ABSTRACT: Publicly funded space missions are a means for states to advance technological development and acquire or maintain strategic knowledge while providing telecommunications services, earth observation, exploration, and investigation of the fundamental laws of the universe. The Laser Interferometer Space Antenna (LISA) is the European Space Agency’s large-class science mission of the next decade and sees a substantial contribution from the Italian Space Agency. This talk will introduce the key aspects of LISA and use it as an example to explain the organization and development process of these complex international projects (including why they take so long). BIO: Carlo Zanoni is a Mechanical Engineer and an expert in leading the development of new systems for world-class science infrastructures. He is now at the National Institute of Nuclear Physics (INFN) where he oversees systems engineering activities on part of the European Space Agency’s LISA mission. He previously worked at the European Southern Observatory (ESO) in Germany, monitoring industrial contracts for the Extremely Large Telescope, and was a Graduate Engineer at the European Organization for Nuclear Research (CERN), in Switzerland and France, where he guided the construction of new superconducting systems for the upgrade of the Large Hadron Collider. He has also worked at Stanford University, Airbus Space, and the University of Trento.

1. Building large science projects in space
Carlo Zanoni
27.02.2023

2. Science and exploration projects

3. ESA’s Science Missions

4. Laser Interferometer Space Antenna
• ESA’s L-class mission
• Launch: 2035
• First observatory of gravitational waves in space
LISA

5. Gravitational Waves
GW are variations of the
intensity of gravity.
GW detection via
measurement of the
distance change between
free-falling bodies.
∆𝑑
𝑑
~10!"#
Credit: LIGO/T. Pyle

6. Gravitational Waves
GW are variations of the
intensity of gravity.
GW detection via
measurement of the
distance change between
free-falling bodies.
∆𝑑
𝑑
~10!"#
Credit: LIGO/T. Pyle
Free falling bodies

7. Gravitational Waves: [Hz - kHz]
Need to isolate the free-falling bodies («test
masses») from external disturbances.
LIGO and VIRGO
[10 Hz – 10 kHz]

8. LIGO and VIRGO in low frequencies?
Gravitational Waves: [mHz - Hz]

9. Measurement in space
1 2
Need to isolate the freefalling bodies - «test masses» - from
external disturbances.
Space provides perfect insulation from ground sources.

10. Measurement in space
1 2
solar pressure
micrometeoroids
thermal gradients
Need to isolate the freefalling bodies - «test masses» - from
external disturbances.
Space provides perfect insulation from ground sources, BUT…

11. Measurement in space
2
solar pressure
micrometeoroids
thermal gradients
1

12. Measurement in space
2
solar pressure
micrometeoroids
thermal gradients
1
The spacecraft (S/C) introduces other
disturbances:
1. Gravity
2. Magnetic fields
3. Electrical fields
4. ….
Observing gravitational waves in space is
feasible, but not easy.

13. Measurement in space
2
solar pressure
micrometeoroids
thermal gradients
1
∆𝑑
𝑑
~10!"# Satellites distance:
2.5 million km
∆𝑑 = ~ 𝑓𝑚
(10!"#
𝑚)
The spacecraft (S/C) introduces other
disturbances:
1. Gravity
2. Magnetic fields
3. Electrical fields
4. ….
Observing gravitational waves in space is
feasible, but not easy.

14. Laser Interferometer Space Antenna
Test Mass

15. Laser Interferometer Space Antenna

16. Laser Interferometer Space Antenna

17. Performance needs
𝑅𝑀𝑆 = -
$!
$"
𝑃𝑆𝐷 𝑓 𝑑𝑓
1. Interferometer noise
2. Acceleration noise

18. How do we know it will work?
In 2015, ESA launched a space mission LISA-Pathfinder, hosting a
shortened LISA arm.
2.5M km → 35 cm

19. LISA Space Segment
MOSA: Moving Optical Sub-Assembly

20. LISA Space Segment: MOSA
MOSA: Moving Optical Sub-Assembly
• Telescope
• Optical Bench
• Gravitational Reference Sensor The GRS is the main responsible for the
acceleration noise mitigation

21. LISA Space Segment: GRS
LPF GRS
(credit: Airbus)

22. The long path to launch
0 Feasibility internal study
A Concept
B Preliminary Design
C Final Design and Fabrication
D
Assembly, integration and
test, and Launch
E Operations
F Close out
Concept of
Operations
System
Requirements
Sub-system
Requirements +
High Level Design
Component
Design
Implementation,
Fabrication
Component
Verification
Sub-system
Verification
System
Verification
System
Validation

23. The role of industry
0 Feasibility internal study
A Concept
B Preliminary Design
C
Final Design and
Fabrication
D
Assembly, integration
and test, and Launch
E Operations
F Close out
Agencies + institutes
Competitive
industrial studies
Single prime
contractor (s/c) +
single providers
(payload)
Scientists
no requirements
iterative
definition of
requirements
requirements
are "frozen"

24. The role of paperwork
Weight of documents
>>
Weight of S/C

25. From performance to EH tolerances
1. Total acceleration noise
2. Acceleration noise budget for actuation
3. No actuation along sensitive axis (x)
4. But spurious noise due to cross-coupling
from other axes
• Sources: voltage and thrusters' noise
5. Geometrical deviations determine ~ 50% of
cross coupling (torque to force)
6. Fabrication and assembly tolerances of the
electrodes
Example

26. High reliability
desired
More design, more
testing, more
redundancy
High costs
The reliability-to-cost trap
LAUNCH COST
Cannot fix things in
space!
Public money

27. An example

28. Gravitational Reference Sensor?
Credit: NASA/JPL-Caltech/University of California, Irvine

29. Objectives:
§ Create growth
§ Develop strategic technologies
§ Keep in Europe key personnel and
know-how
How is Europe doing?
Criticalities:
§ Cumbersome and inefficient
development
§ Europe is lacking key technologies
and losing access to space in 6
months

30. Carlo Zanoni
carlo.zanoni@unitn.it
carlo.zanoni@infn.it
https://www.linkedin.com/in/carlo-zanoni/
INFN-TIFPA (Trento)
Questions?
END