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Space Mission Design Lecture 11
Quiz 2 Today
What's happening in space:
Elektron/Atmosphere Status: The crew turned the Elektron off Friday night
before they went to sleep. Elektron was reactivated on GMT 262/0815 in 32
amp mode, but failed at 0822 due to off-nominal shutdowns of the primary and
backup micropumps. Elektron was reactivated at 262/1216 and transitioned to
64 amp mode at 1231, but failed at 1354 due to a primary pump shutdown.
MCC-M has concluded that the Elektron H2 and O2 lines contaminated by Liquid
Unit (??) #7 are unclogged and operating nominally. In addition, the primary
pump in ??#5 cannot handle air bubbles and needs to be replaced. New
external "disc pumps" which are not susceptible to gas bubbles will probably
be installed; no decision has been made yet as to when these pumps will be
installed. The Elektron is currently off.
An oxygen repress was completed (utilizing Progress O2 assets), which raised
the total cabin pressure by 10.8 mm Hg.
Progress Fuel Transfer: The Progress 15P fuel transfer to the FGB tanks was
completed nominally.
Spacecraft Systems CO2 Removal
ECLSS subsystem drawings (PowerPoint)
Jump to Homework Assignment 3
Environmental Control and Life Support Systems
ECLSS
Objectives
Understand what environmental control is required for spacecraft
Know what sub-systems make up an ECLSS
Know the function of spacecraft ECLSS
ECLSS
Systems required for humans to live safely and be healthy and comfortable on a spacecraft
Must function well
Reliable
Maintainable
Operable (autonomous)
Redundancy
Water Supply
Stored Water
Reclamation of condensate or urine
Student Presentation to cover ISS Water Recovery
Food Supply
Bring it
High mass
Packaging
Grow it
Initial high mass
Support systems (Light, water, processing)
High crew workload (Psych support?)
High risk
Sanitary Hygiene
Waste management system
Trash management
Cleaning supplies
Disinfectants/fungicides
Toiletries
Towels
Waste Management
Student presentations to cover ISS and Shuttle waste management
Fire Detection and Suppression
Smoke detectors
Fire extinguishers
CO2
Halon
Water
Emergency Breathing Apparatus
For contaminated atmosphere/smoke
Oxygen Supply Systems
Technology options to provide O2
Physico-chemical
Storage
Electrolysis
Chemical release
Bioregenerative
Plants
Algae
Shuttle O2 Storage
Stores liquid oxygen
Used for breathing and electrical power production
Cryogenic
Thermally insulated, double walled vacuum annulus tanks
-176 °C
High pressure - 5 MPa
Heaters maintain pressure
Up to 5 spherical tanks (+4 more for EDO- OV105)
Tank volume = 320 liters
Tank mass = 98 kg
O2 mass = 354 kg / tank
Inconel 718 inner and 2219 Aluminum outer shells
Regulates at PPO2 = 20.3 to 23.8 kPa
Soyuz and Shinzou O2 Storage
Store gaseous oxygen
High pressure tanks
4 external, V = 20 liters (0.02 m3 ) at 22 MPa
1 internal, V = 12 liters
Provide total of 20,360 liters O2 at 1 Atm for breathing
ISS O2 Storage
Stores gaseous oxygen
On US Airlock
High pressure cylindrical tanks
2 external, V = 428 liters at 18.6 MPa
Provide total of 15,664 liters O2 at 1 Atm
In Service Module
High pressure portable tanks
1 internal, V = 20 liters at 31 MPa
Provide total of 640 liters O2 at 1 Atm
Electrolysis
Uses electrical power to split H2O
Electrical power (input)
2 H2O ? 2 H2 + O2
Used on MIR
In use on ISS - Russian Elektron
Student presentation to cover Elektron
Chemical Release
ISS Solid oxygen generator
Back up O2 production
Burn Potassium Perchlorate candle
Heat (output)
KClO4 ? KCL + 2 O2
Exothermic chemical reaction at 400-500 °C
Packaged in a cassette (~ 30 cm length x 8 cm dia)
Produces 600 liters O2
Biological O2 Production
Algae
Easy to grow
Low TRL
Higher Plants
Complex care
T, RH, CO2, water
Lighting
Toxic organic gas control
Ventilation
Nutrients
6-10 m2/person
Atmospheric Purification
CO2 Removal
Harmful impurities / trace contaminates removal
Carbon Dioxide Removal
Technology options
Removal systems
Carbon Dioxide Removal Assembly CDRA
Vozdukh
Lithium Hydroxide
Regenerative system
Sabatier
Biological
The primary means of CO2 removal system on board the ISS:
Vozdukh
Operation principal:
Use of regenerable chemical adsorbers to separate and remove carbon dioxide from the atmosphere of the ISS
System Components
Preliminary Drying Unit
Atmosphere Scrubbing Unit
Gas-Liquid Heat Exchanger Assembly
Automation Unit
Control Panel
Air Flow Rate Sensor
2 Filter Assemblies with filters
Emergency Vacuum Valves
Modes of Operation
Semi-automatic
In this mode, the Vozdukh is controlled by the onboard computer system and the automatic control unit
The crew can select submodes which automatically control air flow, cycle time, and carbon dioxide absorbtion rate
Autonomous
5 modes of autonomous operation
Selected by the crew
Vozdukh Control Panel
Sabatier Reactor
CO2 regeneration system
Reaction discovered in 19th century by French chemist and Nobel Prize winner Paul Sabatier
CO2 + 4H2 => CH4 + 2H2O
Exothermic reaction that occurs spontaneously at temperatures above 150°C while a catalyst is present
Sabatier CO2 Regeneration
Uses CO2 taken from CO2 removal system
Combines with hydrogen
Methane can be used or vented overboard
Water can be stored and used by the crew or electrolysized to generate O2 and H2
H2 can then be used again in the Sabatier process
Sabatier Reactor
Hollow cylinder
H2 and CO2 enter in the mixing chamber
Reactants flow over ruthenium catalyst
Heaters around the chamber raise the temperature so the reaction will begin
Possible Applications
As a part of the Carbon Dioxide Removal Assembly (CDRA) on the ISS to use removed CO2 and generate water or O2
On the Martian surface as an in-situ propellant plant producing methane and oxygen
Sabatier Functional flow diagram
Biological CO2 removal system
Algae
Easy to grow
Low TRL
Higher Plants
Complex care
T, RH, CO2, water
Lighting
Toxic organic gas control
Ventilation
Nutrients
6-10 m2/person
Atmospheric Purification
Technology options
Absorption
Regeneration
Filters
Biological
Combinations
Student presentation to cover TCCS
Pressure Monitoring and regulation
Absolute pressure monitors
Pressure change monitors
Air flow monitors
Regulators
Positive and negative pressure relief valves
Gas Analysis
U.S. Major Constituents Analyzer
Measures N2, O2, H2O, CO2, H2, CH4
Mass spectrometer
Student presentation to cover Russian Atmospheric Monitoring and Gas Analysis
Temp and Humidity Control
Air conditioner
Humidity condenser
Air circulation
Temp and Humidity Control
On ISS:
Air conditioner
Humidity condenser
Air circulation
Student presentation to cover Shuttle cooling systems
AERO 4730 Homework Assignment 3 Fall 2004
There are many decisions to be made in the selection of systems for human spacecraft. One of those is to decide if the design should incorporate regenerative life support systems or use expendable supplies. An example is to carry stored oxygen, generate oxygen chemically, use biological production of oxygen, or regenerate waste water into oxygen.
Your assignment is to write a report to compare and contrast the use of expendable versus regenerative technologies for a carbon dioxide removal system in a human spacecraft. Make a final recommendation for the final design choice and justify your answer by using an analytical analysis. Consider mass, volume and power required as the 3 most important criteria.
Mission: The spacecraft is to be used to take 3 crew members from Earth to the moon, stay for 4 weeks and return to the Earth. For planning and design, the total time in space including contingency time must be 45 days.
Data for different CO2 removal systems to consider.
| Parameter | LiOH | CRDA | Sabatier | Vozduch | Others? |
| Mass | 7 kg/4p/d (one canister) | 30 kg/p | 38 kg/p | 48 kg/3p | ? |
| Volume | 0.005 m3/canister | 0.15 m3/p | 0.07 m3/p | 0.7 m3/3p | ? |
| Power required | 0.012 kW (fan) | 0.3 kW/p | 0.02 kW/p | 0.25 kW/p | ? |
| TRL | 9 | 9 | 7 | 9 | ? |
| Operating pressure | 101.3 kPa | 680 kPa | 101.3 kPa | 101.3 kPa | ? |
| Others? | ? | ? | ? | ? | ? |
Nomenclature: /p = per person /d = per day (Watch the units i.e. 7kg/4 persons)
LiOH Lithium Hydroxide canisters (Shuttle)
CDRA U.S. Carbon Dioxide Removal System (ISS)
Sabatier part of a developmental regenerative system
Vozduch Russian CO2 removal system (ISS)
TRL = Technology Readiness Level how ready it is to use in space
Scale of 1 to 9, with 1 being basic principles observed and reported, and 9 being fully operational.
TRL 7 System prototype has been demonstrated in a space environment
TRL 9 Actual system is flight proven through successful space mission operations
If needed, for cost for launch to LEO use $20,000/Kg
Administrative
instructions:
The paper should be 6-10 pages in length not including
the cover sheet, table of contents, list of tables and figures, and
reference page.
The cover sheet should include the following centered
on the page : Title of your paper, class name and number (AERO 4730), your
name, date.
You should include at least the following sections:
cover sheet, table of contents, list of tables and figures, introduction, a
discussion of the problem statement, discussion of the technologies
available, discussion of your methodology, the trade study itself, results,
discussion of the results, conclusion, references.
The paper should be double spaced with margins of
approximately 1 inch. Use 12 point font for the text.
References must be cited in the text of the paper and
should be listed at the end of the paper in a standard accepted format.
Required references in addition to your textbook:
At least three from scholarly
sources - books, technical journals, professor's space library
The paper is due at the start of
class on October 7, 2004.
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