1651 Words7 Pages

Celestial Mechanics

Orbital Maneuvers

Earth, Moon, Mars, and Beyond

Rodolfo G. Ngilangil Jr. MBA, BSAE

Impulsive Maneuvers

Impulsive maneuvers are those in which brief firings of onboard rocket motors change the magnitude and direction of the velocity vector instantaneously. The position of the spacecraft is considered to be fixed during the maneuvers. This is true for high-thrust rockets with burn times short compared with the coasting of the spacecraft.

Orbital Maneuvers - 2

Hohmann Transfer - Definition

The Hohmann transfer is an elliptical orbit tangent to both circles at its apse line. The periapse and apoapse of the transfer ellipse are the radii of the inner and outer circles.

The Hohmann transfer is the most*…show more content…*

Determine the most efficient transfer from orbit 1 to a circular orbit of altitude 16 000 km (orbit 3), and the required delta-v.

Orbital Maneuvers - 14

Phasing Maneuvers

A phasing maneuver is a two-impulse Hohmann transfer from and back to the same orbit. Phasing maneuvers are used to change the position of a S/C in its orbit.

Orbital Maneuvers - 15

Phasing Maneuvers - Assignment 2 :

S/C at A and B are in the same orbit 1. At the instant shown, the chaser vehicle at A executes a phasing maneuver so as to catch the target S/C back at A after just one revolution of the chaser’s phasing orbit 2. What is the required total delta-v.

Orbital Maneuvers - 16

Phasing Maneuvers - ssignment 3 A

It is desired to shift the longitude of a GEO satellite from 99.1°W to 111.1 °W in three revolutions of its phasing orbit. Calculate the delta-v requirement.

Orbital Maneuvers - 17

Non-Hohmann Transfers with A Common Apse Line - 1

Transfer between two coaxial elliptical orbits in which the transfer trajectory shar es the apse line but is not necessarily tangent to either the initial or target orbit. The problem is to determi ne if there exists such a trajectory joining points A and B.

Orbital Maneuvers - 18

Non-Hohmann Transfers with A Common Apse Line - 2

rA = rB = e3 =

2 h3

1 µ 1 + e3 cos θ A 1 µ 1 + e3 cos θ B

2 h3

rB − rA rA cos θ A − rB cos θ B cos θ A −

Orbital Maneuvers

Earth, Moon, Mars, and Beyond

Rodolfo G. Ngilangil Jr. MBA, BSAE

Impulsive Maneuvers

Impulsive maneuvers are those in which brief firings of onboard rocket motors change the magnitude and direction of the velocity vector instantaneously. The position of the spacecraft is considered to be fixed during the maneuvers. This is true for high-thrust rockets with burn times short compared with the coasting of the spacecraft.

Orbital Maneuvers - 2

Hohmann Transfer - Definition

The Hohmann transfer is an elliptical orbit tangent to both circles at its apse line. The periapse and apoapse of the transfer ellipse are the radii of the inner and outer circles.

The Hohmann transfer is the most

Determine the most efficient transfer from orbit 1 to a circular orbit of altitude 16 000 km (orbit 3), and the required delta-v.

Orbital Maneuvers - 14

Phasing Maneuvers

A phasing maneuver is a two-impulse Hohmann transfer from and back to the same orbit. Phasing maneuvers are used to change the position of a S/C in its orbit.

Orbital Maneuvers - 15

Phasing Maneuvers - Assignment 2 :

S/C at A and B are in the same orbit 1. At the instant shown, the chaser vehicle at A executes a phasing maneuver so as to catch the target S/C back at A after just one revolution of the chaser’s phasing orbit 2. What is the required total delta-v.

Orbital Maneuvers - 16

Phasing Maneuvers - ssignment 3 A

It is desired to shift the longitude of a GEO satellite from 99.1°W to 111.1 °W in three revolutions of its phasing orbit. Calculate the delta-v requirement.

Orbital Maneuvers - 17

Non-Hohmann Transfers with A Common Apse Line - 1

Transfer between two coaxial elliptical orbits in which the transfer trajectory shar es the apse line but is not necessarily tangent to either the initial or target orbit. The problem is to determi ne if there exists such a trajectory joining points A and B.

Orbital Maneuvers - 18

Non-Hohmann Transfers with A Common Apse Line - 2

rA = rB = e3 =

2 h3

1 µ 1 + e3 cos θ A 1 µ 1 + e3 cos θ B

2 h3

rB − rA rA cos θ A − rB cos θ B cos θ A −

Related

## Taking a Look at Orbital Mechanics

661 Words | 3 PagesOrbital mechanics is the application of ballistic and celestial mechanics to motion, especially pertaining to rockets and spacecraft. Many famous physicists and mathematicians have helped develop equations, formulas, and laws to understand different aspects of orbital mechanics; such as Newton with centripetal force and the gravitational constant (GM) and also Kepler and his three laws of planetary motion. Though my interest did not sprout from who was involved with orbital mechanics, but the orbital

## Orbital Parameters Of Earth And Mars

729 Words | 3 PagesQuestion 5 It is assumed that Earth and Mars are in Circular orbits. The initial relative phase angle is stated to be 30o. Calculate the transfer orbit of a time of flight (TOF) 120 day. The orbital parameters such as ΔVs must be calculated. In addition, the propulsion considerations must be evaluated for the case when mission is to be Evaluate the orbital parameters, ΔVs and propulsion parameters when the mission is to be executed by a 500 kg spacecraft, which utilizes 450 s specific impulse propellant

## Introduction When we walk along the beach, we often notice that the water level rises and recedes

2500 Words | 10 PagesIntroduction When we walk along the beach, we often notice that the water level rises and recedes at certain times during the day which are known as low and high tides. These high and low tides that we observe on the beaches are caused by waves that form out far out in the ocean that travel along and crash into our coastline. If you have been to the beach more than once, you probably noticed that the high and low tides doesn’t always happen at the same time each day; they change. These waves are

## This is an essay I did on explaining how gravity works as well as how it effects the tides... How high tide and low tide work

1146 Words | 5 PagesIntroduction "Gravity is a force of attraction that exists between any two masses, any two bodies, any two particles. Gravity is not just the attraction between objects and the Earth. It is the attraction that exists between all objects". (NASA gravity 2000) Gravity is a very essential part of life on earth. We are in the exact position in the sun's gravitational field to keep us in orbit and keep life ongoing on our planet. Gravity is a downward force on any body of mass, the larger the mass of

## The Moons Of Saturn : Orbital Motion

1208 Words | 5 PagesThe moons of Saturn are numerous and diverse ranging from tiny moonlets less than 1 kilometer across to the enormous Titan, which is larger than the planet Mercury. Saturn has 62 moons with confirmed orbits, 53 of which have names and only 13 of which have diameters larger than 50 kilometers (Porco 2009). Twenty-four of Saturn 's moons are regular satellites; they have prograde orbits not greatly inclined to Saturn 's equatorial plane, while the other 38 are irregular satellites (Turrini et al. 2009;

## The Gravitational Slingshot Essay

1567 Words | 7 PagesThe Gravitational Slingshot The gravitational slingshot is a way that scientists have truly harnessed the gravitational pull of a planet by using it to launch satellites and other useful projectiles towards their desired locations. This method was developed through the use of Newton's Laws of Gravity and Kepler's Laws of Planetary Motion. When these ideas of gravity and the shape of a planet's orbit were brought together piece by piece, this new theory changed how a projectile traveling

## Essay on Gravitation Lab

860 Words | 4 PagesGo to http://phet.colorado.edu/simulations/sims.php?sim=My_Solar_System and click on Run Now. 1. Move the slider all the way to accurate, click on the tape measure and the grid. 2. Click the radio button for 4 objects and run the simulation until the purple planet (body 2) has made one complete orbit (one year). 3. After the first orbit (year), turn off the traces (show traces box) and watch another orbit (year) of the purple planet (body 2). Question One: Is blue moon (body 3) circling

## Kepler 's Laws Of Planetary Motion

1017 Words | 5 PagesKepler’s Laws Johannes Kepler formulated the Three Laws of Planetary Motion. The first is the Law of Orbits, stating that all planets move in elliptical orbits with the sun at one focus. The second law is the Law of Areas. This is the idea that a line that connects the planet to the sun sweeps out equal areas in the plane of the planet’s orbit in equal time intervals. Last is the Law of Periods which states that the square of the period of any planet is proportional to the cube of the semi major

## Knowledge Is The Importance Of Knowledge

946 Words | 4 PagesKnowledge is the understanding of something such as facts, information or descriptions. Many might say that we acquire knowledge through experience which is true however, a combination of stories and facts play a major role in gaining knowledge. A fact is a statement that is true and can be proven through experimentation. Stories on the other hand are accounts of imaginary or real people and events told for entertainment. One area of knowledge which mainly consists of facts but takes the form of

## Non Gravitational Effects On Jupiter 's Satellites

1161 Words | 5 PagesNon-gravitational effects on Jupiter’s satellites The non-gravitational forces affecting on the natural satellites orbits were studied recently using observations. This effect creates a quadratic term in orbital longitude and a secular changing of the semi-major axis. Causes may be only hypothetical. It is assumed that the causes of the effects are in the tides in the body of the planet and in the body of satellite (Emelyanov 2015; private communication). Lainey et al. (2009) considered an extensive

### Taking a Look at Orbital Mechanics

661 Words | 3 Pages### Orbital Parameters Of Earth And Mars

729 Words | 3 Pages### Introduction When we walk along the beach, we often notice that the water level rises and recedes

2500 Words | 10 Pages### This is an essay I did on explaining how gravity works as well as how it effects the tides... How high tide and low tide work

1146 Words | 5 Pages### The Moons Of Saturn : Orbital Motion

1208 Words | 5 Pages### The Gravitational Slingshot Essay

1567 Words | 7 Pages### Essay on Gravitation Lab

860 Words | 4 Pages### Kepler 's Laws Of Planetary Motion

1017 Words | 5 Pages### Knowledge Is The Importance Of Knowledge

946 Words | 4 Pages### Non Gravitational Effects On Jupiter 's Satellites

1161 Words | 5 Pages