Colorado Space Grant Consortium

Gateway To SpaceASEN 1400 / ASTR 2500

Class #17

T-39

- Announcements

- One Minute Report Questions

- Guest Lecture on Systems Engineering

Today:

- Hardware for teams…

- Pressure sensors and other hardware UNO $$$

- Latest grades posted later today

- Feedback on DD Rev A/B next Tuesday

- DD Rev C assigned today and due 11-16-12

- Don’t forget about HW #8 – Review it first

Announcements:

- Traveling tomorrow – Planned

- Guest speaker is not coming – Not Planned

- So tomorrow is…

Announcements:

Colorado Space Grant Consortium

Next Time…Spider

Plus remote introduction

(Originally the lecture scheduled for November 15th)

- What kind of rocket is Dreamchaser?

- What is Dreamchaser used for?

- Where do dropped engines go? Orbit, outerspace?

- Biggest advance from past to present rockets?

- Do all space programs work together now?

- How do private companies get funded? 

One Minute Report Questions:

- Why do they chose solid vs. liquid, vs. hybrid? 

- As an aerospace major, how well versed should I be with coding/programming?

- What happened to the Orion space missions?

- What does the future of space exploration look like?

One Minute Report Questions:

8Colorado Space Grant Consortium

Questions?

9Colorado Space Grant Consortium

Homework #7 Review

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NASA Mission Announcement – ChuSat

Design a spacecraft in 30 minutes that will meet the following two requirements:

1. The total mass of the power, science instruments, and propulsion shall not exceed 900 lbm.a. The propulsion mass shall include the mass of

propellant

Homework #7:

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NASA Mission Announcement – ChuSat

Design a spacecraft in 30 minutes that will meet the following two requirements:

2. The spacecraft shall collect a minimum of 20 hours of scientific dataa. The spacecraft shall collect data in the 1x10-9

to 1x10-10 wavelengthsb. The spacecraft shall collect data in the 1x10-3

to 1x10-4 wavelengths

The following subsystem capabilities and specifications are at your disposal.

Homework #7:

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Homework #7:

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Homework #7:

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Homework #7:

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Homework #7 - (Answer)

Science- Infrared Sensor 75 W 30 lbm- X-ray Sensor 100 W 40 lbm

Total Science Mass 70 lbm

If only one sensor is on at a time is the requirement of 20 hours met?

Only have one sensor on at a time, therefore the Science power requirement is 100 W, not 175 W.

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Power

Need at least 1,000 W to stay alive plus 100 W for science therefore you need to have at least 1,200 W solar array and battery

Total weight = 60 lbm for solar array= 120 lbm for battery

Total = 180 lbm

You will find out the Fuel cell is way too heavy

Homework #7 - (Answer)

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In-Class Exercise: (Answer)

Propulsion

Need at least 80 lb of thrust therefore you need the following

Two 25 lb thrusters = 20 W 25 lbm Three 10 lb thrusters = 20 W 15 lbm

Total Power = (40+60 W) = 100 WTotal Mass = (25+25+15+15+15) =95 lbm

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In-Class Exercise: (Answer)

Total Mass

Science = 70 lbmPower = 180 lbmPropulsion = 95 lbmTotal = 345 lbm (minus propellant)

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In-Class Exercise: (Answer)

Propellant Mass

2x25 lb = 50 per/100 lbm = 100 lb3x10 lb = 20 per/100 lbm = 60 lbTotal = 160 lb per 100 lbm

345 lbm / 100 lbm * 160 lbm = 552 lbm

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In-Class Exercise: (Answer)

Total Mass

Science = 70 lbmPower = 180 lbmPropulsion = 95 lbmTotal = 345 lbm (minus propellant)

Propellant = 552 lbm

Total mass = 897 lbm

Colorado Space Grant Consortium

Systems EngineeringJessica BrownLockheed Martin

Rachel LandessLockheed Martin

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Introduction to Systems Engineering

Rachel LandessKeith MorrisJessica Brown

October 23, 2012

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What is Systems Engineering• Is a systematic, interdisciplinary approach

that transforms customer needs into a total system solution

• A framework of interrelated activities that spans Design, Management, and Realization of systems

• Balances customer needs with system capabilities

• Led and organized by Systems Engineers– But all functions play a role

• It is the technical “glue” which makes separate design disciplines and subsystems function together to provide an integrated system

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Be a “Systems Thinker”• The Design Engineer

– The specialist's viewpoint– Views the system from the inside– Concerned with other system elements

only as they affect their own design task– Not necessarily how their system may

affect others• Systems thinkers

– Views the system from the outside. – Concerned with the effect of all system

elements as they affect overall system design / performance / cost / schedule

– Concerned no matter where the hole in the boat is

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Systems Engineering must focus on the entire problem: optimize the whole, not the parts!

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The Art & Science of Systems Engineering

• Art of Systems Engineering– Technical Leadership– Understanding how all the individual

pieces go together to make the big picture

• Science of Systems Engineering– Systems Management– Managing all the details for every

piece of the system and keeping them in synch• Cost, Schedule, Performance, &

RiskTo be Successful, we must balance both technical leadership and systems management into complete systems engineering

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Systems Engineering “V” Model

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Architecture• System Architecture is the overall structure of the program, internal

interfaces, and how it interacts with external interfaces– System Level – Constellation of Satellites, Ground stations, etc.– Spacecraft Level – Subsystems and interfaces that make up

spacecraft– Subsystem – Components and technologies that make up subsystem

– Architect’s role is to ensure customer requirements and needs are properly addressed in the system• Identifies utility and flexibility of the system• Optimizing architecture can make spacecraft trades easier

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Spacecraft Architecture

(image credit: NASA/GSFC)

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Concept of Operations• Concept of Operations (CONOPS)

– How the system will be used– Links technical requirements with user’s needs

• Requirements do not fully represent customer’s wishes…– Operational scenarios, timelines, block diagrams, orbital

maneuvering among the products– Example: Assignment Requirements do not specify how often

payloads need to operate, could reduce overall power required

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Con Ops Example – ALL-STAR

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3.0 Mission shall consist of...

3.1 System shall interface to...

3.2 System shall interface to...

3.3 System shall provide...

3.1.1 Subsystem shall provide...

3.1.1.1 Component shall consist of...

Level 0(Mission)

Level 1(System)

Level 2(Subsystem)

Level 3(component

Requirements Management• A requirement is a “single, verifiable

shall statement”• Requirements dictate the form, fit

and function the system design shall meet

• Requirements address both characteristics as well as capabilities– Characteristics=what the system

shall be– Capabilities=what the system

shall do• Higher level requirements are

decomposed to lower level requirements

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Why are requirements important

Clearly communicating requirements is essential

How the customer explained it

How the project manager understood it

How the engineers designed it

How materials ordered it

How it was built How the customer really wanted it

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Design Integration• Balance the needs of the customer with the

capabilities of the spacecraft• Balance the needs of the individual subsystems

– Allocate mass, volume, power constraints– Relate it to their assignment

• Ensuring subsystems are talking with one another– Making sure they are compatible

• Identifying subsystem interfaces

Its kind of like Herding Cats

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Risk Management• Risk management is done throughout the entire

program life cycle• Risk is defined in two dimensions

– Probability of occurrence– Consequence if the risk occurs

• Identify risks while there is still time to react• Put in place mitigation strategy to minimize or

eliminate risks• Sources of risks include:

– Poorly defined technical tasks or cost estimations

– Poorly defined requirements and interfaces– Low technological maturity (technical risks)– Unrealistic project planning or inadequate

resources– Inadequate workforce skill level

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4

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1 2 3 4 5Consequence

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Risk Matrix

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Hardware Integration• Assembly of spacecraft hardware

Spitzer Space Telescope from design to integration

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Verification and Validation• Verification

– “Did we build the system right”• Validation

– “Did we build the right system”• System Testing

– Functional tests– Vibe tests (drop tests)– Shock tests (swing tests)– Thermal Vacuum tests– Acoustic tests

ALL-STAR and team at vibe test at Lockheed Martin

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Mission Operations• Starts when spacecraft development is

initiated and continues through final disposal of space asset

• Provide mission requirements support for development of operational systems– Used to plan and control launch vehicle

and spacecraft operations• Developing mission profiles, operational

procedures and related operational documentation

• Balance and allocate operational requirements with operational performance

• Determine operations integration tasks– Defining capabilities and constraints

associated with launch vehicles, spacecraft and mission control and ground systems

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Summary• Systems Engineering is an integrated composite of

people, products, and processes– Forms a structured development process– Spans design, production, and operation of systems

• Balances the needs of the customer with the capabilities of the system

• Uses technical leadership and systems management– Integrates all disciplines and specialty groups into

team– Manages cost, schedule, performance, and risk

• There is no perfect solution– Systems engineering produces the optimal solution

for the entire spacecraft