Starship SN11 lands in bits as SpaceX refine forward plan

by Chris Bergin

Surrounded by a blanket of fog, Starship SN11 launched on Tuesday before suffering an issue ahead of landing.

Over at the Production Site, Super Heavy prototype BN1 was stacked ahead of what was expected to be a rollout and ground testing, before Elon Musk noted shortly after SN11’s launch that it will be scrapped. SN15 is now expected to be the next visitor to the suborbital pad.

SN11:

The fourth flight in the current phase of Starship testing, SN11 aimed to mirror her three sisters’ flight successes, with the goal of nailing the final objective of landing at a slow enough velocity that would avoid a RUD (Rapid Unscheduled Disassembly).

SN10’s flight came the closest, actually successfully landing, albeit at a velocity that resulted in the vehicle hitting the concrete hard and ultimately leading to it exploding minutes later.

SN11’s landing was to use of two engines – instead of down-selecting to just one – as a way to counter the potential loss of thrust and increase redundancy during the landing burn.

Before SN11 attempted its aerial acrobatics, a series of tests were required to prepare the vehicle for its launch day.

An initial attempt at the Static Fire – lighting all three Raptor engines for a couple of seconds to gain performance data – resulted in an abort.

As such, this test was outstanding, before occurring Monday, a full week after the first attempt, following a pause mostly likely caused by the local authorities wishing to avoid too many road closures during Spring Break, as opposed to a technical issue. No Raptors were swapped out of the vehicle during the pause.

The test appeared to be good from a visual and audio standpoint, although such tests undergo a “Quick Look” review, prior to being fed into the Launch Readiness Review (LRR).

Ahead of last Monday’s Static Fire came two tests relevant to the flight, with the aero surfaces being put through their paces over the weekend, along with the RCS (Reaction Control System) thruster firings.

Both systems have performed without issue during the three previous test flights.

Following the Static Fire, SpaceX opted to repair one engine, which in turn requires a second Static Fire test.

That test took place last Friday morning, allowing for a potential launch later that day following a data review.

However, that was scrubbed, with Elon noting the need for additional reviews to take place. The new target was noted as Monday afternoon. However, Elon tweeted the required attendance of an FAA inspector – who had not arrived at Boca Chica in time – pushed the launch to Tuesday.

Tuesday’s launch occurred early into the window, with the launch site covered in fog. The ascent phase appeared to go well ahead of the flip and return for landing.

The SpaceX feed struggled with drop outs, before the final frame was received just as the Raptors relit for the flip and landing burn. At some point, the vehicle failed and exploded over the launch site.

“Looks like engine 2 had issues on ascent & didn’t reach operating chamber pressure during landing burn, but, in theory, it wasn’t needed,” noted Elon on Twitter. “Something significant happened shortly after landing burn start. Should know what it was once we can examine the bits later today.”

SN15 and Super Heavy:

There was to be a relative pause in Starship test flights after SN11, with SN15 sporting new upgrades that will push the vehicle to new heights ahead of the orbital flight later this year.

Test objectives for SN15 are unknown at this time, with options including a repeat of the SN8-11 test objectives, utilizing the known flight parameters while shaking out the improvements to the vehicle, through to pushing to a much higher target altitude.

How viable “days” are will depend on how soon they move the vehicle into the High Bay for nosecone mate.

The vehicle is currently residing in the Mid Bay and will likely remain there until the High Bay is vacated to allow for nosecone mating.

The High Bay is currently focused on operations associated with the BN1 Super Heavy prototype, which saw its two tankage sections – the LOX (Liquid Oxygen) and CH4 (Liquid Methane) tanks – mated last week.

This first-time stacking of a Super Heavy booster is part of BN1’s pathfinder operations, which was to include the challenge of transporting such a tall stack down Highway 4 to the launch site.

Such a road trip wasn’t to occur until after SN11 has launched, allowing it to take up residence at the suborbital launch site where it will undergo numerous test objectives, including proof testing and potentially a Static Fire test, albeit with just a few Raptor engines, as opposed to the 28 a fully operational Super Heavy will utilize.

However, that rollout will now involve BN2, with the decision made to scrap BN1, per Elon’s latest series of tweets on the subject.

“BN1 is a manufacturing pathfinder, so will be scrapped. We learned a lot, but have already changed design to BN2. Goal is to get BN2 with engines on orbital pad before end of April. It might even be orbit-capable if we are lucky.”

Tankzilla through the roof – photo by Mary (@bocachicagal)

Future Super Heavy boosters won’t require the huge Crawler Crane, with a new Bridge Crane finally arriving at Boca Chica last week.

This system, not unlike the crane seen inside the Vehicle Assembly Building (VAB) at the Kennedy Space Center, will allow for all heavy lifting tasks to be completed via the heavy-duty device that will translate along the High Bay roof.

With BN2 expected to enjoy a test hop at least, all eyes will be on BN3 and Starship SN20, with the highly ambitious target of launching by July now confirmed by Elon Musk in response to questions relating to the report by NASASpaceFlight.com last week.

“That’s our goal” is how Elon described it as a large amount of work that continues to take place at the Orbital Launch Site from where the orbital Super Heavy and Starship duo will launch from.

Most of the work is currently focused on the tank farm that will host numerous new “commodity tanks” that will include hosting the vast amounts of LOX and CH4 required to fill the thirsty vehicles.

A new huge GSE (Ground Support Equipment) tank is also being constructed at the Production Site, which is being made out of the same steel ring construction as the prototype Starships.

The cadence of Starship operations is well-known, although the hashtags tend to be #wenhop instead of #wenmars, which is ultimately the driving force.

While NASA continues to focus on the late 2030s, early 2040s for human footprints on Mars, and other organizations mention the 2050s, SpaceX remains steadfast in a fast-track approach to setting up a Mars base in the 2020s.

Mars Base Alpha is set to become a city on the Red Planet, supplied by Starship – a rocket that makes the goal viable by being the first fully and rapidly reusable interplanetary launch system.

This article will be updated during the test week for SN11. For live updates follow NASASpaceFlight’s Twitter account and the live Sn11 update thread.

Most content via Mary (@bocachicagal) – Lead Image via Jack Beyer (@thejackbeyer).

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