Post Tue Jul 19, 2011 9:47 am

New military satellites launched into orbit

The end of September has been dominated by the military component of the satellites launches and as with all the operations of this type, despite the lack of information, the two launches we are speaking about-one accomplished by USA and the other one by China- have generated a big interest in the media or between the space analysts.
The first launch has been performed on 20th of September at 04:03 GMT when an Atlas 5 rocket has flown from the Vandenberg Air Force station in California marking the fourth event of the American launcher in 2010.

Flown as a 501 type Atlas 5, this has the lowest transport capacity from the Atlas 5 series –being able to carry into a LEO orbit a mass of up to 8250 kg, into a SSO orbit a mass of up to 5945 kg or into a GTO orbit a mass of up to 3970 kg.
Compared with its sister versions, the 501 type does not have the CCB (common core booster) system, its first stage being powered only by a single RD-180 engine with an old Russian design and having a secondary Centaur stage powered by a single RL-10A4-2 engine.
The fairing is built by the Swiss company RUAG, has a diameter of 5.4 m and three possible versions: a small one 20.7 m in length, a mid-size version of 23.4 m and a long version of 26.5 m, being able to accommodate a variety of satellite platforms.

Another 501 type flight has been executed in April 2010 when the passenger was the X37B Boeing-NASA prototype, while the other 2 flights mentioned earlier for 2010 took place with rocket versions 401 (in February 2010 with Solar Dynamics Laboratory SDO) and 531 (in August 2010 with the newest Advance Extreme High Frequency Satellite).
The debut of an Atlas 5 rocket took place in 21st of August 2002 when the first passenger was the telecomm satellite HotBird 6. Since then a total number of 23 flights have been served by the Atlas 5 rockets.
We have to remind here that both Atlas 5 and Delta 4 rockets have been developed for the EELV (Evolved Expendable Launch Vehicle) program which intended to increase the launch vehicle capacity for the US Army.

Despite the lack of information mentioned at the beginning of the article, it is however known the indicative of the satellite –NROL-41 (USA215) and the name of the owner- the National Reconnaissance Office.

The first amateur observations of the satellite’s orbit are speaking about a retrograde 1057x1072 km elliptical orbit with an inclination of 123 degrees. The new NORAD 37162 satellite has a visual magnitude of 6.5. Information comes also from the type of faring used- a weight relatively low but still with a big volume- which suggests a low density spacecraft, probably carrying a large antenna.
Combining this conclusion with the high orbit used (not favorable for the optical observations of the targets on Earth), one could suggest a radar class satellite as in some of the past cases when several platforms have been placed in retrograde 53 degrees inclination orbits.

The second launch took place Wednesday 22nd of September at 02:42 from the Jiuquan Space Center in China- the fourth launch of this year involving a Long March CZ-2D rocket.
This has been the 13th launch of this rocket, the 131st of the entire Chinese space history (the first placed in 1970) and the 9th flight of the last 50 days- which reflects clearly the ambitions of the Chinese space program.
The main satellite carried into orbit, the Yaogan 11 (placed in an ellipse 627x657 km by 98 degrees inclination) has been built by the Space Sciences Academy. Apparently, there was also a secondary payload onboard- 2 ZPDS (Zhe Da Pi Sing/Zhejiang University Pico Sat) pico-satellites 150x150x150 mm by 3.5 kg weight.
As with the previous cases, the Chinese part claimed they have launched a scientific Earth observation and disaster preventing satellite, however the specialists are speaking about a military spy SAR (synthetic aperture radar) mission – in fact a telescope operated exclusively by the Chinese army to capture pictures of various targets on ground.

The Yaogan Weixing class is grouping all the remote sensing Chinese satellites in two major subcategories: the first subcategory -electro optical digital imaging satellites are launched on board the CZ-2C/D rockets from the Jiuquan Space center while the secondary subcategory-synthetic aperture radar imaging satellites are launched from Taiyuan Space Center on board the CZ-4B/C launchers.

The first subcategory is derived from the old FSW4 platform and replaces the film capture with a digital capture, having a ground resolution of 0.6-1m.
The second subcategory is a bigger 2.5 tons platform equipped with retractable solar panels and a SAR instrument which can produce high quality images independent of the operating conditions.

The remote sensing Yaogan series has been developed by China since 2006. Then, on 27th April 2006, China was launching Yaogan 1 from the Taiyuan. Meanwhile, were launched Yaogan 2 (25th of May 2007), Yaogan 3 (12th of November 2007), Yaogan 4 (1st of December 2008), Yaogan 5 (15th of December 2008) and Yaogan 6 (22nd of April 2009). Finally, the Yaogan 8 was launched on 15th of December last year and later a triple launch putted on orbit Yaogan 9A/9B/9C.

The Chinese Long March launcher (now at the 4th generation) can transport up to 4200 kg into a LEO orbit or alternatively up to 1500 kg into a geostationary orbit, but the next generation the 5th will increase the transport capacity to 25000kg for LEO and 14000kg for GTO.
Coming back to the current rocket version used for this flight- the 2D- it can carry 3500 kg for LEO orbits and 1300 kg for a SSO orbit.

Currently, China is running several space experiments. Recently, there have been reported actions in minisatellite formation flying where 2 satellites launched in August have closed their distance under the 200m proving an orbital rendez-vous.

Moon is equally important for China. After the successful first mission of the Chang’e-1 spacecraft around the Moon, another mission will start soon the exploration of the Earth’s natural satellite. On long term, hopefully until 2025, China intends to replace the automatic exploration with humans which could bring back also soil probes.
On even longer term, following the recently launched international trend, the attention of the Chinese space agency will move to Mars, where the first satellites will be launched in the interval 2014-2033 and a human expedition will be put in place no sooner than 2040-2060.

More, at the beginning of March, and under the international refuse of his participation at the international space station -ISS, China released to the public his intention to produce its own space laboratory.
Starting with 1992, China manifests an interest for the human space flight. Its first serious initiative in this field was the so called 921 military project, an improvement of the previous 714 and 863 projects (initiated in 1967 and respectively 1986).
Unfortunately the effort was bigger than expected and it took more than 11 years and 2 billions dollars for China to send an astronaut in space, becoming thus the third country in the world succeeding this (on 15th of October 2003).
Since then the interest moved from the simple orbital flight to the more ambition objective of having a permanent station in space.
Even thought is inspired by the MOL program which was abandoned by USA in 1969, the first Chinese laboratory Tiangong 1 appears today much closer to the design of the European project ATV. It is in fact a laboratory fully equipped with sensors of last generation and who is going to work mostly autonomous.
In parallel there will be more effort spent for the development of the Shenzhou program which will play a role in the space-taxi concept.
The accent will go on the capacity of this vehicle to perform flights with a human crew onboard.
As with the ISS, the Chinese astronauts will come periodically on board of the station, they will be able to inspect it, they could collect the recorded data and could do some other manual experiments.
Separate of the Tiangong station, China plans the launch until 2020, of even a bigger and better station (20-25 tones in weight) which will have technology inspired by the Russian Mir laboratory.

But all these ambitious plans for the future cannot be sustained without permanently increasing and improving the performances of the launch vehicles, and this is a strategic direction where China is going to invest a lot of money in the next years, hoping to close the distance which still separates it from the other two big actors USA and Russia.