Dual Success For SpaceX

It's been a weekend of amazing successes for SpaceX. The private space company delivered its eighth Dragon resupply capsule to the International Space Station and stuck an experimental landing of the spent Falcon 9 booster rocket on a drone ship in the Atlantic. SpaceX has previously tried landing the first stage of a Falcon 9 used in missions. Both times, the rocket made it to its target on the drone ship, but failed to land upright, resulting in RUD events (rapid unscheduled disassembly).

This tweet from early Sunday morning, April 10, shows Dragon safely docked to the ISS Harmony module, next to an Orbital Sciences' Cygnus cargo craft and a Soyuz crew capsule on the lower right. In total, six spacecraft are currently docked to the International Space Station.

SpaceX Dragon cargo ship, Orbital ATK’s Cygnus, and Soyuz crew capsule in this view from ISS https://t.co/uuY7qzZ0Ls pic.twitter.com/9qzTOiATDG

— Spaceflight Now (@SpaceflightNow) April 10, 2016

But let's go back to launch day, Friday, April 8, and take a look at all that SpaceX accomplished this weekend:

Image credit: SpaceX

Falcon 9 with its Dragon payload on the launch pad at Cape Canaveral

Image credit: SpaceX

Mission patch for SpaceX's eighth commercial resupply mission (CRS-8) to the International Space Station

If you look closely, you'll find the patch full of interesting details. For example, the eight stars in the design represent the eight missions to the ISS that SpaceX has flown so far, with one star dimmed out to symbolize last June's failed launch.

Image credit: SpaceX

Close-up of Dragon capsule atop Falcon 9, which stands over 200 feet (60 m) tall

Image credit: Space X

Graphic illustrating the stages of launch, landing and mission completion (click to enlarge)

The drone ship name in the above graphic is Just Read The Instructions. The ship on which Falcon 9 stuck its historic landing is Of Course I Still Love You.

The following trio of still pictures captured by SpaceX's chaser plane near the drone ship shows the landing's most breath-taking moments. This is the first time that SpaceX has successfully landed a rocket used in a mission on a drone ship at sea. The private space company previously succeeded at landing a Falcon 9 first stage on-shore.

Image credit: SpaceX

Image credit: SpaceX

Image credit: SpaceX

Whether Falcon 9's first stage lands on a drone ship or on shore after delivering a payload depends on several factors. Elon Musk explained some of them on Twitter.

@arstechnica Reasons for ocean landing are technical, not economic. Orbit requires extreme horizontal velocity. Getting to space needs none.

— Elon Musk (@elonmusk) April 8, 2016

Following are two tweets from SpaceX with landing video clips that were posted to the company's twitter account within hours of the landing.

Onboard view of landing in high winds pic.twitter.com/FedRzjYYyQ

— SpaceX (@SpaceX) April 9, 2016

Landing from the chase plane pic.twitter.com/2Q5qCaPq9P

— SpaceX (@SpaceX) April 8, 2016

Here is SpaceX's 36-minute launch and landing live webcast. About 30 seconds in, a legend appears at the bottom that lists the consecutive events being covered. It is well worth the time to review the launch and what SpaceX labeled "experimental landing". While the landing is one of the most jaw-dropping and certainly the most historic aspect of the CRS-8 mission, a successful landing was not the primary mission objective. That was getting a Dragon resupply capsule, including its important science cargo, safely to the International Space Station. SpaceX succeeded on both counts, with several cherries on top.

The reactions from employees at SpaceX headquarters in Hawthorne, CA after the successful launch and landing on Friday say it all. Elon Musk and the team at SpaceX have mastered another crucial step towards routine usage of reusable rockets, drastically lowering the cost of reaching targets in orbit and beyond and making space more accessible than ever before. SpaceX plans to re-fly a used rocket within a few months.

Video credit: SpaceX

Live webcast from SpaceX's headquarters during Friday's successful launch to the ISS and landing on one of the company's drone ship.

Below is the Storify of my live tweets and conversations during Friday's pre-launch, launch and landing events, with some additional remarks for this blog post.

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:

WHOA RT @thestormreport: PHOTO: #Antares after the explosion in Wallops Island, Virginia. Photo via @EddieInTheYard. pic.twitter.com/FbCnTHTvI8 — Claudia Totenkopf (@ct_la) October 28, 2014

 
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.