SpaceX: An Overview

SpaceX is a company that designs, manufactures, and launches rockets and spacecraft. Elon Musk founded the company in 2002. His goals are to revolutionize spaceflight, provide commercial access to space, and eventually colonize other planets[1]

The Rise of Elon Musk

The rise of Elon Musk; from Blastar to blast-off!

Elon Musk was born in South Africa on June 28, 1971. Musk developed an interest in computers at an early age, and taught himself how to program them. He was 12 when he sold his first software, a game called Blastar. At age 17, Musk moved to Canada to attend Queen’s University and avoid mandatory service in the South African military. In 1992, he left Canada to study at the University of Pennsylvania. He later graduated with an undergraduate degree in economics and a bachelor’s degree in physics. Musk then headed to Stanford University in California, to pursue a PhD in energy physics, however, he dropped out only 2 days after he started attending. He dropped out to try and take advantage of the internet boom, that was just beginning.

In 1995 Elon Musk founded the Zip2 corporation with his brother, Kimbal Musk. Zip2 provided and licensed online city guide software for newspapers. It was used by companies such as The New York Times, and Chicago Tribune. In 1999, Elon Musk sold Zip2 for 341 million dollars to a division of Compaq Computer Corporation. Using money from the sale, Kimbal and Elon Musk founded X.com, which later became known as PayPal. He sold PayPal to Ebay, in October 2002, for 1.5 billion dollars.

During that same year, Elon Musk also became a US citizen, and founded SpaceX. SpaceX’s original goal was to build spacecraft for commercial use. SpaceX started by launching small rockets, as they were relatively cheap, and easy to build. In 2005 SpaceX was awarded an indefinite contract by the US military, allowing it to purchase up to 100 million dollars worth of rocket launches. In 2008, NASA announced that SpaceX won the NASA Commercial Orbital Transportation Services contract, which would have SpaceX deliver supplies to the International Space Station, and possibly transport crew. The contract was for 1.6 billion dollars worth of deliveries. This made SpaceX the world’s first private contractor to deliver cargo to the ISS.

The Birth of SpaceX

A Falcon Heavy rocket blasting off from a SpaceX launch site.

SpaceX had a rough start, the first three launches were failures. The first launch, a Falcon 1 launch in March 2006, failed minutes into its flight due to a fuel line leak. The second launch, another Falcon 1, was launched in March, 2007, and was lost in space, minutes after taking off. In August 2008, the third launch was also a failure, when the first and second stages failed to separate. The fourth launch was successful. In September 2008, SpaceX’s first Falcon 1 made it into Earth’s orbit.

The Bumpy Road to Reusable Rockets

The bumpy road to reusable rockets

One of SpaceX’s greatest accomplishments is landing and reusing rocket stages. The development of reusable rockets began on September 21, 2012. SpaceX built a prototype around the empty tank of an early version of the Falcon 9 rocket. The US Federal Aviation Administration, that licensed the test, didn’t allow it to go more than half a mile above the ground. The 8 tests, of taking off and landing with the prototype, gave SpaceX necessary data for developing the software and hardware that would later guide rocket stages back to earth. The tests took place at a facility in McGregor, Texas.

The next prototype was built around a second generation Falcon 9 tank. It was 40 meters tall with retractable legs. Its first test was a success and it flew more than 1,000 meters into the air before landing, however on its second test, a sensor was blocked, which caused strong winds to push it off course. An automatic process caused it to self-destruct before it drifted outside of the safe testing area. 

The first time SpaceX attempted to land a rocket’s stage was before the Falcon 9 tests. It was during SpaceX’s first completely commercial mission, launching a Canadian satellite called Cassiope into orbit. The launch was successful, however the first stage of the rocket lost control during the descent, and plunged into the ocean.

The next Falcon 9 rocket launched with the intent of landing, was on April 18, 2014. It was the first mission that an operational Falcon 9 flew with landing legs attached. Its landing was largely successful, however it was slightly off target, and plunged into the ocean, instead of landing on the platform.

On July 14, 2014, another Falcon 9 was launched, carrying cargo to the International Space Station. The delivery was a success. The rocket was launched without landing gear, as it was not intended to land. The first stage fell back into the ocean after detaching, but it slowed itself enough that it hit the ocean slowly. The rocket was used as a test, to see if it could slow down enough, to potentially land safely. It proved that the Falcon 9 rocket could reenter the atmosphere at super-sonic velocities, restart the main engines twice, and hit the surface slowly.

SpaceX often lands spent rocket stages on remotely controlled ships. These drone ships are large mobile floating platforms. Landing rockets at sea is an important capability, because if a rocket malfunctions, there isn’t anything that could be damaged nearby. If the rocket is off course, it will merely land in the sea, and be lost.

On January 10, 2015, a Falcon 9 attempted to land on a drone ship. The hydraulic fans controlling it’s decent stuck, and it flew out of control and crashed. Two months later, a Falcon 9 was launched, with a delivery of supplies and instruments to the International Space Station. The first stage was supposed to land on a drone ship, however a sticky valve prevented it from shutting off the engine in time, which caused it to fall over and explode.

A Falcon 9 rocket was launched from Cape Canaveral on December 22, 2015. It was SpaceX’s second launch for the company Orbcomm. The rocket took-off, and flew straight up to the edge of the atmosphere, and the first stage detached and came back down, and landed, marking the first successful landing of a used rocket stage. It was a vertical take-off launch. The term VTVL is often used now, for vertical take-off, vertical landing.

The next attempted landing, was onto a drone ship on January 7, 2016. However it was a failure, as one of the rocket legs failed to lock into place when it opened, and the rocket fell over, and exploded. There was another failed landing on March 4, 2016, as the rocket didn’t have enough fuel left over to slow itself down. The rocket didn’t have enough fuel because it had to deliver the satellite into a much higher orbit than usual. It crashed into the landing platform while moving too quickly, and exploded.

The first successful landing onto a drone ship took place on April 8, 2016. After a mission to the ISS, the rocket landed. It was later re-flown, which made it the first ever orbital rocket to be reused. A month later another rocket is successfully landed on a drone ship after delivering a satellite into a geostationary orbit.

As the technology for reusable rocket stages was perfected, Elon Musk started building all of his rockets with reuse in mind. SpaceX recovered every single rocket launched in 2017.

The Falcon 9 and Falcon Heavy Rockets

SpaceX’s most used rockets, the Falcon 9 and the Falcon 9 Heavy.

SpaceX uses two different kinds of launch vehicles, the Falcon 9, and the Falcon Heavy. The Falcon 9 is a two-stage rocket. The Falcon 9 rocket is designed to launch satellites or the dragon capsule, another creation of SpaceX. The Falcon 9 is 12 feet in diameter, 230 feet tall and weighs 1,207,920 pounds. It can deliver a payload of 50,000 pounds to a low earth orbit, a payload of 18,000 pounds to a geosynchronous orbit, or a payload of 8,800 pounds to Mars. It was designed to be easily reusable. Having only two stages minimizes the separations. The first stage has 9 engines, that are positioned so that even if two of them fail, the rocket can still complete its mission. The tanks are composed of an alloy of aluminum and lithium. It uses liquid oxygen and RP-1 (refined petroleum) as fuel. The rocket generates around 1.7 million pounds of thrust, at sea level and 1.8 million as it exits the atmosphere[7]. The difference in thrust comes from atmospheric pressure. The atmospheric pressure counteracts the pressure from the rocket’s combustion, causing less thrust to be produced.

The second stage of the Falcon 9 rocket is only powered by a single Merlin vacuum engine. Its purpose is to deliver the payload into the desired orbit, once the rocket is already in space. The tanks are made of the same aluminum-lithium alloy as the first stage. The second stage can be restarted multiple times if it is carrying multiple payloads that require different orbits[7]. 

The Falcon Heavy rocket is designed for much heavier payloads. It is the most powerful operating rocket today, by a factor of 2. Its total width, is 40 feet, and it is 230 feet tall. It has 2 stages, and 2 boosters. It weighs 3,125,735 pounds. It can deliver a payload of 140,000 pounds to low Earth orbit, 58,800 pounds to geosynchronous orbit, 37,000 pounds to Mars, or even 7,700 pounds as far as Pluto. The rockets are built with a 40% safety margin, meaning that they can withstand forces up to 40% greater than the maximum planned.

The first stage of the Falcon Heavy is made up of three cores. There are two cores on opposite sides of the center core. The side cores are connected to the center core at the top and bottom. Each core is very similar to the Falcon 9 rocket, with aluminum-lithium tanks and 9 Merlin engines. At liftoff all three cores fire at full thrust, but shortly after liftoff, the center core throttles down while the booster cores keep firing at full thrust. Once the booster cores separate and land, the center core throttles back up to full thrust.

The second stage is almost identical to the second stage of the Falcon 9, with a single Merlin engine and aluminum-lithium tanks. Its purpose is also the same.  Both rockets rely on the Merlin engine, which was developed by SpaceX. 

When launching a rocket, the primary difficulty isn’t lifting the rocket into space, it’s accelerating the rocket to orbital velocity. Orbital velocity differs depending on the distance from the earth. The orbital velocity for a low Earth orbit is 17,000 miles per hour. Low Earth orbit is an orbit centered around 1,200 miles from the surface of the Earth. Orbital velocity decreases as you get farther from the Earth. The equation used to calculate orbital velocity is SQRT((G*M)/R). G is the gravitational constant, M is the mass of the central body, and R is the radius of the orbit.

Because of orbital velocity, the location for launches is very important. Launch sites all tend to be near the equator, to take advantage of the fact that the Earth rotates. At the equator, the Earth is moving at about 1,000 miles per hour. That means the rockets launched on or near the equator start out traveling at 1000 miles per hour, meaning they need to accelerate less to achieve an orbit.

SpaceX’s Launch Sites

SpaceX’s South Texas (Boca Chica area) launch site. Photo from SpaceX.

SpaceX owns several different launch locations, all very far south in the USA. There is one in Texas, two in Florida, and one in California.

The launch site in Texas is called the SpaceX South Texas Launch Site. It is located in the Boca Chica area at the southern end of Texas. It is suited for orbital launches, as it is as close to the equator as you can get in the United States. Being close to the equator takes advantage of the lessened acceleration requirements. It is also far from any populated area, so in the event of a failed launch, the risk of injury is minimal.

Launch complex 39A is located near the Kennedy Space Center. Launch complex 39A was the site of many historic launches, including the Apollo missions, and Skylab. SpaceX has made numerous changes to the launch site, to support launches of larger rockets, such as the Falcon Heavy these changes include a greatly expanded hangar and reinforced launchpad. SpaceX also benefits from already existing local infrastructures, that supported the previous launches there. These include weather monitoring, ground support, payload processing facilities, and long-range tracking cameras.

SpaceX owns another launch site in Florida, on Cape Canaveral, Space Launch Complex 40 (SLC-40). It is in the Cape Canaveral Air Force Station, with Patrick Air Force Base to the south and NASA’s Kennedy Space Center to the north. Because of the proximity to other launch sites, SLC-40 benefits from many of the same services that they do, be it for fuel, parts, security, location, or weather monitoring services.

SpaceX’s Plans for the Future

Artist’s conception of a BFR approaching the Red Planet.

SpaceX has many ambitious plans for the future. One such plan is the Starship. The Starship is collectively the cargo carrying Starship spacecraft and its launch vehicle, the Falcon Super Heavy.  The Starship is designed to be able to carry crew along with cargo.

The Falcon Super Heavy rocket will carry the Starship. It will be 223 feet tall, and 30 feet in diameter. It will be able to generate 16 million pounds of thrust, and will carry 6.6 million pounds of propellant. Both the Starship and Falcon Super Heavy will use Raptor engines instead of Merlin engines. The Falcon Super Heavy will use 37 Raptor engines while the Starship stage will use 7. Raptor engines will be larger and run on liquid methane, rather than RP-1. This is because RP-1 can cause problems with residue build-up, in a process that is known as coking. Another reason methane will be used, is because it is theorized that methane could be extracted from the surface of Mars, making re-fueling the Starship possible on Mars.

SpaceX’s Competitors

There are companies other than SpaceX that are expanding into commercial spaceflight, and making their own innovations. Some of the more notable examples are Boeing, Sierra Nevada Corporation, Virgin Galactic, Xcor Aerospace, and Made in Space.

Boeing manufactures and sells airplanes, rotor-craft, rockets, satellites, missiles, and telecommunications equipment. Their scope has only recently expanded to include rockets. The rocket they developed is the CST-100 (Crew Space Transport – 100) or Boeing Starliner. They have yet to sell any, as the rockets are still in the development and testing phase. It is designed to carry up to 7 passengers, and would be viable to orbit for up to 7 months, and reliable for 10 launches. It is also designed to be compatible with other launch vehicles such as the Atlas V, Delta IV, Falcon 9, and Vulcan.

Another company that competes with SpaceX is the Sierra Nevada Corporation. They cover other areas than space-craft, such as national security and defense. One of their major projects is the Dreamchaser. It is designed to be launched from any conventional rocket, and can deliver up to 12,000 pounds of cargo. Like the Boeing Starliner, it is still in development, and has not yet been put into commercial use.

Launch Statistics

SpaceX has made a total of 91 launches, as of March, 2020. This includes 83 Falcon 9 launches, 3 Falcon Heavy launches, and 5 Falcon 1 launches. SpaceX has only failed a total of 5 launches, 3 of which were from the early testing and development of the Falcon 1. The most launches in one year, was during 2018, when a total of 21 rockets were launched, 9 new Falcon 9 rockets, 11 previously used Falcon 9 rockets, and one Falcon Heavy. 2020 is planned to be a close second, with 20 launches. There have already been 6 used Falcon 9 launches as of March, 2020. SpaceX has successfully landed 50 cores, or the first stage.

SpaceX has launched a total of 343,223 kilograms, or 756,677 pounds, of payload into various orbits. The majority of this was launched into a geostationary transfer orbit. This is an orbit designed to transfer from one orbit, to another, in the same plane, using the minimum amount of fuel possible. Another large portion of the launches were into polar orbits. Recently SpaceX has been doing mostly LEO (low earth orbit) launches.

SpaceX has a wide range of customers. Most of the launches are commercial, but many are for public agencies such as NASA, USAF and NRO. 60% of the launches are commercial, while 25% are for NASA, 1% and 2% from the NRO (National Reconnaissance Office) and USAF (United States Air-Force) respectively. SpaceX has performed 67 launches for commercial sources, 28 for NASA, 3 for the USAF, and 2 for the NRO. SpaceX has launched 10 rockets for its own purposes, or 9% of its total launches. SpaceX employs 7,000 people and was founded more than 18 years ago.

Plans to Colonize Mars

SpaceX has many goals that seem like near impossibilities. Probably the most notable of these is SpaceX’s claim that it will put people on Mars, by 2025. SpaceX plans to accomplish this using the Big Falcon Rocket (BFR), which is still being developed. SpaceX plans to launch a BFR carrying a Starship, into orbit by 2020 or 2021. This is the technology that will be used to transport crew and cargo to Mars. SpaceX plans to launch two loads of cargo to Mars, by 2022. This is because Mars’s orbit only brings it relatively close to the Earth once every two years. The rockets are planned to land on Mars by late 2022, or 2023. These launches would be carrying cargo necessary for the future base on Mars, such as tools and materials to construct habitats, generate power, and gather water. They also plan to make use of methane found on Mars, to potentially power return flights[12].

There is nothing planned for Mars in the year 2023, however SpaceX plans to fly Yusaku Maezawa around the Moon. Yusaku Maezawa is a Japanese billionaire who bought SpaceX’s services. It will be the first time that SpaceX has sent anyone to the moon, and Maezawa will be the thirteenth person to ever visit the moon[12].

In 2024, SpaceX plans to launch another BFR with a human crew, bound for Mars. SpaceX is unsure if it will need multiple launches or not, as the supplies needed to survive on Mars might be too much for a single launch, even with the previously delivered supplies from 2022. SpaceX plans to have the first people set foot on Mars in 2025, with the spaceships serving as temporary homes for the astronauts. By sometime in 2028 SpaceX plans to have completed the first Mars base, known as Mars Base Alpha. Mars Base Alpha would contain only the necessities to survive, but it will expand from there. From this point on, everything is less sure, but SpaceX projects that they may have a rudimentary city built on Mars by 2030[12].

Conclusion

It is important to stop and think about the amazing accomplishments SpaceX has made, bringing topics that were mere science fiction into reality. Landing and reusing rockets was never even considered before SpaceX accomplished it. They have even created a plan to colonize Mars. SpaceX is an amazing company that has completely changed the spaceflight industry.

References

[1] = https://www.spacex.com/about 

[2] = https://www.biography.com/business-figure/elon-musk 

[3] = https://www.whereisroadster.com/spacex/ 

[4] = https://www.oakton.edu/students/8/iiliev5728/Final%20Progect/SpaceX.htm 

[5] = https://www.nytimes.com/interactive/2018/science/spacex-falcon-launch.html 

[6] = https://qz.com/1016072/a-multimedia-history-of-every-single-one-of-spacexs-attempts-to-land-its-booster-rocket-back-on-earth/ 

[7] = https://www.spacex.com/falcon9 

[8] = https://www.spacex.com/falcon-heavy 

[9] = https://www.physicsclassroom.com/class/circles/Lesson-4/Mathematics-of-Satellite-Motion

[10] = https://www.fastcompany.com/3026685/the-worlds-top-10-most-innovative-companies-in-spacSe 

[11] = https://www.sncorp.com/

[12] = https://www.businessinsider.com/elon-musk-spacex-mars-plan-timeline-2018-10#2028-finish-building-mars-base-alpha-10

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