*Thanks to user wetherhold for the GIF used in the article
By Farzad Mesbahi
If you've clicked on this post I'm assuming you've already watched this video. If not, please take a moment and join in on the delirious excitement that follows:
What you've just witnessed is probably the second biggest thing that's ever happened in the history of spaceflight (moon landing probably taking first place.) This is the first ever full recovery of a first stage rocket booster after it placed an object on its way to orbit. That may sound relatively simple, but it is important to understand what putting something in orbit actually means (and why it's a very difficult thing,) so let's define it:
- To place an object (like a satellite) around earth so that the rate of speed of the object allows it to fall forever by offsetting the gravitational pull of the earth in a proportionally equal amount
Here's a GIF that graphically explains the above nerdy and overly complicated explanation:
In this example, you can think of the first stage booster as the apparatus that gives the ball the speed necessary to fall into orbit (basically the cannon itself plus the first 1/10th of the rotation of the ball around earth.) The ball then becomes the second stage and the satellite that it may be carrying. The second stage in the GIF then acts as the apparatus to tweak its position in orbit, and give it that additional oomph that is needed to place it exactly where it needs to be. As you can see, the object would need to move really, REALLY fast to be placed in orbit (around 17,000 mph.) This speed does change depending on the distance from the earth that the orbit needs to take place.
What SpaceX has accomplished is taking that first stage rocket booster and landing it safely back on earth. Here's a graphical representation of what that looks like (thanks to Reddit user /u/zlsa for posting):
In this example the booster performed a very similar maneuver to the one accomplished just yesterday, but instead of landing on a drone ship (which SpaceX tried to do multiple times with varying but ultimately failed results) the booster landed on a land-based landing pad miles out from the original launching point in Cape Canaveral, Florida.
Let's give a breakdown as to why SpaceX's accomplishment is such an enormously huge deal.
- Since the beginning of spaceflight, humanity's only way to put something in orbit has been the usage of a giant rocket usually referred to as a Stage 1 rocket. This rocket is incredibly expensive (SpaceX builds theirs for around $20m) and in classical settings is only usable once. This is because before 12/21/2015 at round 8:40 pm EST, the only way to recover a first stage rocket booster was to have it land in the ocean, at which point a boat-type thing would come over to recover it. Since the ocean has a crap-ton of salt the minerals in the water become a big corroding agent to all the parts in the rocket, which renders most of it unusable after that first flight. A good way of thinking of it is building a 747 airplane and only having it fly once from its destination and throwing it in the ocean after it lands, never to fly again. Can you imagine how much a plane ticket would cost if that was the case? (it would be something like $1.5m for a one-way ticket)
- The first stage rocket booster is by far the most expensive part of the rocket, which means that if it was recoverable and reusable, it would significantly reduce the cost of spaceflight. Numbers have been thrown around that peg the savings anywhere between 70% to 98% compared to today's methods if reusability is fully achieved. Either number would be a huge development for the space industry. Although refueling the spacecraft is also an expensive endeavor, the cost relative to the total rocket is about 1% (it costs about $200k to refuel a Falcon 9 rocket, which was used to accomplish the feat we're talking about.)
- In addition to the cost savings, retrieving the rocket back to its home launch pad (or nearby) allows SpaceX to rapidly reuse it, which will enable the company to have many more spaceflights in any given period of time compared to today. This is huge for both SpaceX and the space industry
It is also important to note that for this specific mission, 11 satellites were placed in what's called Low Earth Orbit (LEO,) which is a distance of between 99 and 1,200 miles from the surface of the earth.
Now, the reason why the title says what it says is because of two of very important things that we outlined: rocket reusability and LEO. Here's why it's important:
- The internet is usually handled today by ground-based ISPs (internet service providers) like Comcast, Time Warner, and many local providers, where they run a coax or fiber wire from the provider to your house. There's very few companies that offer satellite based internet due to what we've covered - it is very expensive to put something in orbit. Not only that, but putting something in LEO very aggressively limits the coverage of any given satellite (the internet rays from the satellite won't be able to cover much ground because they are so close to the earth.) In order to give as much coverage as possible and limit the number of launches, companies will place their satellites in Medium or High Earth Orbit (MEO or HEO, a distance of 1,200 to 22,000 miles for MEO, or 22,000+ for HEO.) The key problem here is that the farther away the satellite goes, the higher the latency becomes, due to the fact that the internet rays will take longer to travel to and from the satellite. This is why the adoption of satellite-based internet is not widespread - it's expensive and high latency (and usually pretty slow) and only used primarily in business and/or cellular settings where cost can be justified.
- Reusability, now being an option, changes the entire game. If SpaceX was to achieve the savings they are forecasting in rocketry (a factor of 100, so a $20m rocket becomes $200k which is the same as the fuel cost) it will enable companies to put satellites in orbit 100 times for the price of two rockets today, which includes accounting for rocket costs for 100 launches. Another way of thinking of it is a 98% savings on current costs. Imagine walking into a store that offered 98% off anything they offered - pretty good time for a shopping spree, right?
It is now possible to think about a situation where companies are able to send LEO satellites around the earth that would cover large swaths of land. Instead of sending 1 MEO or HEO satellite to orbit to provide crappy coverage with slow latency, they would be able to send 100 satellites in LEO and provide absolute killer internet for the same price and coverage area (or potentially greater area.) This will enable a much larger adoption since the product is significantly better than what we have today. All of us have run into dead or slow spots in a given city or town - imagine having the same internet speeds and performance that we all get at home from a FIOS or cable service, but instead having it literally anywhere. Pretty good if you ask me.
What's even more interesting is that SpaceX is looking to build its own satellites to do exactly that (https://www.washingtonpost.com/business/economy/spacex-founder-files-with-government-to-provide-internet-service-from-space/2015/06/09/db8d8d02-0eb7-11e5-a0dc-2b6f404ff5cf_story.html.) SpaceX can potentially position itself as a huge internet provider not only on earth, but on any other planetary body out in space (like Mars.) It is now the sole proprietor of the tech that's necessary to significantly cut the costs to put things in orbit. If there's one thing for certain is that when SpaceX goes public (not if), one can stand to gain a boatload of money given the immense implications of what they've just achieved.
See you guys on Mars!
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