12/11/08
Space Shuttle
ECLSS Overview (slides are posted in the notes on the homepage)
Recap of what we covered
Summary of what else you need to know
Final Exam Review
What we covered,
primary course material
An Introduction to
Human Spaceflight (
Designing Human
Space Missions (
The Space
Environment Hazards and Effects (
Surface Environments
(
Physiology of
Spaceflight (
Human Factors of Crewed
Spaceflight (
Psychology of
Spaceflight (
Safety of Crewed
Spaceflight (
Orbit Selection and Astrodynamics (
Entry, Descent,
Landing and Ascent (
Designing and Sizing
Space Elements (
Transfer, Entry,
Landing and Ascent Vehicles (
Designing, Sizing
and Integrating a Surface Base (
Environmental
Control and Life Support Systems (ECLSS) (
--
supplemented with additional details from Eckart
Crew Accommodations
(
Extravehicular
Activity (EVA) Systems (
What is not covered in this course
Planetary Surface
Vehicles (
Space Robotics (
Estimating the Cost
of Crewed Space Systems (
International Crewed
Missions (
Mars Design Example
(
Quick overview of the rest from an integration
perspective
In-situ Resources (
Thermal Control (
Attitude
Determination and Control (
Designing Power
Systems (
Structures (
Propulsion Systems (
Selecting Launch and
Transfer Vehicles (
Mission Operations
for Crewed Spaceflight (
Command, Control and
Communications Architecture (
Space Logistics
Support (
In-situ Resources (
- fuel,
O2, water, food, materials, power
Thermal Control (
Heat Sources
Humans
Avionics / Lighting / Power
Equipment / Payloads
External Radiative
Incident solar, Earth IR and Earth albedo
Planetary Surface
conductive
Other vehicles
Heat Sinks
Space
radiative, evaporative, sublimative
Equipment / Payloads
Planetary Surface
conductive / convective
Other vehicles
Objective: Collect, transport and
remove heat to maintain thermal equilibrium
Designing a Thermal Control System
Identify duration and destination of mission phases
Define thermal
environment(s) hot/cold
- natural and induced
Determine heat
sink(s)
- short
duration (expendables, capacitors)
- long
duration (radiative)
Size thermal system
by summing loads high/low
- electrical
power = heat
Determine thermal
ranges for crew and equipment
Identify heat
transport paths
Develop thermal
models to analyze energy balance
- consider hot/high and cold/low
boundary conditions
Size system and
select hardware (processes)
- consider averages, peaks and
redundancy needs
Attitude Determination and Control (
From the habitats perspective, primarily concerns are Mass and CG
ADCS also contributes to the mass
RCS and propellant, Gyros, etc.
Probably dont want to use spin stabilized, unless considering artificial gravity
Designing Power Systems (
Function: Provide safe, reliable, consistent source of regulated energy
3 primary elements
Source, Storage, Management/distribution
Sum requirements from all systems
Peak, average and startup spikes
Define source options (time dependent, see Fig 20.2 in the HSMAD)
Down-select
Add distribution mass
Coordinate with thermal for dissipation needs
Structures (
Primary backbone, main load carrying structure of the vehicle (launch and delta-P)
Secondary appendages (booms, solar panels, equipment, etc.)
Tertiary mechanisms, hinges, brackets, etc.
May also include integrated function of MMOD, radiation and thermal protection
Estimated 21% of s/c dry mass for structures and mechanisms, greater for human s/c
Analysis Requirements
Strength, stiffness and natural frequencies
Dynamic envelope and coupled loads
Mass and CG
Positional stability and thermal expansion coefficients
Environmental compatibility and degradation
Fatigue lifetime and maintenance
Propulsion Systems (
Determine inert mass (everything but the propellant) of prop system
Evaluate selected system thrust and performance (Isp)
Determine propellant mass needed for maneuvers and add to total mass
Define propellant handling parameters
Selecting Launch and Transfer Vehicles (
Determine required delta Vs via Orbit Determination Analysis
Launch / Ascent
Abort / Contingency scenarios
Control thrusters
Orbital maneuvering
Rendezvous and Prox Ops
Descent and landing
Select existing or design new rockets
May consist of multiple vehicles and more than one launch and landing
Mission Operations for Crewed Spaceflight (
Identify mission operation components for crewed spaceflight (Con Ops)
Describe mission operation functions (what)
Distinguish between ground, autonomous, and crew control elements (how)
Outline concepts for mission planning
Objectives, training, real-time support
Classifications for mission procedures
Nominal, Alternative, Malfunction, IFM
Define communication transport needs
Voice, images, video or data
Uplink and downlink
Command, Control and
Communications (
Key Requirements
Data type and rate, and frequency availability
Source to destination distance
End-to-End (E/E) delay (i.e., time lag)
Allowable bit error rate (BER)
Internal / external comm and data transfer
EVA / Rover comm
Telemetry, Tracking and Control (TT&C) drivers
Relay Satellite / Ground Station Coverage
Architecture options and supporting systems
Wireless vs. hardwired
Mass, power and thermal requirements
Space Logistics Support (
a.k.a. Life Cycle Engineering
Cradle to Grave
Human space missions operate with very limited (and expensive in terms of launch mass) resources, which amplifies the need for innovative solutions - especially since most designs are one-off concepts
A program already in production wont benefit, changes are too costly
Intimately linked with mission concept
Summary
1. Define top-level Mission Objectives and Constraints
2. Decide on # of crew, duration and destination
3. Heuristically estimate habitable volume (based on 2)
4. Derive Minimal Functional Requirements needed to keep the crew alive and accomplish the mission goals
5. Define operating environment and spacecraft subsystems
a. Atmospheric Conditions (pressure and gas makeup)
b. Structures, ECLSS, (EVA) Crew/PL Accommodations, C3, Power, Thermal, Prop
6. Develop an integrated functional schematic
7. Identify technologies candidates that can meet each identified function
8. Determine consumable & infrastructure mass & volume
a. m = f (# crew, mission duration, power, cooling, prop, etc.), but not prop fuel yet
9. Determine total pressurized volume
a. Habitable + internal Infrastructure & Consumables (including leakage)
10. Calculate total structural mass
a. m = f (total volume, delta-P, launch/landing loads, CG, thermal, MMOD, rad, leakage)
11. Sum up integrated s/c mass from above results including external components, crew, suits and payloads
12. Sum up delta V requirements to perform required flight ops
13. Determine propulsion fuel mass
a. prop mass = f (delta V, Mbo)
14. Compare results to heuristic data as a sanity check
15. Conduct Probability and Risk Analysis (MTBF, FMEA)
16. Add new functions and/or additional components to reduce risk (redundancy, FOS) or improve performance (operational efficiency, human factors)
17. Iterate until satisfactory design achieved
Final Exam
Part 1 Take home CAETE students, email me for this ~6 days in advance of when you schedule your in-class proctored exam
click here for Water Recovery System ppt info slides
Part 2 in class Monday 1:30
Closed book, neighbors
Comprehensive
Review Exam 1 and 2
Design Process
Define requirements and constraints
Determine functions needed and range of options
Make us of heuristics and historic insight
Generate vehicle concepts and alternatives
Brainstorming period
Concept of Operations (ConOps)
Select options for further development
Based on trade studies, risk analysis (FMEA)
Establish conceptual design
Sufficient detail to assess feasibility, reliability & cost
Develop Logistics plan
Evaluate and down-select to baseline
Verify solution against requirements and constraints
Iterate until time or funding runs out