Wednesday, January 20, 2016

The story of SpaceX's attempts to land a rocket, and what it means for the space industry

In the real world, the third time isn't always the charm, but it's a giant step in the right direction. Elon Musk, the founder and CEO of SpaceX, knows that better than anyone else.

Take 2: SpaceX's Falcon 9 rocket comes in to land on an autonomous barge,
named "Just Read the Instructions." It would land off balance and tip over,
then ultimately explode. (April 14, 2015)
by S. Alex Martin

Rockets are really, really good at going up. The trick is bringing them back down. Most modern rockets work in two stages. The first stage propels the payload (satellites, supplies for the International Space Station, etc) into Low Earth Orbit, and the second stage carries the payload to its destination.

Normally when the first stage of a Falcon 9 rocket separates from the second stage at 50 miles up, where it's traveling about 6,300 mph (7,400 kmh), which is Mach-10, or 10x the speed of sound. The first stage does a U-turn, climbing to between 90 and 120 miles high, then begins its descent. The engines slow the rocket down to around Mach-6, then continue with controlled backburns and bring the nearly 250-foot tall stage to a complete stop the instant before touching down on target.

Achieving this has been compared to throwing a pencil over the Empire State Building and having it land straight up-and-down in a shoebox on the other side.

Source: SpaceX

SpaceX began testing its return maneuvers in September 2013, and completed four experiments without using a barge or landing pad. The goal was to collect data about GPS reliability, response lag, and reverse-thrusting efficiency. Coupled with the Grasshopper Program, SpaceX honed in all the key elements of landing a rocket.

A "grasshopper" rocket hovers in midair before returning to its launch pad.
Source: SpaceX

Then, in January 2015, SpaceX attempted the first official Falcon 9 landing onto a barge in the Atlantic Ocean. In order to attempt this, SpaceX had to bring the margin of error for landing on a predetermined target from 6.2 miles (the error of its previous tests), down to a mere 33 feet. While the landing was ultimately a failure, the Falcon 9 rocket did reach the barge. Watch the Video.

On the second attempt, April 2015, the Falcon 9 rocket came even closer to landing. While the January attempt had come in nearly sideways, the April attempt was more-or-less standing up--but its horizontal velocity caused it to careen sideways right after touching down. Watch the Video.

June 28, 2015--Elon Musk's 44th birthday--was supposed to be the third barge-at-sea landing attempt. The launch, meant to resupply ISS, seemed perfect, but almost three minutes after liftoff, the rocket disintegrated due to a strut that snapped during the ascent, releasing a container of pressurized helium into the rocket's liquid oxygen tank and causing an overpressurization event. Watch the Video.

I'd like to exchange my gift: an overpressurization event caused the Falcon 9 to
disintegrate three minutes after launch on Elon Musk's birthday in late June 2015.
Source: NASA

SpaceX entered a hiatus, postponing future launches. Over the next six months, they designed and built an upgraded version of the Falcon 9, dubbed Full Thrust. The first launch of this upgraded Falcon 9 was immortalized on December 21, 2015, when the first stage carried 11 Orb-Com satellites into Low Earth Orbit, then turned around and made a perfect landing on solid ground nine minutes after launching. It marked the first time in history a rocket of this size and velocity had ever returned undamaged to Earth.

Upon inspections, Elon Musk announced the rocket was "ready to fire again," but noted that this particular Falcon 9 would never launch again. It will likely be added to a museum's collection of historic rockets. Watch the Video.

A mission control operator declared, "The Falcon has landed," seconds
after Falcon 9's successful touchdown December 21, 2015.
Source: SpaceX

What does this success mean for the space industry? Cost. Every single rocket that has ever been launched has been scrapped as trash. It costs over $100 million to build and launch a single rocket, then it's never used again. Think of it as driving to work and buying a new car every single day. That is, inevitably, unsustainable. A reusable rocket costs only $200,000 to refuel, and an estimated half-million to refurbish, rather than approximately $60 million to rebuild completely.

On top of that is a price tag of $50-$60 million to launch the Falcon 9 into space -- and that's cheap in the space industry. NASA's space shuttle cost an average of $1.5 billion per launch. To bring commercial launches down into the low tens-of-millions would save money and allow even faster progress, with more and more launches and better R&D in the space industry.

So that's why all eyes were on SpaceX Sunday, January 17, 2016. It was SpaceX's fourth attempt to land on a barge at sea, this time in the Pacific Ocean. The rocket was an older Falcon 9, not the newest upgraded version like the one that successfully landed in December.

The primary mission of the launch, to deliver the Jason-3 ocean mapping satellite into orbit, was a success. And the rocket made it to the barge, which was 200 miles off the coast of California. It looked like the landing was a success, until one of the support legs snapped and the rocket fell over in what's being hailed as one of the coolest explosions in rocketry.

Source: Elon Musk

In Elon's terms, RUDs are: Rapid Unscheduled Disassemblies. That's geek-speak for "big fiery explosion." But it's exactly what you would expect from a guy who's trying to change the world, and having fun doing it. He says he's "optimistic about [the] upcoming ship landing," slated for February 6 at the earliest. Click Here for a Full 2016 Launch Schedule.

UPDATE: The SES-9 mission was delayed four times, but finally launched on March 4, 2016.  The recovery of the first stage did not succeed due to a necessary re-allotment of fuel to get the satellite into GeoSync faster.


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