By April 2002 Musk abandoned his idea for a publicity stunt and instead turned towards founding a rocket launch company. This dismayed Robert Zubrin and many others, as they expected that Musk, like rocket entrepreneur Andrew Beal, would fail utterly.
Space Exploration Technologies, or SpaceX, was founded in June 2002 with the goal to drastically cut the cost of access to space. With eBay buying out PayPal for $1.5 billion, Musk suddenly had $180 million to fund SpaceX and any other venture.
It took until March 24, 2006 for SpaceX to finally launch its first rocket, the small Falcon 1, which failed soon after launch.
Maiden launch of Falcon 1 – Credit Thom Rogers/SpaceX
The same year SpaceX was given seed money by NASA to fund a much larger ten-engined rocket – nine engines on the first stage, one on the second stage – called the Falcon 9, canceling plans for the smaller Falcon 5 rocket.
Before the decision was made to go ahead with the Falcon 9 though, Musk made plans to eventually build something called the BFR, or “Big Falcon Rocket”, which at that time was planned to have the biggest engine in history according to Musk biographer Ashlee Vance.
After the second Falcon 1 failed on March 21, 2007, defense consultant Pete Worden talked to Musk, who despite the recent failure struck up a conversation about settling Mars. Musk’s Mars ambitions had finally eclipsed Robert Zubrin’s.
However, with SpaceX’s failures and both SpaceX and Musk’s car firm, Tesla, losing money, Musk had to prioritize getting the Falcon 1 into orbit and earning money. A third failure followed on August 3, 2008, after which Musk only had enough money for one more attempt.
Luckily the fourth launch on September 28, 2008 was successful.
While the success alleviated immediate concerns about SpaceX, Musk was going through personal issues while his finances were becoming ever more perilous. His firms were bleeding cash in the midst of the Great Recession even as Musk’s personal wealth dropped ever lower. In the end, he was saved by two events. One was the sale of software startup Everdream, which together with other funds helped Musk raise $20 million, which was then matched by other Tesla investors and ended up saving Tesla.
SpaceX, however, still needed help, which arrived unexpectedly on December 23, 2008, when NASA awarded SpaceX $1.6 billion in a COTS contract to deliver supplies to the International Space Station. His dreams of settling Mars and revolutionizing the car industry had been saved.
On June 18, 2009, the first public mention of the Raptor rocket engine was made by SpaceX’s Max Vozoff at the American Institute of Aeronautics and Astronautics (AIAA) Innovations in Orbit: An Exploration of Commercial Crew and Cargo Transportation event.
More details of the Raptor engine were given in July 2010 at the 46th Joint Propulsion Conference. It was to have a vacuum thrust of 667 kN (150,000 lbf), produce an ISP of 470.1 seconds, and be capable of throttling from 50 to 100%. It was supposed to have been a hydrogen/oxygen upper stage engine to power an upgraded version of SpaceX’s Falcon 9 medium lift launch vehicle then under development.
Conceptual ideas for the massive Falcon X, Falcon X Heavy and Falcon XX super heavy lift launch vehicles were also presented at the 2010 Joint Propulsion Conference. These were to be powered by very large Merlin 2 engines producing 7,565 kN (1,700,766 lbf) of thrust, with an ISP of 285.0 seconds at sea level and 321.4 seconds in a vacuum. These vehicles were to be essentially larger cousins of SpaceX’s Merlin 1 engine, which were kerosene/liquid oxygen burners that used the simple gas generator cycle. Shortly after the presentation, Musk disavowed that the ideas shown were firm plans for future rockets.
SpaceX’s future Mars rocket designs would be most heavily influenced by the firm’s Falcon 9 medium lift launch vehicle. When it debuted on June 4th, 2010, the 318 tonne rocket was a mixture of design elements old and new.
The Falcon 9 boasted first stage engine out capability, an ability last seen on the US Saturn IB rocket in 1975. It also featured common bulkheads to save mass and trim the rocket’s height, a feature used in 1960s era Saturn rockets, all versions of the Centaur stage, and the Ariane 5 launch vehicle.
New features in the design included friction stir welding of parts and lightweight aluminum-lithium alloy construction, both of which trimmed dry mass and upped the payload mass. Fabrication costs were lowered by using a single set of tooling to build both common diameter stages and by incorporating off the shelf redundant electronics. As a result, the Falcon 9 v1.0 was amongst the cheapest performers when it debuted. Musk, however, knew that in order to enable the colonization of Mars, he needed reusable rockets.
To enable this, Musk had SpaceX employ a two-track development strategy. The first track would focus on reusable rocket testing, while the second would focus on upgrading the Falcon 9 launch vehicle to provide enough margin for reuse. In 2011 development started on a Falcon 9 core stage with metal legs attached called the Grasshopper.
Grasshopper test – credit SpaceX
This vehicle was flown eight times in increasingly long “hops” in order to improve SpaceX’s experience with vertical rocket landings.
Eventually, the original Grasshopper was retired in 2013 and an even larger Grasshopper 2, based on the core stage of a Falcon 9 v1.1, was pressed into service.