The China National Space Administration (CNSA) successfully launched its Long March-3B rocket on Monday, carrying a pair of satellites that will expand its Compass global navigation system. The launch took place at China’s Xichang Satellite Launch Center in Sichuan province. As you may know, Sichuan is smack dab in the middle of the country. So, these launches sometimes drop debris near populated areas. This time, several boosters from the Long March-3B actually hit buildings in a small village.
The Long March-3B is an expendable rocket that uses four small strap-on boosters attached to the core stage. These boosters use hypergolic (N2O4/UDMH) fuel, whereas the core runs on a more conventional cryogenic (liquid oxygen and hydrogen) mixture. After the side boosters are emptied, they drop off to unburden the rocket. This is where we run into an issue.
Most rocket launches are carried out from coastal locations — in the US Kennedy Space Center on the Florida coast is probably the most famous. The reason for this is simply that it’s safer to drop expendable rocket parts in the ocean rather than on land. The CNSA doesn’t seem too concerned about that, but maybe it should be.
Well we were joking about the Long March 3B booster landing bingo, but this really isn’t a laughing matter. This was the result of this morning’s launch! https://t.co/H8vXZ43un1 pic.twitter.com/cdXpSC7q1t
— Chris B – NSF (@NASASpaceflight) February 12, 2018
Following the latest Long March-3B launch, pictures emerged on the Chinese Weibo social network of the side boosters on the ground in a village. Several of them actually struck buildings. In one image, you can see a plume of brown-orange gas escaping from the impact site. There are currently no reports of casualties from the impacts, but it’s unclear if that information would even be made public. Following another recent launch, a booster with significant remaining fuel fell in the hills next to a village. Residents filmed the resulting explosion.
— ChinaSpaceflight (@cnspaceflight) January 12, 2018
The impact of the boosters might be the least dangerous aspect anyway. These boosters contain hypergolic propellant (unsymmetrical dimethylhydrazine), which ignites spontaneously when it comes in contact with an oxidizing agent. It is extremely toxic, corrosive, and carcinogenic. Releasing it into a populated area would be a regulatory nightmare in the US. Even SpaceX, which has nailed reusable rockets, conducts its launches from coastal facilities. No one has to dodge a runaway Falcon 9 core.
China shows no signs of changing its launch practices despite these near misses. The next satellite launch for CNSA comes in late February at the Jiuquan Satellite Launch Center in Inner Mongolia. It’s not on the coast, but the region is much less densely populated.