The Synchronized Position Hold Engage and Reorient Experimental Satellite (SPHERES) are a series of miniaturized satellites developed by MIT's Space Systems Laboratory for NASA and US Military, to be used as a low-risk, extensible test bed for the development of metrology, formation flight, rendezvous, docking and autonomy algorithms that are critical for future space missions that use distributed spacecraft architecture, such as Terrestrial Planet Finder and Orbital Express. [1]
Each SPHERES satellite is an 18-sided polyhedron, with a mass of about 4.1 kg and a diameter of about 21 cm. They can be used in the International Space Station as well as in ground-based laboratories, but not in the vacuum of space. The battery-powered, self-contained units can operate semi-autonomously, using CO2-based cold-gas thrusters for movement and a series of ultrasonic beacons for orientation. The satellites can communicate with each other and with a control station wirelessly. The built-in features of the satellites can be extended using an expansion port. [2]
From 2006, three SPHERES units are being used in the International Space Station for a variety of experiments. The SPHERES Guest Scientist Program allow scientists to conduct new science experiments using SPHERES units, and the Zero Robotics Program allow students to participate in annual competitions that involve developing software to control SPHERES units. [3]
The SPHERES program is expected to continue until 2017, and possibly further. [3] [ needs update ]
The SPHERES project led to a newer project called Astrobee. [4]
The initial development of SPHERES started in 1999, by a team of students at Massachusetts Institute of Technology, as part of an aerospace engineering program. The concept of the satellite was conceived when Professor David Miller challenged the students to develop a device similar to the combat training remote seen in the 1977 movie Star Wars Episode IV: A New Hope and more recently in Star Wars: Episode II – Attack of the Clones . Several prototypes were developed during the course of the program, and were tested in ground laboratories as well as in parabolic flights using NASA's reduced gravity aircraft. [5]
After the initial development, the SPHERES program was taken over by MIT's Space Systems Laboratory. In collaboration with Aurora Flight Sciences, the design was refined and six flight-ready satellites were built, out of which three were delivered to the International Space Station. [5]
The SPHERES project is primarily funded by Defense Advanced Research Projects Agency (DARPA). [2]
Each SPHERES satellite resembles an 18-sided polyhedron, similar to a cuboctahedron. The aluminum structure of the satellite is enclosed in a semi-transparent plastic shell. The shell is red, blue, orange or black in color, to help with easy identification. The three satellites in the International Space Station are red, blue and orange. Each unit has a maximum diameter of 22.9 cm and has a mass of 4.16 kg including the consumables. [5] [6]
A Texas Instruments C6701 DSP running at 167 MHz serves as the onboard computer. Flight software and experiment related instructions are written in C programming language. [1]
The satellites can communicate with each other using a 916.5 MHz, 16 kbit/s radio link. Communication with the control station (a laptop computer) is done using an 868.35 MHz, 16 kbit/s radio link. [6] SPHERES satellites are able to connect to the International Space Station's on-board Wi-Fi network for tasks that require a higher data bandwidth. [2]
SPHERES satellites determine their position and attitude by using 23 on-board ultrasonic receivers (Murata MA40S4R) and 5 external ultrasonic reference beacons. The ultrasonic time-of-flight measurements from the external beacons to the on-board receivers are used to calculate the satellite's position with respect to the external reference frame. [1]
For rapid determination of position, the ultrasonic time-of-flight information is supplemented with the data from on-board accelerometers (3x Honeywell QA-750 single-axis accelerometers) and gyroscopes (3x Systron Donner QRS14 single-axis rate gyroscopes). [1]
SPHERES satellites are powered using two non-rechargeable 12v battery packs. Each battery pack consists of eight 1.5v AA battery cells that are spot-welded in series. [2]
The satellites are able to translate in the micro-gravity environment with 6 degrees-of-freedom, using twelve cold-gas thrusters that use liquid CO2 as propellant. The liquid CO2 are stored in a small on-board container, similar to those that are used in paintball guns. The CO2 is converted to a gaseous state before being ejected through the thrusters for propulsion. Desired thrust is achieved through pulse modulation of thrust solenoids. [1]
The maximum linear acceleration of the satellites is 0.17m/s2, with an accuracy of 0.5 cm. The maximum angular acceleration is 3.5 rad/s2, with an accuracy of 2.5 degrees. [7]
SPHERES program utilizes supporting facilities located at NASA's Ames Research Centre.
The 3 DoF laboratory facilitates simultaneous testing of up to three SPHERES satellites on a flat, nearly friction-less granite surface. The satellites are mounted on air carriages – stands that eject a stream of CO2 to create a cushion of air – allowing the units to translate on X and Y axis, and rotate on Z axis. [8]
The MicroGravity Test Facility (MGTF) facilitates testing of a single mobile SPHERES satellite, using six degrees-of-freedom. In this, the unit is held by a gimbal with 3 DoF, which is suspended from a translation crane with 3 DoF. The laboratory is able to provide a navigational reference frame in a similar configuration as in the International Space Station using five ultrasonic beacons, and the output of cold gas thrusters are analysed to simulate the expected movement in a micro-gravity environment. [8] [9]
The Flight Assembly Laboratory is used to prepare and test consumables – battery packs and liquid CO2 containers – used by the SPHERES units.
Individual cells of the battery packs are tested, spot-welded in series and tested again as a pack. The battery packs are discarded after use.
Spent CO2 containers are returned to the Flight Assembly Laboratory for re-filling and safety testing before being flown back to the International Space Station. [8]
The delivery of SPHERES satellites to the International Space Station were originally planned for 2003. However, due to the loss of Space Shuttle Columbia in February 2003, the delivery did not take place until 2006. [1]
The first SPHERES unit was delivered to ISS by the unmanned resupply mission Progress M-56 (ISS-21P) during April 2006. The second unit was delivered by the Space Shuttle mission STS-121 in July 2006. The final unit was delivered by the Space Shuttle mission STS-116 in December 2006. [10]
The SPHERES experiment aboard the International Space Station commenced on 18 May 2006. [5]
SmartSPHERES experiment equipped the three SPHERES satellite aboard the International Space Station with Nexus S smartphones that were delivered via the Space Shuttle mission STS-135. Each satellite was enhanced through the use of processing power, wireless networking, camera, sensors and the touch sensitive display of the connected smartphone. The availability of the Android operating system's source code enabled the devices to be used as a compact, low-cost, low-power computers. [11] [12]
The experiment studies the use of SPHERES satellites to conduct autonomous and remotely operated environmental and inventory surveys aboard the Space Station, with the aim of reducing the astronaut's time spent on routine tasks. Knowledge gained will also help the development of future space vehicles that could perform extravehicular activities, and assist astronauts with their tasks. [11]
The SmartSPHERES experiment is managed by the Intelligent Robotics Group of the Ames Research Center with funding from Enabling Technology Development and Demonstration program of NASA's Exploration Systems Mission Directorate. [11]
The SPHERES-VERTIGO (SPHERES-Visual Estimation and Relative Tracking for Inspection of Generic Objects) experiment aims to develop software and hardware that can generate three-dimensional maps of cooperative or non-cooperative objects using computer vision, and navigate relative to such objects solely by reference to the generated maps. [13]
As part of the experiment, new Simultaneous Localization and Mapping (SLAM) algorithms are developed and tested. [13]
To facilitate SPHERES-VERTIGO experiment, each SPHERES satellite aboard the ISS are equipped with an add-on "goggle" – a device connected to SPHERES using the expansion port, and carries a stereo camera, ultrasonic sensors, a single-board computer, high-speed communication facilities and batteries. [13]
Technologies developed will be used in future autonomous space vehicles that can operate alone or in groups to map asteroids, inspect tumbling satellites or de-orbit space debris. [13]
The experiment is part of the SPHERES Integrated Research Experiments (InSPIRE) program, funded by DARPA. [13]
DOD SPHERES-RINGS (Department of Defense SPHERES-Resonant Inductive Near-field Generation System) experiment aims to develop software and hardware capable of Electromagnetic Formation Flight (EMFF) and wireless power transfer in microgravity environment. [14]
The experiment uses two hardware assemblies connected to SPHERES satellites, consisting of aluminum resonant coils, coil housing with fans, electronics and batteries. [14]
Individual SPHERES units are maneuvered with respect to each other by generating controlled attractive, repulsive and shear forces using the electromagnetic coils. The same coils are used to wirelessly transfer power between SPHERES satellites through resonant inductive coupling. Software algorithms that avoid collision between satellites are also developed as part of the experiment. [14]
Knowledge gained through the experiment will help the development of propellant-free, plume-free clustered space vehicles, increase their operating lifetime, reduce spacecraft mass and associated operating risks. [14]
Article: SPHERES-Slosh
An expansion to the SPHERES satellites that forms a ring (halo) around the satellite to provide six expansion port attachment sites. Two were flown to the ISS.
Docking mechanism that enables two SPHERES satellites to attach rigidly together. Six were flown to the ISS.
Zero Robotics is an annual international competition conducted by MIT, where participating student teams program the SPHERES satellites to solve a specific challenge. The competition is held under two tiers; the middle school tournament and the high school tournament. [15]
The initial rounds of the competition are conducted via simulations. The finalists' programs are loaded into SPHERES satellites aboard the International Space Station, and are executed by astronauts. The event is broadcast live to MIT, Europe and Australia. [15]
The International Space Station (ISS) is a large space station assembled and maintained in low Earth orbit by a collaboration of five space agencies: NASA, Roscosmos (Russia), JAXA (Japan), ESA (Europe), CSA (Canada), and their contractors. ISS is the largest space station ever built. Its primary purpose is performing microgravity and space environment experiments.
Carl Erwin Walz is a retired NASA astronaut currently working for Orbital Sciences Corporation's Advanced Programs Group as vice president for Human Space Flight Operations. Walz was formerly assigned to the Exploration Systems Mission Directorate at NASA Headquarters in Washington, D.C. He was the Acting Director for the Advanced Capabilities Division in the Exploration Systems Mission Directorate, and was responsible for a broad range of activities to include Human Research, Technology Development, Nuclear Power and Propulsion and the Lunar Robotic Exploration Programs to support the Vision for Space Exploration.
The Destiny module, also known as the U.S. Lab, is the primary operating facility for U.S. research payloads aboard the International Space Station (ISS). It was berthed to the Unity module and activated over a period of five days in February, 2001. Destiny is NASA's first permanent operating orbital research station since Skylab was vacated in February 1974.
STS-127 was a NASA Space Shuttle mission to the International Space Station (ISS). It was the twenty-third flight of Space ShuttleEndeavour. The primary purpose of the STS-127 mission was to deliver and install the final two components of the Japanese Experiment Module: the Exposed Facility, and the Exposed Section of the Experiment Logistics Module (ELM-ES). When Endeavour docked with the ISS on this mission in July 2009, it set a record for the most humans in space at the same time in the same vehicle, the first time thirteen people have been at the station at the same time. Together they represented all ISS program partners and tied the general record of thirteen people in space with the first such occurrence of 1995.
The Minus Eighty-Degree Laboratory Freezer for ISS (MELFI) is a European-built experiment storage freezer for the International Space Station. It comprises four independent dewars which can be set to operate at different temperatures. Currently temperatures of −80 °C, −26 °C, and +4 °C are used during on-orbit ISS operations. Both reagents and samples will be stored in the freezer. As well as storage the freezer is designed to be used to transport samples to and from the ISS in a temperature controlled environment. The total capacity of the unit is 300 litres.
The United States Naval Academy (USNA) Small Satellite Program (SSP) was founded in 1999 to actively pursue flight opportunities for miniature satellites designed, constructed, tested, and commanded or controlled by Midshipmen. The Naval Academy's aerospace laboratory facilities are some of the most advanced and extensive in the country. These facilities include structures labs, propulsion and rotor labs, simulation labs, wind tunnels with flow velocities ranging from subsonic to supersonic, computer labs, and the Satellite Ground Station. The SSP provides funds for component purchase and construction, travel in support of testing and integration, coordination with The US Department of Defense or National Aeronautics and Space Administration (NASA) laboratories or with universities for collaborative projects, and guides Midshipmen through the Department of Defense (DoD) Space Experiments Review Board (SERB) flight selection process.
Grapple fixtures are used on spacecraft or other objects to provide a secure connection for a robotic arm.
The International Space Station is a platform for scientific research that requires one or more of the unusual conditions present in low Earth orbit. The primary fields of research include human research, space medicine, life sciences, physical sciences, astronomy and meteorology. The 2005 NASA Authorization Act designated the American segment of the International Space Station as a national laboratory with the goal of increasing the use of the ISS by other federal agencies and the private sector.
The NASA Launch Services Program (LSP) is responsible for procurement of launch services for NASA uncrewed missions and oversight of launch integration and launch preparation activity, providing added quality and mission assurance to meet program objectives. LSP operates under the NASA Space Operations Mission Directorate (SOMD).
The Robotic Refueling Mission (RRM) is a NASA technology demonstration mission with equipment launches in both 2011 and 2013 to increase the technological maturity of in-space rocket propellant transfer technology by testing a wide variety of potential propellant transfer hardware, of both new and existing satellite designs.
Kounotori 3, also known as HTV-3, was the third flight of the Japanese H-II Transfer Vehicle. It was launched on 21 July 2012 to resupply the International Space Station (ISS) aboard the H-IIB Launch Vehicle No. 3 manufactured by Mitsubishi Heavy Industries (MHI) and JAXA. Kounotori 3 arrived at the ISS on 27 July 2012, and Expedition 32 Flight Engineer and JAXA astronaut Akihiko Hoshide used the International Space Station's Canadarm2 robotic arm to install Kounotori 3, to its docking port on the Earth-facing side (nadir) of the Harmony module at 14:34 UTC.
SpaceX CRS-4, also known as SpX-4, was a Commercial Resupply Service mission to the International Space Station (ISS), contracted to NASA, which was launched on 21 September 2014 and arrived at the space station on 23 September 2014. It was the sixth flight for SpaceX's uncrewed Dragon cargo spacecraft, and the fourth SpaceX operational mission contracted to NASA under a Commercial Resupply Services contract. The mission brought equipment and supplies to the space station, including the first 3D printer to be tested in space, a device to measure wind speed on Earth, and small satellites to be launched from the station. It also brought 20 mice for long-term research aboard the ISS.
The Nanoracks CubeSat Deployer (NRCSD) is a device to deploy CubeSats into orbit from the International Space Station (ISS).
SpaceX CRS-21, also known as SpX-21, was a Commercial Resupply Service mission to the International Space Station which launched on 6 December 2020. The mission was contracted by NASA and was flown by SpaceX using a Cargo Dragon 2. This was the first flight for SpaceX under NASA's CRS Phase 2 contract awarded in January 2016. This was also the first Cargo Dragon of the new Dragon 2 variant, as well as the first Cargo Dragon flight that was docked at the same time as a Crew Dragon spacecraft. This mission used Booster B1058.4, becoming the first NASA mission to reuse a booster previously used on a non-NASA mission. This was also first time SpaceX launched a NASA payload on a booster with more than one previous flight.
SpaceX CRS-22, also known as SpX-22, was a Commercial Resupply Services (CRS) mission to the International Space Station (ISS) that launched at 17:29:15 UTC on 3 June 2021. The mission is contracted by NASA and is flown by SpaceX using a Cargo Dragon 2. This is the second flight for SpaceX under NASA's CRS Phase 2 contract awarded in January 2016.
Charles Edward "Ed" Whitsett Jr. (1936-1993) was a USAF officer and NASA engineer specializing in solutions for effective human movement in zero gravity. The pinnacle of his work was the astronaut maneuvering unit (MMU) which enabled satellite rescue and repair. For this capability, Whitsett along with NASA, Martin Marietta, Bruce McCandless, and Walter W. Bollendonk received the 1984 Robert J. Collier Trophy for "the greatest achievement in aeronautics or astronautics in America."
Cygnus NG-16, previously known as Cygnus OA-16, was the sixteenth flight of the Northrop Grumman robotic resupply spacecraft Cygnus and its fifteenth flight to the International Space Station (ISS) under the Commercial Resupply Services (CRS-2) contract with NASA. The mission was launched on 10 August 2021 at 22:01:05 UTC, for a (planned) 90-day mission at the ISS. This was the fifth launch of Cygnus under the CRS-2 contract.
SpaceX CRS-23, also known as SpX-23, was a Commercial Resupply Service mission to the International Space Station, successfully launched on 29 August 2021 and docking the following day. The mission was contracted by NASA and was flown by SpaceX using the Cargo Dragon C208. This was the third flight for SpaceX under NASA's CRS Phase 2 contract awarded in January 2016. It was the second mission for this reusable capsule.
SpaceX CRS-27, also known as SpX-27, was a Commercial Resupply Service mission to the International Space Station (ISS) launched on 15 March 2023. The mission was contracted by NASA and was flown by SpaceX using Cargo Dragon C209. This was the seventh flight for SpaceX under NASA's CRS Phase 2.