Sea Launch/Zenit Thrust: 8,180,000 N Fueled Weight: 450,000 kg Payload to LEO: 13,740 kg Cost per launch: $100,000,000 Cost per kg: $7,300 Launches: 31/28 Present:

Colorado Space Grant Consortium Gateway To Space ASEN 1400 / ASTR 2500 Class #20 Gateway To Space ASEN 1400 / ASTR 2500 Class #20 T-30

-Announcements -One minute Report Questions -Mid Semester Team Evaluations - Orbits and Mission Design – Part II -Launch is in 30 days Today:

4 Announcements… pCDR peer reviews… - 3 rd place is Team #5 - 2 nd place is Team #7 - 1 st place is Team #4 DD Rev A/B Grades HW #8 Due 4:00 PM November 9 th Office Hours and Questions in Class

5 Mid Semester Team Evaluations… Please pass them forward now New grades posted next Tuesday Community Service project will be included

Colorado Space Grant Consortium Next Tuesday… Guest Lecture on ADCS Next Tuesday… Guest Lecture on ADCS

One Minute Reports: Geostationary VS. Geosynchronous

One Minute Reports: - What types of orbits do they do around other planets? - Is there a polar orbit that is also geosynchronous? - Could spacecraft ever be launched from Colorado? - How do you get on elliptical orbit? - What is the advantage of elliptical orbit vs. a circular orbit around the Earth? - Does the angle at which you launch a satellite affect its eccentricity? - How many different orbits are there? - Do you have launch a satellite at an angle to get it into orbit or can you shoot it straight up?

Types of Rockets:

One Minute Reports: - Who owns the geosync orbit space? UN through the International Telecommunications Union - When is our Movie Night? - What is the amount of time between turning on the Sat at launch? - Do you have to write a journal about every chapter? - How will the in-class simulation work? - Do we need to have all the satellite building and testing done before the in-class simulation? - What chances do students have to go to those big conferences? -

One Minute Reports: - Where does Tom Kelly work now?

One Minute Reports: -- What is an acoustic test? - Are vibration tests done with mass models or the actual products? - Did they use Velcro on floor to keep them in place? - Has an emergency ever occurred on an EVA? - Is Grumman still making space vehicles? - Arduino is beginning to look like a next of wires? - Why is water blue? - Why is this class so awesome? - What is the craziest thing I ever did…

Colorado Space Grant Consortium Orbits and Mission Design – Part 2 ASEN 1400 / ASTR 2500 Class #19 Orbits and Mission Design – Part 2 ASEN 1400 / ASTR 2500 Class #19

Orbits: A Brief Historical Look

Earth, the Moon, Mars, and the Stars Beyond A Brief Discussion on Mission Design

Universal Gravitation, Applied: What is an orbit?

Newton’s Laws: Newton Continued , Principia Published Law of Universal Gravitation (Attraction)

Orbit History: Kepler’s 3 Laws of Planetary Motion: 1.All planets move in elliptical orbits, sun at one focus

Orbit History: Kepler’s 3 Laws of Planetary Motion: 2.A line joining any planet to the sun, sweeps out equal areas in equal times

Orbit History: Kepler’s 3 Laws of Planetary Motion: 3.The square of the period of any planet about the sun is proportional to the cube of the of the planet’s mean distance from the sun. If you can observe the period of rotation, you can determine the distance PlanetP (yr)a (AU)T2T2 R3R3 Mercury Venus Earth1.00 Mars Jupiter Saturn

Types of Orbits: Orbits are conic sections: Circle Ellipse Parabola Hyperbola From Kepler’s Law, the central body is at a focus of the conic section

Kepler: Kepler’s Laws...Orbits described by conic sections Velocity of an orbit described by following equation For a circle (a=r): For a ellipse (a>0): For a parabola (a=  ):

Earth, the Moon, Mars, and the Stars Beyond A Brief Discussion on Mission Design

Orbit Introduction: What is an orbit? - The path of a satellite around the Earth (or any central body) What shape is it? - Orbits are conic sections - Circles, Ellipses, Parabolas, Hyperbolas How are orbits described? - Position and Velocity at any one time - Keplerian Elements (from Kepler’s Laws)

Orbit Definition: Velocity & Position - Given position and velocity of a satellite at time t, you can calculate the position and velocity at any other time

Orbit Definition: Keplerian Elements - Semi major axis (a) - Size - Eccentricity (e) - Shape

Orbit Definition: Keplerian Elements - Inclination (i) - Angle to the Equator

Orbit Definition:

Keplerian Elements - Right Ascension of Ascending Node (RAAN, Ω) - Rotation about the Earth’s Spin Axis

Orbit Definition: Keplerian Elements - Argument of Perigee (ω) - Rotation of the conic section in the plane

Orbit Definition: Keplerian Elements - True Anomaly (θ) - Defines the position of a body in orbit - Angle between the Position Vector and the vector to Perigee - Elliptical only

Types of Orbits (cont.) Geosynchronous/Geostationary (equator)

Types of Orbits (cont.) Critical Inclination

Types of Orbits (cont.) Repeating Ground Trace

Polar/ Sun Synchronous Types of Orbits (cont.)

Molniya

Circular Orbit: For a 250 km circular Earth Orbit Orbital Velocity

Circular Orbit: Orbital Period

Circular Orbit: For a 500 km circular Earth Orbit Orbital Velocity

Circular Orbit: For a 500 km circular Earth Orbit Orbital Period Conclusions???

Changing Orbits: How about 250 km to 500 km How would you do it?

Changing Orbits: Changing orbits usually involves an elliptical orbit or Transfer Orbit Perigee = close Apogee = far

Changing Orbits: 1) Velocity of initial orbit 2) Velocity of final orbit 3) Velocity at perigee 4) Velocity at apogee

Changing Orbits: Since orbit is elliptical at Vper and Vapo a > 0, so where

Changing Orbits: So back to our  V’s 3) Velocity at perigee

Changing Orbits: So back to our  V’s 4) Velocity at apogee

Changing Orbits: 1) Velocity of initial orbit 2) Velocity of final orbit 3) Velocity at perigee 4) Velocity at apogee

Changing Orbits: Therefore:  V 1 is to start transfer

Changing Orbits:  V 2 is to circularize orbit

Changing Orbits: What if we did the whole thing in reverse? Go from 500 to 250 km? What happens to the answer?

Changing Orbits: 1) Velocity of initial orbit 2) Velocity of final orbit 3) Velocity at perigee 4) Velocity at apogee

Changing Orbits: Therefore:  V 1 is to start transfer

Changing Orbits:  V 2 is to circularize orbit

Changing Orbits: Time to do transfer is the same

How well do you understand Hohmann Transfers? to 2? 2 to 3? 3 to 1? 1 to 3?

Circular Orbit:

Changing Orbits: Also something called “Fast Transfer” It is more direct and quicker However it takes more fuel  V 1 and  V 2 are much bigger