Testing SpaceX's Starhopper suborbital car in Boca Chica, Texas, achieved a new milestone Wednesday night with a Static Fire test of its Raptor engine. The test comes after over a week of Wet Dress Repetals (WDR) and pre-burn tests. Thursday had technically resulted in its first jump, albeit just inches due to being attached to the pillow. Starhopper testing:
SpaceX's Starhopper races up test operations in Boca Chica, Texas, ahead of what is expected to incremental series of tests, fires and hops.
In the opening days of the test sequence, observers in the East Texas test and launch plant showed numerous cryogenic experiments by Starhopper's fuel tanks containing liquid oxygen (LOX) and liquid methane to burn the vehicle's Raptor engines .
These tests involved burning Starhopper with LOX and liquid methane and testing the pressure systems, observed via icing of fuel lines leading to the vehicle and venting of cryogenic cooking at launch / Test site.
These refueling pressures and pressurization tests occurred after Starhopper were transported from the construction site to the launch / test stand down the road and continued without any of the vehicle's Raptor engines being installed, which Elon Musk should notice, should happen in short order.
In rapid succession, residents of Boca Chica Village were alerted by mail of impending tests and road protection that would occur as early as the week of March 18.
The summons of residents showed that a security checkpoint would be erected on the road leading to Boca Chica Village and that residents had to show proof of residence to access their homes; Some passengers in these vehicles must also show proof of stay.
This indicated that no guests will be allowed past the security checkpoint during flight test operations of Starhopper.
With the latest arrival and installation of the first Raptor engine into Starhopper, there was speculation as to whether the test Boca Chica residents were being told would be a durable static fire or the first jump to Starhopper.
Elon Musk confirmed via Twitter that it would "hopefully" be a jump – but just a barely to get off the ground , and not a low altitude suborbital jump.
These suborbital works require all three Starhopper Raptor engines installed.
This is quite a deviation from how SpaceX has previously gone with vehicle testing – to keep a static fire in place and instead let the individual Raptor lift Starho pper from the ground – albeit just a little – on its very first integrated firing.
In January, Mr. Musk indicated that Starhopper flight tests could begin as soon as February-March 2019 – which may come true – if there were no unforeseen circumstances.
A significant storm affected the Boca Chica test site earlier this year – knocking the top of Starhopper over and harming it ; It was thought that this would require a rebuilding of the cone.
But Mr. Musk noted on Twitter (March 17) that the company no longer builds a nose cone for Starhopper – that they "No Need It" – and the extra construction seen at Boca Chica late is actually the first orbital Starship vehicle.
During a period of over a week, StarHopper underwent almost daily refueling tests, the WDR and some pre-burners tests. Some of these tests worked to reduce a problem of ice formation on the prevalence, as Elon Musk explained a few days ago
Thursday came the milestone of the first Raptor firing at Hopper.
The fire appeared to last a few seconds and was classified as "green" per Elon Musk tweet shortly after firing . Mr. Musk described it as the first hop, although it was not noticeable on video purchased by NSF's BocaChicaGal, a local resident who has taken a series of photos and videos of SpaceX's Boca Chica site for this site.
It was not unexpected, given that the hopper was sealed and had only jumped a few inches on this first test. When the tits are removed, Hopper jumps several meters and then at stepwise greater heights.
SN3 Raptor is already undergoing testing at SpaceX's test site in McGregor, Texas – as seen from the air by NSF's Gary Blair (L2 McGregor section).
Starship design continues to evolve:
At the same time, as Starhopper continued toward his introducing test at Boca Chica, Elon Musk spent some time to answer questions about how the design of Starship continues to evolve, albeit not as drastically as it has before – a good signal that the design rerouting phase eventually comes as construction operations begin.
In particular, two exciting and important pieces of Starship and Super Heavy information were revealed by Mr. Musk this weekend: 1) a hot s Hield will be used on the wind side of Starship and 2) SpaceX seeks regulatory approval to launch and build Starship / Super Heavy in both Texas and Florida.
In a Twitter post on March 17, 2019, Mr. Musk launched a video of SpaceX tester starcraft heat shield hexagonal tiles that will cover the wind side of the vehicle;
17. March 2019
17. April 2019
Testing of Starship Heatshield Hex Tiles pic.twitter.com/PycE9VthxQ
– Elon Musk (@elonmusk) March 17, 2019
] Via The Twitter update, Mr. Musk noted, that the tiles consisted of their flying color tests, and achieved white hot lap temperatures of approximately 1650 Kelvin (1,377 – or 2,510 ℉).
Mr. Musk also showed that the hexagonal shape was chosen because it does not allow a straight path for hot gas to accelerate through holes in the heat shield – a critical component for reentry heating.
Furthermore, Musk points out that the toy side of Starship will not require any heatshield at all thanks to its stainless steel construction, and that any hotspots observed during testing will have perspiration cooling added to them.
Transpiration cooling is the action of pumping coolant – in this case liquid methane – through the skin structure of the Starship to absorb additional heat in specific areas of the vehicle during reentry.
Musk noted that these changes to Starship were necessary to ensure that it could "fly again immediately after landing" with "zero refurbishment."
As part of the Twitter extravaganza, Mr. Musk also confirmed that NASASpaceflights Michael Baylor at SpaceX is working on regulatory approval to fly the orbital missions of Starship from both Boca Chica, Texas and "Cape Kennedy, Florida."
Gravitation Innovation renders SpaceX Starship on Super Heavy. Bhttps: //t.co/judWHxkOJE pic.twitter.com/j8tDQvvPgM
– Chris B – NSF (@NASASpaceflight) March 14, 2019
He also confirmed that The company wanted to build Starship and Super Heavy simultaneously in both locations, eliminating the need for long-distance transportation of the major California vehicles.
Elon's use of the "Cape Kennedy" nomenclature certainly did not show if Starship was launching from Cape Canaveral Air Force Station or from Kennedy Space Center.