GASPACS (Get Away Special Passive Attitude Control Satellite)
was a
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
sponsored 1U
CubeSat
A CubeSat is a class of miniaturized satellite based around a form factor consisting of cubes. CubeSats have a mass of no more than per unit, and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats ...
developed entirely by undergraduate members of
Utah State University
Utah State University (USU or Utah State) is a public land-grant research university in Logan, Utah. It is accredited by the Northwest Commission on Colleges and Universities. With nearly 20,000 students living on or near campus, USU is Utah's ...
's
Get Away Special
Getaway Special was a NASA program that offered interested individuals, or groups, opportunities to fly small experiments aboard the Space Shuttle. Over the 20-year history of the program, over 170 individual missions were flown. The program, whi ...
(GAS) team. The primary mission objective of GASPACS was to deploy a 1-meter inflatable aerodynamic boom to passively stabilize its
attitude
Attitude may refer to:
Philosophy and psychology
* Attitude (psychology), an individual's predisposed state of mind regarding a value
* Metaphysics of presence
* Propositional attitude, a relational mental state connecting a person to a pro ...
.
GASPACS was the world's first CubeSat to be developed entirely by undergraduate students, and was also the world's first CubeSat to utilize a
Raspberry Pi
Raspberry Pi () is a series of small single-board computers (SBCs) developed in the United Kingdom by the Raspberry Pi Foundation in association with Broadcom. The Raspberry Pi project originally leaned towards the promotion of teaching basic ...
Zero as its flight computer.
Overview
GASPACS was a 1U CubeSat, meaning it measured 10 centimeters by 10 centimeters by 10 centimeters (3.9 in).
GASPACS's primary mission objective was to deploy and photograph a 1-meter (39 inches) inflatable aerodynamic boom.
This custom first of its kind "AeroBoom" was designed by the undergraduate members of the USU GAS team.
The AeroBoom was designed as an alternative to
Gravity-gradient stabilization
Gravity-gradient stabilization (a.k.a. "tidal stabilization") is a method of stabilizing artificial satellites or space tethers in a fixed orientation using only the orbited body's mass distribution and gravitational field. The main advantage ove ...
for spacecraft using passive
attitude control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
Controlling vehicle ...
in
Low Earth orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...
, or other active forms of attitude control such as
magnetorquer A magnetorquer or magnetic torquer (also known as a torque rod) is a satellite system for attitude control, detumbling, and stabilization built from electromagnetic coils. The magnetorquer creates a magnetic dipole that interfaces with an ambient ma ...
s or
reaction wheel
A reaction wheel (RW) is used primarily by spacecraft for three-axis attitude control, and does not require rockets or external applicators of torque. They provide a high pointing accuracy, and are particularly useful when the spacecraft must be ...
s.
The AeroBoom worked similarly to the feathers on an arrow. Molecules of air in the Earth's upper atmosphere struck the AeroBoom, causing a stabilizing torque.
The secondary objective of GASPACS was to measure and analyze attitude behavior to verify the AeroBoom was providing passive attitude control.
GASPACS was selected and sponsored by NASA through the CubeSat Launch Initiative program in 2014. The CSLI contract provided launch services for GASPACS.
![GASPACS_moments_after_deployment_from_the_International_Space_Station](https://upload.wikimedia.org/wikipedia/commons/6/6d/GASPACS_moments_after_deployment_from_the_International_Space_Station.jpg)
GASPACS was delivered to
Nanoracks
Nanoracks LLC is a private in-space services companywhich builds space hardware and in-space repurposing tools.The company also facilitates experiments and launches of CubeSats to Low Earth Orbit.
Nanoracks's main office is in Houston, Tex ...
on September 23, 2021.
On December 21, 2021, GASPACS was launched to the
International Space Station
The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...
aboard
SpaceX CRS-24
SpaceX CRS-24, also known as SpX-24, was a Commercial Resupply Service mission to the International Space Station launched on 21 December 2021, at 10:07:08 UTC. The mission is contracted by NASA and is flown by SpaceX using a Cargo Dragon. T ...
, as part of NASA mission
ELaNa 38.
One month later, on January 26, 2022, GASPACS was deployed from the ISS via a
Nanoracks CubeSat Deployer
The Nanoracks CubeSat Deployer (NRCSD) is a device to deploy CubeSats into orbit from the International Space Station (ISS).
In 2014, two CubeSat deployers were on board the International Space Station (ISS): the Japanese Experiment Module ...
by U.S. astronauts
Raja Chari
Raja Jon Vurputoor Chari (born June 24, 1977) is an American test pilot and NASA astronaut. He is a graduate of the United States Air Force Academy, Massachusetts Institute of Technology, and U.S. Naval Test Pilot School, and has over 2,000 flyi ...
and
Thomas Marshburn
Thomas Henry Marshburn (born August 29, 1960) is an American physician and a NASA astronaut. He is a veteran of three spaceflights to the International Space Station and holds the record for the oldest person to perform a spacewalk at 61 years o ...
.
NASA requires all CubeSats deployed from the ISS to wait a minimum of 30 minutes after deployment to begin booting up and starting their mission. After this required lapse of time, GASPACS autonomously booted up and deployed its antennas.
47 minutes after deployment a ground station in Tokyo, Japan recorded the first successful observation of GASPACS's beacons.
These beacons included an
AX.25
AX.25 (Amateur X.25) is a data link layer protocol originally derived from layer 2 of the X.25 protocol suite and designed for use by amateur radio operators. It is used extensively on amateur packet radio networks.
AX.25 v2.0 and later occupies t ...
identifier, as well as an audio beacon. The audio beacon consisted of the satellite's N7GAS callsign in
Morse code
Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...
, followed by a digitalized rendition of "The Scotsman
'', USU's spirit song.
18 hours after deployment from the ISS, GASPACS passed over the mission control ground station located on USU's campus and transmitted a photograph of the satellite's inflated boom, confirming primary mission success.
In the weeks following deployment, several sections of attitude data from the onboard accelerometer were downlinked, confirming the effectiveness of the AeroBoom mechanism.
GASPACS construction
GASPACS was constructed utilizing the following components:
Raspberry Pi Zero W
GASPACS was the world's first CubeSat to use a Raspberry Pi as its flight computer.
The Pi was responsible for running all onboard computing, running the Python scripts developed by the team.
A secondary mission of the satellite was to test the viability of cheap commercial microcontrollers such as the Raspberry Pi.
Raspberry Pi Camera Module 2
The Pi Camera was used to confirm successful deployment of the AeroBoom. 18 hours after deployment, GASPACS transmitted the first photograph taken by the camera, confirming the successful deployment of the boom. GASPACS has taken several additional photographs, many including Earth in the background.
Custom Interface Board
The USU GAS team designed their own custom
Printed circuit board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
. This 3 level PCB held all of the major electrical components. Sensors include an accelerometer, magnetometer, and a UV sensor.
The PCB also included a DF Robot Beetle. This Beetle acted as a
watchdog
Watchdog or watch dog may refer to:
Animals
*Guard dog, a dog that barks to alert its owners of an intruder's presence
* Portuguese Watch Dog, Cão de Castro Laboreiro, a dog breed
* Moscow Watchdog, a breed of dog that was bred in the Soviet U ...
to ensure the Raspberry Pi functioned properly. The Beetle monitored the Pi at 0.25 Hz to detect malfunctions due to
radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...
. In the case of a malfunction, the Beetle automatically turned the Pi off, and then back on. This process was designed to revert any upsets due to radiation back to normal. Another component included on the interface board was a custo
burn wiremechanism used to deploy the AeroBoom.
EnduroSat components
GASPACS incorporated many
EnduroSat
EnduroSat AD is a Bulgarian aerospace manufacturer headquartered in Sofia. It was founded in 2015 by Raycho Raychev.
The company designs, builds, and operates CubeSats and Nanosatellites for commercial and scientific missions and is developing ...
components in its
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...
. The EnduroSat electrical power system included a battery, and was charged by solar panels, which included Sun sensors and temperature sensors. GASPACS also contained an EnduroSat transceiver and antenna for communications, and their 1U structure.
AeroBoom payload
GASPACS's payload was the AeroBoom.
The AeroBoom consisted of a layer of
Polyvinylidene fluoride
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride.
PVDF is a specialty plastic used in applications requiring the highest pur ...
plastic, pressurized with 2.2 psia of air. This tube was encased in a sleeve of braided fiberglass. The outermost layer of the AeroBoom was a final sleeve of
Fluorinated ethylene propylene
Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene. It differs from the polytetrafluoroethylene (PTFE) resins in that it is melt-processable using conventional injection molding and screw extrusion ...
plastic.
The air inside the AeroBoom pressurized upon reaching the vacuum of space, and was held inside of a custom designed AeroBoom box by fishing line until AeroBoom deployment.
To deploy its AeroBoom, GASPACS ran a current through its
Nichrome
Nichrome (also known as NiCr, nickel-chromium or chromium-nickel) is a family of alloys of nickel, chromium, and often iron (and possibly other elements) commonly used as resistance wire, heating elements in devices like toasters, electrical kettl ...
burn wire circuit. The Nichrome heated up, burning through the fishing line, releasing the AeroBoom.
Mission status
The
North American Aerospace Defense Command
North American Aerospace Defense Command (NORAD ), known until March 1981 as the North American Air Defense Command, is a combined organization of the United States and Canada that provides aerospace warning, air sovereignty, and protection ...
designated GASPACS as NORAD ID 51439.
Three days after deployment, on January 29, 2022, GASPACS faced a major setback when power was lost on the Y-channel. This caused a significant reduction in the available power. GASPACS entered a perpetual charge cycle, charging up for approximately six hours on its remaining solar panels before reaching the power required to turn back on. Once booted up, GASPACS would stay powered on for approximately an hour before shutting off due to low power, and repeating the cycle. This continuous power cycle greatly reduced the quantity of data GASPACS was able to transmit to Earth.
On May 6, 2022, loss of the Z-channel was confirmed. This once again drastically reduced GASPACS's available power. Despite this, GASPACS continued to power on when possible, and ground operators were able to receive several packets of telemetry data, photo data, and AX.25 beacons.
The satellite decayed from orbit on 22 May 2022.
References
{{DEFAULTSORT:GASPACS
CubeSats
Spacecraft launched in 2021
Utah State University
Raspberry Pi
2021 in the United States
Satellites in low Earth orbit