HTV-5 Cargo Overview

Share |

HTV-5 Cargo Overview

HTV-5 is the fifth mission of the Japanese H-II Transfer Vehicle, ferrying supplies to the International Space Station. The mission will deliver 6,057 Kilograms of cargo to the Space Station comprised of 5 metric tons of pressurized cargo delivered via the Pressurized Logistics Carrier of the HTV spacecraft and around one metric ton in the Unpressurized Logistics Carrier.

The HTV-5 mission brings to ISS a number of different items including multiple science facilities for the Japanese Kibo Laboratory, large payloads for the US Segment, consumables for the six-person ISS crew and maintenance items to keep the orbital laboratory in operation. Because the ISS Program was recently hit by the loss of several cargo missions (Cygnus Orb-3 in October, Progress M-27M in April, and Dragon SpX-7 in June) HTV-5 had around 215 Kilograms of late-load items added to its cargo manifest to make up for lost maintenance hardware that is needed with some urgency on the US Segment of the Station.

HTV-5 marks a record for the amount of Cargo Transfer Bags (CTBs) facilitated aboard any HTV flown to date owed to improvements made to packing of individual bags. In total, HTV-5 transports 242 CTBs to ISS, compared to HTV-1 that only carried 208 bags, marking a 15% increase. Additionally, the capacity for late cargo loading has been increased to 92 CTBs, allowing a considerable amount of cargo to be loaded from 10 days to 80 hours prior to liftoff.

HTV-5 is carrying a number of large internal payloads such as the Multi-Purpose Small Payload Rack 2 and a new Galley Rack to be installed in the Unity module of the Space Station. Also onboard the craft are utilization payloads for the Kibo Laboratory including a Mouse Habitat Unit, an Electrostatic Levitation Furnace and components for existing science payloads active on ISS. As external payload, HTV-5 is carrying the Calorimetric Electron Telescope to be installed on the JEM Exposed Facility. Making use of HTV's capability of disposing external hardware, three items will be placed into the Unpressurized Logistics Carrier, the Superconducting Submillimeter Wave Limb-Emission Sounder (SMILES), the Multi-Mission Consolidated Equipment (MCE) and the Space Test Program - Houston-4 Payload.

Photo: NASA

CALET - Calorimetric Electron Telescope

Image: JAXA/ASI

CALET, the Calorimetric Electron Telescope, sets out to address a number of open questions of High-Energy Astrophysics such as the origin of cosmic rays, the mechanisms behind the acceleration of cosmic rays and galactic propagation, the existence of dark matter and its structure, and nearby sources of cosmic rays. The search for signatures of dark matter has become a focus of particle astrophysics since dark matter is hypothesized to be one of the major constituents of the universe.

CALET is capable of making direct measurements at the highest energy levels in the cosmic ray electron spectrum for the observation of discrete sources of high energy particle acceleration in our local region within the Milky Way. The telescope payload has a mass of 650 Kilograms and looks forward to a two to five-year stay attached to the Japanese Experiment Module Exposed Facility, Port #9, looking zenith.

CALET consists of a detector system and data processing units, support sensors and an interface unit that attaches the payload to the Exposed Facility. The detector system is comprised of a Charge Detector, an Imaging Calorimeter, a Total Absorption Calorimeter and the CALET Gamma Ray Burst Monitor. The support sensors include a GPS receiver and an Advanced Stellar Compass for precise position and orientation determination.

Image: NASA/JAXA/ASI

Image: NASA

The CALET instrument interfaces with the JEM Exposed Facility via a standard Flight Releasable Attachment Mechanism which includes power and data interfaces with the Station's systems. CALET requires a peak power of 650 Watts and operates at data rates of 35kbps in low data mode and 600kbps in high data mode. The payload measures 1.85 by 0.8 by 1.0 meters in size, complying with the envelope available for external JEF payloads.

The three main sensor elements of CALET are the Charge Detector, the Imaging Calorimeter and the Total Absorption Calorimeter. The Charge Detector consists of two layers each consisting of 14 organic scintillator paddles provided by ELJEN Technology. Each of the paddles measures 45 centimeters by 3.2 by 1 cm with the different layers arranged orthogonally. The organic scintillator material absorbs the energy of incident ionizing radiation and re-emits the absorbed energy in the form of light that can be measured in a detector. CALET uses Photomultiplier Tubes with eight-millimeter photocathodes to detect the emission of radiation from each scintillator paddle. Through data processing, the charge of each incident particle can be measured in a range from Z=1 to Z=40.

Imaging Calorimeters are characterized by a finely granulated readout with a high degree of segmentation featuring a large number of readout channels as opposed to conventional calorimeters consisting of large crystals connected to a single read-out channel. This allows for a detailed measurement of particle identity, travel direction and energy as well as the creation of Particle Flow Algorithms. Imaging Calorimeters have a sandwiched design, alternating between active detector elements and passive absorber elements.

The CALET Imaging Calorimeter makes use of seven Tungsten plates as absorbers and 16 layers of 448 Scintillating Fibers, one stack of eight layers in the x-plane, the other in the y-plane to enable directional measurements.

Image: JAXA

CALET Detector System

Image: JAXA/ASI

CALET Imaging Capabilities

Each of the fibers measures 44.8 by 0.1 by 0.1 centimeters. Emissions from the fibers are read out by a suite of Multi-Anode (64) Photomultipliers coupled to Readout Electronics based on application-specific integrated circuits that digitize the signals from each fiber with precise time-stamps for event logging. The arrangement of active elements within the system has been chosen to provide the precision necessary to separate incident particles from backscattered particles, precisely determine the starting point of the shower and determine the incident particle trajectory. The primary purpose of the CALET Imaging Calorimeter is the measurement of particle direction while the energy measurement is accomplished with the Total Absorption Calorimeter.

Located atop the Imaging Calorimeter is a silicon detector array consisting of two layers with 6,400 pixels, each square in shape with a side length of 1.125 centimeters and a thickness of 500 microns. The Silicon Detector Array delivers the necessary charge resolution for the measurement of light and heavy nuclei.

The Total Absorption Calorimeter consists of 12 layers each comprised of 16 Lead-Tungstate logs that act as absorbing material, each measuring 32.6 by 1.9 by 2.0 centimeters in size. Subsequent layers are arranged orthogonally. Events are triggered by a Photomultiplier Tube that is located atop the uppermost layer to send a start pulse. The remaining layers feature avalanche photodiodes for the measurement of the depth of penetration of any given particle to assess its energy. The Total Absorption Calorimeter has a field of view of 45 degrees around the zenith. It separates electrons and gamma rays from incident hadrons.

Image: JAXA

Imaging Calorimeter

Image: JAXA

Total Absorption Calorimeter

A separate Gamma-Ray Burst Monitor can detect particle events from a few keV X-Rays to gamma-rays in the TeV range with durations varying from short duration gamma ray bursts, x-ray flashes to longer burst events. It has a time resolution of 62.5 microseconds and an energy range of 3% at 10 GeV. Two components make up the Gamma Ray Burst Monitor, the Soft Gamma-Ray Monitor SGM and the Hard X-Ray Monitor HXM. SGM uses a single Bismuth Germanate scintillator 102 by 76 millimeters in size covering an energy range of 100 to 20,000 keV. The HXM features a dual detector element using Lanthanum Bromide scintillators 12.7 millimeters thick and 66 by 79 centimeters in diameter. It covers an energy range of 7 to 1,000 keV. A Beryllium entrance window is used for the measurement of soft X-Rays below 10 keV.

Gamma Ray Burst Monitor Components

Image: JAXA/ASI

The non-detecting area of the entire CALET detector system is surrounded by a segmented scintillator array to serve as an Anti-Coincidence Detector, being triggered by all particles arriving from a direction that does not strike a detector from above, instructing the instrument to reject that measurement.

The thickness of the calorimeter sensors allows measurements well into the Terra-Electron-Volt (TeV) energy region with excellent energy resolution. The coupling of an imaging and total absorption calorimeter permits an accurate identification of the starting point of electromagnetic showers as well as the lateral and longitudinal development of showers.

CALET will deliver electron spectra in the trans-TeV region to look for nearby cosmic-ray sources, it will track dark matter annihilation electron/positron signatures in electron/gamma energy spectra at energies of 10 GeV to 10 TeV, it will provide spectral data sets starting with protons to heavier elements up to iron at 20TeV/n plus heavier elements (Z=26-40) at a few GeV/n.

CALET will also measure the electron flux at energies below 10 GeV to support solar physics and record Gamma-ray and X-Ray events in the low-energy range from 3keV to 30 MeV. Gamma-ray measurements for an indirect measurement of dark matter decay will also be supported by CALET.

CALET delivers its data flow to the ISS Data System where science data is stored or downlinked in real time depending on TDRSS availability. Downlinked data is relayed to the Marshall Spaceflight Center from where raw data is transmitted to Tsukuba Space Center, going through the JAXA Operations Control System to reach the CALET Ground System. Raw data is directed to an archiving system and to the various processing locations where higher science products from Level 1 quick look data to Level 3 calibrated calorimeter and Gamma-Ray Burst Monitor Data is created, archived and made available via a web server.

Mouse Habitat Experiment

Image: JAXA

The Japanese Mouse Habitat Experiment in some ways is similar to the U.S.-led Rodent Habitat set up on the Space Station in 2014, however, there are a number of significant differences including the use of artificial gravity and the accommodation of one mouse per cage for individual studies of behavioral changes. The Mouse Habitat Experiment consists of two major segments, the main Onboard Cage Unit for the accommodation of mice for 30 to 180 days and Transportation Cage Unit that accommodates the animals for up to ten days from launch to transfer to ISS and from the end of the ISS-based experiment to the return to Earth aboard a visiting vehicle.

Flying rodents to ISS provides an extremely valuable opportunity for a variety of studies from the mechanisms of bone loss in space over the adverse effects of space radiation to aging studies as well as a range of other studies looking at changes undergone by cells, tissues and organ systems as a result of prolonged exposure to space.

The Mouse Habitat will be set up in the Cell Biology Experiment Facility CBEF in the Kibo module that provides two research sections. One Cage Unit facilitating six mice will be set up in the Micro-g section where mice experience the full space environment (microgravity, radiation) and the artificial gravity section that makes use of the short-arm centrifuge of CBEF which had so far only been used to expose plants to an artificial gravity environment, but as ground studies have shown, the centrifuge is also suitable to create a gravity environment for small mammals. Having six mice exposed to artificial gravity takes the microgravity environment out of the equation so that a comparison between the micro-g experiment and artificial-G experiment can highlight the adverse effects caused solely by radiation and those caused by microgravity alone. This will be the first long-term experiment involving mammals in an artificial gravity environment.

Each cage unit, around 15 centimeters in diameter includes systems to provide the mice with food and air circulation. Sensors installed within the cages record the temperature and humidity environment as well as carbon dioxide and ammonia content within the cage units. Cameras are used to document behavioral changes for the entire duration of the experiment.

The Mouse Habitat Experiment is set up for a live return of all 12 animals involved in a single experiment run, sparing the ISS crew the procedures associated with dissecting and preserving the specimens which will be completed by skilled researchers on the ground with access to more advanced analysis systems to examine collected samples down to a cellular and biochemical level.

The first experiment involving the Mouse Habitat is expected in early 2016, a study of epigenetic alterations.

Image: JAXA

Electrostatic Levitation Furnace - ELF

Image: JAXA

The Electrostatic Levitation Furnace will provide ISS with its second Materials Science facility operating on the basis of electrostatic levitation, alongside the Electromagnetic Levitator that is active aboard the Columbus laboratory, studying fundamental principles of metallurgy. Heating and melting samples of metal alloys or other materials in a zero-G environment followed by the solidification of the sample yields a very pure material without any contaminations. The study of the solidification process and the finished product can provide valuable knowledge concerning the properties of the material that could improve production techniques on Earth for better material properties in alloys, glass and ceramics.

The ELF facility is operated within the Multi-Purpose Small Payload Rack rack inside the Kibo module, supplied with ISS power, data connectivity and gas. The payload has a total mass of 220 Kilograms and is 59 by 88.7 by 78.7 centimeters in dimensions with an additional UV Lamp module that measures 22.6 by 25.9 by 34.7 centimeters. Major components of ELF are the sample delivery and accommodation system, a sample heating laser system, a suite of sensors including position sensors, oxygen and pressure sensors, a pyrometer, plus two cameras, light sources and support electronics.

The primary purpose of the ELF payload is to provide containerless melting and solidification of a variety of samples in a controlled environment to study material properties - providing knowledge needed for the improvement of production techniques for metal alloys, ceramics or different types of glass, among other materials.

A spherical sample with a diameter of 1.5 to 5 millimeters is delivered into the ELF chamber by a sample cartridge that receives samples from a holder containing a number of samples so that prolonged ground-controlled operation of the facility is possible and crew members only have to periodically change out the sample holder.

Within ELF, samples are held in place by Coulomb forces between a charged sample and surrounding electrodes that are biased by a controller that receives real time data from a pair of position sensors to keep the sample floating freely in a small corridor within the experiment chamber. This method of sample levitation in a closed-loop sensor-actuator feedback design allows the payload to accept different samples such as metal, ceramics, glass, and liquids.

Image: JAXA

ELF Positioning System

The positioning system operates at a control period of 1kHz meaning that 1,000 position sensor inputs are processed per second to send up to 1,000 bias commands to the electrodes that operate at a maximum voltage of 3,000 Volts. Overall, the positioning system achieves an sample positioning accuracy of +/-300 micrometers.

Image: JAXA

Heating of the sample is provided by a set of four lasers, in contrast to the Electromagnetic Levitator that makes use of an electromagnetic field and induced Eddy currents leading to heating of the sample. ELF's four lasers are arranged to uniformly heat up a sample to a temperature of over 2,000 °C. The infrared semiconductor lasers operate at a wavelength of 980 nanometers and each has a power output of 40 Watts. The maximum temperature achieved by the system is targeted to exceed the melting point of Zirconia at 2,710 °C. Sample baking can also supported by the ELF payload with temperatures of up to 1,300°C being reached in a matter of seconds.

Temperature measurements can be made by an infrared thermometer that has an operational range of 300 to 3000°C, covering the entire operational temperature range of ELF. To observe the material during the heating/melting and cooling/solidification process, ELF includes three sensors - a pyrometer and two cameras.

The highly sensitive digital pyrometer observes the sample to provide a high-resolution thermal image of the material to collect information on thermal gradients across the sample surface. It has a field of view of 5.7 by 4.3 millimeters, requiring the sample to be kept in a precise position to enable full-surface measurements during the entire experiment process. The pyrometer hosts an Indium-Gallium-Arsenide detector sensitive at wavelengths of 1.45 to 1.80 micrometers, operating at a sampling frequency of 100 Hz.

The two cameras are the Magnifying Camera primarily used for density measurements and the Overview Camera that provides video of the solidification process. The Magnifying Camera has a resolution of 640 by 480 pixels corresponding to a field of view of 19 by 14 millimeters in the fully zoomed-out mode and 2.4 by 1.8 millimeters when fully zoomed in. The Overview Camera has a wide dynamic range and covers a field of view of 24 by 18 to 3.0 by 2.4 millimeters on a 640 by 480-pixel CCD detector. It collects 30 images per second. Illumination of a sample (if not self luminous) is provided by a UV-LED.

To keep the sample at a specified charge, ELF uses the photoelectric effect. A Deuterium Lamp with a power of 30 Watts delivers UV radiation required to keep the sample within the required charge range.

For measurements of surface tension and viscosity of a sample at different temperatures, ELF utilizes a vibration excitation that can be varied from 1 to 600 Hz while a voltage excitation for conducting materials is also available and can be set from -3kV to +3kV.

The ELF experiments can be run in different environments to allow the facility to conduct a variety of studies. The major variable for experiments is the environment inside the chamber that can be varied from a high-quality vacuum to a number of gas compositions. Available gas combinations for ELF are ISS supply gas (99.99% Nitrogen by volume), Argon supplied by Kibo's unique systems, or standard air at any pressure up to 2 bar.

The operational requirements for the crew are kept low by the ELF concept, only requiring crew members for the initial setup and periodic maintenance of the payload as well as the exchange of the sample holder that facilitates up to 15 samples. The samples are automatically removed from the holder and released into the sample cartridge where samples are directed into the experiment chamber. After the run is complete, the processed sample is moved back to the holder and the next sample can be inserted by the ground commanding the motor within the holder to rotate the next sample into the cartridge. Once all samples have been processed, the holder can be returned to the ground for detailed analysis of the samples.

Image: JAXA

Multi-Purpose Small Payload Rack 2 (MSPR-2)

Image: JAXA

The addition of MSPR-2 will provide more space aboard the Japanese Experiment Module for scientific payloads and provide more work space for crew members conducting scientific experiments. It will become the home of the ELF payload among a number of other science payloads, providing all necessary commodities to science facilities such as power, thermal control, fault protection, data up- and downlink capability, gas supply and a vent line.

MSPR-2 facilitates work spaces and a work table for a variety of utilization tasks from serving as a work bench for hardware maintenance operations to being a state of the art science facility. The Work Volume of the MSPR is 350 liters (30 by 90 by 70cm), enabling it to accommodate large science facilities such as the Acquatic Habitat and combustion experiments.

The Work Bench provided by the MSPR can be stowed into the module and extended whenever needed for science or maintenance activities - it provides a work area of 0.5 square meters and includes a power supply for a Station Support Computer. A Small Experiment Area offers a volume of 70 liters (30 by 41.2 by 52.9cm) and all resources needed by small experiments such as chemical studies, also providing vibration isolation to be able to accommodate experiments that can not tolerate disturbances by crew activities in other portions of the rack.

MSPR interfaces with a Laptop Computer running specific software to deliver experiment data to the ground and enable ground controllers to remotely command rack and payload functions.

Power delivered by the MSPR comes at voltages of 5, 16 and 28 VDC with a total capacity for all payloads around 500 Watts. Video can be downlinked from the MSPR in real time, supporting three NTSC channels or a single High-Definition Television feed to enable teams on the ground to follow experiments ongoing inside the facility in real time. Data connectivity from the MSPR is provided via USB and Ethernet, connected to the MSPR control laptop and the Station LAN for downlink of data to the ground, either as data playback or real time data.

Exposed Experiment Handrail Attachment Mechanism ExHAM-2

ExHAM-2 is the second accommodation system for small experiment payloads for the Japanese Experiment Module Exposed Facility (JEM-EF or JEF) to provide access to space exposure studies to a variety of experiments without the need for spacewalking Astronauts to install exposure payloads. The system is a cuboid mechanism that hosts a grapple fixture for the JEM Remote Manipulator System Small Fine Arm so that it can be transferred to the outside of ISS via the JEM airlock for robotic installation on a JEF hand rail using a clamping mechanism on the underside of the payload.

A total of 20 experiment samples can be facilitated by ExHAM, seven on its upper surface and 13 around the side surfaces of the structure. Each experiment cell measures 10 by 10 by 2 centimeters.

ExHAM modules can be launched with experiments already attached or experiment samples can be launched individually for checkout and installation by the ISS crew followed by the transfer to the outside via the JEM airlock and the installation on the exterior to remain exposed to the space environment (microgravity, radiation, atomic oxygen...) for a specified period of time according to the experiment's requirements. After return to the inside of ISS, the samples are packed up and returned to the ground for detailed laboratory analysis.

ExHAM simplifies the conduct of materials studies in the space environment and gives a number of institutions from universities to industry partners an opportunity to conduct space exposure experiments.

Photo: JAXA/NASA

Image: JAXA

NanoRacks External Platform (NREP)

Photo: NanoRacks

NREP represents an external payload facility that can host compact research payloads in the space environment, becoming the first external commercial research capability for the testing of scientific investigations, sensors, and other components in space. NREP can hold a variety of powered and non-powered payloads and expose them to the space environment for a specified period of time for data collection before the payloads are returned to the ground for analysis.

NREP hosts interfaces that can attach it to the Exposed Facility of the Japanese Experiment Module's payload accommodations (Flight Releasable Attachment System) through which power and data connectivity is provided. The platform itself has its own power distribution system that can deliver power to installed experiments as required and an onboard computer routes commands send on customer request from the ground to the payload and science data from the payload to the ground through ISS communications assets.

Payloads can be attached and removed from NREP in a plug-and-play fashion, to be returned to the inside of ISS via the JEM robotic arm and the Kibo airlock for eventual return to the ground.

Completing all these operations without the need for a spacewalk to install/retrieve payloads allows access to space exposure research to a multitude of institutions from universities to private industry.

Possible applications of NREP include biological testing, sensor target testing, satellite communications components testing, power systems testing, air, water, and surface monitoring, avionics, communications, imaging technology, microbial populations in spacecraft, microgravity environment measurement, radiation measurements and shielding, robotics, small satellites, space structures, spacecraft and orbital environments, spacecraft materials, and thermal management systems.

Water System Components

HTV-5 is delivering to ISS some long-awaited spare parts for the USOS Water Systems, specifically a Fluids Control Pump Assembly and Multifiltration Beds for the Water Recovery System. The Fluids Control Pump Assembly is a critical part of the Urine Processor Assembly that turns urine into potable water through vacuum distillation. Within the UPA, the 45.6-Kilogram Fluids Control Pump Assembly is in charge of pumping urine to the Distillation Assembly and remove both concentrated urine brine waste and product water from the Distillation Assembly once the distillation process is complete.

The Multifiltration Beds are an important component within the Water Processor Assembly that finishes the water processing chain, recycling crew perspiration and urine into potable water. After the removal of particles and debris from the water through standard sieving, the water passes through the Multi-Filtration Beds, chemical filter systems that are capable of removing organic substances and inorganic impurities.

Photo: NASA

Fluids Control Pump Assembly

However, as the filter remains in operation, its substrates will get saturated by the removed substances and the efficiency of the filtration bed will decrease. Periodic water checks using onboard systems such as the Total Organic Carbon Analyzer are performed to keep track of the water quality aboard the Space Station and water samples are regularly sent back to the ground. Strict limits are in place for the TOCA value and the maximum concentrations for known contaminants. Any violation of these criteria would either require a switch of the filtration beds or the crew to stop using recycled water.

Multi-Filtration Beds were up for launch aboard the Cygnus Orb-3 spacecraft in October 2014 but were lost when the Antares launch vehicle exploded seconds after liftoff. Because the manufacture of these units is relatively time-consuming, new spares did not become available until June 2015 and were packed inside the Dragon SpX-7 spacecraft for liftoff atop Falcon 9. By that time, TOCA measurements had shown that the filtration beds presently in use on ISS were saturated and organic levels were on the rise, approaching the safe limit. Unfortunately, Dragon SpX-7 did not reach its destination either, its flight being cut short when the Falcon 9 experienced a fatal problem just two and a half minutes after liftoff.

NASA conducted studies of water samples returned by the most recent Soyuz spacecraft to identify the species that were causing the high TOCA readings. Knowing the type of contamination, teams were able to waive the upper limit and continue to allow the crew to use WRS water without any health concerns. Over the months of June/July, readings started to level out below the critical safety limit, but new Multi-Filtration Beds are needed rather urgently to restore water processing capabilities aboard the Station.

Node 1 Galley Rack

HTV-5 is carrying a new Galley Rack to be installed inside the Unity Node of the International Space Station. It facilitates a Potable Water Dispenser for hot and cold beverages and a food warmer to prepare meals for consumption by the ISS crew.

SAFER

HTV-5 is brining to ISS a spare SAFER - Simplified Aid for EVA Rescue. SAFERs are attached to the Extravehicular Mobility Unit's Life Support System backpack and contain pressurized nitrogen gas that can be released by a series of thrusters to be used in the event an Astronaut becomes untethered and floats away from ISS structure. Manually controlling the thrusters, crew members can maneuver themselves back to ISS structures and re-tether themselves. The system is considered a last resort to prevent crew members from floating away from the Space Station in an EVA mishap.

Water

30 water bags are loaded inside HTV-5 containing a total of 600 liters of water to replenish the Station's water storage. Water is needed aboard ISS for crew consumption, personal hygiene and the generation of Oxygen through electrolysis of water.

KOUNOTORI Advanced SPace Environment Research equipment

KOUNOTORI Advanced SPace Environment Research equipment (KASPER) is an attached payload that will remain with HTV-5 throughout its mission, located on the aft segment of the HTV Service Module. It consists of a surface potential and plasma current sensor plus two debris detectors, the Chiba-koudai Debris Monitor (CDM) and the Space Debris Monitor (SDM).

CDM can detect small debris from a few microns to about 100 microns in size while SDM can sense debris with sizes of 100 microns to a few millimeters across. The entire KASPER unit weighs around 8 Kilograms and is 75 by 50 by 12 centimeters in size, drawing a maximum power of 30 Watts.

Image: JAXA

CubeSats

S³ - Shootingstar Sensing Satellite

Image: PERC

The Shootingstar Sensing Satellite also called S-CUBE or S³ is a 3-Unit CubeSat, measuring 30 by 10 by 10 centimeters in size with a total mass of 3.99 Kilograms. Its primary objective is the detection of shooting stars from Low Earth Orbit to demonstrate the use of a CubeSat in the field of planetary science. Outfitted with different detection systems, S³ aims to measure the ultraviolet signature of meteors, collect visible imagery of meteors from orbit and obtain information on the size distribution and composition of meteors. S³ is a project of the Planetary Exploration Research Center (PERC) of the Chiba Institute of Technology and Tohoku University.

The S³ spacecraft subsystem is largely based on the Raiko CubeSat design that was successfully flown in 2012. Power generation is accomplished with body-mounted Gallium-Arsenide multi-junction solar cells plus two deployable solar panels that are stowed against two opposite side panels in the satellite's launch configuration. Power is stored in NiMH batteries and the satellite operates on a 9.6-Volt power bus.

Attitude control is provided by a Gravity-Boom that is deployed after launch, stabilizing the satellite via a gravity-gradient. Additionally, three-axis control can be accomplished using three magnetic torquers to keep the satellite in an Earth-pointing attitude. The Attitude Determination System makes use of a suite of sun sensors and a three-axis magnetometer that is needed to calculate the current that has to be applied to the magnetic torquers to achieve the required torque values for the desired attitude change.

The communications system of the satellite, based on Raiko, uses Ku- and S-Band transmitters and S-Band and UHF receivers to achieve command uplink rates of 1.2kbit/s in UHF and 1kbit/s in S-Band and downlink rates of up to 100kbit/s in UHF and 500kbit/s in Ku-Band, enabling the downlink of full resolution meteor imagery from the science payload. The heart of the S³ satellite is a Main Processor Unit which processes and executes commands sent from the ground in parallel to the Power Control Unit that can only execute basic spacecraft functions and manage the power system components while the Main Processing Unit can run advanced command sequences including payload commanding. Data, telemetry and science data, is stored in the Flash memory of the Main Processor Unit.

S³ hosts two main payloads, a Wide Angle Camera and a Photo-Multiplier. Both are tasked with the observation of the luminous emission of meteors induced by hypervelocity entry into Earth's atmosphere.

Image: PERC

Because meteors oftentimes originate from asteroids and comets, the analysis of their spectrum can reveal information about the composition of the parent object - allowing scientists to learn about different comets and asteroids without the need for a mission to a distant target.

However, in the past, the Earth-based observation of meteors has been facing a number of problems starting with a bias of observations from the northern hemisphere and a general lack of observations from the southern hemisphere and the ocean. Space-based observation is not biased by the distribution of observatories and can not be influenced by weather and is therefore ideally suited for the observation of meteors. Furthermore, observations from orbit are not hindered by the Ozone layer that absorbs ultraviolet radiation and prevents ground-based observatories from recording the UV-signature of meteors.

The last space-based meteor observation mission was flown in 1999 and recorded spectra of a number of Leonid meteors, showing an abundance in Iron and Magnesium plus traces of Carbon and Sulfur. A meteor observation payload was planned to be set up on the International Space Station in 2014, but was lost in the Antares launch failure in October of that year. Unfortunately, a replacement payload also failed to make it to ISS, being lost in the Dragon SpX-7 launch failure in 2015.

Photo: PERC

Wide Angle Camera

The Wide Angle Camera of the S³ satellite is a light-weight system weighing in at just 34 grams, hosting a Charged Coupled Device onto which an image is focused by wide-angle optics to be able to observe across a broad field of view. The detector has a diagonal length of 6 millimeters and hosts 659 by 494 pixels with a standard side length of 7.4 micrometers. The detector is read out by dedicated electronics that use a 10-bit analog-to-digital conversion. The Wide Angle Camera covers the visible range of the spectrum.

The Photo-Multiplier hosted on the S³ satellite is equipped with a bandpass filter that rejects any emissions coming from Earth to distinguish between Magnesium emissions from meteors and lights on Earth. Just weighing 6.5 grams, the Photo-Multipliers are 8 millimeters in diameter and are sensitive across a wavelength range of 160 to 320 nanometers. The detection of a UV-Magnesium signature by the Photomultiplier acts as a trigger for the Wide Angle Camera, activating it to acquire an image of the meteor.

The minimum success criteria for the S³ mission is to detect at least one meteor with the Photomultiplier Tube and subsequently triggering the camera to gather an image of the meteor to allow for an estimation of meteoroid size from its brightness. Full mission success if defined as obtaining the flux of meteors - collecting a statistically significant amount of data to assess the size distribution of meteors. An optional mission objective is the spectral analysis of meteors to identify species such as sulfur.

SERPENS

SERPENS (Sistema Espacial para Realização de Pesquisa e Experimentos com Nanossatélites) is a student-built 3-Unit CubeSat developed by a consortium of Brazilian Universities in a project involving over 100 students to gain experience in the development, manufacture and operation of a space mission. The 3U satellite consists of two sectors developed separately.

Sector A includes the Attitude Determination and Control System, Electrical Power System, Data Handling Systems, a Telemetry & Command Communications System, and an INPE Transponder and Pulsed Plasma Thruster for demonstration in orbit. The second Sector includes its own Electrical Power System, Data Handling Architecture and Communications System, hosting an amateur radio payload. Sector A accounts for 2U of the Cubesat while Sector B fills the remaining 1U.

Image: INPE/SERPENS Project

The Pulsed Plasma Thruster for CubeSat Propulsion (PPTCUP) attempts to minimize the well-established design of Pulsed Plasma Thrusters which are flight-proven electric propulsion systems used in a variety of space applications.

Image: Mars Space Ltd.

Pulsed Plasma Thrusters use a propellant, commonly a solid fuel, that is ablated by an electric arc. Through the heat of the arc, gas released from the fuel is turned into a plasma that is located between two electrodes. Due to its charged nature, the plasma completes the circuit between the electrodes and allows electrons to flow which generates a strong electromagnetic field and associated Lorentz force that is exerted on the plasma, causing it to accelerate and be expelled from the thruster at high velocity, which, according to Newton’s Third Law, causes a force of the spacecraft. The pulsed nature of the thruster is due to an interval of time needed to recharge the electrodes after each burst of fuel.

PPTCUP was developed by Mars Space Ltd, Clyde Space and the University of Southampton. It consists of a thruster board and discharge chamber. Overall, the thruster assembly weighs 180 grams including 7g of Teflon fuel and delivers a thrust of 40 micronewtons at a power consumption of 2 Watts. The entire thruster assembly fits into a 90 by 90 by 27-millimeter envelope.The thruster operates at a specific impulse of 608 seconds and in its original version is certified for 1.5 million shots. For durability, the system uses copper-tungsten electrodes. All thruster functions are controlled by a PIC16 microcontroller.

Image: INPE/SERPENS Project

PPTCUP is planned to be used in CubeSat Projects for drag compensation, orbit maintenance, formation flying and orbit transfers. Used for Drag Compensation, the thruster is able to increase the life of a low orbiting CubeSat by up to 200%. The thruster may also be used as a de-orbiting device to lower the perigee of a CubeSat for faster orbital decay in order to comply with the 25-year de-orbiting rule.

Image: INPE/SERPENS Project

SERPENS Sector B

The INPE Transponder Installed on the Satellite will be used to deliver Data Collection System data packets from remote terminals deployed across Brazil to ground stations. Data Collection Platforms can be deployed virtually at any location on the globe to provide in-situ measurements of meteorological data that is then uplinked to satellites and transmitted to ground stations for collection, processing and distribution.

The DCPs operate in the UHF band at 401/402 MHz. These platforms include remote weather stations, buoys at sea to measure sea state and alert in the event of tsunamis as well as other measurement stations that are deployed in remote locations. Data received via the DCS UHF antenna at data rates of 100 to 300bit/s is relayed to the ground via the S-Band antenna for processing and distribution.

The HUMSAT transponder is used as part of a store and forward communications system that is currently deployed on a number of pathfinder satellites to evaluate a simple communications architecture that could be established by deploying a number of store and forward satellites into orbit.

Using receivers, the satellite receives small packets of data that are stored in the onboard memory and relayed by the satellite transmitter at a given time to be delivered to a recipient. This system could be used for the transfer of messages in areas with poor communications infrastructure.

GOMX-3

GOMX-3 is a 3U CubeSat flying under the Global Air Traffic Awareness and Optimizing through Spaceborne Surveillance Program initiated by GOMSpace, a company finding its roots in projects developed at Aalborg University in Denmark. The satellite sports a Software Defined Radio Payload for the reception of Automatic Dependent Surveillance-Broadcast (ADS-B) signals sent by commercial aircraft. The monitoring of aircraft over ocean areas is of particular interest to demonstrate a low-cost system for the tracking of aircraft over areas not currently covered by radars.

The second satellite communications payload is to be used to receive signals from Geostationary Communications Satellites for an assessment of signal quality in the L-Band range. A third party payload flying on the satellite is a miniaturized high data rate X-Band transmitter and patch antenna developed by Syrlinks through funding from the French Space Agency CNES. New satellite platform systems (reaction wheels, fine sun sensors and thermopiles) are also being demonstrated by GOMX-3 to provide a precise attitude determination and control system for accurate pointing of directional communication antennas.

The 3U CubeSat features body-mounted triple-junction solar cells employing maximum power point tracking to optimize the performance of the arrays for the given illumination and thermal environment. Power is stored in a BP4 battery module and a P31US Power Module distributes power to the satellite subsystems. Attitude Determination is provided by a series of sun sensors and two magnetometers while attitude actuation is accomplished through the use of miniaturized reaction wheels and magnetic torquers which can be used for momentum dumps from the wheels in a very efficient and accurate small-satellite attitude control system.

The GOMX satellite is outfitted with a NanoMind Onboard Computer that handles command and attitude control processing, receives data from all subsystems and payloads, stores it and conditions it for downlink.

Image: GOMSpace

The primary communications system of the satellite is a half-duplex UHF transceiver operating in the 435-438 MHz range to reach a nominal data rate of 9.6 kbit/s. The satellite makes use of a CubeSat Space Protocol, a network-type protocol implemented by all subsystems across the space link and the ground system, easing the integration and testing of systems as well as simplifying operations since every component is assigned a node with access to command resources available within the network.

Image: GOMSpace

The main payload of the GOMX-3 satellite is the Software Defined Radio, SDR, that can receive Automatic Dependent Surveillance – Broadcast signals from commercial aircraft. These signals represent periodic transmissions of data by an aircraft's Mode-S transponder at the 1090MHz frequency, containing the aircraft ID, its position, altitude and intent.

These signals are used by air traffic control for areas in which a ground receiving architecture is present, but given the short range of the ADS-B signals, they are not useful over land areas with poor infrastructure and oceanic coverage is very limited. Nevertheless, ADS-B has become a significant part of air traffic control, being used in the same manner as information provided by radars. ADS-B will become mandatory for all aircraft in the near future and there is a strong desire to ultimately phase out the traditional radars and purely rely on ADS-B since the receivers are much easier to maintain.

Given the short range (80 Nautical Miles) of ADS-B, there were some doubts as to whether the signals could be received from orbit - a necessity in the overall goal of establishing global ADS-B coverage. The GOMX-1 satellite was the first spacecraft to demonstrate that ADS-B signals could be received in Low Earth Orbit without any problems.

GOMSPACE proposes two concepts for the utilization of ADS-B signals by satellites - a small constellation of six LEO CubeSats to collect ADS-B data and send it back to ground stations with a delay, mainly for use in statistical applications, and a constellation of up to 70 satellites capable of relaying ADS-B signals in real time to Geostationary Satellites that then send the data to relevant ground stations for distribution.

The ADS-B receiving payload on the GOMX-3 satellite consists of a helical antenna deployed after launch, providing a 10dB gain at the desired 1090MHz frequency. Furthermore, the payload is comprised of an RF front end interfacing with the antenna, a Field Programmable Gate Array used as receiver and a Main Controller handling data acquired by the system and transmitting it for storage in the spacecraft memory. Signal decoding is provided by the FPGA, receiving and digitizing the ADS-B signal blocks that consist of a preamble for time synchronization and 112 bits of data sent at a symbol rate of 1MHz.

14 Flock-2b Satellites

Flock 1/2 is a satellite constellation of CubeSats dedicated to Earth Observations using a fleet of small satellites to generate high-resolution images of Earth achieving resolutions of three to five meters. The operational constellation began deployment in 2014 and uses a combination of shorter and longer lived orbits being launched from the International Space Station and different orbital launch vehicles.

The satellites are designed, developed, manufactured and operated by Planet Labs based in San Francisco that markets the Earth Observation data products to a range of customers for a variety of applications.

The Flock spacecraft are based on the three-unit CubeSat specification having a launch mass of about 5 Kilograms and being 100mm × 100mm × 340mm in size featuring body mounted solar panels and two deployable solar arrays with three panels each using triangular advanced solar cells.

Photo: NASA

The solar arrays are spring-loaded and deployed by burn-wires once the satellites are released into their independent orbits. Flock spacecraft contain Lithium-Ion batteries that provide power to the various systems. A power distribution unit delivers power to all subsystems. The load bearing satellite structure consists of three skeleton plates, with L rails along each corner edge. Laser etched side panels are used for the Flock satellites.

Image: Planet Labs

Attitude data is provided by three-axis magnetometers to accomplish three-axis stabilization via a reaction wheel system and magnetic torquers for momentum management. Fine pointing data is provided by a Star Camera. Flock satellites use a single-board computer to control all spacecraft and payload functions with a watchdog board able to reboot the flight computer in the event of errors or radiation related upsets.

The satellites use an X-Band system for the downlink of acquired images and systems telemetry at data rates of up to 120Mbit/s. Primary command uplink is done via S-Band, although a low-speed Telemetry and Command System operating in the UHF band is also available and in use for early commissioning operations and as a backup.

The main payload of each satellite is an optical telescope of unknown specifications to acquire high-resolution images of Earth. The telescope has an aperture diameter of 90mm and is protected by an aperture cover that is deployed via springs. The optical axis is down the central axis of the satellite to achieve a maximum focal length.

The Flock satellites are going through constant modifications and improvements, even within a group of satellites, not all are necessarily identical. Variations that have been introduced include the use of improved detectors and infrared filters.

>>>Flock Overview Page

AAUSAT-5

AAUSAT-5 known by its full name Aalborg University Cubesat 5 is a student-built satellite complying with the 1U CubeSat form factor. The satellite carries two receivers for the Automatic Identification system.

The Automatic Identification System is used by sea vessels that send and receive VHF messages at the 162MHz frequency containing identification, position, course and speed information to allow the monitoring of vessel movements and collision avoidance as well as alerting in the event of sudden speed changes.

These signals can be transmitted from ship-to-ship and ship-to-shore to allow the monitoring of a local area, but deploying space-based AIS terminals allows a broad coverage and data relay to ground stations for monitoring of large sea areas. However, due to the large footprint of satellites, overlapping and signal collisions become a problem, especially for frequented traffic routes.

Image: AAU

The AAUSAT AIS receiver is based on a Software Defined Radio Design using a 16-bit Digital Signal Processor being fed by an Analog-to-Digital Converter within the RF Front End of the system. The Digital Signal Processor includes 32MB of RAM and 8MB Flash memory. The bulk of received AIS messages is stored on an SD Card and transmitted to the spacecraft via two analog data connections for downlink via 437MHz UHF. Overall, the system is capable of receiving over 1000 samples per second.

Disposal Items

Making use of HTV's capability of disposing items via destructive re-entry, the Pressurized Logistics Carrier will be filled with trash and no-longer-needed items over the course of the craft's stay on ISS. On the exterior, robotics will be underway to retrieve the Exposed Pallet from the spacecraft, remove and install the CALET telescope payload, and then install three disposal payloads on the Exposed Pallet to conclude their stay on the Space Station.

HTV-5 will dispose of the following external payloads: SMILES - the Superconducting Submillimeter-Wave Limb-Emission Sounder, the Multi-Mission Consolidated Equipment, MCE, and the Space Test Program Houston 4 payload.

SMILES had been installed on Kibo's Exposed Facility since 2009, being delivered by the very first HTV mission. The instrument is outfitted with a series of sensors tasked with the detection of submillimeter radiation emitted by minor constituents within the atmosphere. The instrument was also used to measure global ozone and its variation over time. SMILES features a mechanical cooler providing an operational thermal environment maintained at 4 Kelvin to the Submillimeter Wave Sensor of the instrument sensitive at the 640GHz frequency to measure emissions from a number of gases at an unprecedented accuracy.

The Multi-Mission Consolidated Equipment provided an experiment platform to five different payloads with a total mass of 450 Kilograms, measuring 1.8 by 0.8 by 1.0 meters in size. Hosted on MCE was the Ionosphere, Mesosphere, upper Atmosphere and Plasmasphere Mapping IMAP Experiment that facilitated a series of sensors covering a broad range of the spectrum from the extreme ultraviolet to near-infrared to study Earth's upper atmosphere by looking at airglow and resonant scattering. GLIMS, the Global Lightning and Sprite Measurement Mission, used a CMOS camera, photometers, and VHF interferometer to observe lightning and sprites to assess their global distribution and to look at the variation of Transient Luminous Events across the globe. The Space Inflatable Membranes Pioneering Long-term Experiment exposed an inflatable membrane structure to the space environment for an extended period of time. The REXJ Robot Experiment on JEM used a robot with extended arm an tether to validate its spatial migration and working functions. Finally, the COTS-HDTV-EF experiment demonstrated the use of a commercial camcorder to demonstrate its functionality for the acquisition of Earth imagery.

NASA's Space Test Program is dedicated to fly small payloads loaded with different technical and other demonstrations to space for assessments in the space environment. A number of STP payloads have already been flown in the past including Department of Defense, university and NASA experiments. The STP-H4 payload included eight experiments dedicated to the demonstration of thermal tiles, a CubeSat computer processor, thermal control equipment, sensors capturing optical and radio signatures of lightning, high-resolution small cameras for CubeSats, ship-tracking equipment, miniature radiation sensors, a wind/temperature spectrometer and a small electrostatic analyzer. All these payloads underwent detailed testing and verification of their performance in the space environment over an extended time period and have now completed their mission.

Image: JAXA

SMILES

Image: JAXA

Multi-Mission Consolidated Equipment

Photo: NASA

STP-H4