Portland State Aerospace Society
Encyclopedia
The Portland State Aerospace Society (or PSAS), founded in 1997, is a student group at Portland State University
building high powered rocket
s with the vision of putting nanosatellites
into Earth orbit. Pursuing this vision has led to building advanced avionics
, adaptable airframe
s, and high energy rocket engine
s. PSAS attempts to be open
in its development, including posting CAD drawings and schematics, and maintaining its GPL
and MIT
-licensed software in git
and Subversion.
, and more advanced telemetry
.
LV1b was an extension of the LV1 rocket to add a GPS module, an improved flight computer, and improved IMU. It was flown to 13.53 km (11,600 feet) in October 2000.
.
LV2.1 was the second flight of LV2 in August 2005, with the complete avionics system. The modular aluminum airframe measured 11 feet tall, 5.25 inches wide, and weighed 115 pounds. The avionics system included a 133 MHz Pentium flight computer running Linux
, using 802.11
telemetry broadcast via custom-made cylindrical patch antenna
s, a GPS module, IMU
module, temperature sensor, altimeter
, and recovery node. The various nodes ran on PIC microcontroller
s and were connected via a CAN bus. The motor was an ammonium perchlorate
and aluminum mixture.
The rocket reached a maximum altitude over 18,000 feet AGL
. Rocket telemetry was successful, but the nosecone appeared to not release at apogee when the recovery charges were fired. The result was a descent in "lawn dart" mode, where no parachute
s open and the rocket lands nearly straight into the ground.
flight computer and ARM
microcontroller nodes connected via USB.
A successful launch of the new airframe and recovery hardware was made on May 31, 2009. This flight used commercial flight avionics, as well as carrying an experimental avionics/telemetry system (TeleMetrum) developed by Keith Packard
and a digital video recorder.
Flights in 2010 tested active roll control using small mid-body canard fins. The second flight introduced a rear fin canister on bearings ("spin can") to avoid coupling with the canard vortices, an effect noticed on the first flight.
hybrid rocket
engine, development of real-time control algorithms for in-flight steering (a requirement for orbital spaceflight
), CAN bus debugging hardware ("CANtelope"), enhancing the Linux
USB driver, and development of open source
GPS firmware.
Portland State University
Portland State University is a public state urban university located in downtown Portland, Oregon, United States. Founded in 1946, it has the largest overall enrollment of any university in the state of Oregon, including undergraduate and graduate students. It is also the only public university in...
building high powered rocket
High powered rocket
High-power rocketry is a hobby similar to model rocketry. The major difference is that higher impulse range motors are used. The National Fire Protection Association definition of a high-power rocket is one that has a total weight of more than 1500 grams and contains a motor or motors...
s with the vision of putting nanosatellites
Miniaturized satellite
Miniaturized satellites or small satellites are artificial satellites of unusually low weights and small sizes, usually under . While all such satellites can be referred to as small satellites, different classifications are used to categorize them based on mass .One reason for miniaturizing...
into Earth orbit. Pursuing this vision has led to building advanced avionics
Avionics
Avionics are electronic systems used on aircraft, artificial satellites and spacecraft.Avionic systems include communications, navigation, the display and management of multiple systems and the hundreds of systems that are fitted to aircraft to meet individual roles...
, adaptable airframe
Airframe
The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage and exclude the propulsion system...
s, and high energy rocket engine
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
s. PSAS attempts to be open
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
in its development, including posting CAD drawings and schematics, and maintaining its GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
and MIT
MIT License
The MIT License is a free software license originating at the Massachusetts Institute of Technology . It is a permissive license, meaning that it permits reuse within proprietary software provided all copies of the licensed software include a copy of the MIT License terms...
-licensed software in git
Git (software)
Git is a distributed revision control system with an emphasis on speed. Git was initially designed and developed by Linus Torvalds for Linux kernel development. Every Git working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on...
and Subversion.
LV0
The first airframe, LV0 was a proof of concept for some of the radio systems, including real-time broadcast video. LV0 was launched in June 1998.LV1
The second airframe, LV1 was flown to 3.6 km (12,000 feet) in April 1999. It added an emergency uplink system, an Inertial Measurement UnitInertial measurement unit
An inertial measurement unit, or IMU, is an electronic device that measures and reports on a craft's velocity, orientation, and gravitational forces, using a combination of accelerometers and gyroscopes. IMUs are typically used to maneuver aircraft, including UAVs, among many others, and...
, and more advanced telemetry
Telemetry
Telemetry is a technology that allows measurements to be made at a distance, usually via radio wave transmission and reception of the information. The word is derived from Greek roots: tele = remote, and metron = measure...
.
LV1b was an extension of the LV1 rocket to add a GPS module, an improved flight computer, and improved IMU. It was flown to 13.53 km (11,600 feet) in October 2000.
LV2
The third airframe, LV2 was first flown as an airframe only (with commercial flight computer) in September 2002. It reached apogee at around 18,000 feet and a maximum velocity of 900 miles per hour, over Mach 1Speed of sound
The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at , the speed of sound is . This is , or about one kilometer in three seconds or approximately one mile in five seconds....
.
LV2.1 was the second flight of LV2 in August 2005, with the complete avionics system. The modular aluminum airframe measured 11 feet tall, 5.25 inches wide, and weighed 115 pounds. The avionics system included a 133 MHz Pentium flight computer running Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, using 802.11
IEEE 802.11
IEEE 802.11 is a set of standards for implementing wireless local area network computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee . The base version of the standard IEEE 802.11-2007 has had subsequent...
telemetry broadcast via custom-made cylindrical patch antenna
Patch antenna
A patch antenna is a type of radio antenna with a low profile, which can be mounted on a flat surface. It consists of a flat rectangular sheet or "patch" of metal, mounted over a larger sheet of metal called a ground plane. The assembly is usually contained inside a plastic radome, which...
s, a GPS module, IMU
Inertial measurement unit
An inertial measurement unit, or IMU, is an electronic device that measures and reports on a craft's velocity, orientation, and gravitational forces, using a combination of accelerometers and gyroscopes. IMUs are typically used to maneuver aircraft, including UAVs, among many others, and...
module, temperature sensor, altimeter
Altimeter
An altimeter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth underwater.-Pressure altimeter:...
, and recovery node. The various nodes ran on PIC microcontroller
PIC microcontroller
PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1650 originally developed by General Instrument's Microelectronics Division...
s and were connected via a CAN bus. The motor was an ammonium perchlorate
Ammonium perchlorate
Ammonium perchlorate is an inorganic compound with the formula NH4ClO4. It is the salt of perchloric acid and ammonia. It is a powerful oxidizer, which is why its main use is in solid propellants...
and aluminum mixture.
The rocket reached a maximum altitude over 18,000 feet AGL
Above ground level
In aviation and atmospheric sciences, an altitude is said to be above ground level when it is measured with respect to the underlying ground surface. This is as opposed to above mean sea level , or in broadcast engineering, height above average terrain...
. Rocket telemetry was successful, but the nosecone appeared to not release at apogee when the recovery charges were fired. The result was a descent in "lawn dart" mode, where no parachute
Parachute
A parachute is a device used to slow the motion of an object through an atmosphere by creating drag, or in the case of ram-air parachutes, aerodynamic lift. Parachutes are usually made out of light, strong cloth, originally silk, now most commonly nylon...
s open and the rocket lands nearly straight into the ground.
LV2.3
The fourth airframe and replacement avionics are currently being designed. The airframe will retain the modular design, moving to 5.5 inches (139.7 mm) tubing (a more standard size). The next avionics system plans to use a PowerPCPowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
flight computer and ARM
ARM architecture
ARM is a 32-bit reduced instruction set computer instruction set architecture developed by ARM Holdings. It was named the Advanced RISC Machine, and before that, the Acorn RISC Machine. The ARM architecture is the most widely used 32-bit ISA in numbers produced...
microcontroller nodes connected via USB.
A successful launch of the new airframe and recovery hardware was made on May 31, 2009. This flight used commercial flight avionics, as well as carrying an experimental avionics/telemetry system (TeleMetrum) developed by Keith Packard
Keith Packard
Keith Packard is a software developer, best known for his work on the X Window System.Packard is responsible for many X extensions and technical papers on X...
and a digital video recorder.
Flights in 2010 tested active roll control using small mid-body canard fins. The second flight introduced a rear fin canister on bearings ("spin can") to avoid coupling with the canard vortices, an effect noticed on the first flight.
Other projects
Other areas of research include design and testing of an oxygen/paraffinParaffin
In chemistry, paraffin is a term that can be used synonymously with "alkane", indicating hydrocarbons with the general formula CnH2n+2. Paraffin wax refers to a mixture of alkanes that falls within the 20 ≤ n ≤ 40 range; they are found in the solid state at room temperature and begin to enter the...
hybrid rocket
Hybrid rocket
A hybrid rocket is a rocket with a rocket motor which uses propellants in two different states of matter - one solid and the other either gas or liquid. The Hybrid rocket concept can be traced back at least 75 years....
engine, development of real-time control algorithms for in-flight steering (a requirement for orbital spaceflight
Orbital spaceflight
An orbital spaceflight is a spaceflight in which a spacecraft is placed on a trajectory where it could remain in space for at least one orbit. To do this around the Earth, it must be on a free trajectory which has an altitude at perigee above...
), CAN bus debugging hardware ("CANtelope"), enhancing the Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
USB driver, and development of open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
GPS firmware.