Mission Planning

Electric Propulsion

-Class of space propulsion which makes use of electrical power to accelerate propellant via electrical and/or magnetic means -Require very little mass to accelerate spacecraft since propellant is ejected up to twenty times fester than from a classical chemical thruster -Limited in energy to suitable for low-thrust (micro and milli-newton) long-duration applications -Uses propellant of rare gas (i.e. xenonon or argon), a liquid metal or conventional propellant -Three types : (1) electro thermal, (2) electrostatic and (3) electromagnetic thrusters

Living & Working in Space

-Objects have no apparent weight

Mixture Ratio

Ratio of oxidizer to fuel

Orbital Mechanics

-1609 Johannes Kepler published his three laws for orbital motion -Isacc Newton proved them in 1666 (Kepler thought around planets around sun but Newton found it was all satellites) -Kepler's laws state that all satellites move in elliptical orbits -Major axis is longer and contains foci -Minor axis is perpendicular to major axis (shorter) -Kepler's First Law: Each planet revolves around the Sun in an elliptical path, with the Sun occupying one of the foci of the ellipse -Eccentricity: 0 perfect circle --> 1.0 long ellipse (max) --> Calculate by dividing distance between foci by length of major axis -Distance between the apogee (or perigee) and the center of the major axis is called the semi-major axis -True anomaly: degree value between 0 and 360 that tracks satellite progression of orbit -Kepler's Second Law: A line joining a planet and the Sun sweeps out equal areas during equal intervals of time -Kepler's Third Law: The squares of the planets' orbital periods are proportional to the cubes of the semi- major axes of their orbits - essentially states that the time to complete one orbit depends on the size not shape --> any two orbits of different eccentricity can take the same amount of time to complete if their major axes are the same length -Apogee: Farthest point from object orbiting around -Perigee: Closest point from object orbiting around

Mission Control

-1965, the Mission Control Center (MCC) has been the nerve center for America's human space program -Johnson Space Center -With ISS --> flight control teams of experienced engineers and technicians are on duty 24/7 -"Front room" is continually staffed with flight controllers - dozens experts working in back rooms in perimeters -Each mission - about 50 members per teams - 3 teams working a 9-hour shift -Information shown through controls computer display or projected group displays - tracking scree, live video, animated simulations, data steams -Headsets and messages keep all controllers in contract -Double-check every system to be sure all operations are proceeding as expected --> Have experience/expertise to deal with unexpected events -Flight controllers spend only a fraction of their time in actual flight control - spend remaining hours training - using the mission control center, simulators, and a team of trainers to give them real flight problems to overcome

Mission Planning Components

-A Mission Objective -Trajectories and Orbits -Spacecraft -Launch Vehicle -Mission Operating Systems -Mission Management and Operations

Microgravity

-Affects on human body: At first, blood shifts from lower body towards heart and head ("headward fluid shift") - heart size increases but soon the body thinks there is increase in total blood volume - lowers volume of blood and heart shrinks - when returns to Earth, heart has hard time adapting to pulling blood up to brain (drinks lots of fluid before to limit this) Bone density decreases Muscles weaken, especially leg and back muscles Maintain strict exercise program to prevent muscles and bones Stress of launch inhibits white cell growth and red cell mas decreases early in space craft -Affects on plants Germinating seeds grow normally growing towards light - Roots grow whichever way they please - stay within the moist medium in which the plant is growing Problems have been discovered in plants' reproductive systems; that is, in their ability to flower and produce seed necessary to have a forced convection at both the roots and the shoots during all stages of a plant's life -Send animals to space Small vertebrates sent to space to see see how space effects their bodies and invertebrates and single celled organisms also sent

Virtual Reality

-Allow astronauts to experience different parts of their mission without needing to use a mock-up or simulator

Cost of Chemical Systems

-As the payload gets bigger, the cost increases -Small payloads, the lowest cost shown is about $2100 per pound for payloads of less than 30,000 pounds -Increasing to payloads of about 50,000 pounds, the cost is closer to $5000 to $10,000 per pound

Single-System Trainers (SSTs)

-Astronauts' first exposure to the spacecraft -Simulators contain computer models with software that allows astronauts to interact with controls and displays like those of the spacecraft. The astronauts work procedures and react to malfunctions in a similar spacecraft environment -Each astronaut is assigned an instructor who helps him/her learn about the operations of each subsystem, using checklists similar to those found on a mission -Mission specialists and payload specialists are given training in the aft deck SSTs as they learn how to operate the payload, to activate payload experiments and controls, and to use any assistive equipment, like a robotic arm

Mission Objective

-Begin with need (Ex: Do we need to detect forest fires?, Do we need to monitor glacial retreat?, etc.) -Develop mission statement composed of three things The mission objective - WHY conduct the mission? The mission users or customers - WHO will benefit? The mission operations concept - HOW will the mission elements work together?

Antimatter Propulsion System

-Can be created through various nuclear reactions -Many antimatter particles have a charge, and they can be stored in a magnetic bottle without reacting the matter -2006, the NASA Institute for Advanced Concepts (NIAC) funded a team designing an antimatter-powered spaceship- calculated just 10 thousandths of a gram of antimatter would be enough to send a ship to Mars in 45 days -Downside is that its extremely hard to make beyond storing -world's production from its nuclear power plants of antimatter is only between one and ten nanograms per year - most expensive substance on Earth - valued at approximately $62.5 trillion per gram

Nuclear Pulsed System

-Concept uses a nuclear sudden impulse device (aka nuclear bomb) detonated behind the spacecraft - momentum is transferred from the blast wave to the spacecraft, propelling the spacecraft forward - pusher plate also absorbs some of the momentum as 100% transfer of momentum from the blast wave to the spacecraft would generate g forces too large for humans to withstand -Products from the blast usually have very high Isp equivalent to exhaust speeds of 20-30 km/s- propulsion produced in this fashion tends to be unstabl -Partial Test Ban Treaty of 1963 brought an end to having nuclear devices in space

The Spacecraft

-Designed for specific mission in effective, cost-efficient way -Payload: Part of spacecraft that actually performs the mission -Bus: Provides all the functions necessary to make the payload work (Electrical power, temperature maintenance, data processing/storage, spacecraft orientation, and communication to other spacecraft and subsystems)

Radiation

-Exposed to fairly high levels of extraterrestrial radiation -Half of expected exposures for the International Space Station are from galactic cosmic ray exposure -Astronauts who spend three months in the Space Station will be subjected to over three times the maximum recommend dosage of radiation for one year -Solar flares can direct a large amount of solar particles through space, and crews are required to "take cover" in the most protected part of the space station during those events -Doses typical of those caused by solar disturbances may impair crew performance while doses typical of the galactic cosmic ray environment are likely to result in long-term effects (increase in the probability of cancer induction) -Effects of long-term exposure to large amounts of radiation can include an increased risk of cancer, cell damage, and damage to reproductive systems -Aluminum hull shielding on ISS to help deflect some of the radiation

The Rocket Equation

-Faster rocket Maximize fuel speed. Maximize fuel mass. Minimize the mass of the spacecraft. ΔP = ML - (ML) / (e^(ΔP/Ev)) ΔP = Amount of propellant consumed in kilograms ML = Mass of Rocket at beginning of burn ΔV= Delta- V of the burn in meters/second Ev = Exhaust velocity in meters/second -Typical chemical rocket motors have exhaust velocities of 2-5 km/s while spacecraft speed for just LEO requires speed of 9 km/s -Specific impulse or Isp indicates how many pounds (or kilograms) of thrust are obtained by the consumption of one pound (or kilogram) of propellant in one second -High Isp (corresponding to high propellant speed) in general means higher efficiencies in terms of mass expended. However, if the velocity of the propellant is much faster than the desired speed of the spacecraft, then you end up wasting energy. Therefore, there is a need to match the speed of the propellant with the actual application. -Propellant type and nozzles impact this - longer nozzles better for low pressure (space)

Thermal Protection

-For the orbiter - outer skin is usually composed of aluminum and graphite epoxy - Thermal protection system (TPS) materials, placed over the outer skin, protect the orbiter in temperatures that ranged from -250°F in the cold of space to reentry temperatures that could reach 3,000°F - TPS commonly reinforces carbon- carbon (RCC) -RCC protects areas that experienced temperatures over 2,300°F - Black high- temperature insulation tiles for below 2,300°F

Mission Operating Systems

-Ground and space based infrastructures need to coordinate all the other elements of a space mission includes: -Testing facilities, Building of the spacecraft, and preparing the launch vehicle for launch -Iterative process - outcomes continue to impact the process

Hybrid Rocket Motors

-Has both solid and liquid fuel components - during flight, liquid oxidizer is pumped into combustion chamber where it is ignited and burns the solid fuel grain -Oxidizer tends to be liquid oxygen or nitrous oxide -The fuel can be ABS plastic or synthetic rubber -Advantages: Can be throttled by controlling the flow of the oxidizer into the chamber, relatively inexpensive fuel and relatively inert if failure in motor, and high exhaust velocity of 4 km/s -SpaceShipOne and SpaceShipTwo

Liquid Bi-propellant Engines

-Have oxidizer (usually liquid oxygen) separate from liquid fuel and then pumped into combustion chamber where ignited then vented to exhaust nozzle -Fastest sppeds obtained through a mixture of liquid oxygen (LOX) and liquid hydrogen -Disadvantage: Liquid hydrogen needs cryogenics to remain in liquid form (highest density mass density) -Liquid oxygen and kerosene for Falcon (SpaceX) has slightly lower exhaust velocities but doesn't require cryogenic cooling -Deep space - mixture of dinitrogen tetroxide and hydrazine is used -Space Shuttle, Saturn V upper stages, Delta IV and Ariane 5

Development of the MCC

-In 1950s, during Mercury Program was at Cape Canaveral in Florida and space capsules controlled almost entirely from the ground -July 1995, MCC was retired and restored to way it was in 1969 Moon landing -At that time, 2 new new Flight Control Rooms (FCRs, "flickers") were built -White FCR: Continues shuttle missions -Blue FCR: Backup - Converted for use for ISS -Red FCR used in training of flight controllers taking place concurrently with mission support -All FCR are functionally identical

Laser Beam Energy

-Lasers (light) and masers (microwave) can be used instead of solar sails since they are more energy dense but they need very intense lasers (terawatt range) -Can also be used for launches by creating super heated atmosphere under mirror system - doesn't have to carry the fuel - disadvantage is that even for a few kilograms of payload, lasers of several hundred kilowatts are required -Alternative would be particle/plasma beams for propulsion (only in space to prevent scattering) - advantage is that significantly less power can provide the thrust

Solid Propellant Engines

-Mixtures of solid oxidizer with combustible material held together with rubberized adhesive - 2-3 km/s -Most common form uses ammonium perchlorate (~70%) combined with about 16-20% fine aluminum powder, held together with 11-14% hydroxyl-terminated polybutadiene (HTPB) -Advantages: Simple design, substantial flight heritage, high reliability, compact size, long storage times, high payload mass fraction, and low costs -Disadvantages: Impossible to turn off once lit, cracking or air bubbles in the fuel grain can cause the entire rocket to explode or rupture, and rubber seals are needed which can fail and vent hot gas -Estes Rockets, Space Shuttle and Delta IV Heavy

Sail Technology

-Momentum can be obtained by reflecting photons from the Sun -Downside: Pressure from solar photons is only about 10-5 N/m2 at Earth orbit - several tens of square meters for even small spacecraft is required -Examples: mylar sails with the 5 µm thickness and a mass per area (grammage) of 7 g/m2, and aluminized kapton films with a grammage of 12 g/m2 - 100 m2 reflective sail could at best generate 1 mN of thrust while weighing 1 kg -10 kg spacecraft would then obtain an acceleration of 10-4 m/s2. Thus, to produce a ΔV of 1 km/s would require nearly 4 months -IKAROS, Sunjammer, LightSail -Alternative is magnetic sail where it reflects solar wind - dynamic pressure from the solar wind is only about 4 nPa or about 10-3 of that from solar photons - but a solid surfaces is not needed since a magnetic field can produce the reflection - superconducter at first - now plasma to create magnetosphere like that of planets

Eating & Drinking in Space

-On Mercury missions, limited to bite-sized cubes, freeze-dried powders, and semi liquids stuffed in aluminum tubes -Gemini missions - bite-sized cubes coated with gelatin to reduce crumbling, and freeze-dried foods were encased in a special plastic container to make reconstituting them easier - food choices as shrimp cocktail, chicken and vegetables, butterscotch pudding, and applesauce, and were able to select meal combinations themselves -Apollo astronauts were the first to have hot water, which made rehydrating foods easier and improved the food's taste - first to use the "spoon bowl," a plastic container that could be opened and its contents eaten with a spoon -Space Station food is re-supplied about every 90 days. This food comes in three forms: natural form rehydratable thermostabilized -Natural food refers to food that does not need to be processed - Examples: Crackers, tortillas, nuts, granola bars, condiments, candy, and cookies -Rehydratable foods have had the water removed from them - hot water is injected into the pouch to restore the food to its normal form - Examples: Cottage cheese, shrimp cocktail, scrambled eggs, noodles, mashed potatoes, quiche, borsch, milk, rice, macaroni & cheese, sausage patties, teriyaki vegetables, spaghetti with meat sauce, and grits -Thermostabilized foods are heated to a level sufficient to kill harmful microorganisms and enzymes and then packaged in cans, cups, or pouches - Examples: Chopped pork with eggs, beef with vegetables, split pea soup, tofu with Hoisin sauce, minestrone soup, grilled pork chop, tomato basil soup, chicken in white sauce, lasagna -Half of the food is provided by NASA and the other half by Russia - stored at ambient temperatures ranging from 60 to 85 degree Fahrenheit - must be shelf-stable with a shelf life of two years -Many of the beverages are in dehydrated form, and all beverages and drinks are contained in drink bags with straws - pre-filled with powdered coffee, tea, milk, or flavored instant drinks -For ISS astronauts choose 28-day flight menus approximately 120 days pre-launch - based on single service, disposable containers -Also included is a "safe haven" food system, provided to sustain crew members for 22 days under emergency operating conditions resulting from an on-board failure -Included is a "safe haven" food system, provided to sustain crew members for 22 days under emergency operating conditions resulting from an on-board failure - utilize a minimal amount of volume and weight. The Safe Haven food system is independent of the daily menu food and will provide at least 2000 calories daily per person

The Neutral Buoyancy Laboratory

-One of the largest swimming pools in the world - contains over six million gallons of water, is 40 feet deep, and was designed to be large enough for the entire shuttle payload bay to fit inside of it. It is used for astronauts to practice their spacewalks, or EVA's -Astronauts are suited up in spacesuits and released in the pool with certified safety divers to assist - underwater environment allows astronauts to practice procedures in a scenario very similar to weightlessness - Any task that has to be done on an EVA is first simulated up to 10 times in the pool

Monopropellant Engines

-Only use single propellant passing though a catalyst, causing reaction that generates heat and byproducts - 2.3 km/s -Most common types is hydrazine and when passes over catalyst such as iridium metal, decomposes to ammonia, nitrogen gas, and hydrogen gas -Reaction can be very tightly controlled by fast switching valves - ideal for altitude control -Advantages: Simple, robust and reliable performance, minimal plumbing and substantial flight heritage -Disadvantages: Low exhaust velocity (not efficient for use as main thrust engine), toxic fuel and lifetime issues with use of a catalyst

Orbital Change Maneuvers

-Posigrade Burns: (For a circular orbit) Burn that increases the forward velocity of vehicle causing the eccentricity of the orbit to increase - the burn point becomes perigree and intersects old orbit or (At apogee of elliptical orbit) Burn that reduces eccentricity of orbit - Called Hohmann transfer when done after initial circular orbit burn -Retrograde Burns: Decreases forward velocity of vehicle and thus lowers alitude of orbit on every point except burn point and orbit becomes smaller - If done at apogee of an ellipse, orbit becomes more eccentric - If done at pedigree of an ellipse, orbit becomes less eccentric -Orbital Assist: Technique to change spacecraft's velocity relative to the Sun by swinging through planet's gravitation pull - larger planet = larger pull a) Observer on Planet Initial Velocity: -W = -V-U Final Velocity: W = V + U b) Distant Observer where Sun is at rest Initial Velocity: -W + U = -V Final Velocity: W + U = V + 2U

Electrostatic Thrusters

-Produce higher propellant velocities or Isp by using a gas with lower density, fully ionizing propellant -Works by injected propellent (usually a noble gas like xenon) between anode and cathode where electrons are accellerated towards anode, colliding with propellant, ionizing it and these ions are accelerated towards the back end of the thruster by the negate charge on the cathode (range of voltages from a few hundred volts to several kilovolts) to produce desired ISP - Ejected ions need to be neutralized by addition of electron beam to prevent ions from accelerating back to spacecraft -Exhaust speeds can reach between 15 to 50 km/s with efficiencies between 60 to 80% -Typical thrust levels obtained are 40 mN/KW -Deep space 1, Dawn, Hayabusa -One of the problems with electrostatic thrusters is that if they are to be scaled to higher powers, then the thruster has to become increasingly larger - limited to plasma physics processes so the only wat to increase thrust is to increase the area

Arc jet thruster

-Propellant (usually hydrazine or ammonia) flows between two electrodes with high voltage places between them - point on the center electrode causes the intensification of the electric field there - partial ionization of propellant and current/arc flows between two electrodes - density is sufficiently high that both neutrals and charged particles have multiple collisions as they transit between the electrodes - collisions produce heating of the propellant, which is converted into thrust, as the hot gas exits the nozzles - similar to arc welding systems -Able to produce exhaust velocities between 4-16 km/s using about 400 W to 100 kW with a power efficiency of about 30 to 50%

In-flight Crew Escape System

-Provided for use only when an orbiter would be in controlled gliding flight and unable to reach a runway -Alternative to water ditching or landing on terrain other than a landing site -Crew would make the escape decision at an altitude of approximately 60,000 feet and would immediately activate the flight control system autopilot - 90 seconds for a maximum crew of eight to bail out - 12-second intervals - crew wore brightly colored orange safety suits called partial-pressure shuttle launch and entry garments outfitted with a parachute, a life raft, a radio, food, water, a first-aid kit, and survival gear

Mock-ups

-Provided the astronauts with a location for more dress rehearsals that do not involve complex computer systems -When the shuttle was flying, these mock-ups could also be rotated back into launch position. Crews practiced getting into and out of these mock-ups wearing their launch and entry suits as well as the basic emergency egress procedures; i.e., if the shuttle were to land in the water, or if the crews need to bail out while the shuttle is in flight

Analog Missions

-Remote field tests in locations that are identified based on their physical similarities to the extreme space environments of a target mission -Aquarius in Florida Keys 5.6 km off coast --> NEEMO mission provide astronauts with a realistic approximation of situations they will likely encounter on mission in space - since 2001, NEEMO has completed more than 20 missions -Short Distance Mobility Exploration Engineering Evaluation analog field tests were designed to measure the benefits of using pressurized vehicles, versus unpressurized vehicles, and to incorporate the findings into upcoming lunar missions --> Moses Lake, WA - lunar like environment tests ATHLETE Rover, K10, Lunar Truck, Lance Blade and Lunar Manipulator -Volcanic Terrains In-Situ Resource Utilization Demonstrations - NASA performs analogs to identify processes that, using hardware or by employing operations, can harness local resources (in-situ) for use in human and robotic exploration - demonstrating technologies for end-to-end oxygen extraction, separation, and storage from the volcanic material and other technologies that could be used to look for water or ice at the lunar pol -Haughton Mars Project: Devon Island, Nunavut, Canada - Similar to Mars - perform multiple representative lunar science and exploration surface activities, using existing field infrastructure and surface assets. They demonstrate scientific and operational concepts, including extravehicular activity traverses, long-term high-data communication, complex robotic interaction, and on-board rover and suit engineering.

IN-Air Launches

-Rocket is taken up to higher altitude then launched --> Known as sub-orbital launch, and reaching space with a parabolic trajectory that doesn't complete a full revolution around the Earth -Provides fuel savings by increasing altitude at which the rocket is launched and reducing atmospheric drag -SpaceShipOne and SpaceShipTwo -First variant of this was the launched in 1949 when a high attitude balloon was used to lift the rocket to 70,000 ft. before launch - rockoon - accurate positioning and launching cannot be achieved with a free balloon -Pegasus Rocket developed in the 1990's with payloads able to achieve LEO - produced cost savings by using the plane with its aerodynamic lift to get the payload up to 40,000 feet, where the atmosphere is only ~20% of that at sea level - cost savings come from (1) high altitude at launch, (2) less drag, and (3) higher speed at launch

Electromagnetic Thrusters

-Simplest form is pulsed plasma thruster (PPT) -PPT - original design uses noble gases but recent systems use solid propellant (Teflon) to avoid valves and storage - spark plug used to create some ablation ablation and ionization of material on the surface of Teflon then arc is created between cathode and anode - strong magnetic field and current is not as strongly damped out - interaction of current and magnetic field produce electromagnetic acceleration of plasma - 6-20 km/s - power efficiency is about 10% - Small size of systems make them candidates for propulsion units on small spacecraft such as Cubesat -Hall thruster uses radial magnetic field over which an axial electric field is applied - field strength of magnetic field is typically set such that electrons are magnetized while ions - electron trajectories are in the azimuthal direction, or the arc of the horizon, in the presence of both the magnetic and electric field - resulting current produces acceleration that reinforces the electric field acceleration so that ions experience strong axial acceleration - 15 to 20 km/s with power efficiencies about electrostatic thrusters - station keeping with about 240 spacecraft using Hall thrusters - SMART-1 -Variable Specific Impulse Magnetoplasma Rocket (VASIMR) uses intense radiofrequency RF waves to produce ionization of propellant, xenon or hydrogen - initial ionization is produced by waves at high frequency that drive the electrons into azimuthal motion - preheating system uses about 30 kW - preheated plasma then moves down the axial magnetic field, where more intense waves, at lower frequencies, produce strong heating of the ions - second stage uses about 200 kW - heated plasma is then expelled out the back of the magnetic nozzle to produce a very intense plasma stream

Electro thermal

-Simplest is to run the propellant over a hot incandescent filament before it is expelled out the nozzle of the thruster -Very simple and power efficient but specific impulse is smallest of all electric propulsion systems -Used for Iridium satellite constellation

Launch Vehicles

-Takes lots of energy to get into orbit --> higher orbit = more energy -Launch Vehicle: Rocket seen on launch pad during countdown - provides necessary velocity change to get spacecraft into space - single rocket cannot currently deliver spacecraft efficiently to space --> several smaller rockets or stages --> usually three stages -Upper Stages: Extra amount of energy need to get spacecraft out of parking orbits into mission orbit -Thrusters are used to adjust the spacecrafts orientation as needed

Mission Management & Operations

-Takes the mission from systems design to on-orbit reality - when spacecraft gets to orbit, mission operations begins --> mission control -NASA Headquarters (HQ) --> Washington, D.C. manages NASA Field Centers, establishes management policies, and analyzes all phases other Space Station program -Johnson Space Center (JSC) --> Houston, Texas directs station program - mission control operates the U.S. on-orbit segment (USOS) and manages activities across the station in close coordination with the international partner control centers - JSC is primary center for spacecraft design, development, , mission integration, and astronaut training. -Kennedy Space Center (KSC) --> Cape Canaveral, Florida --> prepares modules and spacecraft for missions, coordinates each countdown, and manages launch and post-landing operations -Marshall Space Flight Center (MSFC) --> Payload Operations and Integration Center (POIC) controls the operation of U.S. experiments and coordinates partner experiments aboard the station - MSFC oversaw development of most U.S. modules and the station's Environmental Control Life Support System -Telescience Support Centers (TSCs) --> Huntsville, Alabama - equipped to conduct science operations on board the station - Ames Research Center (ARC) in Moffett Field, California; Glenn Research Center (GRC) in Cleveland, Ohio; and Johnson Space Center -The control centers of NASA are: -Payload Operations and Integration Center (POIC), Marshall Space Flight Center -Mission Control Center (MCC), Johnson Space Center

Reduced Gravity Flights

-The C-9 is an airplane used by NASA to allow astronauts, engineers and scientist to work for very short periods of time in micro-gravity -Works by flying parabolas in the sky - first up steeply and then down - at the top of the curve (for about 25 seconds) , everything inside of the plane is free-falling and, thus, weightlessness is experienced

Tracking

-To track satellite's exact location --> use XYZ coordinate system called J2000 --> elements include position, velocity, and time produce a state vector - Z points through north pole - X points towards a star in Ares constellation in first day of year 2000 (J2000) - Y is perpendicular to plane created by other axis -Orbital title angle: inclination of orbit relative to equator - 0 is at equator and 90 is north/south pole - 0-90 is posigrade (west to east - 90-180 is retrograde (east to south) -Engineers use symbol i or term inclination to describe satellite's tilt -Ground Track Map: Provides information about what points on the Earth a satellite is flying over -Now use three TDRSS to track satellites -Used longitude and latitude

Trajectories & Orbits

-Trajectory: Path an object follows (launching spacecraft need to follow specific trajectory to escape Earth efficiently) -Orbit: Fixed path (usually elliptical) in which spacecraft travels around a celestial body -Parking orbit: Temporary orbit where spacecraft stays until transferring to final mission orbit -Orbit's size, shape, and orientation determine whether the payload can observe the subject and carry out the mission.

Space Tethers

-Two types of tethers -In one, the tether is an insulator and is only used for capture and release of the payload -In the other form, the tether is a conductor known as the electrodynamic tether that currents are induced along. These currents can provide electrical power and assist in orbital transfers for the main spacecraft in addition to providing capture and release of the payload -Space elevator would have to have a point that connects to each at right beyond geosynchronous orbit or about 36,000 km

Fixed-Based Simulators

-Used to give the crew the feel of on-orbit operations and are the next step in simulator training - do not move but operate in every other way exactly like on a vehicle -Practiced hundreds of times in these simulators before an astronaut flies into space -Integrated simulations involve the ground control teams, and take place during the last ten weeks before flight. The teams in the MCC have already gone through many hours of coursework and study to become flight controllers

Nuclear Electric Propulsion

-Voyager 1 and 2 spacecraft -Recent include Cassini (to Saturn) and Galileo (to Jupiter) - Radioisotope Thermal Generators (RTG) -RTG's use the decay of radioactive elements like plutonium-238 (Pu238) to generate heat - thermocouples convert this heat to electricity with effeciency of 3 to 7% -capable of generating power levels of a few tens to a few hundreds of watts, with about 0.5 kW produced per kilogram -Pu238 has the lowest shielding requirements and the longest half-life -Advanced Stirling Radioisotope Generator (ASRG) uses radioactive element such as Pu238 to drive piston - capable of generating nearly 140 W of power using less than one kilogram of Pu238 -Space Nuclear Reactors: Downsides: More massive than RTGs but more powerful Nuclear Engine for Rocket Vehicle Application (NERVA) - late 1950s to early 1960s -ystems proposed under NERVA were huge - with the largest system considered being able to generate 4000 MW of thermal power - expel hydrogen Jupiter Icy Moon Orbiter (JIMO) use nuclear power to create electrical power

Oxidizer

Agent that releases oxygen for combination with a fuel

Propellant

Chemical mixture burned to produce thrust in rockets and consists of a fuel and an oxidizer

Contingency aborts

Designed to permit flight crew survival following more severe failures when an intact abort is not possible - contingency abort would generally result in a ditch operation and loss of the vehicle

Intact aborts

Designed to provide a safe return of an orbiter to a planned landing site

Propulsion

How fast one can go is limited by two key parameters: -How quickly you can throw material out the back? -What is the mass that you are trying to push? -Related by law of conservation of momentum - momentum is product of an object's mass and velocity - related to Newton's Laws of Motion: If apply a force to an object for some time, momentum will change, called impulse /- a large change in momentum will impart a large force -Rockets move because of the momentum of their fuel - Before launch, total momentum of a rocket and its fuel is zero - during launch, the downward momentum of the expanding exhaust gases need to equal momentum of the rocket -Types of fuel: Chemical - RP-1 room temp, cryogenics (fuel and oxide at extremely low temp, ex liquid hydrogen and oxygen), hypergolic (fuel spontaneously combusts on contact with each other), solid rocket Ion rockets - electrons shot out after being charged Nuclear Rocket - cool nuclear core with liquid hydrogen - expel gas -Specific impulse: Efficiency, thrust to mass

Physiological Health

Neuroscience -Vestibular system, consisting of the semicircular canals and the otolith organs of the inner ear, maintains balance and equilibrium by sending information to the brain about the position and movement of the head - reactions occur in microgravity: postural illusions, tumbling sensations, dizziness, and space motion sickness -Initial awkwardness since conflict from vestibular system which no longer correspond with visual and other sensory information - Upon return to Earth, most astronauts experience some instability and difficulty in walking and standing - increased reliance upon visual cues and a possible change in the way the receptors in the joints sense the angle of the limbs - usually gone within week Space Motion Sickness (SMS) -Experienced by 50%/more astronauts for first few days -Loss of appetite, malaise, nausea, vomiting, gastrointestinal disturbances, and fatigue -Anti-motion sickness drugs are commonly used to treat space motion sickness -Come from vestibular system Autonomic Nervous System -Return to Earth - common problem is astronaut's inability to stand without fainting - "orthostatic intolerance" - insufficient blood being pumped to the brain - heart adapting to microgravity Sleep and Circadian Rhythms -Trouble sleeping during a flight -ISS orbits the Earth about every 90 minutes, so the normal light-dark cycles experienced on Earth are absent -Sleep in sleeping bags - no UP or DOWN in space - choose to orient themselves in whatever direction is most comfortable for them

Astronaut Training

Responsibilities -Commander: Makes critical decisions on behalf of the crew in coordination with ground control - take control and flies during approach and landing -Pilot: Commander's back up -Mission Specialists: Coordinating all on-board operations -Payload specialists: Professionals from physical or life sciences field or highly skilled technicians who can operate spacecraft's payload equipment - two years training before launch Entry Requirements -education and experience requirements are at least a bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. -At least 1,000 hours pilot-in-command time in jet aircraft; flight test experience is highly desirable. -Ability to pass a NASA Class I space physical, which is similar to a military or civilian Class I flight physical, and includes the following specific standards: for vision distance, visual acuity - 20/70 or better uncorrected, correctable to 20/20, each eye. For -Blood Pressure-140/90 measured in a sitting position. -Height between 64 and 76 inches. -To retain their proficiency at flying in a job that only allows them to fly very infrequently, pilots keep current by flying the T-38 high-performance training jets several hours each month Course of Study -Astronaut training takes place at Johnson Space Center (JSC) in Houston, Texas -Astronauts study spacecraft systems, currently Multi-Purpose Crew Vehicle, Space Launch System, and the Space Station, in addition to rendezvous and proximity operations (orbital mechanics), how to wear and work in a spacesuit, and how to work, eat, sleep, and go to the bathroom in microgravity -Astronauts take many science classes, and basic medical training -After you have been selected, and for the first year, you are considered an astronaut candidate. After one year of school and basic training, you graduate to become a full-fledged astronaut -Basic astronaut candidate training includes aircraft safety, including instruction in ejection techniques, parachute use, and survival to prepare them in the event the spacecraft is disabled and they have to eject or make an emergency landing -Advanced training program consists of 16 different courses covering all crew training requirements. Courses range from guidance, navigation, and control systems, to payload deployment and retrieval systems. Advanced training continues even after a crew has been given a flight assignment -Starting at about ten weeks before the mission, the astronaut team begins to simulate the mission with the MCC flight control team, who will assist them in the flight

Fuel

Substance that burns when combined with oxygen producing gas for propulsion

All spacecraft have two main components, the ___ and the ___. a) equipment, stages b) stages, equipment c) payload, rocket d) payload, bus

d) payload, bus

What are sites like Moses Lake, WA, Black Point, AZ, and the Hawaiian Islands preparing NASA for? a) A return trip to the lunar surface. b) Creating a base on Venus. c) Surviving sand storms. d) Living on the International Space Station.

a) A return trip to the lunar surface.

To prepare astronauts for living & working in space, we must consider the following factors: a) All listed! b) radiation c) micro-gravity d) emergency procedures

a) All listed!

The measurement of the amount of squash in an ellipse is called its ____. a) eccentricity b) foci c) distance d) axis

a) eccentricity

Solar sails... a) require no fuel for in-space propulsion. b) must be made of heavy materials to be practical. c) can only propel spacecraft away from the Sun. d) are a new idea that has never been tested.

a) require no fuel for in-space propulsion.

Which bodily system senses gravity to maintain balance and equilibrium? a) Neurological b) Vestibular c) Cardiovascular d) Gastrointestinal

b) Vestibular

Specific impulse indicates how many pounds (or kilograms) of _____ are obtained by the consumption of one pound (or kilogram) of _____ in one second. a) thrust, delta V b) thrust, propellant c) mass, fuel

b) thrust, propellant

This propulsion system simply ionizes and ejects propellant to produce thrust. a)Rockoon b)Electric Propulsion c)Nuclear Propulsion d)Space Elevators

b)Electric Propulsion

A VASIMR propulsion system, which basically energizes and accelerates ___ to create thrust, may be the way we are able to get humans to Mars. a)hydrogen b)plasma c)plutonium

b)plasma

At which NASA center does astronaut training take place? a) Kennedy Space Center, Cape Canaveral. b) Marshall Space Flight Center, Huntsville. c) Johnson Space Center, Houston. d) Gateway, The Moon.

c) Johnson Space Center, Houston.

All missions start with a ___. a) mission statement. b) spacecraft c) need d) orbit

c) need

An orbital assist is a technique to change a spacecraft's velocity, relative to the Sun, by swinging through a planet's _____ . a) atmosphere b) core c) orbit d) gravitational pull

d) gravitational pull

Types of propellents

liquid, solid, or hybrid

Retrograde horizontal

pointing backwards along the orbital path.

Outward radial

pointing directly away from the center of the Earth.

Inward radial

pointing directly towards the center of the Earth

Posigrade horizontal

pointing forward along the orbital path.