StunningSmall Satellite

Written+by+Tong+Zijun

September 20， 2015， with a carrier rocket of new generation， Long March No. 6 launched 20 small satellites， a single sheer number shocked the world.

In recent years， with the power of micro-nano manufacturing technology， the remote sensing resolution of some small satellites has reached 0.31 meters， while others built by LEO small satellite constellation have achieved a seamless global personal communication… New initiative steps like this will lead to a new wave of small satellite industry.

Sudden emergence of modern small satellites

Scientists generally call ones launched before the 1970s the "traditional （simple） small satellites"， and those after the 1980s "Modern （high performance） small satellites." In the 21st century， more and more countries have begun to attach importance to the development of small satellites and the entire world set off a new upsurge of small satellites.

Since 2013， the world has for three consecutive years successfully launched over 130 small satellites， the orbit ratio of which exceeds 60% among the total number of spacecraft in the same period. Small satellites have become an important driving force for the rapid development of space activities， forcing next major change in space development.

Due to the use of micro-nano manufacturing， and other high-tech as well as new design ideas， comparing to the ones before the 1970s， modern small satellite has been through a leap in development. With more power and higher technology， modern small satellites have been widely used in commercial communications， aerospace remote sensing， space research， planetary exploration， defense and military fields， etc.

Ascendant CubeSat

In 1999， Professor Tom Kenny Stanford University put forward a new concept on "Pico satellite"， defining it as a CubeSat， that is， with the weight of 1 kg， a volume of about 10 cm × 10 cm × 10 cm positive cubic satellite （also known as 1U）； and a number of CubeSats can compose of Cubic NanoSat. Both CubeSat and Cubic NanoSat are pioneering trend of modern small satellites.

For example， using 50 to 100 CubeSats， its possible to achieve global coverage with high spatial resolution obtained at the same time （2 to 3 meters） and high temporal resolution （revisit time of 15 to 45 minutes， a short time that is able to revisit more timely detection of changes in the ground scene）， costing just over 100 million US dollars. It is these advantages that makes CubeSat popular among universities and start-up space companies. In recent years， the number of launched CubeSats is also rising fast. According to statistics， in the year 2014， the number researches 103.

In addition， through the development of CubeSats， many countries have realized their space dreams. For example， in 2013， Ecuador and Peru achieved a national breakthrough by launching independently developed CubeSats. Because of standardized， modular advantages of low cost， short development cycle， etc.， if used in a distributed system， it can play a greater role， and has broader prospects for development.

Promising PhoneSat

In recent years， based on the CubeSat， there appeared PhoneSats with huge influence. The so-called PhoneSat is the one using CubeSat as platform and smart phones as payloads.

February 2013， the British company Surrey Satellite developed the world's first PhoneSat-- STRaND-1. It is a 4U cube satellite， weighing about 4 kg， controlled by phones. In addition to solar panels and a propulsion system， it also has all the components and functions of traditional satellites， and is the world's first spacecraft using 3D printing technology to prepare components.

April 2013， NASA's three smartphones satellites （2 PhoneSat1.0 and a PhoneSat2.0） was set off， all of which are 1U CubeSat with the operating system of Google Android， on-board computer of chipsets for smartphones， camera shooting images of Earth 500-megapixel phone lens.

Using smart phones as a major consumer load， the cost of these three satellites is very low， such as PhoneSat 1.0 costing only $ 3，500， while PhoneSat 2.0 costing only $ 8，000. During the flight they completed missions including sending back the satellite's own battery and temperature data to the ground， using mobile phones to take pictures of Earth and sending them back to the ground as well as conducting communication tests with "Iridium" constellation， etc.

Currently， due to their characteristic of ultra-lightweight， ultra-compact， low cost， etc.， small satellitesare attracting much attention， and they will surely flex their muscles in the future development of aerospace industry.