NorSat-1

NorSat-1 Mission

The NorSat-1 Norwegian satellite is a next-generation micro-satellite, designed to operate three payload instruments:

1. An Automatic Identification System (AIS) receiver to acquire messages from maritime vessels.
2. A Langmuir Probe instrument, intended to measure ambient space plasma characteristics.
3. A Compact Lightweight Absolute Radiometer (CLARA), intended to observe total solar irradiation and variations over time.

NorSat-1 is based on a next-generation satellite bus (University of Toronto, Space Flight Laboratory), which offers fine attitude control, high power generation, and high downlink rates. This next generation bus, referred to as the NEMO platform, straddles the border between a nano-satellite and a small micro-satellite, and represents the next evolution in microsatellite miniaturisation. NorSat-1 uses the same system architecture and technologies developed for the NEMO-AM mission (aerosol monitoring mission for the Indian Space Research Organization) and NEMO-HD mission (high-definition Earth observation for Slovenian Space-SI). These are themselves based on SFL’s space-proven and highly successful Generic Nano-satellite Bus which is currently flying in the AISSat-1 mission for Norway, and is also the basis for more than 10 other missions currently under development.

SFL has the experience and technology to deliver a high-quality mission for NorSat-1 at a reasonable cost. NorSat-1 provides ample power generation to operate all spacecraft payloads continuously, while maintaining attitude control, average telemetry downlink rates exceeding 1 Mbps, and a benign thermal environment for payloads and bus electronics. NorSat-1 has on-board data processing and storage capabilities, with greater than 20 orbits worth of payload data and bus telemetry storable by on-board computers. NorSat-1 will achieve these capabilities with a total launch mass (including separation system) of less than 30 kg.

Links

NorSat-1 on Norwegian Romsenter website
NorSat-1 on Earth Observations Website

Videos

Launch on 14 July 2017 (Roskosmos)
Launch on 14 July (YouTube)
Soyuz rocket on launch-pad, 11 June 2017 (YouTube)

Source and credits: Norwegian Romsenter, PMOD/WRC

PMOD/WRC Instrument: CLARA

The PMOD/WRC has constructed CLARA (Compact Lightweight Absolute Radiometer), a payload onboard the Norwegian NorSat-1 micro-satellite. CLARA is a new generation of radiometer to measure the Total Solar Irradiance (TSI) which is the mean energy input from the Sun to the Earth. Measurements of TSI from space have been conducted since 1979 by various institutes, and has an average value of 1361 W.m^-2.

Scientific Objectives

The main science goal of CLARA is to measure TSI with an uncertainty better than 0.4 W.m^-2. The CLARA space experiment sets new standards for TSI radiometers in terms of a reduction in weight and size without compromising on accuracy and stability. Along with its predecessors, VIRGO and PREMOS, CLARA continues the long-term involvement of the PMOD/WRC in solar research.

Design and Heritage

CLARA is the latest radiometer in a long line of pyrheliometers developed at PMOD/WRC, continuing its long lasting heritage of spaceborne Total Solar Irradiance (TSI) measurements. Similar to most radiometers built at PMOD/WRC, CLARA uses electrical substitution in its black-body cavity to measure TSI. All three cavities can be used as either a measuring cavity, a reference cavity or for degradation measurements. Based on the success of the engineering model in 2014, the design of the Flight Model (FM) and Flight Spare (FS) were finalised. The overall concept of the instrument and all electronics were developed by PMOD/WRC.

CLARA’s development also benefited from the knowledge and expertise of many Swiss industry partners. The on-board software and the Electrical Ground Support Equipment (EGSE) were designed by dlab GmbH, Winterthur. RUAG Space in Zürich reviewed the mechanical design, performed mechanical and thermal analysis, provided all structural and thermal components, and conducted most of the environmental tests on the flight model. We were also able to use the infrastructure of the Fachhochschule Nordwestschweiz to perform vibration tests.

Being an absolute radiometer by design, each of CLARA’s components were calibrated in-house against traceable SI units. CLARA was also compared against a Standard Group of TSI pyrheliometers belonging to PMOD/WRC. In addition, CLARA was then compared to the TSI Radiometer Facility (TRF) in Boulder, Colorado. These calibrations ensure a consistency with previous TSI measurement experiments and a traceability to NIST.

In September 2015, the CLARA Flight Model was delivered to the University of Toronto Institute for Aerospace Studies (UTIAS) to be integrated on the Norwegian NORSAT-1 microsatellite. In addition to the CLARA experiment, the NORSAT-1 satellite carries a next-generation Automatic Identification System (AIS) receiver, provided by Kongsberg Seatex and a Langmuir probe (plasma detector) developed by the University of Oslo. The Operational Readiness Review was held in Oslo at the end of 2016. PMOD/WRC worked on the simulation of operation sequences and on finalizing the data evaluation software. The satellite launch finally occured on 14 July 2017 from the launch site Baikonur, Kazakhstan.

Source and credits: Norwegian Romsenter, PMOD/WRC

Mission Facts

Source and credits: Norwegian Romsenter, PMOD/WRC