SpaceX renovating former Falcon 9 test stand at McGregor

by Ian Atkinson

SpaceX is renovating the former Falcon 9 first stage test stand at their McGregor, Texas test site. Recent aerial photos show that workers have installed scaffolding near the stand, and have removed the large tower formerly used to access stages on the stand. Elon Musk confirmed the work is related to converting the stand to test Raptor engines. SpaceX is also continuing work on a new second stage test stand.

Test stand renovation:

The former first stage test stand – nicknamed the “tripod”, after its shape – was built by Beal Aerospace. Beal owned and operated the McGregor facility from the late ’90s until 2000 when the company closed its doors.

After SpaceX took over the facility in 2003, they planned on modifying the tripod to support the first stage of the Falcon 5 – a planned medium-lift launch vehicle. Eventually, SpaceX cancelled the Falcon 5 in favor of a larger launch vehicle – the Falcon 9.

On top of the tripod, SpaceX added a tall tower with retractable floors to give engineers access to the entire first stage. Later, a large, water-cooled flame diverter was added at the base of the stand to help divert the exhaust of the first stage’s engines.

The tripod was used to test the 9 Merlin engines of each Falcon 9 first stage from 2008 until mid-2015. Its first test – a firing of two of the qualification first stage’s engines – occurred in 2008.

When SpaceX switched from the Falcon 9 v1.1 to the upgraded Falcon 9 Full Thrust, they opted to construct a larger, partially-underground test stand for the first stages. This would solve multiple problems at once – such as lowering the sound levels of the tests, not needing to update the tripod to work with the Full Thrust’s chilled propellants, and having the ability to test all three Falcon Heavy boosters at once.

In the end, SpaceX opted not to test the complete Falcon Heavy at McGregor- instead only testing one booster at a time. They would only test the three cores together on the launch pad, when they perform the traditional static fire test. As such, the stand has remained in a single-core configuration.

After the final v1.1 first stage – for the Jason-3 mission – was tested on the tripod, the stand was mothballed. From late 2015 to the present day, all Falcon 9 first stages have been tested on the new test stand.

The tripod has sat idle since 2015 – in essentially the same condition that it was left in when Jason 3’s first stage was removed.

However, recent aerial images show that the stand is all but sitting idle.

SpaceX’s McGregor Tripod test stand under modification – via Gary Blair Aerial Photo for NSF/L2

The tripod’s access tower has been completely removed and laid on its side. Many items that were formerly on the top deck of the tripod have been removed – including propellant lines and a large tank from behind the tower.

According to SpaceX CEO Elon Musk, the tripod stand is being modified to be a new vertical Raptor test stand.

Currently, SpaceX only has two horizontal Raptor test stands. This is likely enough for the near future – although with each Super Heavy booster requiring between 24 and 37 Raptors, SpaceX will need every test stand they can get.

Earlier this year, SpaceX CEO Elon Musk stated that SpaceX was planning to convert Starhopper into a vertical Raptor test stand after its final 150m flight.

It is unclear if SpaceX still intends to use Starhopper as a test stand – or where the tests with it would even occur.

The second horizontal Raptor stand was completed earlier this year. Two Raptors were seen installed in the twin stands earlier this month.

Two Raptor engines, one installed in each horizontal test stand. The newest stand, upper left, with the original stand, right. Credit: Zoomed/Cropped plane photo from outside of the facility perimeter by Gary Blair for NSF/L2.

The serial numbers of the two Raptors are unknown. However, they are not any of the three Raptors that were temporarily installed on Starship Mk. 1 – as Mk. 1’s were still installed when the picture was taken.

Also at McGregor, SpaceX is continuing work on a new second stage test stand. The stand is similar in design to the newer first stage stand and is located away from existing stands at the test site.

Construction began in 2015 – but was halted after just the flame trench was built. Work resumed in late 2017 and has progressed slowly since.

In recent pictures, a Falcon 9 second stage – minus its Merlin Vacuum engine – has appeared near the stand. This may be used for fit checks and to qualify the fueling systems. Also, the propellant lines from the nearby storage tanks to the stand appear to have been connected.

The under-construction second stage test stand. A second stage tank is visible just behind the flame trench, and the stand’s propellant lines can be seen on the left. Credit: Gary Blair for NSF/L2.

The new stand will help lighten the load on the existing second stage stand – especially once SpaceX begins ramping up the Starlink launch cadence.

It may be able to take over second stage testing completely – which would lower the impact on the adjacent test stands.

(All aerial photography by local pilot Gary Blair who takes periodical photos when flying near the area for NSF’s L2 McGregor Updates.)

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