Context: On May 25, the National Aeronautics and Space Administration (NASA) launched one of the two climate satellites to study heat emissions at Earth’s poles from New Zealand. The second satellite will be launched in the following days.
About PREFIRE (Polar Radiant Energy in the Far-InfraRed Experiment) Mission:
- NASA aims to launch two cube satellites, or CubeSats to measure far-infrared radiation from the Earth’s poles.
- The mission has been named PREFIRE (Polar Radiant Energy in the Far-InfraRed Experiment) and was jointly developed by NASA and the University of Wisconsin-Madison (US).
- Each of the PREFIRE satellites is a 6U CubeSat. They measure around 90 cm in height and nearly 120 cm in width when the solar panels (which will power the satellite) are deployed. The two satellites will be placed in a near-polar orbit (a type of low Earth orbit) at an altitude of about 525 kilometres.
- Each of the PREFIRE CubeSat is equipped with a thermal infrared spectrometer — known as Thermal Infrared Spectrometer (TIRS) — to measure the amount of infrared and far-infrared radiation from the Arctic and Antarctica.
Need and significance of the mission:
- The Earth’s energy budget is the balance between the amount of heat incoming to Earth from the Sun and the amount of heat outgoing from Earth into space. The difference between the two determines the planet’s temperature and climate.
- A large amount of the heat radiated from the Arctic and Antarctica is emitted as far-infrared radiation — wavelengths of 3 μm to 1,000 μm within the infrared range of electromagnetic radiation. However, there is currently no way to measure this type of energy. As a result, there is a gap in knowledge about the planet’s energy budget.
- The climate satellites will measure how much heat the Arctic and Antarctica — two of the coldest regions on the Earth — radiate into space and how this influences the planet’s climate. The data collected by the satellites would help scientists better understand the energy budget of the planet.
- The CubeSats will also measure the amount of far-infrared radiation trapped by atmospheric water vapour and clouds at the poles and how this influences the greenhouse effect in the region.
What are SmallSats?
- Small spacecraft (SmallSats) focus on spacecraft with a mass less than 180 kilograms.
Small spacecraft can be differentiated into a large variety of size and mass.
- Minisatellite, 100-180 kilograms
- Microsatellite, 10-100 kilograms
- Nanosatellite, 1-10 kilograms
- Picosatellite, 0.01-1 kilograms
- Femtosatellite, 0.001-0.01 kilograms
What are CubeSats?
- CubeSats are are a class of nanosatellites whose basic design is a 10 cm x 10 cm x 10 cm (which makes up for “one unit” or “1U”) cube — just a little bigger than a Rubik’s cube — and weight not more than 1.33 kg.
- Depending on the CubeSat’s mission, the number of units can be 1.5, 2, 3, 6, and 12U.
- Owing to their low cost and less mass in comparison to traditional satellites, they are placed in orbits for technology demonstrations, scientific research, and commercial purposes.