This month's AE presenter: James AuBuchon
Date of presentation: 23 Sept 2019
Subject: How to Build a Space System III, Orbits
Description: Jim continued his series on how to build a space system with the third installment about orbits.
An orbit is the path taken by a celestial body under the gravitational influence of another body.
They may be open or closed. The orbital characteristics of man-made space systems may be selected to best serve the mission of the space system.
Closed orbits in a two-body system are ellipses with each body orbiting the barycenter (center of gravity) of the system.
If one of the two objects is extremely massive (in comparison to the other), the barycenter may be within the more massive body.
Such is the case in the Solar System, the Earth-moon system, and man-made satellites orbiting a planetary body.
Six parameters are required to describe an orbit. The six Newtonian parameters are equivalent to the six Keplerian parameters.
Either parameter set can be used. Orbits may be perturbed by a long list of factors, hence the need for station-keeping in man-made satellites.
Perturbations can be deliberately introduced to change the orbit for operational reasons.
Orbits of man-made satellites are selected to optimize altitude,
inclination, and synchronicity with the rotational period of the central
body, and eccentricity.
These choices represent various operational trade-offs and are selected to suit the mission of the satellite.
Some of these trade-offs are discussed in greater detail.
Satellites can be caused to orbit about Lagrange points.
23 September 2019
26 August 2019
Presentations: August 2019
This month's AE presenter: Jeff
Date of presentation: 26 Aug 2019
Subject: Why does the 737-200 still fly in Canada?
Subject: Saving the Dark
Description: Jeff gave two separate short presentations this time, rather than a single longer one. Here are brief descriptions of both:
First, why does the 737-200 still fly in Canada? This aircraft, the second iteration of the well-regarded 737 series, stopped production in 1988, meaning the youngest of these aircraft are over 30 years old. Of the worldwide fleet of 58 still in commercial service as of July 2018, 17 (about 29%) are flying in Canada. What makes this plane so popular there?
The biggest advantage is that it can be relatively easily fitted with a gravel kit: a combination of gravel deflectors attached to the nose wheel, vortex dissipators attached to the engine nacelles, and structural enhancements to the lower fuselage. These devices allow this large plane to conduct operations on unpaved fields that are the norm in northern Canada, allowing the plane to bring in basic necessities and to provide those living in remote settlements a way to travel to and from the region.
Given that much of northern Canada is peppered with these remote and temporary settlements (small towns, mining camps, etc.) that may only be accessible by air and for which permanent paved landing structures will probably never be available, the 737-200 is a vital lifeline to those who live there.
The second presentation was a repeat of a presentation first given just over a year ago, in July 2018, entitled "Saving the Dark". This presentation concerned the growing problem of light pollution in and around urban and suburban areas, and detailed a number of issues, such as: the effects that excessive light can have on the health of both humans and wildlife; the waste of energy involved in producing light that isn't needed or even useful; and ways in which we can strive to reduce the amount of light pollution we produce.
I felt that it was a good idea to repeat this presentation, even though it has been barely a year since originally presented, since there is a substantial number of new faces in the squadron who wouldn't have been here to see it when I first presented it.
Date of presentation: 26 Aug 2019
Subject: Why does the 737-200 still fly in Canada?
Subject: Saving the Dark
Description: Jeff gave two separate short presentations this time, rather than a single longer one. Here are brief descriptions of both:
First, why does the 737-200 still fly in Canada? This aircraft, the second iteration of the well-regarded 737 series, stopped production in 1988, meaning the youngest of these aircraft are over 30 years old. Of the worldwide fleet of 58 still in commercial service as of July 2018, 17 (about 29%) are flying in Canada. What makes this plane so popular there?
The biggest advantage is that it can be relatively easily fitted with a gravel kit: a combination of gravel deflectors attached to the nose wheel, vortex dissipators attached to the engine nacelles, and structural enhancements to the lower fuselage. These devices allow this large plane to conduct operations on unpaved fields that are the norm in northern Canada, allowing the plane to bring in basic necessities and to provide those living in remote settlements a way to travel to and from the region.
Given that much of northern Canada is peppered with these remote and temporary settlements (small towns, mining camps, etc.) that may only be accessible by air and for which permanent paved landing structures will probably never be available, the 737-200 is a vital lifeline to those who live there.
The second presentation was a repeat of a presentation first given just over a year ago, in July 2018, entitled "Saving the Dark". This presentation concerned the growing problem of light pollution in and around urban and suburban areas, and detailed a number of issues, such as: the effects that excessive light can have on the health of both humans and wildlife; the waste of energy involved in producing light that isn't needed or even useful; and ways in which we can strive to reduce the amount of light pollution we produce.
I felt that it was a good idea to repeat this presentation, even though it has been barely a year since originally presented, since there is a substantial number of new faces in the squadron who wouldn't have been here to see it when I first presented it.
15 July 2019
Presentation: July 2019
This month's AE presenter: Kailash Kalidoss
Date of presentation: 15-July-2019
Subject: The return of Supersonic Flight
Description: Kailash's presentation gave a brief overview of supersonic travel - what it means to consumers, the technicalities surrounding it, a history of the prestigious Concorde, its glory and shortfall. Most importantly, it captures a vision for the future, in the form of a company named BOOM which is developing next-generation efficient commercial supersonic aircraft.
Any flight performed at a speed greater than Mach 1.3 is deemed supersonic.
The Concorde was the most prestigious (and in fact the only commercial) supersonic aircraft to date. It was jointly developed by Britain and France and was in operation between 1976 and 2003. Due to operational, environmental, regulatory and design challenges, the Concorde could never scale in a big way. There were very few operational routes and its cost was exorbitant.
Following the fatal crash of a Concorde in France in 2000, and post 9/11 financial meltdown, the company, its funding, and unsustainable operations made the airplane defunct. It was pulled out of service in 2003.
There has been no replacement for this commercial supersonic aircraft to date. However, an American company named BOOM is trying to address this void in the aviation market. BOOM is capable of Mach 2.2 and is only slightly smaller than Concorde. Its design is futuristic and lighter through the usage of reinforced carbon fiber for most of its parts.
The company claims that it would operate at a per-passenger cost comparable to a subsonic business class ticket. Also, due to the better performance and a range of 4500 nm without a refuel, it opens many more routes across the globe. The traditional London to New York route that takes 7-8 hours in a subsonic aircraft can theoretically be achieved in 3 hrs. 15 min by BOOM. This 55-75 seat aircraft is looking to change aviation in the future.
Video Link: https://www.youtube.com/watch?v=c-HbJn3LAHc
Date of presentation: 15-July-2019
Subject: The return of Supersonic Flight
Description: Kailash's presentation gave a brief overview of supersonic travel - what it means to consumers, the technicalities surrounding it, a history of the prestigious Concorde, its glory and shortfall. Most importantly, it captures a vision for the future, in the form of a company named BOOM which is developing next-generation efficient commercial supersonic aircraft.
Any flight performed at a speed greater than Mach 1.3 is deemed supersonic.
The Concorde was the most prestigious (and in fact the only commercial) supersonic aircraft to date. It was jointly developed by Britain and France and was in operation between 1976 and 2003. Due to operational, environmental, regulatory and design challenges, the Concorde could never scale in a big way. There were very few operational routes and its cost was exorbitant.
Following the fatal crash of a Concorde in France in 2000, and post 9/11 financial meltdown, the company, its funding, and unsustainable operations made the airplane defunct. It was pulled out of service in 2003.
There has been no replacement for this commercial supersonic aircraft to date. However, an American company named BOOM is trying to address this void in the aviation market. BOOM is capable of Mach 2.2 and is only slightly smaller than Concorde. Its design is futuristic and lighter through the usage of reinforced carbon fiber for most of its parts.
The company claims that it would operate at a per-passenger cost comparable to a subsonic business class ticket. Also, due to the better performance and a range of 4500 nm without a refuel, it opens many more routes across the globe. The traditional London to New York route that takes 7-8 hours in a subsonic aircraft can theoretically be achieved in 3 hrs. 15 min by BOOM. This 55-75 seat aircraft is looking to change aviation in the future.
Video Link: https://www.youtube.com/watch?v=c-HbJn3LAHc
30 June 2019
Presentation: June 2019
This month's AE presenter: Jeff
Date of presentation: June 2019 (exact date TBD)
Subject: Strange Aircraft
Description: For June, Jeff dusted off his old Strange Aircraft presentation, which was actually one of the first ones he gave upon being appointed Squadron AEO. (It's a good presentation and I'd hate for it to be forgotten!)
This time around, there were several people knowledgeable about specific planes mentioned, and a lively discussion (the best kind!) ensued.
Date of presentation: June 2019 (exact date TBD)
Subject: Strange Aircraft
Description: For June, Jeff dusted off his old Strange Aircraft presentation, which was actually one of the first ones he gave upon being appointed Squadron AEO. (It's a good presentation and I'd hate for it to be forgotten!)
This time around, there were several people knowledgeable about specific planes mentioned, and a lively discussion (the best kind!) ensued.
31 May 2019
Presentation: May 2019
This month's AE presenter: James Aubuchon
Date of presentation: May 2019 (exact date uncertain)
Subject: How to Build a Space System II, the Space Environment Proper
Description: Space is by its nature a difficult environment in which to place and operate any kind of system. The space environment is characterized by high vacuum, temperature extremes, thermal cycling, and low gravity.
Though a small speck can damage a satellite, over 500,000 pieces of orbital debris larger than 10 cm are currently tracked by NASA. There are over 40 known meteor showers that pass through Earth’s upper atmosphere. There are also cosmic rays, micrometeoroids, and other particulates. The chemical environment includes very reactive atomic oxygen and the Van Allen radiation belts. There is an induced environment as the result of venting and outgassing from the space system itself which can interact with the space system.
Space weather variations, due mainly to the Sun, make the environment more challenging. While visible light is approximately constant, X-ray and ultraviolet light are highly variable in time and space.
Solar wind, solar flares, coronal mass ejections, solar energetic particles, x-ray flares, solar radio bursts, & solar proton events are unpredictable and are sometimes huge to monumental. These can react directly with the space system or with the Earth’s magnetosphere to cause geomagnetic storms. They can energize the ionosphere and the Van Allen radiation belts.
Direct effects on the space system may include radiation damage which can cause single event upset, latchup, loss of orientation, execution of phantom commands, and degradation of solar panels. They may result in spacecraft charging with subsequent spark discharge and possible damage. Effects on the atmosphere may result in scintillation of satellite to ground communication.
These are some of the factors which make space a difficult environment. Taken individually, any one might prove hazardous to endurance, navigation, or general operation of a space system. Taken collectively, they make operating any such system in space a massive and yet delicate undertaking.
Date of presentation: May 2019 (exact date uncertain)
Subject: How to Build a Space System II, the Space Environment Proper
Description: Space is by its nature a difficult environment in which to place and operate any kind of system. The space environment is characterized by high vacuum, temperature extremes, thermal cycling, and low gravity.
Though a small speck can damage a satellite, over 500,000 pieces of orbital debris larger than 10 cm are currently tracked by NASA. There are over 40 known meteor showers that pass through Earth’s upper atmosphere. There are also cosmic rays, micrometeoroids, and other particulates. The chemical environment includes very reactive atomic oxygen and the Van Allen radiation belts. There is an induced environment as the result of venting and outgassing from the space system itself which can interact with the space system.
Space weather variations, due mainly to the Sun, make the environment more challenging. While visible light is approximately constant, X-ray and ultraviolet light are highly variable in time and space.
Solar wind, solar flares, coronal mass ejections, solar energetic particles, x-ray flares, solar radio bursts, & solar proton events are unpredictable and are sometimes huge to monumental. These can react directly with the space system or with the Earth’s magnetosphere to cause geomagnetic storms. They can energize the ionosphere and the Van Allen radiation belts.
Direct effects on the space system may include radiation damage which can cause single event upset, latchup, loss of orientation, execution of phantom commands, and degradation of solar panels. They may result in spacecraft charging with subsequent spark discharge and possible damage. Effects on the atmosphere may result in scintillation of satellite to ground communication.
These are some of the factors which make space a difficult environment. Taken individually, any one might prove hazardous to endurance, navigation, or general operation of a space system. Taken collectively, they make operating any such system in space a massive and yet delicate undertaking.
15 April 2019
Presentation: April 2019
This month's AE presenter: Jeff
Date of presentation: 15-Apr-2019
Subject: Crew Dragon
Description: In this month's scintillating presentation, Jeff talked about the project called "Crew Dragon", a NASA-funded project being designed by SpaceX. Crew Dragon is one of two variants of the larger project "Dragon 2", which itself is the successor to the earlier Dragon series of cargo transports by SpaceX. The Crew Dragon variant is designed to carry up to seven astronauts, while the Cargo Dragon variant is exclusively for cargo. A trial run successfully docked with the International Space Station on 8-Mar-2019.
Date of presentation: 15-Apr-2019
Subject: Crew Dragon
Description: In this month's scintillating presentation, Jeff talked about the project called "Crew Dragon", a NASA-funded project being designed by SpaceX. Crew Dragon is one of two variants of the larger project "Dragon 2", which itself is the successor to the earlier Dragon series of cargo transports by SpaceX. The Crew Dragon variant is designed to carry up to seven astronauts, while the Cargo Dragon variant is exclusively for cargo. A trial run successfully docked with the International Space Station on 8-Mar-2019.
25 March 2019
Presentation: March 2019
This month's AE presenter: James Aubuchon
Date of presentation: 25-Mar-2019
Subject: How to Build a Space System I, Dealing with the Earth’s Atmosphere
Description: A space system must ascend (and possibly descend) through the atmosphere. We must communicate with that system through the atmosphere. Some very small portion of the atmosphere remains even at the altitude of man-made satellites. The atmosphere has layers determined not by arbitrary boundaries, but by physical characteristics. Still, there is more than one layering system.
The best known (Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere) is determined by temperature gradient (not temperature). For example, temperature decreases with altitude in the troposphere and increases with altitude in the stratosphere.
The atmosphere is also layered by chemical composition. The atmosphere can be divided into the lower homosphere in which the atmosphere is well stirred and the higher heterosphere where chemical layering is more pronounced. There is also an ozone layer, and an ionosphere (which, itself, has layers).
There is a lower acoustic zone and a higher anacoustic zone in which sound will not propagate. These classifications schemes overlap one another.
The physical characteristics of the various layers were discussed. The exosphere blends smoothly into outer space where the gravity of the Earth is no longer strong enough to prevent the solar radiation from removing particles from the Earth’s atmosphere.
Date of presentation: 25-Mar-2019
Subject: How to Build a Space System I, Dealing with the Earth’s Atmosphere
Description: A space system must ascend (and possibly descend) through the atmosphere. We must communicate with that system through the atmosphere. Some very small portion of the atmosphere remains even at the altitude of man-made satellites. The atmosphere has layers determined not by arbitrary boundaries, but by physical characteristics. Still, there is more than one layering system.
The best known (Troposphere, Stratosphere, Mesosphere, Thermosphere, Exosphere) is determined by temperature gradient (not temperature). For example, temperature decreases with altitude in the troposphere and increases with altitude in the stratosphere.
The atmosphere is also layered by chemical composition. The atmosphere can be divided into the lower homosphere in which the atmosphere is well stirred and the higher heterosphere where chemical layering is more pronounced. There is also an ozone layer, and an ionosphere (which, itself, has layers).
There is a lower acoustic zone and a higher anacoustic zone in which sound will not propagate. These classifications schemes overlap one another.
The physical characteristics of the various layers were discussed. The exosphere blends smoothly into outer space where the gravity of the Earth is no longer strong enough to prevent the solar radiation from removing particles from the Earth’s atmosphere.
18 February 2019
Presentation: February 2019
This month's AE presenter: Jeff
Date of presentation: TBD, sometime in February
Subject: TBD, but I bet it was good
Description: Yay! A presentation was delivered in February, I promise! However, due to a senior moment, I can't remember anything about it at this time. Will fill in the rest when I do remember.
Date of presentation: TBD, sometime in February
Subject: TBD, but I bet it was good
Description: Yay! A presentation was delivered in February, I promise! However, due to a senior moment, I can't remember anything about it at this time. Will fill in the rest when I do remember.
31 January 2019
No presentation: January 2019
Well, I guess I can't reuse last month's excuse, can I? Especially since it was specific to December!
Actually, I had a presentation "in the can" and ready to go for much of the month, but the calendar was full and I had no opportunity to deliver it in January. I did eventually deliver this presentation in February instead.
Now, if only I could remember what it was about...
Actually, I had a presentation "in the can" and ready to go for much of the month, but the calendar was full and I had no opportunity to deliver it in January. I did eventually deliver this presentation in February instead.
Now, if only I could remember what it was about...
31 December 2018
No presentation: December 2018
If there's one month that often gets singled out with no presentation delivered, it might (or might not) be December. Due to the holidays and other familial arrangements, there are usually fewer meetings in December, and those are often packed with other activities that are significantly higher priority than AE. That was the case in December 2018, and there was no presentation delivered that month. Sorry.
That's my story and I'm sticking to it.
That's my story and I'm sticking to it.
19 November 2018
Presentation: November 2018
This month's AE presenter: David
Date of presentation: 19-Nov-2018
Subject: Cruise Missiles
Description: David presented a brief history of cruise missiles. Cruise missiles have had a major impact on our world today as they have often been the first weapon used in modern conflicts. A cruise missile is a unmanned aircraft, similar to a drone, except that it is typically meant to hit its target and not return (with some exceptions). Cruise missiles differ from ballistic missiles, which have a boost phase and fall back to the target by gravity.
Cruise missiles were first conceptualized in WWI with the modification of Navy Curtis N-9 biplanes to fly into ships. The Army also developed the Kettering Bug, another pilotless biplane, to attack land targets. These weapons were too late for WWI, but the V1 Buzz Bomb was used extensively in WWII and widely regarded as the first effective cruise missile. Ground and Air launched cruise missiles culminated with the BGM-109 Tomahawk and AGM-86 ALCM missiles used today.
Date of presentation: 19-Nov-2018
Subject: Cruise Missiles
Description: David presented a brief history of cruise missiles. Cruise missiles have had a major impact on our world today as they have often been the first weapon used in modern conflicts. A cruise missile is a unmanned aircraft, similar to a drone, except that it is typically meant to hit its target and not return (with some exceptions). Cruise missiles differ from ballistic missiles, which have a boost phase and fall back to the target by gravity.
Cruise missiles were first conceptualized in WWI with the modification of Navy Curtis N-9 biplanes to fly into ships. The Army also developed the Kettering Bug, another pilotless biplane, to attack land targets. These weapons were too late for WWI, but the V1 Buzz Bomb was used extensively in WWII and widely regarded as the first effective cruise missile. Ground and Air launched cruise missiles culminated with the BGM-109 Tomahawk and AGM-86 ALCM missiles used today.
31 October 2018
No presentation: October 2018
Once again, events have conspired to deprive our audience of our monthly words of wisdom (if not wit) for the month of October 2018.
17 September 2018
Presentation: September 2018
This month's AE presenter: James Aubuchon
Date of presentation: 17-Sept-2018 (not 100% certain of exact date)
Subject: The source of subsonic lift
Description: Guest presenter James "Jim" Aubuchon delivered the September 2018 presentation on aerodynamics, explaining how the source of subsonic lift is Van der Waals Forces, and not the Bernoulli Effect as commonly believed.
The Bernoulli Effect is a valid observation made on liquids and published in 1738. In some circumstances, it applies to gases. However, it is an observed effect and not a fundamental cause. Similarly, Newton’s Laws are statements of observed behavior and are not fundamental causes. The fundamental forces of flight are gravity, which must be overcome, and the electromagnetic force, which provides lift. In subsonic flight, the electromagnetic force is applied to the aircraft via Van der Waals forces. The popular explanation of lift in terms of different airflow transit times above and below the wing is wrong.
The most intuitive way to visualize lift is in terms of Newton’s Laws. The wing directs airflow downward behind the wing, hence the air exerts an upward force on the wing. For a Cessna 182, air within about 5 meters above the wing is directed downward. Downwash and Van der Waals forces cause lift, not Newton’s Laws or the Bernoulli Effect. The Bernoulli Effect is useful in aircraft design to calculate the pressure distribution on aircraft surfaces, but, again, is not the proximal cause of lift.
Date of presentation: 17-Sept-2018 (not 100% certain of exact date)
Subject: The source of subsonic lift
Description: Guest presenter James "Jim" Aubuchon delivered the September 2018 presentation on aerodynamics, explaining how the source of subsonic lift is Van der Waals Forces, and not the Bernoulli Effect as commonly believed.
The Bernoulli Effect is a valid observation made on liquids and published in 1738. In some circumstances, it applies to gases. However, it is an observed effect and not a fundamental cause. Similarly, Newton’s Laws are statements of observed behavior and are not fundamental causes. The fundamental forces of flight are gravity, which must be overcome, and the electromagnetic force, which provides lift. In subsonic flight, the electromagnetic force is applied to the aircraft via Van der Waals forces. The popular explanation of lift in terms of different airflow transit times above and below the wing is wrong.
The most intuitive way to visualize lift is in terms of Newton’s Laws. The wing directs airflow downward behind the wing, hence the air exerts an upward force on the wing. For a Cessna 182, air within about 5 meters above the wing is directed downward. Downwash and Van der Waals forces cause lift, not Newton’s Laws or the Bernoulli Effect. The Bernoulli Effect is useful in aircraft design to calculate the pressure distribution on aircraft surfaces, but, again, is not the proximal cause of lift.
06 August 2018
Presentation: August 2018
This month's AE presenter: Jeff
Date of presentation: 6 Aug 2018
Subject: The TESS Mission
Description: Jeff gave a brief presentation outlining the goals and progress of NASA's Transiting Exoplanet Survey Satellite (TESS) mission. TESS is a space telescope, designed to search for exoplanets using the transit method in an area 400 times larger than that covered by the Kepler mission.
Date of presentation: 6 Aug 2018
Subject: The TESS Mission
Description: Jeff gave a brief presentation outlining the goals and progress of NASA's Transiting Exoplanet Survey Satellite (TESS) mission. TESS is a space telescope, designed to search for exoplanets using the transit method in an area 400 times larger than that covered by the Kepler mission.
04 August 2018
Event: Drone Testing
David organized a mini-event at Baylands Park in Sunnyvale, CA. Several squadron members participating in our Quadcopter Kit AE Stem Project met at Baylands Park to fly the STEM Quad Lugs quadcopter. This quadcopter, built at the squadron by squadron members, was stable on the easy settings, near impossible to control on the sensitive settings. It will continue to fly in the future, and will be used at recruiting events. This successfully concludes this STEM project.
While there, the group also flew other member-owned quadcopters and fixed wing RC aircraft. The park had other RC modelers flying their aircraft, and the group spent quite a bit of time watching them as well.
While there, the group also flew other member-owned quadcopters and fixed wing RC aircraft. The park had other RC modelers flying their aircraft, and the group spent quite a bit of time watching them as well.
Subscribe to:
Posts (Atom)