Second launch for Long March 11 – lofts five satellites
The Chinese have conducted the second launch of the Long March-11 solid fuel rocket – this time carrying five small satellites into orbit. The launch took place from a mobile launch platform from the Jiuquan satellite Launch Center at 23:42 UTC on Wednesday.
Onboard the LM-11 rocket was the XPNAV-1 pulsar navigation satellite. Along for the ride were the Xaiaoxiang-1 and three Lishui-1 satellites
With a launch mass of 240 kg, the XPNAV-1 ( X-ray Pulsar NAVigation) satellite will test autonomous spacecraft navigation. X-ray pulsar navigation is a navigation tool in which periodic X-ray signals emitted from pulsars are used to determine the location of a spacecraft in deep space.
Current ground-based navigation methods are limited by the time delay between spacecraft and the Earth. However, for certain type of pulsars, called “millisecond pulsars,” pulses of radiation occur with the regularity and precision of an atomic clock.
As a result, in some scenarios, the pulsar X-ray can take less time to estimate a location. This leads to more precise measurements of a spacecraft’s location.
As X-rays from pulsars are absorbed by the atmosphere, scientists have to test this technique in space. This satellite is to detect the details of X-ray signals of 26 nearby pulsars and to create a pulsar navigation database. This target could be achieved within five to 10 years.
Developed by the Aerospace Science and Technology Corporation (CASC) Fifth Academy, the satellite carries two detectors to test its functions in responding to the background noise of the universe, outline pulsar contours, and create a database for pulsar navigation.
X-ray pulsar navigation techniques will help to reduce the reliance of spacecraft on ground-based navigation methods and are expected to achieve autonomous spacecraft navigation in the future.
Xiaoxiang-1 is a 6U Cubesat designed, developed and manufactured by the Changsha Gaoxinqu Tianyi Research Institute. Weighing 8 kg and placed on a 500 km LEO orbit, the small satellite will test new stabilization system for imaging devices installed in satellites.
The three Lishui-1 satellites were developed by the Zhejiang LiTong Electronic Technology Co., Ltd. These are small commercial remote sensing satellites.
The Long March-11:
The Long March-11 (Chang Zhwng-11) is a small solid-fueled quick-reaction launch vehicle developed by the China Academy of Launch Vehicle Technology (CALT) with the goal to provide an easy to operate quick-reaction launch vehicle, that can remain in storage for long period and to provide a reliable launch on short notice.
LM-11 is a four stage solid-fueled launch vehicle equipped with a reaction control system on the fourth stage.
The vehicle has a length of 20.8 meters, 2.0 meters in diameter and a liftoff mass of 58,000 kg. At launch it develops 120.000 kg/f, launching a 350 kg cargo into a 700 km SSO. The CZ-11 can use two types of fairing with 1.6 meters or 2.0 meters.
LM-11’s first launch took place on September 25, 2015, when successfully orbited the Pujiang-1 and the three Tianwang small sats from the Jiuquan satellite Launch Center.
The Jiuquan Satellite Launch Center, in Ejin-Banner – a county in Alashan League of the Inner Mongolia Autonomous Region – was the first Chinese satellite launch center and is also known as the Shuang Cheng Tze launch center.
The site includes a Technical Centre, two Launch Complexes, Mission Command and Control Centre, Launch Control Centre, propellant fuelling systems, tracking and communication systems, gas supply systems, weather forecast systems, and logistic support systems.
Jiuquan was originally used to launch scientific and recoverable satellites into medium or low earth orbits at high inclinations. It is also the place from where all the Chinese manned missions are launched.
The LC-43 launch complex, also known by South Launch Site (SLS) is equipped with two launch pads: 921 and 603. Launch pad 921 is used for the manned program for the launch of the Chang Zheng-2F launch vehicle (Shenzhou and Tiangong). The 603 launch pad is used for unmanned orbital launches by the Chang Zheng-2C, Chang Zheng-2D and Chang Zheng-4C launch vehicles.
Other launch zones at the launch site are used for launching the Kuaizhou and the CZ-11 Cha ng Zheng-11 solid propellant launch vehicles.
The first orbital launch took place on April 24, 1970 when the CZ-1 Chang Zheng-1 rocket launched the first Chinese satellite, the Dongfanghong-1 (04382 1970-034A).