Wikipedia dixit:
“SpaceX’s Rocket Development and Test Facility in McGregor, Texas is used for research and development of new rocket engines and thrusters as well as for testing final manufactured engines, various components, and engines during development. Although SpaceX manufactures all of their rocket engines and thrusters at their Hawthorne headquarters, each must pass through McGregor where the company tests each new engine off of the assembly line as well as those being developed for future missions to orbit and beyond before each one can be used on a flight mission. […] Extensive and repeated rocket engine testing is a key to increasing reliability and thereby mission success, while lowering operating cost for SpaceX. Dragon spacecraft, following use on a space mission, splashdown and recovery, are shipped to McGregor for de-fueling, cleanup, and refurbishment for potential reuse in flight missions. The first scaled methane-fueled Raptor rocket engine, manufactured at the Hawthorne facility in California, shipped to McGregor by August 2016 for development testing.
In 2011, the company announced plans to upgrade the facility for launch testing a VTVL rocket, known as Grasshopper, and then constructed a half-acre concrete launch facility in 2012 to support the test flight program. After 8 flights of Grasshopper, and 5 flights of its successor “F9R Dev1” between 2012 and 2014, the FAA permit to fly Grasshopper flight tests in Texas expired in October 2014.
The company originally purchased the McGregor testing facilities of defunct Beal Aerospace—on land which was formerly a munitions manufacturing plant during World War II — where it refitted the largest test stand at the facilities for Falcon 9 engine testing. SpaceX has made a number of improvements to the facility since purchase, and has also extended the size of the facility by purchasing several pieces of adjacent farmland. The area to support the test facility was initially just 256 acres (104 ha) but by April 2011 this more than doubled to over 600 acres (240 ha). With only three initial employees onsite, the facility grew to over 140 employees by late 2011. As of October 2012, the McGregor facility consisted of seven test stands operated 18 hours a day, six days a week, and was building more test stands because production was ramping up and the company had a large manifest in the next several years. As of September 2013, the McGregor facility operated 11 test stands involved in the rocket engine test program, and was averaging two tests each day. The largest test stand by 2013 was the 82 meters (269 ft) tall Falcon 9 tripod. As of March 2015, the facility comprised 4,000 acres (1,600 ha), with 12 test stands; it had run over 4000 Merlin engine tests, including some 50 firings of the integrated nine-engine first stage.
In May 2016, the McGregor City Council instituted more restrictive rules on rocket engine, rocket stage, and low-altitude flight testing. SpaceX has not commented publicly on how the new rules will affect their testing operations, nor whether they will be evaluating other locations where they might conduct such testing.”
Video credit: SpaceX