SINGAPORE (ANN/THE STRAITS TIMES) – Nanyang Technological University (NTU) has developed Singapore’s first satellite to fly closest to Earth, set to launch in mid-2025.
Named the Extremely Low Earth Imaging Technology Explorer (Elite), this 1.3-meter-tall satellite will orbit just 250 kilometres (km) above Earth, significantly closer than most satellites.
Flying at such a low altitude presents challenges, as the satellite will encounter highly reactive gases and atmospheric friction.
Currently, only a few satellites operate in such close proximity to Earth. Despite the harsh environment, Elite will undertake a crucial research mission expected to last around 1½ years.
NTU’s Elite satellite is groundbreaking not only for its close orbit but also for its innovative technologies. It will test new, locally developed devices, potentially opening the door for more Singaporean satellites to operate in similar orbits in the future.
Elite is NTU’s 14th satellite and its most complex yet, about the size of a small fridge. Its launch in 2025 will coincide with a period of heightened solar activity, adding an extra layer of complexity to this ambitious project.
While powerful solar storms and flares treat people on Earth to dazzling auroras far beyond the poles – as seen during the major storms in May – such strong activity from the Sun can be a menace to satellites, worsening friction and destroying sensitive microchips.
But instead of feeling apprehensive about the upcoming launch, NTU Satellite Research Centre wants to embrace that challenge.
“It’s a good thing for us because we can prove that we can operate a satellite in high solar activity,” said Lim Wee Seng, executive director of the Satellite Research Centre.
Since Elite will be half the distance from Earth compared with a conventional satellite, it can capture better quality images up to 50 centimetre (cm) in resolution.
Such satellites could allow first responders to better monitor the spread of volcanic ash after an eruption, for example. Telecommunication could also improve, as a satellite closer to Earth will reduce network delays.
With fewer spacecraft in a 250km orbit, Elite will be able to manoeuvre through space without the risk of colliding with another vehicle or disused satellite, added Lim.
The latest model of the 180 kilogrammes (kg) space vehicle was shown to President Tharman Shanmugaratnam when he visited NTU Satellite Research Centre on June 11.
President Tharman toured Singapore’s first satellite-building facility and was briefed on the country’s local space ecosystem by NTU and the Office for Space Technology and Industry, the national space office.
The current Elite model has been undergoing a series of stress tests at Thailand’s space agency, including vibration and exposure to thermal vacuum conditions, to ensure that its design is fit to fly in space.
Once this model clears the rigorous tests, NTU will build the actual Elite satellite, with a plan to reach outer space in June 2025.
Singapore is not a space-faring nation, but its niche lies in building high-tech space components and small satellites. The country is home to more than 60 local and international space-tech firms, with a combined total of over 2,000 professionals and researchers.
Since 2011, Singapore has launched more than 30 satellites.
A key obstacle facing space vehicles at very low orbit is atmospheric drag, which can slow down the satellite, causing it to veer off-course and re-enter the Earth’s atmosphere within days. More solar flares would also make conditions worse for the machine.
To prevent this, Elite will have a novel and fuel-efficient engine built by Aliena, an NTU deep-tech spin-off, to help the satellite fight the friction.
Aliena’s chief executive Mark Lim said: “The engine needs to deliver a significant amount of thrust with lower power to ensure that we can continue firing the satellite to compensate for drag without bleeding out the batteries.
“You can rapidly fire your engines during unexpected events like severe geomagnetic storms, which could result in the decrease in the altitude of the spacecraft quickly.”
Being closer to Earth, the satellite can capture higher-resolution images of agricultural activities and mining, for example, with smaller camera optics.
To that end, the satellite will be equipped with Singapore’s first locally designed space camera, which can capture pictures of objects as small as 50cm in length.
Conventional satellite cameras have large telescopic lenses. The smaller camera on Elite is a creation of local tech firm LightHaus Photonics.
At 250km from Earth, satellites will encounter atomic oxygen, a highly reactive gas that corrodes and degrades electronic materials. To protect Elite from the corrosive oxygen, NTU Temasek Laboratories is creating an ultra-thin, transparent nanotechnology coating for the spacecraft.
Elite is a joint project between NTU, Aliena, LightHaus Photonics, NUS Temasek Laboratories and ST Engineering Satellite Systems.
As part of its 1½-year mission, the satellite will lower its orbit in stages, collecting data as it descends to Earth and burns up in the atmosphere. It will not end up as space debris or junk.
