[Essay] CubeSats and its use as Glacier Monitoring System in Nepal
[The following post mixes two articles written before on Cubesats and GLOF. You can check the short original paper on Cubesats: Nepal's Future in Natural Disaster Prevention System that was accepted for SERVIR-Himalaya Youth Forum "Empowering Youth with Earth Observation Information for Climate Actions in Nepal" [Here]]
Amid growing environmental concerns, especially in the field of climate change and its adversities on glacier lakes, CubeSats (Cubical Satellites) could pose a solution to develop early warning system to prevent any GLOF (Glacial Lake Outburst Flood) related accidents in Nepal. With consistent, round the clock surveillance system, ground units can keep constant vigilance on areas that are topographically challenging to reach; thus, allowing them to monitor any activities that are deemed to be dangerous. Considering such solutions, one can also suggest that the technology could be applied to fighting forest fires or during search and rescue operations where real time geospatial data could save life and property.
The CubeSat was first envisaged by Professor Jordi Puig-Suari at Cal Poly-San Luis Obispo and Professor Bob Twiggs at Stanford University. The standard specifies that a standard 1-unit (1U) CubeSat shall measure 10X10X10 cubic centimeter and shall not weigh more than 1.33kg. The development cost is expected to lie around 50,000 dollars to 200,000 dollars and the development time estimates to be around two years[1]. With OTS (Off-the-shelf) components and such development costs, even countries devoid of any space technology can now make use of such openly sourced hardware and software to instigate their own satellite in space. Nepal too can explore and exploit such an excellent relatively low-cost idea.
One of the major issues seen in the Himalayan nation has been the receding of mountain glaciers. Integrated Center for Integrated Mountain Development (ICIMOD) has frequently stated that the glaciers in the Hindu Kush-Himalaya region is on the decline[2]. As this represents the third largest ice reserve after the two poles, this could well mean that water supply for 1.3 billion people is at stake. Unfortunately, there are graver concerns; one of which is the Glacial Lake Outburst Flood (GLOF).
Tsho Glacier Lake Outburst Flood that occurred in 1985 in Khumbu Region of Eastern Nepal is an example of what could go horribly wrong when such lakes are not given proper attention. The maximum discharge of the lake was estimated to be around 1,600 meter cubic per second at 2 kilometer downstream from the lake. The water storage of estimated 6.75 hectometer cube was lost in mere minutes. The nearly built Namche hydropower plant along with 30 houses, 14 bridges and cultivation areas were swept with the running water. The threat has since then increased to other lakes as well.
There is, therefore, a need to monitor these glaciers remotely. Today, efforts have been largely focused on land based, wireless monitoring systems that have been placed at the field. However, most GLOF related lakes are located in incredibly remote areas where accessibility, even for the locals, is an issue. If, somehow, Nepal too could have a remote sensing system up in space specially designed to monitor glacier behavior, unprotected lives could be saved in time. Early warning systems like these are currently out of reach of Nepali citizens but could change with the introduction of CubeSats. The only problem now is that whether such small satellites can actually have remote sensing capabilities.
A satellite’s capability is linked to what payload it carries. Standford’s QuakSat launched in 2003 for instance, had an AC magnetometer as payload which sensed ULF magnetic signals from R>6 earthquakes. Another example, which is currently under development at NASA, is the FireFly which will have its own VLF receiver and photometer to detect lightning[3].
Although it is true that a CubeSat is a miniaturized version of an actual mainstream satellite and can function like one, the system is not without limitations. With size and power being very limited resources, high end payloads which demand power and size acquisition have to be overlooked. Not only this, for higher resolution images to be downlinked in real time, proper communication channel has to be in place and this has yet to develop properly[4]. If Nepal is to actually monitor glacial lakes by using remote sensing cameras using CubeSats, this could be a major headache.
Fortunately, developments are underway. In the Axelspace Mission Idea Contest that took place in Tokyo in 2011, Surrey Satellite Technologies (SSTL) presented the idea of a distributed multispectral imaging system in a 3UX3U CubeSat. The initial development payload will have their own SSTL Multispectral Imager (MSI) which will be capable of providing channel-filtered panchromatic digital optics system providing 22m GSD imagery from an altitude of 686 km in red, near infrared, green and blue spectral bands[5].
Another recent example is the Flock 1 developed by Planet Lab which was built from low-cost non-traditional aerospace units capable of imaging for monitoring deforestation, agricultural yields and natural disasters. The concept was actually derived from NASA’s PhoneSats which only cost them a grand total of 4k dollars and which made use of Nexus S hardware developed by Samsung[5].
Since technologies like MEMS (MicroElectroMechanical System) are on the rise, I personally feel that the future is bright for nano-scale satellites. Smaller circuitry and systems could pave way for smaller, powerful multi-spectral remote sensing cameras and heat profiling sensors for lower orbit CubeSats specifically designed to monitor glacier activity. If so, it is not that hard to imagine a day where Nepal too will have an independent monitoring system 292km above Mt. Everest.
[1] J. Bouwmeester, J.Guo, Survey of worldwide pico- and nanosatellite missions, distributions and system technology, Acta Astronaut, Vol. 67, Issues 7-8, Pages 854-862, Oct-Nov 2010.
[2] http://www.icimod.org/dvds/201104_GLOF/reports/final_report.pdf
[3] Rainer Sandau, Status and trends of small satellite missions for Earth observation, Acta Astronaut, Vol. 66, Issues 1-2, Pages 1-12, Jan-Feb 2010.
[4] Daniel Selva, David Krejci, A survey and assessment of the capabilities of Cubesats for Earth observation, Acta Astronaut, Vol. 74, Pages 50-68, May-June 2012.
[5] Richard Long, Distributed Multi-Spectral Imaging System (DiMSIS), Surrey Satellite Technology Limited, 2010.
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