1. Cassini-Huygens -
Organizing and Running a
Multifaceted Mission
Greg Fletcher
(210) 522-6269, gfletcher@swri.org
Program Manager, Southwest Research Institute
Used with Permission

2. Outline
• Deep Space Missions
• Cassini-Huygens Mission Background
• Spacecraft Overview
• Project Organization
• Science Payload
• INMS (Ion and Neutral Mass Spectrometer)
• Staffing Plan Management
• Distributed Operations Concept
• Process Driven
• Schedule Driven
• Decision Making
• Secrets to Cassini’s Success
Southwest Research Institute – Chemistry & Chemical Engineering Division

3. What are Deep Space Missions
All About?
If you’re a scientist:
It’s all about
the science!
Southwest Research Institute – Chemistry & Chemical Engineering Division

4. What are Deep Space Mission
About for Program Managers?
It’s all about managing the scientists
and Engineers
and Software Designers
and Budget
and Schedule
If you don’t do it well, it will get
away from you…
Southwest Research Institute – Chemistry & Chemical Engineering Division

5. Cassini-Huygens Mission
Background

6. Cassini-Huygens Mission
Background
• Cassini-Huygens is a joint
NASA/ESA/ASI robotic spacecraft
currently in orbit around Saturn
• Goal is to explore the Saturn
system, with its many moons, and
rings
• Launched on October 15, 1997
• Reached Saturn orbit July 1, 2004
• Huygens Probe landed on the
surface of Titan January 14, 2005
• Cassini Orbiter continues to
collect data studying Saturn, the
Rings, Titan, Saturn’s many other
moons, and Saturn’s
magnetosphere
• Hundreds of scientists and
engineers from the United States
and 16 European countriesChemical Engineering Division
Southwest Research Institute – Chemistry &

7. Cassini-Huygens Spacecraft
Overview

8. Cassini-Huygens Spacecraft
Overview
• Cassini spacecraft, including the
Huygens Probe, is the largest, most
complex interplanetary spacecraft NASA
has flown to date
• Approximately the length of a school bus
from the tip of the main antenna to the
main engines
• Launch mass of approximately 5,600 kg
(12,000 lb), including 3,132 kg (6,900 lb)
of propellants
• Height of 6.8 m (22 ft)
• Main antenna width of 4 meters (13 ft),
though RPWS and MAG stick out the
sides by as much as 9 meters (29 ft
• Over 1,630 interconnected electrical
components
• 22,000 wire connections
• Over 14 km (8.7 mi) of cablesEngineering Division
Southwest Research Institute – Chemistry & Chemical

10. Southwest Research Institute – Chemistry & Chemical Engineering Division

11. Project Organization

12. Indicates where
the 12 instrument
PIs/TLs report to
the project
Indicates where
the 12 instrument
teams fit into the
science and uplink
organization
Southwest Research Institute – Chemistry & Chemical Engineering Division

13. Cassini Instrumentation
• 12 instrument teams each based in a different location
CAPS – Southwest Research Institute (SwRI), San Antonio, Tx
CDA – Max Planck Institute for Nuclear Physics, Heidelberg, Germany
CIRS – GSFC, Greenbelt, Md
INMS – Southwest Research Institute (SwRI), San Antonio, Tx
ISS – Space Science Institute, Boulder, Co
MAG – Imperial College, London, UK
MIMI – Applied Physics Labs, Columbia, Md
RADAR – Jet Propulsion Laboratory, Pasadena, Ca
RPWS – University of Iowa, Iowa City, Io
RSS - Jet Propulsion Laboratory, Pasadena, Ca
UVIS – University of Colorado, Boulder, Co
VIMS - Lunar and Planetary Labs, U of Arizona
Southwest Research Institute – Chemistry & Chemical Engineering Division

14. INMS (Ion and Neutral Mass
Spectrometer)

15. INMS (Ion and Neutral Mass
Spectrometer)
• Measures neutral and ion species from 1 to 100 AMU (m/q)
• Designed to measure Titan’s atmosphere, but can measure
any particles that are present in high enough concentrations
Example of INMS data (spectra) Example of INMS data (spectra)
with basic processing applied Engineering Division
Southwest Research Institute – Chemistry & Chemical
with labels showing what is
represented in each signal group.

16. INMS Organization By Task
• INMS team is broken into smaller teams by area of
responsibility
• Some members of the team are in more than one group
• Only one person on the team is dedicated full time to Cassini
Southwest Research Institute – Chemistry & Chemical Engineering Division

17. INMS Organization By Task
• ScienceTeam
− Responsible for deciding what types of observations
INMS should make for each target, like Titan, Enceladus,
the Rings, and Saturn’s magnetosphere
− Analyzing data and publishing results
Southwest Research Institute – Chemistry & Chemical Engineering Division

18. INMS Organization By Task
• OperationsTeam
− Creating command files based on the science plan
− Monitoring health and safety, including long term trends
− Data production
− Data archival
Southwest Research Institute – Chemistry & Chemical Engineering Division

19. INMS Organization By Task
• Development Team
− Design and develop INMS ground system (ION)
− Design and develop Flight Software
− Develop analysis toolkit for data processing and analysis
Southwest Research Institute – Chemistry & Chemical Engineering Division

21. Tethys Epimetheus Enceladus
Hyperion

22. Staffing Plan Management (1 of
2)
• Long duration deep space missions like Cassini present
unique staffing challenges
• New people working on Cassini today were newborns when
the Cassini program office was formed at JPL in 1988
− Key people retire or are promoted into management roles
• On missions like Cassini, key staff members such as
operations team members can take up to two years to fully train
• Post Doctoral staff members with the right experience can
take years to find
− In some cases, we take on students as undergraduates,
and keep them on through their Post-Doc and beyond
Southwest Research Institute – Chemistry & Chemical Engineering Division

23. Staffing Plan Management (2 of
2)
Good News:
• Having only one full time staff member on INMS allows
flexibility
− Allows for more people to be cross trained to avoid single
point failures
− Scheduling vacations and travel for key people is easier
Bad News:
• Having very few full time employees means that nearly
everyone works on other programs
− Risk of not having resources available exactly when they
are needed due to high priority events on other programs
• As a manager you have to decide how to best
staff your program
Southwest Research Institute – Chemistry & Chemical Engineering Division

24. Distributed Operations

25. Distributed Operations
• Distributed operations means the 12 instrument teams are
based in different locations around the world (CDA is in
Heidelberg, Germany, MAG is in London, UK)
• Science and operations for each instrument are run from the
remote sites
• JPL plays the following roles:
− Program Office (Cassini PM and Project Scientist)
− Spacecraft Operations (SCO) team
− Coordination function for science planning
− Merging, processing and loading instrument and
spacecraft commanding
Southwest Research Institute – Chemistry & Chemical Engineering Division

26. Distributed Operations (cont)
How do scientists, engineers and managers from so many
institutions communicate?
Telecons
Telecons
and more Telecons…
Southwest Research Institute – Chemistry & Chemical Engineering Division

27. Distributed Operations (cont)
• Instrument teams’ co-investigators are also distributed at
different sites
• INMS has science team members at:
- University of California Berkeley
- University of Kansas
- Johns Hopkins Applied Physics Labs
- Goddard Space Flight Center
- University of Maryland
- University of Arizona Lunar and Planetary Labs
- Imperial College, London, UK (Affiliate)
- Central University, Taiwan
Southwest Research Institute – Chemistry & Chemical Engineering Division

28. Distributed Operations (cont)
• Additional communication needs to be facilitated to coordinate
the INMS team internally
− Weekly Telecons
− Team meetings two to three times per year
− Phone calls to team members as necessary
Southwest Research Institute – Chemistry & Chemical Engineering Division

31. Disadvantages of Distributed
Teams
• Makes communication across the program complicated
− Scheduling meetings across 18 times zones means that
some of the teams have to participate at off hours
• During the initial planning of the science timelines there were
as many as 28 hours of telecons per week
− Smaller teams often only had one or two people covering
all the these meetings, which doesn’t leave much time for
getting other work done
− Leads to consistently working long days for an extended
period
Southwest Research Institute – Chemistry & Chemical Engineering Division

32. Disadvantages of Distributed
Teams (cont.)
• High volume of email to keep up with negotiations regarding
details of the plan
• Negotiations between 12 teams is difficult enough in person,
let alone by phone and email
Southwest Research Institute – Chemistry & Chemical Engineering Division

33. Advantages of Distributed
Teams
• Allows experts from around the world to participate in the
program as instrument PIs
− PIs are then in turn supported by a science team who are
experts in relevant fields
• Encourages young people to get involved in space science
by providing funding to Universities and Institutes for graduate
students
Southwest Research Institute – Chemistry & Chemical Engineering Division

34. Process and Schedule

35. Process Driven
• Well documented processes reduce risk by preventing
mistakes
− No margin for error in spaceflight
− Mistakes in flight can be catastrophic
• Cassini program has a formal process for delivery and merge
of all instrument and spacecraft subsystem commanding
• INMS Operations team has a checklist for every task we
perform
• Formal review process for INMS instrument commanding prior
to each delivery port
• Process for review of housekeeping data
• Process for responding to flight anomalies
• Process for upload of ‘realtime’ commands
Southwest Research Institute – Chemistry & Chemical Engineering Division

36. Schedule Driven
• Most spaceflight missions are schedule driven by hard
deadlines
− Launch date has a hard window due to trajectory based
on planetary alignments
− Command deliveries have hard deadlines based on
observation events
• If an instrument misses a delivery deadline, they are pulled
from that sequence (and lose about 40 days of observations)
− On Cassini, no instrument or subsystem has ever
missed a delivery deadline
Southwest Research Institute – Chemistry & Chemical Engineering Division

37. Decision Making

38. Decision Making
• After the Cassini Spacecraft was designed and the instrument
teams were selected, Congress decided the mission was going
to cost to much
• Decision was made to remove instrument scan platforms and
re-design the spacecraft to hard mount science payloads
• Saved money up front in spacecraft construction
• More than made up for savings in added operational
complexity
− Drives instrument negotiations for science observations
− Flight rule constraints are far more complicated
− Observation designs are more complicated (instrument
teams actually have to design the spacecraft pointing for
their observations)
Southwest Research Institute – Chemistry & Chemical Engineering Division

39. Decision Making
What is the lesson to be learned from this?
Every decision managers make, effects
everything that happens on the program
from that point on, so…
Good decision making skills are essential
to be a successful program manager
Southwest Research Institute – Chemistry & Chemical Engineering Division

40. Tough PM Decisions
• First efforts to create an integrated science plan started
slowly because the scientists assigned to the planning were
creating a timeline that was so complicated it could not be
implemented
− Program management recognized this within the first
two weeks and created guidelines to allow the science
plan to match the workforce available to implement the
timeline
Southwest Research Institute – Chemistry & Chemical Engineering Division

41. Tough PM Decisions
• Huygens team realized they had a problem with Doppler
shift in the transmitter that would cause loss of critical data
− Solution to this problem was complicated and there
were a number of decisions and actions taken to remedy
the problem
− Single largest action was the Cassini navigation team
modified the first two orbits around Saturn, changing the
trajectory for the probe mission without effecting the orbits
after Rev 3
Southwest Research Institute – Chemistry & Chemical Engineering Division

42. Management Challenges
• Facilitating communication among your team, and to other
teams as appropriate
• Spaceflight programs can be very demanding, and teams
are often working against hard deadlines like launch dates or
events in orbit
− Working long hours is fairly routine, so managers need
to be careful not to burn out team members
− Plan the work to be complete well in advance, so there
is ample time to review and make corrections
• Scientists, engineers and software developers are all very
bright, creative, independent people and are typically
challenging to manage
• Delegate appropriately
− Spread the work load as evenly as possible
− Delegate authority with the responsibility
Southwest Research Institute – Chemistry & Chemical Engineering Division

43. Secrets to Cassini’s Success
• Effective communication!
• Tremendously talented and dedicated
scientists and engineers who are all vested
in the program’s success
• Cooperation and trust between teams
• Managers who know how to organize,
plan and follow through
Southwest Research Institute – Chemistry & Chemical Engineering Division

44. Backup Slides

45. Cassini Trajectory from Earth to
Saturn
Southwest Research Institute – Chemistry & Chemical Engineering Division