I am getting pretty tired of reading about Elon Musk’s latest achievements. How can the guy who founded Tesla with its Model S sedan now considered the safest vehicle in the world, also be the one who is going to make spaceflight almost as cheap as air travel? It’s confounding to think that an entrepreneur can drive innovation better than all the governments put together? Of course I say this all with tongue-in-cheek humor because it is people like Musk that push the limits by gambling on invention to create the billions they earn. And sometimes government provides a helping hand but most of the time Musk and people like him are driven by an inner conviction and a vision of a foreseeable future. It sure has been fun to watch.
Musk’s spaceflight vision is for a multi-stage reusable rocket that would reduce the cost of delivering a payload into low-Earth orbit from $22,000 US per kilogram ($10,000 a pound) to $22 ($10). What that means is creating a launch vehicle whose components are all reusable except for the fuel. The SpaceX Falcon rocket series is the one Musk is perfecting to do just that. It would consist of reusable first, second and payload stages (see image below). All would be capable of returning to the launch site after doing its job. That means building durability into every stage giving them the capability of withstanding the G-forces exerted on them in leaving Earth’s gravity well. It also means different timing in launch phases because each stage would carry fuel for returning to the launch site. That means shorter duration staging in the launch sequence.
Musk’s mathematics are interesting. Today every launch of a Falcon 9 rocket costs about $60 million US give or take $5 million. Of that fuel and oxidizer cost 0.35% ($200,000). So each launch you are throwing away $60 million. If all of the components are recoverable and serviceable then the cost of each launch drops to the cost of fuel, oxidizer, personnel and supporting infrastructure. A turn around of a few days could mean a hundred or more launches a year. At that rate instead of $450 million US per launch as in the age of the Space Shuttle, Musk hopes to drive costs down from SpaceX’s current $63 million covering 8 flights per year, to $20 million at a rate of 1.25 launches per month, to finally less than $3 million with 2 or more launches per week.
Musk is well on his way to accomplishing this goal. His Grasshopper test flights, which I have written about, are proving the reliability of maneuverable, reusable rockets. And with each success in the SpaceX program we see the cost of delivering a kilogram of payload dropping. When we get down to that $22 a kilogram ($10 per pound) we will cost out sending a 90 kilogram (200 pound) human like me into low-Earth orbit. With a 100% markup per person a spaceflight will be no more expensive than the price of a luxury airline ticket today on Virgin Atlantic from Heathrow in London to JFK in New York City.
Musk’s current testing of his reusable Grasshopper involves more vertical takeoffs and landings this year including increasing the height and speed of his rocket to test G-force stresses on the design. By the end of 2013 the Grasshopper will go supersonic. After that a new generation of Falcon rockets even more maneuverable than the Grasshopper will make an appearance. And if all goes well we will see reusable rocket launches become the primary mode of getting to orbit before the end of the decade. Now that’s the way to make spaceflight affordable.