Saturday, May 18, 2013

Kunpeng 7

 2013-U01


A large rocket was launched to over 10000 km apogee on 2013 May 13. It was described as “the Kunpeng-7 test flight”.

A Ba cloud was released at about 10000 km. US tracking suggested a near-geosync apogee. The Chinese report said that a barium release was carried out at around `1 wan' (10000) km, and that the rocket went higher than `1 wan' km, but did not specify how much higher. The US Dept of Defense reports that it tracked the launch on a path to `nearly GEO' with reentry 'over the Indian Ocean': Since GEO is at 35780 km, the vague phrase `nearly GEO' might seem to imply an apogee closer to 30-35 thousand km than 10 thousand . However, US intelligence has been floating the possibility of a GEO-altitude Chinese ASAT test; one might therefore worry that if they only tracked it early in flight with resulting large apogee uncertainties, they may be prone to getting the answer they expected. It is hard to draw firm conclusions without a more precise statement from the DoD (or, for that matter, from China).

For the record the full statement from LtCol Catherine Wilkinson, Dept of Defense, kindly forwarded by Tomotaro Inoue of Kyodo News, is:

"We detected a launch on May 13 from within China. The launch appeared to be on a ballistic trajectory nearly to geosynchronous Earth orbit. We tracked several objects during the flight but did not observe the insertion of any objects into orbit and no objects associated with this launch remain in space.

"Based upon observations, we assess that the objects reentered the atmosphere above the Indian Ocean. We defer any further questions to the government of China."

The rocket appears to have been launched on a 32 deg inclination path SE from Xichang (based on NOTAM analysis) and according to reports on nasaspaceflight.com its flight was observed widely in SE China and Hong Kong. The Kunpeng-7 magnetosphere science payload was reported to have included a Langmuir probe, particle detectors, a magnetometer, and a barium cloud release. Because of the relatively unusual secrecy preceding the launch some analysts concluded that the mission was actually a military one. The only previous large military program known to have launched from Xichang in recent years was the antisatellite test program; the launch vehicle for Kunpeng-7 was reported to be from the CASIC company and was probably a variant of the DF-21 missile used in that program or its DF-31 cousin.

This is the highest altitude suborbital flight since Gravity Probe A in 1976, and possibly since Blue Scout Jr O-2 in 1961. If the rocket reached 30000 km, its flight may have lasted 8 to 9 hours and impacted in the Indian Ocean - moving east for the first hour or so, and then to the southwest as it slowed and the Earth's rotation overtook it, passing perhaps over Malaysia and Sumatra, then east again in the final hour of descent. Flights like this can loosely be described as sounding rockets, but the more precise term of art is 'vertical probe', which was used to describe similar Soviet and US high altitude suborbital flights in the 1960s and 1970s.

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