RAX
Encyclopedia
Radio Aurora Explorer is the first National Science Foundation
sponsored CubeSat
mission . The RAX mission is a joint effort between SRI International in Menlo Park, California and the University of Michigan in Ann Arbor, Michigan. The chief scientist, Dr. Hasan Bahcivan, led his team at SRI to develop the payload while the chief engineer, Dr. James Cutler, led a team of students to develop the satellite bus in the Michigan Exploration Laboratory (MXL). There are currently two satellites in the RAX mission.
The RAX-1 mission, launched in November 2010, was a demonstration of the team’s technological capabilities – it made great strides in CubeSat design, and was able to execute bistatic radar measurements that had never before been performed on a satellite of its size. RAX-2 builds on this heritage by completing the scientific portion of the overall mission; it is a reflection of students learning from practical experience, and swiftly implementing new, more inventive technologies firsthand. RAX team members were able to get practical spacecraft troubleshooting experience, and applied lessons learned from RAX-1 to RAX-2, which performs the same mission concept with improved bus performance and additional operational modes. RAX-2 launched on October 28, 2011 as part of the NASA ELaNa 3 mission.
The goal of the RAX-2 mission is to enhance understanding of FAI formation so that short-term forecast models can be generated. This will aid spacecraft operators with planning their mission operations around periods of expected communication disruption. The RAX-1 mission made great strides in CubeSat design, and was able to execute bistatic radar measurements never before been performed with such a spacecraft. RAX team members applied the lessons learned from RAX-1 to the design of a second flight unit, RAX-2, which will perform the same mission concept of the first RAX that launched in November of 2010, with improved bus performance and additional operational modes. Science measurements will be enhanced through interactive experiments with high power ionospheric heaters where FAI will be generated on demand.
Over the course of the seventeen-month development, the team also built additional testing facilities to evaluate sensors and prototypes. An in-house Helmholtz Cage was constructed to create and simulate the changes in magnetic fields experienced by the satellite throughout its orbit over time. The cage was designed to characterize the magnetometers and run hardware-in-the-loop testing with RAX. This essentially puts the CubeSat into a virtual orbit, and allows the team to generate appropriate magnetic fields to test RAX’s ability to determine how it is oriented. The Helmholtz Cage is also used to evaluate magnetic cleanliness and final integration testing.
Space Test Program
’s (STP) STP-S26 mission, launched from Kodiak Launch Complex on Kodiak Island
in Alaska
, USA. The rocket used for this launch was a Minotaur IV
rocket developed by Orbital Sciences.
RAX-2 launched on October 28, 2011, as a secondary payload on NASA's NPP (NPOESS Preparatory Project
) mission. The CubeSat launch was sponsored by NASA as part of the ElaNA-3 (Educational Launch of Nanosatellites) program. It launched from Vandenberg Air Force Base
in central California on a United Launch Alliance Delta II rocket, flying in the 7920-10 configuration. CubeSat separation occurred 98 minutes after launch, and beacons from RAX-2 were heard shortly thereafter.
National Science Foundation
The National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
sponsored CubeSat
CubeSat
A CubeSat is a type of miniaturized satellite for space research that usually has a volume of exactly one liter , has a mass of no more than 1.33 kilograms, and typically uses commercial off-the-shelf electronics components...
mission . The RAX mission is a joint effort between SRI International in Menlo Park, California and the University of Michigan in Ann Arbor, Michigan. The chief scientist, Dr. Hasan Bahcivan, led his team at SRI to develop the payload while the chief engineer, Dr. James Cutler, led a team of students to develop the satellite bus in the Michigan Exploration Laboratory (MXL). There are currently two satellites in the RAX mission.
The RAX-1 mission, launched in November 2010, was a demonstration of the team’s technological capabilities – it made great strides in CubeSat design, and was able to execute bistatic radar measurements that had never before been performed on a satellite of its size. RAX-2 builds on this heritage by completing the scientific portion of the overall mission; it is a reflection of students learning from practical experience, and swiftly implementing new, more inventive technologies firsthand. RAX team members were able to get practical spacecraft troubleshooting experience, and applied lessons learned from RAX-1 to RAX-2, which performs the same mission concept with improved bus performance and additional operational modes. RAX-2 launched on October 28, 2011 as part of the NASA ELaNa 3 mission.
Capabilities and Mission Objectives
RAX is capable of carrying out scientific procedures that previously could only be done with large satellites, thanks in part to new enabling technologies. RAX’s primary mission objective is to study large plasma formations in the ionosphere, the highest region of our atmosphere. These plasma instabilities can create magnetic field-aligned irregularities (FAI), which are dense plasma clouds known to disrupt communication between Earth and orbiting spacecraft. To study FAI, the RAX satellites utilize a large incoherent scatter radar located in Poker Flat, Alaska (known as PFISR). PFISR transmits powerful radio signals into the plasma instabilities, which then scatter in the FAI and are received by the orbiting RAX spacecraft. The signals are then processed by RAX’s onboard computer and transmitted back to Earth for scientific analysis. Earth-based scientists have been unable to study these unique plasma formations from the ground, and RAX will serve as a key transition point between Earth and Space.The goal of the RAX-2 mission is to enhance understanding of FAI formation so that short-term forecast models can be generated. This will aid spacecraft operators with planning their mission operations around periods of expected communication disruption. The RAX-1 mission made great strides in CubeSat design, and was able to execute bistatic radar measurements never before been performed with such a spacecraft. RAX team members applied the lessons learned from RAX-1 to the design of a second flight unit, RAX-2, which will perform the same mission concept of the first RAX that launched in November of 2010, with improved bus performance and additional operational modes. Science measurements will be enhanced through interactive experiments with high power ionospheric heaters where FAI will be generated on demand.
Testing
RAX undergoes the same rigorous testing that its bigger cousins do, to meet many of the same requirements. During testing, RAX was able to successfully upload commands and receive telemetry from a host of sensors. These sensors yielded data including temperature and voltage, GPS position and velocity, spacecraft attitude (for orientation determination), and the general status of all of the RAX subsystems. The ground station software was also tested over radio links, proving that the team will be able to listen and interact with RAX remotely.Over the course of the seventeen-month development, the team also built additional testing facilities to evaluate sensors and prototypes. An in-house Helmholtz Cage was constructed to create and simulate the changes in magnetic fields experienced by the satellite throughout its orbit over time. The cage was designed to characterize the magnetometers and run hardware-in-the-loop testing with RAX. This essentially puts the CubeSat into a virtual orbit, and allows the team to generate appropriate magnetic fields to test RAX’s ability to determine how it is oriented. The Helmholtz Cage is also used to evaluate magnetic cleanliness and final integration testing.
Launch
RAX-1 was sent into orbit on November 19, 2010 by the United States Air Force as a payload manifested on the United States Department of DefenseUnited States Department of Defense
The United States Department of Defense is the U.S...
Space Test Program
Space Test Program
The Space Test Program is the primary provider of spaceflight for the United States Department of Defense space science and technology community. STP is conducted by the Space Development and Test Wing of the United States Air Force...
’s (STP) STP-S26 mission, launched from Kodiak Launch Complex on Kodiak Island
Kodiak Island
Kodiak Island is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the United States and the 80th largest island in the world, with an...
in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, USA. The rocket used for this launch was a Minotaur IV
Minotaur IV
Minotaur IV, also known as Peacekeeper SLV and OSP-2 PK is an active expendable launch system derived from the Peacekeeper missile. It is operated by Orbital Sciences Corporation, and made its maiden flight on 22 April 2010, carrying the HTV-2a Hypersonic Test Vehicle...
rocket developed by Orbital Sciences.
RAX-2 launched on October 28, 2011, as a secondary payload on NASA's NPP (NPOESS Preparatory Project
NPOESS Preparatory Project
The NPOESS Preparatory Project mission is intended to bridge the gap between old and new systems by flying new instruments, on a new satellite bus, using a new ground data network...
) mission. The CubeSat launch was sponsored by NASA as part of the ElaNA-3 (Educational Launch of Nanosatellites) program. It launched from Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
in central California on a United Launch Alliance Delta II rocket, flying in the 7920-10 configuration. CubeSat separation occurred 98 minutes after launch, and beacons from RAX-2 were heard shortly thereafter.