s
Increases Cassini’s sun-relative speed by using gravity during fly-bys
Require 3 bodies: spacecraft, assisting body and central body
Example: Cassini, Venus and the sun

6. TOUR Do Gravity Assists violate the Law of the Conservation of Energy?
Propellant used to change trajectory
Gravity Assists Continue: Cassini, Titan, Saturn
Titan is Saturn’s largest moon.
Larger than Mercury
Has an atmosphere (Nitrogen) that resembles Earth several billion years ago
Do Gravity Assists violate the Law of the Conservation of Energy?
What is the cost of the energy gained?

7. SPACECRAFT POWER Power is a negotiated resource on the spacecraft!!!
Cassini obtains its power from 3 Radioisotope Thermoelectric Generators (RTGs)
NOT NUCLEAR REACTORS
DO NOT USE FISSION OR FUSION
Provide power through the natural radioactive decay of plutonium
Pu-238 (non-weapons grade isotope)
Heat generated by decay is converted to electricity
Power is a negotiated resource on the spacecraft!!!

8. INSTRUMENTATION Optical Remote Sensing
Composite Infrared Spectrometer (CIRS)
Imaging Science Subsystem (ISS)
Ultraviolet Imaging Spectrograph (UVIS)
Visible and Infrared Mapping Spectrometer (VIMS)
Fields, Particles and Waves
Cassini Plasma Spectrometer (CAPS)
Cosmic Dust Analyzer (CDA)
Ion and Neutral Mass Spectrometer (INMS)
Magnetometer (MAG)
Magnetospheric Imagining Instrument (MIMI)
Radio and Plasma Wave Science (RPWS)
Microwave Remote Sensing
RADAR
Radio Science (RSS)

10. SCIENCE: PAC-MAN FEVER

11. SCIENCE: TITAN RADAR confirmed existence of large lakes & rivers
(images from saturn.jpl.nasa.gov)
Side-by-Side comparison of largest lake found on Titan (22 Feb 2007) and Lake Superior

12. Saturn’s Rings Overview
Main rings would span from the Earth to the Moon
The rings are only half of a mile thick
Composed of Ice, Rocks and Dirt
Particles the size of dust to mountains
The Rings are still growing
The E-Ring is fed by eruptions from Enceladus

13. SCIENCE: WAVES IN Rings

14. SCIENCE: WAKES IN RINGS

15. SCIENCE: Prometheus
Shepherding satellite, constraining the inner edge of the F-Ring
Irregular shape: 12.4 mi in diameter
Probably a porous ice body

16. SCIENCE: ENCELADUS
27 November 2005: Jets of Icy Particles burst from Enceladus

17. Searching for Life: Ocean Color
Green Flagellates: 440 and 665 nm
Diatoms: 440, nm
Dinoflagellates: 440, nm
Cyanobacteria: 440, 495, nm

18. Searching for Life Marine Mammal Care Center in San Pedro

19. Harmful Algal Blooms DOMOIC ACID Poisoning
aka Amnesiac Shellfish Poisoning
Toxin released by Pseudo-nitzschia
(Photos provided by Robin Riggs, 2005)

20. Harmful Algal Blooms
HARMFUL ALGAL BLOOM (HAB) occurs when toxic algae grow too quickly
Not all algae or algal blooms are toxic!
Non-Toxic Red Tide in New Zealand
(image from
Pseudo-nitzschia blooms are trickier!
They’re invisible!

21. HABs of SoCal

22. HABs of SoCal

23. CLIMATE SIGNAL
During El Nino events, sea level and SST in California are higher than normal.
Thermocline deepens
Northward flow brings low nutrient waters
Lower Phytoplankton due to less nutrients
Time for RADAR!!!

24. EL NINO DEMO TIME!!!