Human Space Flight

1. Unify (political): Moving towards a global mission

2. Explore(cultural): Expanding human experience     

3. Understand(scientific): Gaining knowledges and insights     

1. Determine how the universe of galaxies, stars and planets began and evolved——-Observe and understand the planetary formation process in the galaxy——WITH telescopes at SEL2

2. Determine the potential for establishing permanent human presence in space———Determine feasibility of in-situ resource production——ON Mars

3. Determine if there is or ever has been extra-terrestrial life in the solar system———Search for past and current life——ON Mars or Europa

Human Spaceflight:            

Pros: 1. Exploring the unexpected.

2. Real-time operations and decisions.

3. Recognize the correlation.

4. Possibility of repairing and modifying

cons: 1. LSS needed 2. Special training needed 3. Safety risks

Robotic:

pros: 1. Automated system 2. Operated in harsh conditions without LSS 3. Reach regions where human can’t

cons: 1. Maintainence 2. Data transfer problem 3. Limited scientific knowledge  

Missions:

Vostok 1, Freedom 7, Voskhod 2, Apollo 8, Apollo 11, Apollo 17

Space stations:

Salyut 1, Skylab, Salyut 7, Spacelab, MIR

1. ISS 2. Tiangong 3. Commercial Flights 4. Artemis

ISECG shows the future plans for going to lunar surface in 2 phases. 1 phase is sending up the lunar space station Gateway and followed with Artemis Missions II and III of crewed test flight orbiting moon and landing on the moon. 2 phase is to build habitation on lunar surface for futher research of moon and prepare for going to mars.

The purposes of human spaceflight mission analysis is to provide an end-to-end model of a human spaceflight mission concept and perform trade studies with regard to key mission drivers.

1. Solution-neutral input defining mission destination and objectives

2. Reference design for key mission elements

3. Trade space analysis

NEOs: Asteroids and Comets that are near or cross the Earth’s orbit

Possible Mission Objectives:

•Perform physical and chemical characterization of the NEO •Return 100 kg or more of samples from diverse sites on the NEO

•Gain experience operating in interplanetary space at significant distances from Earth

•Utilize commercial assets if possible

Crew size: The number of astronauts onboard directly affects the habitation consideration, safety estimation and life support system.

Trajectories: The chosen flight path determines mission duration, deep space propulsion needs, and structural design.

Mission Payload:  

1. Payload calculations must account for fuel needs, particularly for deep space missions requiring multiple burns.

1. Long-duration missions demand additional payload for habitat modules.

•Bottom-up detailed design based on physical principles and machine elements

Bottom-up model needs subsystem models and associated simulations

•Top-down design based on analogies and scaling

Top-down models for crew compartments and habitats is based on linear scaling of equiment mass with crew and linear scaling of consumables mass with crew and mission duration

It is needed for balancing mass and performance and evaluating different design options to achieve the best possible outcome.

Hohmann transfer trajectories are the most fuel-efficient way to move between two circular orbits around the same central body.

Limitations:

Long time travel: when maybe flyby is more efficient.  

Highly elliptical orbit

The Patched Conics method allows for a simplified calculation of trajectories based on the assumption that the spacecraft is at any given time under the influence of only one central body.

The patched conics method provides a way to calculate mission Δvs and transfer / stay times with relatively little effort

The Mission Mode is a description of the basic mission architecture, i.e. a mapping of mission functions to mission elements of form.

1. Powering onboard systems

2. Environmental control and Life support system

3. Propulsion and Navigation

4. Thermal control system

5. Altitude and Orbit control system

1. Solar energy

2. Nuclear energy

3. Chemical energy

1. Using solar arrays to convert solar energy into electrical energy

2. Using Radioisotope Thermoelectric Generator to convert heat into electrical energy

3. Using battery

1. Stored in the battery

2. using reversible fuel cell

3. Flywheel

Control: Using dielectric material to build ISS structure.

Using PCU

Regulation: 1. Regulate the power output from solar panels and energy storage system using DCSU

2.Regulate the voltages during changing of energy storage syste using BCDU        

Distribution: Solar panels 160V DC

Secondary distribution 120V DC

1. Eclipse time

2. Thermal budget

3. Assembly

4. Safety

5. Reliability and operational life

A state of a body that occurs when the forces acting at any point on the body cancel each other out in terms of size and direction.

Yes because the only force that acts on human is gravity, whether from earth or from moon. The gravity still exists.

Drop tower, parabola flight

Texus Sounding rocket

Space environment of radiation, microgravity and residual atmosphere can affect research in fundamental physics, human physiology, biology and material science.

DC: 1. Solar radiation pressure  

2.Atmospheric drag

3.Tidal forces

AC: 1.Altitude Control 2. g-Jitter

Tidal forces: Tidal forces are the dominating residual DC accelerations and of the order µg.

Creates different levels of ug on different area of ISS.

g-Jitter: Resonance response of the ISS to internal and external interference in the frequency range 0.1 – 100 Hz

have impacts on experiments regarding fluid dynamics or crystal growth.

There is no convection in liquid

Sentimentation evenly distributed in liquid

Liquid form spherical droplets.

Liquid stick between two surfaces forming a liquid column because of adhesion.  

Scientific experiments in weightlessness are usually done to study effects that are masked by gravitational forces on earth.

1. lighting candle in ug:study on flames behavior and fuel mixtures on space station may lead to improved fuel efficiency and reduced pollution on earth.

2. Cold atom laboratory: to study the wave nature of atoms.

3. Astrophysics: measures particles in cosmic rays helps us understand the formation of universe. 

4. Protein Crystal Growth

5. Material Testing

The candle burns on earth react with H first to create high energy and leads to convection. Soot particles were burnt in upper flame.

The candle burns in space station is fully diffusion, which the C and H burn completely at the same time.

Robotics development

Space mouse

Cordless screwdriver

Cerami brake disk

Baikonur -Soyuz

Cape Canaveral- Dragon crew- falcon 9

To avoid losing muscles and maintain bone density.

The astronaut need to be tied to the treadmill and weight lifting by using vacuum cylinder to apply resistance.

1. Stop and identify the emergency Mission control center on earth confirms the situation and provide instructions.

2. If there is fire take the portable fire extinguisher

3. Depressurization:putting on mask first -locate the source of leak with pressure sensor   

The earth surface can be seen directly from cupola, and 16 sunrise and sunset coming from horizon.

Undocking from ISS with Crew Dragon

Deorbit burn

Atmospheric reentry

Parachute deployment

Splashdown in ocean

1. Large distance -how to make comms works

2. Vacuum- what kind of wave can get through

3. No massive interferences- could be damaged because of it

4. Radiation-Atenna need to avoid the sun

5. Thermal / Power issues- large range of temperature in space

6. No easy fix/replacement possible

1. Low Earth Orbit(LEO)- Satellites move fast and complete ~16 orbits per day.

2. MEO higher than LEO used for GPS

3. GEO- Satellites appear stationary from Earth because they orbit at the same speed as Earth's rotation. For TV, weather forecasting

The atmosphere may attenuate the frequency because of absorption. with higher frequencies the atmospheric attenuation increases.

1. Voice(communications with mission control center)

2. Video(for payload and experiments)      

3. Telemetry

1. Signal visibilities: eclipse time  

2. Time: GPS time

3. CAPCOM / EUROCOM: communication is specific set between control center and S/C

4. Privacy

Maxwell equations

A radio wave is an electromagnetic radiation generated by time varying electrical currents and travelling at the speed of the light.

In free space, all electromagnetic waves (radio, light, X-rays, etc.) obey the inverse-square law.

1. Linear: the electric field vector is contained in a plane along the direction of propagation

2. Circular (right or left): the electric field has a constant magnitude but its direction rotates with time at a steady rate in a plane perpendicular to the direction of the wave

3. Elliptical: the electric field vector describes an ellipse in a plane perpendicular to the direction of the wave

An antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors.

Advantage: High directivity

Directivity refers to how focused or concentrated the antenna’s radiation is in a particular direction.

Beamwidth refers to the angular width of the antenna’s radiation pattern.

Higher diameter higher D

Higher frequency higher D

1. Gain: How well the antenna converts input power into radio waves

2. Noise Temperature: Noise produced from different sources  

3. G/T: figure of merit of antenna performance

4. EIRP: the total power that would have to be radiated by an isotropic atenna to get the same sigal strength as atenna’s strongest beam.

Modulation is a process of varying one or more properties of a periodic waveform, with a modulating signal that typically contains information to be transmitted.

1. Amplitude

2. Frequency

3. Phase

The frequency spectrum is a representation of a signal's power or amplitude as a function of frequency. It shows how the signal's energy is distributed across different frequency components.

BER is defined as the ratio of the number of wrong bits over the number of total bits.

In reliable channels →high order modulations are preferred due to higher efficiency

In not reliable channels →low order modulations are preferred to limit the BER

Eb/N0 stands for the Energy per Bit to Noise Power Spectral Density Ratio. It's a measure of the signal quality relative to the noise in the system.

The thermal environment needs to be favorable to residence of humans and to the operations of spacecraft equipments.

M_sun= 1371 W/m^2                    

M_E= 237 W/m^2                      

1. Existing temperature margins for spacecraft hardware in operating and non operating modes

2. Restricted heat rejection only by radiation

3. Nonsteady-state external heat

4. Difference in time and location for generated and needed heat or cooling accumulation and demands

• Employ passive thermal control techniques (thermal conduction & radiation, heat capacity)

• Improve or decrease local heat transfer (heat resistance)

• Selection of internal and outer surfaces α/ε (thermal absorption / emission)

• Use active heat transfer for high heat loads

1. Existing temperature margins for S/C hardware in operating and non operating modes

2. Nonsteady-state external heat loads for several mission scenarios

3. Restricted heat rejection only by radiation

4. Difference in time and location for generated and needed heat or cooling accumulation and demands

1. Conduction: Energy is transfered by direct contact

2. Convection: Energy is transfered by the mass motion of molecules

3. Radiation: Energy is transfered by electromagnetic radiation  

1. decide integration depth, integrated system with centeal heat transport system and central heat rejection or autonomus system

2. Topology and dimensions: extensive systems or compact systems

3. Heat transport system: performance, maturity and maintainance  

4. Thermal environment definition range for different utilization

5. Main tasks and users of TCS

ATCS: 1. Radiators 2. Single phase fluid loop 3. Heat pipe

PTCS: 1. Thermal Insulation 2. Thermal protect system 3. Surface finishing

Programm Mercury

Mercury: 1 Crew because it is designed to test basic flight capabilities.

Gemini : 2 crews for more complex tasks preparing for Apollo's Moon missions.    

1. Command and Service Module: Earth launch and entry, in-space maneuvers and habitation  

2. Launch Escape System: separation of Apollo capsule in case of launch abort    

3. Saturn IB launch vehicle：used for LEO missions  

4. Saturn V launch vehicle：used for lunar missions1& Skylab  

5. Lunar module(LM): lunar landing, lunar surface habitation

Space Transportation System   

Components:

1. Shuttle Orbiter(3 main engines and 2 OMS pods, Payload bay and crew cabin)   

2. External Tank

3. 2 reusable solid rocket booster  

All 4 crews sit in flight deck, Pilot and commander in front and 2 Mission specialists in back to check on pilot and commander.

1. Launch abort system: in case of emergency to pull crew module away from the rocket   

2. Service module: for storing the propulsion  

3. Crew module: for habitation  

In use: Orion, Crew Dragon, starliner

Planned: Dream chaser

From the launch abort tower.

Downrange Abort Exclusion Zone.

It is the exclusion zone for Crew Dragon to abort because it is too far away from both sides of coast.

The Soyuz is Russia's human spacecraft, developed during Soviet times and incrementally modernized

Soyuz: Crewed spacecraft  

Progress: Cargo spacecraft    

Crewed spacecreft based on Soyuz

LoM:Loss of mission  

LoC: Loss of crew

Human-rating is a process of reducing probabilities of Loss of Crew (LoC) and Loss of Mission (LoM) of a space system to acceptable levels.

Human-rating is achieved by providing redundancy in key subsystems like launch abort system.

Features such as self-helping mechanisms or passive cooling can be employed.

Trajectories designed to include features such as "free-return"

Orbit control:  

1. Achieve designated lifetime

2. Allow rendezvous manoeuvre

3. Maintain safe on-board operations

4. Allow microgravity experiments

5. Collision Avoidance  

   
   

Attitude control:

1. Maintain solar-electric power generation

2. Allow safe docking operations

3. Maintain communication to Earth

1. Semimajor-axis a

2. Eccentricity e

3. Position-True Anomaly theta

4. Inclination i

5. RAAN (Right Ascension of Ascending Node) omega

6. Argument of perigee w

Orbit is defined by the shape orientation.

Attitude is defined by the orientation of the body fixed coordinate system w.r.t. a reference system

LEO perturbations: Aerodyn. Drag, Aerodyn. torque, gravity gradient torque(design driving parameter)

solar pressure, earth oblateness,

1. Orbit decay:continously lower itself

2. perturbation torque:unintended rotation

   
   

   Atmospheric density.    

The more active the solar activity, the higher the density.

Orbit decay continuously lowers altitude → Reboost counteracts it by restoring the desired orbit.

POP: Perpendicular to Orbit Plane

IOP: In Orbit Plane

ASL: Aligned with Sun Line

PSL: Perpendicular to Sun Line

LH: Local Horizon

LV: Local Vertical

1. Earth Oriented Flight Mode

2. Inertial Flight Mode

Criteria:

1. Mission & Utilization requirements

2. Gravity Gradient Attitude Stability

3. Minimum Drag

4. Mechanical Effort for solar tracking  

Centre of pressure of a space station often has offset ⊥ v to centre of mass, which create torque.

Perturbation: CMG Desaturation    

Aerodyn. Drag: use Thruster to reboost    

1. Contamination due to thruster operation

2. Safety of components and operation

3. Redundancies to guarantee operation in case of failures

4. Servicing/Maintenance

1. Definition of flight mode and configuration

2. rough calculation of orbit decay

3. choose orbital control strategy(permanent or impulsive)   

4. check attitude performance and choose attitude control system

5. calculate required propellant

Food, portable water, hygiene water

1. Atmospheric composition

2. Pressure

3. Temperature

4. Relative humidity

1. Atmosphere management

2. Water management

3. Food management

4. Waste management

   
   

By degree of closure and types of process.

Open, partialy closed and closed

Physico-chemical, hybrid and biological

According to the linear relationship between mission duration and environmental system mass under different classification, when it comes to a break even point it means to choose another system type

CO2 removal:  

1. Using LiOH Cartridges for chemical reaction to remove CO2

2. 4BMS

3. SAWD

4. Sabatier Reactor 

O2 genertation

1. Water electrolysis

1. Multifiltration

2. Vapour Compression Distillation (VCD)

farming

higher plants algae

1. Utilization

2. Radiation

3. ug

4. Volume restriction

5. Power provision

A set of different elements so connected or related as to perform a unique function not performable by the elements alone.

An interdisciplinary collaborative approach to derive, evolve, and verify a life cycle balanced system solution that satisfies customers expectations and meets public acceptability

1. Most important decisions are made, driving mission performance, cost, schedule, risk, etc.

2. Mission and system elements are strongly interdependent

3. crucial for a permission of a project

4. Determine mission and system requirement

top-dowm

1. Define Objectives

2. Characterize the system

3. Evaluate the system

4. Define Requirements

Pressurized module backbone: uses pressurized modules as the primary structural connection between different sections of a spacecraft or space station.

Truss backbone: Uses an external, unpressurized truss structure to support pressurized modules and other equipment

Orbit:

1. Orbital access to target or transfer vehicles   

2. Communication Performance

3. Earth Observation Performance

4. Drag

Flight mode:

1. mission needs

2. rendezvous and docking

3. minimizing drag

4. effects of gravity gadient

1. EPS

2. ECLSS

3. AOCS

4. TCS

1. Determine components

2. Size components:dimensions, mass, kinematics  

3. Develop Topology: Arrangement of components  

-Microgravity level vs Aerodynamic drag (Aerodynamic drag needs reboost which disrupts the micro-g experiments)   

-Attitude Stability and Control (frequent adjustment may create vibration which are not stable)   

-Energy Provision vs Thermal Control (Space arrangement)    

Risk: damage extent x probability  

Safety: Freedom from conditions that can cause death, injury, occupational illness, damage to or loss of equipment or property, or damage to the environment

STS 118 EVA abort after punctuation

Protection Against Environmental Hazards

Suit Longevity and Maintainability

(0) Legal

(1) feasibility evaluation

(2) comparing competing designs

(3) identification of potential reliability problems

(4) to provide reliability input to other tasks , subsystems and designs

Fields:

1. Load studies and requirements specification

2. Functional (Failure) analysis & testing

3. Human Factors / Errors / Training & Certification

4. Documentation & spare parts

ECSS

NASA STD-3001

By doing simple tasks to test the mobility and dextertity.

Cryotest for testing the ability of spacesuit to survive in extreme environment.

Insulating test

1. Planning input: Experiment design & needs

2. Mission plan: what to do when

3. Standard operating procedures: Who is responsible  

4. Experiment procedures: how to do  

SSPP(system safety program plan)        

PHL(Potential Hazards Lists)        

PHA(Process Hazard Analysis)        

SAR(Safety Assessment Report)

1. Incorrect practises are applied

2. performed by incorrect people

3. within the organisation at an incorrect time of the system life cycle.

Mechanical

user error

chemical, laser

electrical

Operation storage maintainance

h/w: random faults       

s/w: systematic faults     

-ariane 5 explosion: because of a bug in inertial reference system led to an unhandled exception when converting a 64-bit floating point number to a 16-bit integer.

Water beagn leaking into Luca’s helmet during EVA walk. And he reported difficulty in hearing and breathing. stuggled to find his way back to airlock.

The Pareto Frontier is a idealized relationship between performance and cost.

Phase B

-Analogy: apply relative scaling to a historical data point  

-Engineering build up(Bottom-up): Use drwaings and bill of material for detailed estimating           

-Parametric(Top-down): Use mathematical relationships to describe products  

1. Specific Cost Model: only products which belongs to the same product family    

2. General Cost Model: reusable model that applies to multiple systems or industries based on MX 

1. Helps to identify relevant costs and to verify an estimate’s completeness

2. Permits consistent comparisons between alterative architectures and system designs

3. Provides a logical link among segments of a program or project

The Advanced Missions Cost Model (AMCM) is a simple model that provides a useful method for quick turnaround, rough‐order‐of magnitude estimating.

Used for estimating the development and productioncost of spacecraft, space transportation systems, and space infrastructure.

1. Country of origin

2. Inflation factors

3. Learning effects

4. Funding profiles

Wright: Describes how unit production cost decreases as total production doubles.

Boeing/Crawford: assumes a slower initial learning phase and better long-term efficiency. 

Risk: A potential, future negative impact, or  consequence

Uncertainty: Uncertainty leads to risk

Reward: The probability that the estimate will be sufficient is the Reward