Wednesday, October 29, 2014

Swan Dive: Antares With Cygnus Payload Explodes

The launch date for Orbital Sciences' third cargo delivery to the International Space Station was set originally for October 27 from NASA Wallops in Virginia. When the launch was scrubbed at the last minute due to a boat that had strayed into the restricted zone, the twittersphere was not amused. Jokes were cracked, serious questions were asked and much debate went on over whether or not a launch should be scrubbed because one fishing boat had gotten a little bit closer to the launch pad than was deemed safe. The launch date was rescheduled to October 28, at 6:22 pm.

Due to the delay I was able to watch the launch live, including the jaw-dropping explosion, after the rocket appeared to sustain a first-stage engine failure a few seconds after liftoff, plunging back to the pad with almost all of its fuel. Twitter users have commented widely on the first video below, saying that the pieces seen flying away from the blast are most likely chunks of solid fuel from the rocket's upper stages. 

Interestingly, during the live coverage (not in the above video), I spotted someone running, crouched down low, between the camera and the launch pad, about 60 seconds before liftoff. It startled me enough to say to my screen: "What are you still doing there? Get out of there!" Later, Orbital Sciences announced that all personnel was accounted for. Still, other twitter users saw the person in the live stream, too. Speculation continues on who that was and if the person was in danger.

 Below is a video of the explosion taken from an airplane:    


A view of the blast from across the water appeared on twitter soon after the launch failure:
Antares carried a Cygnus ("the swan") capsule with supplies, science and satellite payloads destined for the ISS. Given the space station's planning cycles that include stockpiling supplies for astronauts 4-6 months in advance, neither the astronauts nor the station are at risk due to this launch failure. Moreover, another scheduled ISS cargo delivery on a Proton rocket smoothly launched from Baikonur to the ISS later in the day. It will be weeks, if not months, before we know the exact cause for yesterday's failure. 

It seems certain, though, that the investigation will focus on the two Russian-built NK-33 engines that power Antares' first stage. These are engines built and stockpiled in Russia during the space race decades, and acquired by Aerojet for use in launches from the U.S.    

A summary on the NK-33 engine is here, with a more detailed and technical article here A quote from the first article: "If you want to get an engine like this, you can't find it in the United States." Originally made to express confidence in the NK-33, it's a statement that may come back to haunt Orbital Sciences and the company's decision to use Russian engines built decades ago.  

Comparisons to SpaceX are inevitable: The company is another private supplier of ISS cargo launches. It uses modern American-built engines and rockets assembled all in one place. True, SpaceX has less than 15 launches total to its name. Yet the company also saw an engine failure on one of its initial deliveries to the ISS. After the "anomaly", Falcon 9 continued on its way and made the delivery as planned. Falcon 9s are built with multiple redundant systems, including nine first-stage Merlin engines designed to save the mission, or at least the rocket and payload, should a launch fail. In addition, SpaceX is flying its next ISS cargo delivery mission on December 9 from Cape Canaveral. Part of that mission includes an attempted water landing on a floating platform in the ocean, paving the way towards making re-usability a reality.