It’s been a noteworthy week in rocket launches. First, last Monday, China placed another element of their Beidou satellite navigation constellation into orbit. I found some nice amateur footage of it on YouTube — note the duration of time before you begin to hear the roar, and also note the characteristic red clouds at launch. The entire Long March family uses hypergolic propellants, hydrazine and nitrogen tetroxide, and before the mix evens out at ignition, the exhaust contains a lot of nitrogen tetroxide, a highly corrosive chemical still widely used in spacecraft engines, but phased out of American and European launch vehicles some time ago. Still, this launch went off without a hitch, and it is fun to hear the palpable excitement and joy in the voiced of the onlookers.
Then, on Friday, the USAF placed the twelfth and final GPS 2F spacecraft into orbit. This is the last of the Block II GPS spacecraft; the next launch will be the first of the Block III. Launched aboard an Atlas V rocket with Centaur upper stage, the spacecraft was successfully delivered into the correct orbit. The first stage is infamously powered by the RD-180 built by NPO Energomash in Russia. It is a closed-cycle kerosene-LOX engine and among the most sophisticated kerolox engines ever designed. The upper stage is powered by the venerable RL-10 by Rocketdyne, an expander-cycle cryogenic rocket engine powered by liquid hydrogen and liquid oxygen.
And then, somewhat ambiguously, North Korea made a second satellite launch early this morning. They gave few details on the payload, but an object was indeed placed into orbit and is being tracked, so the launch appears to have been successful. Unlike the last launch, I have not heard any reports of the payload tumbling, so this time the payload must have separated properly from the upper stage. (Disclaimer: I don’t speak Korean, so I have no idea what the commentary in this video is, though I think it may be a North Korean release.)
Lastly, and almost as if to show the North Koreans how it’s really done, the Russians <i>also</i> enhanced their navigation satellite constellation, placing a GLONASS satellite into orbit by a Soyuz 2 rocket from Plesetsk Cosmodrome:
The skies got a bit busier this week.