Technology Validation Mission Research Articles

Real-Time Detection and Filtering of Radio Frequency Interference Onboard a Spaceborne Microwave Radiometer: The CubeRRT Mission

The Cubesat radiometer radio frequency interference technology validation mission (CubeRRT) was developed to demonstrate real-time onboard detection and filtering of radio frequency interference (RFI) for wide bandwidth microwave radiometers. CubeRRT's key technology is its radiometer digital backend (RDB) that is capable of measuring an instantaneous bandwidth of 1 GHz and of filtering the input signal into an estimated total power with and without RFI contributions. CubeRRT's onboard RFI processing capability dramatically reduces the volume of data that must be downlinked to the ground and eliminates the need for ground-based RFI processing. RFI detection is performed by resolving the input bandwidth into 128 frequency subchannels, with the kurtosis of each subchannel and the variations in power across frequency used to detect nonthermal contributions. RFI filtering is performed by removing corrupted frequency subchannels prior to the computation of the total channel power. The 1 GHz bandwidth input signals processed by the RDB are obtained from the payload's antenna (ANT) and radiometer front end (RFE) subsystems that are capable of tuning across RF center frequencies from 6 to 40 GHz. The CubeRRT payload was installed into a 6U spacecraft bus provided by Blue Canyon Technologies that provides spacecraft power, communications, data management, and navigation functions. The design, development, integration and test, and on-orbit operations of CubeRRT are described in this article. The spacecraft was delivered on March 22nd, 2018 for launch to the International Space Station (ISS) on May 21st, 2018. Since its deployment from the ISS on July 13th, 2018, the CubeRRT RDB has completed more than 5000 h of operation successfully, validating its robustness as an RFI processor. Although CubeRRT's RFE subsystem ceased operating on September 8th, 2018, causing the RDB input thereafter to consist only of internally generated noise, CubeRRT's key RDB technology continues to operate without issue and has demonstrated its capabilities as a valuable subsystem for future radiometry missions.

6 GHz to 40 GHz CubeSat Radiometer Antenna System

A 6–40 GHz antenna system for the CubeSat Radiometer Radio Frequency Interference Technology Validation mission is presented. The antenna system includes three bottom-tapered helical antenna elements that cover 6–12, 12–22, and 22–40 GHz, respectively. The design procedure for achieving continuous gain coverage versus frequency from 7 dBic at 6 GHz to 21 dBic at 40 GHz is discussed. The helical antenna elements are supported by a carefully designed meshed radome made of 1 mm-thick Ultem 1000 material for minimizing impacts to antenna performance. The entire antenna system has a volume of 2 cm (height) $\times7.3$ cm (width) $\times25$ cm (length), or 365 cm3, which is less than 0.5 U (500 cm3). The total mass of the antenna payload is 116 g. Comparisons between the simulation and measurement performance show good agreements. The final fabricated antenna/radome payload also passed typical CubeSat temperature, vacuum, and vibration requirements and was successfully deployed in space in August 2018.

The LISA Pathfinder Mission

LISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter.The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper

Interplanetary CubeSats system for space weather evaluations and technology demonstration

The paper deals with the mission analysis and conceptual design of an interplanetary 6U CubeSats system to be implemented in the L1 Earth–Sun Lagrangian Point mission for solar observation and in-situ space weather measurements.Interplanetary CubeSats could be an interesting alternative to big missions, to fulfill both scientific and technological tasks in deep space, as proved by the growing interest in this kind of application in the scientific community and most of all at NASA. Such systems allow less costly missions, due to their reduced sizes and volumes, and consequently less demanding launches requirements.The CubeSats mission presented in this paper is aimed at supporting measurements of space weather. The mission envisages the deployment of a 6U CubeSats system in the L1 Earth–Sun Lagrangian Point, where solar observations for in situ measurements of space weather to provide additional warning time to Earth can be carried out.The proposed mission is also intended as a technology validation mission, giving the chance to test advanced technologies, such as telecommunications and solar sails, envisaged as propulsion system. Furthermore, traveling outside the Van Allen belts, the 6U CubeSats system gives the opportunity to further investigate the space radiation environment: radiation dosimeters and advanced materials are envisaged to be implemented, in order to test their response to the harsh space environment, even in view of future implementation on other spacecrafts (e.g. manned spacecrafts).The main issue related to CubeSats is how to fit big science within a small package – namely power, mass, volume, and data limitations. One of the objectives of the work is therefore to identify and size the required subsystems and equipment, needed to accomplish specific mission objectives, and to investigate the most suitable configuration, in order to be compatible with the typical CubeSats (multi units) standards.The work has been developed as collaboration between Politecnico di Torino, Sapienza University of Rome, “Osservatorio Astrofisico di Torino – INAF” (Astrophysical Observatory of Torino) and Deutsches Zentrum für Luft- und Raumfahrt (DLR) in Bremen.

Results from the Deep Space 1 technology validation mission

Launched on October 24, 1998, Deep Space 1 (DS1) is the first mission of NASA's New Millennium program, chartered to validate in space high-risk, new technologies important for future space and Earth science programs. The advanced technology payload that was tested on DS1 comprises solar electric propulsion, solar concentrator arrays, autonomous on-board navigation and other autonomous systems, several telecommunications and microelectronics devices, and two low-mass integrated science instrument packages. The technologies were rigorously exercised so that subsequent flight projects would not have to incur the cost and risk of being the first users of these new capabilities. The performances of the technologies are described as are the general execution of the mission and plans for future operations, including a possible extended mission that would be devoted to science.

Mars microprobe project instrumentation package

The Mars Microprobe Project is a technology validation mission in NASA's New Millennium Program. The project is developing a pair of small, two-piece probes for delivery to the surface of Mars in December of 1999. Descent from orbit to the surface is accomplished with a passive single-stage non-erosive aeroshell designed specifically for this mission. Upon impact each probe separates into a section that penetrates into the Martian regolith and a section that remains on the surface. This design provides an opportunity to collect scientific data both on and up to two meters beneath the surface. The instrumentation package of the Mars Microprobe includes a meteorological instrument for measuring atmospheric pressure and temperature, accelerometers to measure the atmospheric drag on the probe aeroshell during descent, accelerometers for measuring the forces on the probe at impact, temperature sensors in the penetrator to measure the soil thermal conductivity at depth, and an experiment to collect a small sample of the Martian regolith and determine if water is present in the sample. An overview of the instrument design and implementation is reported along with the results of the environmental tests and instrument calibration.

Mission design for deep space 1: A low-thrust technology validation mission

Deep Space 1 (DS1), currently scheduled for launch in July or August 1998, is the first mission of NASA's New Millennium program, chartered to flight validate high-risk, advanced technologies important for future space and Earth science programs. DS1's payload of technologies will be rigorously exercised during the two-year mission. Several features of the project present unique or unusual opportunities and challenges in the design of the mission that are likely to be encountered in future missions. The principal mission-driving technology is solar electric propulsion (SEP); this will be the first mission to rely on SEP as the primary source of propulsion. Another important technology for the mission design is the autonomous on-board navigation system, which requires frequent (at least weekly) intervals of several hours during which it collects visible images of distant asteroids and stars for its use in orbit determination and maneuver planning. The mission design accommodates the needs of these and other technologies for operational use and for acquiring sufficient validation data to assess their viability for future missions. DS1's mission profile includes encounters with an asteroid and a comet.

The new Millennium Program's Mars Microprobe Mission

The second deep-space advanced technology validation mission in NASA's New Millennium Program will demonstrate planetary micropenetrator technologies. Two microprobes, each consisting of a very low-mass aeroshell and penetrator system, are planned to launch in January 1999 and arrive at Mars in December, 1999. The 2 kg probes ballistically enter the martian atmosphere and passively orient themselves to meet peak heating and impact requirements. Upon impacting the martian surface, the probes will punch through the entry aeroshell and separate into a fore and aftbody system. The forebody will reach a depth of 0.5 to 2 meters, while the aftbody will remain on the surface for communications. Each penetrator system includes a suite of highly miniaturized components needed for future micropenetrator networks: primary batteries, power electronics, control and data handling microelectronics, telecommunications equipment, an antenna, and a science payload package. This paper will summarize key features of the microprobe mission and system design, as well as discuss the technologies proposed for flight.