This is only a preview of the February 2015 issue of Silicon Chip. You can view 36 of the 104 pages in the full issue, including the advertisments. For full access, purchase the issue for $10.00 or subscribe for access to the latest issues. Articles in this series:
Items relevant to "6-Digit Retro Nixie Clock Mk.2, Pt.1":
Items relevant to "What’s In A Spark? – Measuring The Energy":
Items relevant to "Spark Energy Meter For Ignition Checks, Pt.1":
Purchase a printed copy of this issue for $10.00. |
Amateur unmanned vehicles pushing the limits on
REACH SKY
FOR
THE
... and way, way beyond
Miniature radio and video transmitters,
flight control computers, miniature
high-definition video cameras, miniature
GPS receivers, solid state gyroscopes
and accelerometers, miniature computers
and high energy density lithium polymer
batteries plus advances in materials science are
enabling amateur enthusiasts to make
unprecedented achievements with unmanned
air vehicles such as balloons, multi-rotor
aircraft, fixed wing aircraft, kites and rockets.
With these technologies they can fly high,
fast and for great distances.
A
chieving feats of altitude speed and long range
is fine but it is also nice for others to know about
these both so they can learn and improve their
own projects and to satisfy people’s curiosity about such
things. Fortunately there are distribution channels such as
YouTube and the Internet more generally that can be used
to publicise such achievements.
In this article we look at the achievements of a number of
amateurs in high altitude, long range and high speed flight
with unmanned radio-controlled (R-C) vehicles, along with
18 Silicon Chip
an amateur-built manned rocket intended for sub-orbital
flight, the subject of our lead illustration above.
Kites
Starting with one of the earliest flying technologies we
have kites. The world record for altitude for a single kite
is held by Australians Robert Moore, Michael Richards,
Michael Jenkins and Roger Martin. On September 23, 2014
they set a world record of 16,038 feet above the launch point
(current practice is still to measure aircraft altitude in feet).
siliconchip.com.au
altitude, long range and high speed
Part 1:
By
Dr DAVID MADDISON
Artist’s conception of spacecraft featuring
Copenhagen Suborbital's HEAT1600 rocket
engine. At the top of the spacecraft is the
astronaut capsule or MicroSpaceCraft (MSC)
and atop that is the Launch Escape System. The
escape system is a rocket that will carry the MSC
to safety in the event that the main propulsion
rocket malfunctions.
No, it’s not a tent they’re standing
in front of: Bob Moore, Roger Mar
tin, Michael Jenkins and Michae
with the huge kite used to set the
l Richards
world record of 16,083 feet in Sep
tember last year. At right is the
altitude and speed readings from
ground track and
the Horux GPS data logger. 12,6
20m of high strength Dyneema
for this record breaking flight.
line were spooled out
The record was achieved at the Cable Downs sheep station near Cobar in NSW. Australia’s Civil Aviation Safety
Authority (CASA) gave them special permission for the
flight and for previous attempts and granted them an
aircraft-free zone, with permission to fly to 17,370 feet.
It took extensive and often delicate negotiations to
achieve approval and some unusual conditions applied
but it was finally granted although, disappointingly, CASA
charged the team a hefty $560 fee (introduced around 2007)
for every flight period, which certainly does nothing to ensiliconchip.com.au
courage other people trying to achieve something. To their
credit, the team persevered with their negotiations and to
CASA’s credit, they eventually did grant permission. Hopefully it will be easier to obtain permission for their future
efforts and other pioneers who want to push the envelope.
An important part of this challenge was being able to
validate the altitude achieved. A combination of GPS data
loggers and GPS telemetry were used from the kite with both
manual recording and PC recording at the ground station.
The line used was over 12km of ultra-high-strength
February 2015 19
Dyneema (the world’s strongest commercial fibre on a
weight for weight basis) which was fed from a mechanical winch.
The GPS equipment on the kite was kept in an insulated
box as the temperature at altitude could be as low as -20°C.
The accuracy of the GPS data was verified against a fixed
survey datum by a registered surveyor. For telemetry GPS/
Flight using a u-blox receiver was used and for GPS data
logging a Holux M-1200e. The Holux unit weighs just 32
grams.
There is an extensive amount of detail on the kite and
its technology at Robert Moore’s website, www.kitesite.
com.au/kiterecord
Weather balloons
Balloons are another early flight technology - but they
too have gone high-tech.
There are two main types of balloon used by amateurs.
The first is a traditional weather balloon, often made of latex.
These can be filled with either helium or hydrogen, although
hydrogen carries significant safety risks if not handled correctly (although, unlike helium it is a renewable resource
and helium prices have – no pun intended – skyrocketed
recently with a world-wide shortage). Weather balloons
can fly as high as 30km (100,000ft) and more.
On February 1st, 2014 an enthusiastic group of Queensland Radio Amateurs (VK4HIA, VK4NBL, VK4AHR, VK4BOO, VK4FSCC and VK4FADI) launched a high altitude
balloon (HAB) near Dalby. It achieved an altitude of 107,837
feet and was equipped with a camera and transmitting
equipment for APRS (Automatic Packet Reporting System),
RTTY (radioteletype) and had a basic FM transmitter. They
documented their achievement with a video posted at “High
Altitude Balloon Launch and Recovery - Dalby, Queensland
VK4HIA – Balloonatics” http://youtu.be/5cRgBPqpJmA
The current record for an amateur high-altitude un-
Frame capture of YouTube video of the “Balloonatics”
(Queensland Radio Amateurs) immediately after the
balloon burst at 107,837 feet (near 32km). When latex
balloons burst they ideally shred into many small pieces
that fall clear of the balloon and don’t interfere with
the parachute or payload (this does not always happen,
however). A piece of balloon debris can be seen in the
lower right corner and the lines are attached to the
payload and parachute.
20 Silicon Chip
manned balloon is 145,590 feet achieved on 11th August
2012 by the Bello Mondo team. Many amateur balloon records and other information is available at www.arhab.org/
Some people launch balloons and use a Raspberry Pi as
the flight computer. A Frenchman, Fabrice Faure, has taken
some amazing photographs and his work is detailed on
his Fab4Space! web site at http://fab4space.com/?lang=en
PICO balloons
The second type of balloon in use is, perhaps surprisingly, the humble mylar “party balloon”. These are the small
silver-coloured balloons that might have “Happy Birthday”
or some other greeting written on them.
These balloons have been used to carry as payload tiny
electronic packages, comprising a GPS receiver, a radio
transmitter, a battery and some even carry tiny solar panels. The entire electronic payload and support string may
weigh less than 13g.
They are known as PICO balloons and require no license
or permission to launch and can drift at an altitude of
around 8,000 metres and can reach very great distances
from their release points.
Note that we are talking about actual party balloons
bought from a party supply shop, not special balloons of
a similar design.
Melbourne amateur radio operator Andy Nguyen, VK3YT,
has released many PICO balloons and details their trips
at http://picospace.net/ From Melbourne, PICO balloons
have flown as far as Adelaide, New Zealand, Fiji and South
America. Most of the long range flights are solar powered
(ie, they contain tiny solar panels), but many Melbourne to
New Zealand trips are powered by a primary lithium battery.
The trackers (the electronic payload containing the
GPS, transmitter, power and control circuitry) are custom
designed and built for minimal weight and power budget.
The total weight of the tracker is less than 13g and the
transmitter power is from 10-25mW.
Andy’s early model trackers transmitted on VHF and
UHF and required line-of-sight tracking via the amateur
radio APRS (Automatic Packet Reporting System) network
or an amateur radio digital mode such as Olivia or THOR.
The range achievable with the balloon at a typical altitude
of 8,000m was 380km.
The Rhone river flowing into the Mediterranean Sea from
the south of France as photographed by Fabrice Faure. The
picture was taken with a camera connected to a Raspberry
Pi computer from an altitude of 86,000 feet.
siliconchip.com.au
Predicting balloon trajectories
Balloon flights require a lot of planning. It is not simply a matter
of releasing a balloon and hoping for the best. One has to make
sure the balloon will travel in the desired direction and also have
knowledge of the likely recovery area and to ensure it does not go
near airports or flight paths.
Smaller balloons require no flight approval but it is still important
to do the safe and responsible thing.
Fortunately there are accurate online tools to predict balloon paths
which should be used before launching any missions. One tool is
“Balloon Trajectory Forecasts” at http://weather.uwyo.edu/polar/
balloon_traj.html It can output a GoogleEarth KML file which will
show the predicted balloon path on a GoogleEarth map. It will even
predict the balloon burst and landing position.
Another balloon modelling program is HYSPLIT (Hybrid Single
Particle Lagrangian Integrated Trajectory Model) available free at
http://ready.arl.noaa.gov/HYSPLIT.php It can predict many types
of atmospheric transport and dispersion paths such as smoke and
volcanic ash plumes but there is also a section for balloons.
As an example of what this model can do, the coordinates for
Melbourne were entered and a map was generated showing the
predicted path of a balloon released from Melbourne at the time
specified. Multiple trajectories can be displayed corresponding to
different altitudes and times of each new “starting point” correspond
to where a split in the trajectory is shown.
Olivia and Thor are multi-frequency shift keying (MFSK)
transmission modes for digital data over radio waves.
Andy is currently testing HF for a longer tracking range
of many thousands of kilometres using weak signal propagation protocols such as JT9, JT65 and WSPR. So far the
maximum range a tracker signal has been received using
A typical PICO balloon launch showing balloon, payload
and two tiny horizontal solar panels.
siliconchip.com.au
WSPR from a PICO balloon is 16,000km – with only 25mW
of transmitter power!
WSPR is an open source software program that uses a
protocol for probing radio propagation paths from very low
power transmitters. Each transmission contains a transmitter’s location, call sign and power. Users who receive
transmissions upload reception reports to the WSPRnet
database http://wsprnet.org/drupal/ The program is capable
WSJT-X software (slightly modified) for monitoring the
extremely weak transmissions from PICO balloons.
Windows for WSPR software are also visible. WSJT is
also an open source program to facilitate low power
transmissions between radio amateurs. WSJT-X is an
experimental version of this program. JT9 and JT65 are
transmission modes supported by this software designed
for extremely weak transmission which when received are
many decibels below the noise floor.
February 2015 21
A PICO payload weight around 12g. Note the
u-blox GPS receiver. This tracker transmitted at
434.650MHz USB with 10mW power. It had a
dipole antenna and the transmit mode was 100
baud RTTY, 425Hz shift, ASCII 8, None, 1.
of decoding signals that are not even audible to the
ear and are -28dB in a 2,500Hz bandwidth.
According to Andy, the main purpose of this work
is to study radio weak signal propagation, and at the
same time have fun working with a community of volunteer
tracking stations around Australia. None of these would
be possible without the network of volunteer tracking stations assisting with the launches. Their contribution to the
success of the PICO balloon flights is greatly appreciated.
Until recently, the longest PICO flight has been from
Melbourne to Brazil which took place from the 12th July
until the 21st July 2014, a distance of 16,000km, just a few
days after the World Cup (see right)!
Unfortunately PICO balloons don’t remain aloft forever.
The weight of rain can bring them down, as can UV degradation of the mylar material causing them to leak helium.
Ground track of Andy Nguyen’s PS-30 flight. It was
launched in Melbourne on 27th December, 2014 and at
the time of writing (12th January, 2015) it is still in flight
and was just off the coast of Africa. If it remains aloft
long enough, wind predictions indicate there is even a
possibility it could return to Australia! It has tiny solar
panels and a 25mW transmitter on board. At night the
electronics go dormant because the low temperature, as
low as -65°C, prevents the battery from working.
You can track the progress of the current flights on Andy’s
web site at http://picospace.net/tracker/new Alternatively
you can track this and other high altitude balloons at
http://tracker.habhub.org/
The law and unmanned aircraft
SILICON CHIP cannot give definitive legal advice about the legality
of various activities described here, either for Australia or overseas
as the laws are subject to change and are also subject to ambiguity
in some cases. It is up to prospective operators to fully familiarise
themselves with the relevant regulations.
Certainly, people in Australia should familiarise themselves with
the Civil Aviation Safety Authority’s (CASA) regulations CASR Part
101. Advisory circulars for Part 101 can be seen at www.casa.
gov.au/scripts/nc.dll?WCMS:STANDARD::pc=PC_91039 and
the regulations themselves are at www.comlaw.gov.au/Details/
F2014C01256/Html/Volume_3#_Toc403541324
You may also be interested in looking at proposals for regulation changes at www.casa.gov.au/scripts/nc.dll?WCMS:PWA::pc
=PARTS101
As with any activity it is important to exercise common sense
and individual responsibility and to set the highest possible example for one’s endeavours. There are always some politicians
and bureaucrats who enjoy nothing else than removing the simple
pleasures from people so if everyone is sensible, it is less likely
for them to do this.
In general, unmanned aircraft should not be operated near
people or building structures and only in remote areas and within
the rules as they apply. There are height and range limits that
apply and aircraft should not be flown beyond visual range for
non-commercial flights (there are exemptions for commercial
operators after extensive training and licensing).
There are also special rules for balloons which can be flown
22 Silicon Chip
beyond visual range under certain circumstances. “Small balloons” that can carry a
payload of no more than 50g such as the
PICO balloons described here are unrestricted
and require no permission to fly but are still
subject to “common sense” considerations.
Long range non-commercial FPV flights are not likely to be
legal in Australia without special permission as they go beyond
visual range and exceed the height limit of 400 feet. Never fly near
airports or in controlled airspace. There are also aircraft weight
limits which apply of 25kg or 150kg if in a club, although there are
no restrictions on aircraft weighing less than 100g.
People have rightly been fined when unmanned air vehicles have
flown too close to people and crashed and injured them (see, for
example, www.abc.net.au/news/2014-11-13/drone-operator-atgeraldton-marathon-fined/5887196).
Note also that in Australia there are limits to the permitted
radio power and frequencies used for uplinks and downlinks to
and from RC aircraft.
For the future of this hobby it is important that operators do
not give the authorities any excuse to regulate it out of existence
as is the case of with many other fun activities.
This is partly because this technology is rapidly changing and
laws don’t necessarily keep up with the state of play and often
because politicians and bureaucrats and some elements of the
media usually do not understand the technology or the fun aspect
of anything.
siliconchip.com.au
The radio controlled (RC) aircraft that was flown to the
edge of space on a weather balloon, prior to launch. It is
a Multiplex Funjet, a very fast RC model in its own right
but in this application it was used as a glider and no motor
was installed.
Apart from that, helium is notoriously difficult to contain
and would eventually leak out.
If you want to participate in tracking these PICO balloons
you can go to Andy’s website and sign up for the mailing
list which will advise you of launch times and path predictions. You will need an inexpensive software defined radio
(SDR) (see SILICON CHIP May & October 2013), an appropriate
antenna and some free modified WSJTX software from the
PICOSPACE website.
The balloons can be tracked at http://spacenear.us or if
it is an APRS payload, at http://aprs.fi
Combining the above two aircraft types, there are also
balloon-kite hybrids.
For those interested in aerial photography from kites
and balloons there is a discussion at www.paulillsley.
com/airphoto/systems/balloons-kites.html, among many
other sites.
Using a balloon as a launch platform
Combining a balloon for the launch vehicle and a radio
controlled aircraft, a Swedish man, David Windestål flew
a balloon to a height of approximately 108,000 feet with a
payload of a radio controlled aircraft which beamed a live
video feed back to the pilot.
Many problems had to be solved such as removing grease
from the servos of the plane as it would freeze at the cold
temperatures at high altitude and also the electronics and
batteries had to be kept warm as lithium batteries are very
sensitive to low temperatures; their voltage drops.
Another problem is that most civilian GPS units are designed not to work at altitudes above 18,000m and speeds
above 1,852km/h so that terrorists or rogue states cannot
use them to control missiles, so the altitude had to be determined barometrically. The distance between the launch
site and the landing site was 101km.
The web site with details of the project is at http://rcexplorer.se/projects/2013/03/fpv-to-space-and-back/ See
YouTube video “Space Glider – FPV to Space and Back!”
http://youtu.be/rpBnurznFio
Along the same lines as above there is an Australian
project known as “Project Thunderstruck” (http://projectsiliconchip.com.au
Artist’s rendering of Project Thunderstruck re-entry
vehicle. It will initially be launched from an altitude of
40km but it is planned to be developed as a sub-orbital and
then an orbital re-entry vehicle.
thunderstruck.org/).
The objective is to carry an aircraft to an altitude of 40km
and then achieve supersonic flight as the aircraft dives back
towards earth. The aircraft will also be capable of carrying
a payload for various experiments.
The supersonic glider will be 2.5m long and is expected
to achieve a speed of Mach 1.5 and 1800km/h. This is the
initial stage in development of a re-entry vehicle for which
it is planned to be able to deliver a payload to space on a
sounding rocket in a non-orbital flight within 2-3 years and
orbital flight in 6 years.
One remarkable part of this project is that the glider
Hydrogen and helium for balloons
Those interested in hoisting some payloads aloft have a choice
of either hydrogen or helium. Hydrogen is relatively cheap and
renewable but it can be hazardous in untrained hands and is not
generally recommended in the ballooning community.
On the other hand, Helium is the lifting gas of choice but unfortunately it is a non-renewable resource and once released it
drifts off into space. Recent reports have suggested that helium
supplies worldwide are in short supply and therefore becoming
more expensive.
Tanks of helium gas can be hired although it is possible to
purchase a small amount of helium in a disposable cylinder. Balloon Time have a 422 litre disposable tank which is enough to
fill around 50 standard latex balloons to a diameter of 230mm.
I have seen such a cylinder in a party supply store in Melbourne
selling for $55. Such a cylinder should be able to be used to fill
mylar PICO balloons which can also be purchased unfilled at
party stores. Those balloons can also be filled with helium at
some party stores.
February 2015 23
The world’s fastest R/C jet. It uses a micro gas turbine
engine and holds the Guiness world record.
Commander Major Jon Fletcher with the paper aircraft that
set the record for highest altitude release. It carried GPS,
transmitter, a camera and support electronics.
will be designed by 12 year old student, Jason Brand, from
Sydney.
Paper aeroplane launched from balloon
People have even launched paper planes from balloons!
On 13th September 2014 Fox Valley Composite Squadron
of the Illinois Wing, Civil Air Patrol, an unpaid volunteer
organisation, launched a paper plane from a balloon at an
altitude of 96,537ft.
Tracking data was acquired via an onboard GPS and
transmitted via the amateur radio APRS network. There
was also an onboard video camera, temperature sensors,
pressure sensors, flight computer and solar panel. The
plane was 760mm long and 370mm across and weighed
424g. The launch took place at Kankakee, Illinois and the
aircraft landed at Rochester, Indiana around 132km away
(straight line distance).
High speed gliders
Dynamic soaring is a process by which radio-controlled
gliders (or other aircraft) can gain airspeed under particular
wind conditions comprising two masses of air moving with
different velocity.
Such circumstances might occur at the top of a hill.
When there is a wind blowing there will be a relatively
slow movement of air near ground level on the downwind
side of the hill and relatively fast moving air higher up.
The air vehicle is flown in loops that repeatedly transition
from the fast moving air body to the slower moving air body
and back to the faster air body and so on. Little air speed is
lost in a properly executed loop so energy is gained every
time the aircraft transitions from the slow moving body of
air to the faster moving air body.
Using this technique, the current word record for an
unpowered RC aircraft is 813km/h (set 22nd November,
24 Silicon Chip
2014). The aerodynamic stresses in tight loops at such high
speeds are extreme and 100G forces can be experienced.
Crashes are not uncommon and at those speeds an impact with the ground leaves few recognisable components.
Structural failure mid-air can also occur. Dynamic soaring
is also the technique by which albatrosses fly vast distances
with little wing movement.
See video “DYNAMIC SOARING NEW WORLD RECORD:
Bruce Tebo flies 505mph at Weldon with his Kinetic 130”
at http://youtu.be/r7gL9uA-McY
Turbine RC aeroplane record
It is possible to purchase (or make, if you are keen)
micro gas turbine jet engines. The speed record for an RC
aeroplane was set on 14th September, 2013 at 708km/h
which is actually slower than that set for the unpowered
glider mentioned above. The turbine engine itself weighs
1.58kg, has 18kg of thrust at 120,000RPM and burns either
diesel or Jet A1. See “very very very fast Turbine powered
RC Jet 440MPH Speed Guinness World Record 2013” http://
youtu.be/sa-TSNeTK-A
As an aside, people have fitted these microturbines to
bicycles, search YouTube for some amazing videos www.
youtube.com/results?search_query=jet+powered+bicycle
Long-range FPV fixed wing flight
With the use of flight control computers that are integrated with GPS, accelerometers, compass and gyroscopes
and FPV (first person view, a video downlink giving the
pilot the view from the aircraft) it is possible to undertake
very long flights.
One person has achieved a very long-range FPV of 80km
round trip using an electrically powered flying wing with
32 1.8W supplementary solar cells in addition to an onboard battery.
Extensive telemetry from the aircraft is shown, including
GPS coordinates. It is not stated where the flight took place
but it can be seen from the coordinates that it was in the
Dominican Republic.
siliconchip.com.au
A note on some high altitude pictures
All 3hrs 25m of it can be seen online – “FPV Long
Range 80km full flight.” http://youtu.be/z_PxhU9i9Ng but
an edited version (3.5minutes) is at “FPV, 80km and back.
2.4Ghz RC.”: http://youtu.be/TfDfkjGNWSQ
Long-range multicopter flight
Multicopters (or as they are popularly known, drones)
were discussed in a feature in SILICON CHIP August 2012.
They are very popular in the R-C community and new
capabilities and records are being added all the time.
Many multicopters are now equipped with FPV and GPS
navigation. A long range multicopter flight of 20km radius
(40km total flight) and is shown in a video at “Long range
quadcopter fpv 20km/40km 2013/12/28” http://youtu.be/
zvEHxpoDJVA
The flight time of 63 minutes is unusually long for a
quadcopter – a typical flight time might be closer to 10
minutes – suggesting that this quadcopter has been highly
optimised for long range flight and well beyond visual range.
The winning formula for long range quadcopter flight
seems to be a light weight frame, the largest possible propellers on high torque motors and a high capacity. low-cell
count battery.
In the video it is instructive to look at the telemetry data
which displays mAh consumed, battery voltage, current
draw, ground speed, elapsed time and heading to get an
idea of what is going on during the flight.
FULL DUPLEX
COMMUNICATION
OVER WIRELESS
LAN AND IP
NETWORKS
Flight control computers
Many radio-controlled aircraft use flight controllers to
help fly and navigate them. These range from basic ones
costing perhaps $30 to full auto-pilots costing up to several
hundred dollars.
One of many examples of a flight controller that is capable
of autonomous flight is the open source APM flight controller. With the addition of a GPS and compass module it
can be sent on missions flying via various GPS way points.
It could be used to deliver a small package to a recipient
via a quadcopter, for example (but check legality before
attempting to do so!).
Coming next month!
We’ve covered kites, balloons, fixed-wing and rotordriven aircraft . . . and we’ve only just scratched the surface
of this exciting field.
Next month, in part 2 of this feature we’ll have a look
at some of the amazing advances (and even more amazing
plans) of amateur rocketeers. They even have a project to
put a man in space!
SC
siliconchip.com.au
IP 100H
SSeee thhee
rreevview in
SILICON CHinIP
DDeecceem
mber 220014
14
(ask
sk us for a
(a
u
s for a ccooppy!)
y!)
Icom Australia has released a revolutionary
new IP Advanced Radio System that works
over both wireless LAN and IP networks.
The IP Advanced Radio System is easy to set
up and use, requiring no license fee or call
charges.
To find out more about Icom’s IP networking
products email sales<at>icom.net.au
WWW.ICOM.NET.AU
ICOM5001
Many high altitude pictures, including those reproduced in this
feature, show pronounced apparent curvature of the earth giving
the impression of a view of the earth from low earth orbit, which
is about five times higher than a weather balloon.
At the altitude of weather balloons there is in fact some visible
curvature of the earth but the very pronounced curvature in some
pictures is more due to the effect of the fish-eye lens used on
many cameras, especially the GoPro, which is a popular choice.
There are numerous software applications to remove this fisheye effect if it is not wanted but don’t be deceived that you are
seeing a view as if it was from orbit.
February 2015 25
|