INCUS (INvestigation of Convective UpdraftS)

Quick facts

Overview

Summary

Mission Capabilities

The three SmallSats will be flown in close succession (30, 90, and 120 seconds apart from each other), which will allow for a novel time-differencing approach to be used for the first time to estimate convective mass flux in tropical convective storms. Each satellite will carry a Ka-band radar (similar to RainCube), and the middle satellite will also carry a radiometer similar to TEMPEST-D. The data gathered from these satellites will be used to predict weather and climate.

Performance Specifications

The Ka-band radars have a horizontal resolution of 3.1 km, a vertical resolution of 0.24 km, radar sensitivity of 12 dBZ, swath width of 9 km and a 7 kg mass. The radiometer can measure at five frequencies of 87, 165, 174, 178, 181 ± 0.5 GHz with horizontal resolution of 16 km, a swath width of 1000 km and a mass of 3.8 kg.

Space and Hardware Components

Each INCUS satellite has a mass of approximately 100 kg, with a power output of 190 W, and data rate of approximately 2.2 GB per day. The middle satellite will utilise the X-SAT Venus class microsat bus built by Blue Canyon Technologies. 
 

Overview

The INvestigation of Convective UpdraftS (INCUS) mission was competitively selected as the 3rd NASA Earth Ventures Mission (EVM-3). INCUS will provide the first tropics-wide investigation of the evolution of the vertical transport of air and water by convective storms (convective mass flux), one of the most influential, yet unmeasured atmospheric processes. 1)

The primary goals of the INCUS mission are to determine the predominant environmental properties controlling convective mass flux in tropical convective storms, the relationship between convective mass flux and high anvil clouds, and the relationship between convective mass flux and the type and intensity of the extreme weather produced. Using the relationships between convective mass flux and environmental factors, high anvil clouds, and extreme weather, the numerical models that predict weather and climate can then be evaluated using these data.

Convective storms are the source of more than half of Earth’s precipitation and are the cause of most severe weather. The frequency of extreme weather has increased over the last 40 years, and is expected to continue increasing with warming climates. Despite the fundamental role that convective storms occupy in the atmosphere, our understanding of convective storm processes is limited. While numerical models can help bridge this gap, there are major uncertainties in their representation of convective clouds. At present, the vertical transport of water and air within our most advanced numerical models can differ from case study observations of convective mass flux by more than 200%. Therefore, INCUS is needed to provide the first tropics-wide investigation of the evolution of the vertical transport of air and water by convective storms, which will bridge the gap and enhance our understanding of these important parts of our atmosphere. 1)

Spacecraft

INCUS is made possible by small size and low power consumption to support three low-cost SmallSats with advanced active and passive measurements of cloud dynamics in the global tropics. Successful technology demonstrators by NASA's Earth Science and Technology Office (RainCube and TEMPEST-D instruments) will be flown together onboard INCUS for the first time on one platform. This will allow the mission to capitalise on their combined capabilities to obtain simultaneous observations of the internal storm structure, rapidly evolving convective mass flux and updraft dynamics, and anvil cloud properties. The three SmallSats will be flown in close succession (30, 90, and 120 seconds apart from each other), which will allow for a novel time-differencing approach to be used for the first time to estimate convective mass flux in tropical convective storms. Three RainCube-like Ka-band radars (one on each SmallSat) and one TEMPEST-D-like radiometer (middle SmallSat only) provide both active and passive remote sensing observations of rapid changes in convective cloud depths and intensities across the global tropics.

The SmallSat carrying the TEMPEST-D-like radiometer will utilise the X-SAT Venus Class microsat bus built by Blue Canyon Technologies. This satellite bus has a pointing accuracy of ±0.002° and a mass capability of 70 kg. 2) 3)

Launch                

The INCUS satellites are planned to be launched in 2026 with a mission duration of 2 years. The satellites have a planned inclination between 22.5° and 39° with an orbital period of approximately 95 minutes. 2)

Mission Status

• March 2023: Phase B starts. The purpose of Phase B is for the project team to complete the technology development, engineering prototyping, heritage hardware and software assessments, and other risk-mitigation activities identified in both the project Formulation Agreement (FA) and the preliminary design. The project demonstrates that its planning, technical, cost, and schedule baselines developed during Formulation are complete and consistent; that the preliminary design complies with its requirements; that the project is sufficiently mature to begin Phase C; and that the cost and schedule are adequate to enable mission success with acceptable risk. It is at the conclusion of this phase that the project and the Agency commit to accomplishing the project’s objectives for a given cost and schedule. 7)
• April 2022: Phase A starts. INCUS was in Phase A (Concept and Technology Development phase) until March 2023. The purpose of Phase A is to develop a proposed mission/system architecture that is credible and responsive to program expectations, requirements, and constraints on the project, including resources. During Phase A, activities are performed to fully develop a baseline mission concept, begin or assume responsibility for the development of needed technologies, and clarify expected reliance on human elements to achieve full system functionality or autonomous system development. This work, along with interactions with stakeholders, helps mature the mission concept and the program requirements on the project. Systems engineers are heavily involved during this phase in the development and assessment of the architecture and the allocation of requirements to the architecture elements.
• 5 November 2021: In 2021, INCUS was funded as the third NASA Earth Ventures Mission.

Sensor Complement

JPL Ka-band Radar

RainCube successfully demonstrated Ka-band precipitation radar technology on a low-cost, quick-turnaround platform. This new technology will enable constellations of small spacecraft that can track storms and provide data about how the storms evolve in short time scales—capabilities that are needed to improve numerical weather and climate models.

Developed at the NASA Jet Propulsion Laboratory (JPL), RainCube has demonstrated a new architecture for miniaturised Ka-band precipitation radars. Following a successful deployment from the International Space Station in July 2018, the RainCube radar was turned on in late August, and successfully acquired vertical range profiling measurements of precipitation and land surface at a nadir-pointing configuration. Since then, it has continued to acquire additional measurements, including the vertical precipitation profile of Typhoon Trami on September 28 2018.

RainCube uses Ka-band radar to “see” into storms. The satellite sends a radar signal towards the storm being observed, and receives a signal back as the radar bounces off raindrops in the storm. This capability provides a picture of the activity inside the storm such that scientists can learn about the processes that make the storm grow or decay.

A network of ground-based weather radars provides much of the information currently used to produce weather forecasts. However, these systems have several limitations that prevent them from providing a global view of storm activity: only developed countries are capable of supporting such networks, measurements over oceans are largely unattainable, and many mountain ranges present significant challenges to these ground-based measurement systems. Weather satellites provide a global view, but can only capture images of the tops of the storms; they do not provide much of the information that is needed to understand what is happening inside the storms. A couple of low Earth orbiting (LEO) spacecraft with downward-looking cloud or precipitation radars have enabled improved understanding of the structure and global distribution of storms, but these missions are usually expensive and thus it is cost-prohibitive to launch a constellation that would enable continuous global coverage. 4)

JPL Microwave Radiometer

The TEMPEST-D radiometer is a five-frequency millimetre-wave radiometer measuring at 89, 165, 176, 180, and 182 GHz. The direct-detection architecture of the radiometer reduces its power consumption and eliminates the need for a local oscillator, reducing complexity. The instrument includes a blackbody calibrator and a scanning reflector, which enable precision calibration and cross-track scanning. The monolithic microwave integrated circuit (MMIC)-based millimetre-wave radiometers takes advantage of the technology developed under extensive investment by the NASA Earth Science Technology Office (ESTO). The five-frequency millimetre-wave radiometer is built by Jet Propulsion Laboratory (JPL), who have produced a number of state-of-the-art spaceborne microwave radiometers. The TEMPEST-D Instrument design is based on a 165 to 182 GHz radiometer inherited from RACE and an 89 GHz receiver developed under the ESTO ACT-08 and IIP-10 programs at Colorado State University (CSU) and JPL. The TEMPEST reflector scan and calibration methodology is adapted from the Advanced Technology Microwave Sounder (ATMS) and has been validated on the Global Hawk unmanned aerial vehicle (UAV) using the High Altitude MMIC Sounding radiometer (HAMSR) instrument. 5)

Ground Segment

The daily terabytes of data the INCUS satellites will collect will be managed, processed and distributed by an expert team at the Cooperative Institute for Research in the Atmosphere (CIRA), a National Oceanic and Atmospheric Administration (NOAA) research centre based at and partnering with CSU since 1980. CSU is no stranger to high-profile research satellite missions, in large part due to its co-location and close ties with CIRA. The groundbreaking CloudSat mission, which sent a cloud-observation satellite into orbit in 2006, was led by then-CSU atmospheric science professor Graeme Stephens and is still operating today. Its data is distributed to users by the CIRA Data Processing Center, which was conceived as part of the original CloudSat mission and has been a critical component to its success. The CIRA team streamlined and economised how satellite data are transformed into useful information for meteorologists, researchers and others.

INCUS will produce about 15 times the data of CloudSat, according to CIRA senior research associate Phil Partain, who leads the Data Processing Center at CIRA and has worked on CloudSat since the early 2000s. “Juggling and dealing with that amount of data is a technical challenge that’s really fun. The science that’s going to come from the INCUS experiment, and measurements that have never been made before, are the most exciting aspects for me,” Partain said. 6)

References  

1) (INCUS) mission, https://incus.colostate.edu/

2) “INCUS Mission Plan and Instruments.” INCUS, https://incus.colostate.edu/mission/mission-instruments

3) “X-SAT Venus Class Microsat | satsearch.” Satsearch, 4 April 2023, https://web.archive.org/web/20230911051818/https://satsearch.co/products/bluecanyontech-x-sat-venus-class-microsat

4) “RainCube Demonstrates Miniature Radar Technology to Measure Storms | Science Mission Directorate.” NASA Science, 31 October 2019, https://science.nasa.gov/technology/technology-highlights/raincube-demonstrates-miniature-radar-technology-to-measure-storms

5) “TEMPEST-D MM-Wave Radiometer.” NASA/ADS, https://web.archive.org/web/20230911051828/https://ui.adsabs.harvard.edu/abs/2016AGUFM.A41H0163P/abstract

6) “Colorado State University satellite mission set to launch in 2026 was built on giants.” EurekAlert!, 6 June 2022, https://www.eurekalert.org/news-releases/955116

7) “Timeline.” INCUS, https://incus.colostate.edu/timeline