26.08.2021

For the second time this month, SpaceX has begun installing 29 Raptor engines on Starship’s first orbital-class Super Heavy booster, potentially paving the way for several crucial milestones.

On August 1st, around the same time as SpaceX finished installing car-sized grid fins on a Super Heavy for the first time, the company began the process of installing multiple Raptor engines on the booster (#4) that might one day support Starship’s first orbital launch attempt. Not long after it began, it became clear that SpaceX was installing a full 29 Raptor engines on Booster 4 (B4) at a breakneck pace, and less than 24 hours later, all had been attached to Super Heavy’s thrust structure.

Barely a day later, Super Heavy Booster 4 was rolled to the orbital launch pad and installed on a massive ‘launch table’ that was itself installed just a few days prior after months of assembly. Four days after engine installation, Starship S20 and Booster 4 were briefly mated together, forming a full Starship stack – the tallest and most powerful rocket ever built – for about an hour. However, while it did serve as a useful learning experience and pathfinder operation, both stages were demated and returned to the factory soon after.

Now, just 12 days after Super Heavy Booster 4 arrived back at the high bay and 11 days after workers briskly removed its Raptors, SpaceX has begun the process of reinstalling those engines – albeit with several new entrants this time around. When SpaceX first fitted B4 with Raptors, it became clear that five or more of had never been tested, making the removal of some of the Super Heavy’s 29 engines more or less inevitable. Indeed, as expected, several new Raptors (engines that weren’t clearly installed the first time around) have joined around two dozen engines that were installed earlier this month.

Given that Booster 4 has already completed a range of fit checks, the implication is that SpaceX is now installing the 29 Raptor engines that will support the first static fire test campaign of a flightworthy Super Heavy. Of course, that testing (likely involving several different static fires of an increasing number of Raptors) could unearth issues or even damage some of those 29 Raptors, so it isn’t quiteaccurate to say that Booster 4 is being fitted with the engines that will help it carry Starship to orbit. Depending on the outcome of those tests, though, most could easily find themselves lifting off on Super Heavy B4 later this year.

For now, though, Super Heavy Booster 4’s next milestone will be its second trip from the build site to the launch pad. That could occur at any point in the next week or two and could find Booster 4 installed beside Ship 20 on the second of two suborbital test stands, though the Super Heavy may instead return to the orbital launch site.

Quelle: TESLARATI

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The Boring Company pitches tunnel project for access to Boca Chica during SpaceX launches

The Boring Company (TBC) met with Cameron County officials to discuss the possibility of a tunnel project running from South Padre Island (SPI) to Boca Chica Beach.

The Boring Company pitched the idea of an SPI-Boca Chica tunnel to Cameron County administrator Pete Sepulveda Jr. and county engineer Benjamin Worsham early this summer. Cameron County officials have been thinking of giving people access to part of Boca Chica Beach even during closures.

SpaceX activity has been steadily increasing as it continues to develop the Starship program. In August alone, Cameron County issued at least 13 public notices ordering temporary and intermittent closures due to SpaceX’s activities.

To give people access to the beach during closures, The Boring Company proposed digging a tunnel from the south end of SPI to the north end of Boca Chica Beach.

“From what we understand from SpaceX is there is a good portion of the beach that can remain open if there was access to it, even though the road is closed and even though a portion of the beach is closed,” Sepulveda told The Brownsville Herald.

Sepulveda noted that the proposal was just a concept for now and an in-depth study was necessary to see if the SPI-Boca Chica tunnel was feasible. The Boring Company would have to consider several factors relating to the tunnel if it wishes to continue with the project, including that the county might not be interested in paying for the project.

“(Paying for it) is not something that the county would be interested in,” Sepulveda said. “That would be prohibitive for us. We really didn’t get into those details, but once we do we wouldn’t be able to participate with any type of funding.”

In Las Vegas, The Boring Company has two tunnels: The Las Vega Convention Center (LVCC) Loop and the Vegas Loop.

The LVCC Loop is managed by the Las Vegas Convention Center Authority (LVCVA) Board, who agreed to pay TBC a monthly fee to maintain operations and test the system. On the other hand, the Vegas Loop is fully funded and operated by The Boring Company. Cameron County may consider a setup like the Vegas Loop the SPI-Boca Chica Boring Company tunnel.

Quelle: TESLARATI

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Update: 8.09.2021

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SpaceX’s first orbital-class Super Heavy booster rejoins Starship at the launch pad

For the second time in five weeks, SpaceX has rolled Starship’s first orbital-class Super Heavy booster from its Starbase factory to the launch pad ahead of a challenging and multifaceted test campaign.

Deemed Super Heavy Booster 4 or B4, the 69m (~225 ft) tall rocket first rolled to the launch pad around August 3rd after SpaceX technicians fitted it with 29 Raptor engines in a single night. Followed by orbital-class Starship prototype S20 a few days later, the two stages of a Starship were stacked to their full height on August 6th, briefly creating the largest rocket ever assembled. Ship 20 was then quickly returned to the build site, where SpaceX workers completed an additional ~10 days of finishing touches – mainly focused on avionics wiring and secondary plumbing.

A week later, Booster 4 followed Ship 20 back to Starbase’s ‘high bay,’ where teams ultimately removed all 29 of its Raptor engines and spent the next four or so weeks performing similar final integration work. Now, after installing what looks like hundreds of feet of wiring, dozens of additional gas and fluid lines, compressed gas tanks, hydraulic ‘sleds’ SpaceX’s first flightworthy Super Heavy has once again returned to the launch site

A bit less than two weeks ago, SpaceX once again installed 29 Raptors on Booster 4. This time around, though, all of those engines are believed to be ready for flight – or, at minimum, static fire testing – after completing qualification testing at SpaceX’s Central Texas development facilities. Intriguingly, every one of Super Heavy’s outer ring of 20 ‘Raptor Boost’ engines is also expected to have its own small umbilical panel that will connect to the orbital launch pad’s ground systems.

When Booster 4 was installed on the brand new orbital launch mount, most of those individual engine connectors had yet to be installed and it’s unclear if SpaceX was actually able to test the complex mechanisms before Super Heavy returned to the build site. This time, all 20 engine umbilical actuators have been installed on the launch mount and it’s safe to assume that those mechanisms will be tested extensively in the coming weeks.

That testing will be part of a much more involved test campaign. Namely, if SpaceX intends to test Super Heavy Booster 4 at the orbital launch site, any booster testing will simultaneously require the shakedown of the orbital pad’s extensive, custom-built tank farm and a wide range of other ground infrastructure that simply didn’t exist at the start of 2021. Booster 4 qualification is no less daunting, as no Super Heavy has ever been fully tested. Now in the midst of being scrapped in place at SpaceX’s suborbital test facilities, Super Heavy Booster 3 did complete a partial cryogenic proof test and a static fire with three Raptor engines, but SpaceX has never fully filled a Super Heavy with >3000 tons (~6.6M lb) of propellant and never static fired more than three Raptor engines simultaneously.

Perhaps the most uncertain part of Super Heavy Booster 4 qualification is its static fire test campaign. However SpaceX gets there, the final challenge will likely be igniting all 29 of B4’s Raptor engines – potentially producing up to ~5400 tons (11.9M lbf) of thrust, thus making Super Heavy the most powerful rocket booster ever tested.

Simultaneously, SpaceX also began reinstalling Raptors on Ship 20 – currently installed at Suborbital Pad B – ahead of the Starship’s first proof test(s) and static fire(s). Stay tuned for updates on SpaceX’s plans for testing the first orbital-class Starship and Super Heavy booster.

Quelle: TESLARATI

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Update: 5.10.2021

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SpaceX’s first orbital-class Starship stretches ‘wings’ ahead of Raptor installation

SpaceX’s first orbital-class Starship prototype was spotted stretching its ‘wings’ on Sunday after completing a successful cryogenic proof test late last week.

While minor relative to almost any other testing milestone, the small step still serves as a reminder that the end goal of Ship 20’s test campaign is a launch on Super Heavy to orbital altitudes and velocities. If that launch goes more or less according to plan, Starship will then attempt to survive an orbital-class reentry for the first time, subjecting it to extreme heat and putting its many thousands of heat shield tiles through their most daunting challenge yet. Dozens of things could (and probably will) go wrong, while almost every system aboard must work perfectly to ensure that Starship makes it through reentry in one piece.

And even if all of that occurs as planned with no major issues, those same systems will still need to hold on for several more minutes to perform a freefall, engine reignition, flip, and landing maneuver that only two other Starship prototypes have completed. As it so happens, one of those crucial systems is Starship’s flaps.

 

Outfitted with actuators powered by Tesla Model 3/Y motors and a pair of Model S batteries, Starship’s four large ‘flaps’ are only capable of simple flapping motions. While they may look the part, Starship flaps aren’t wings and are specifically designed not to produce lift. Instead, in support of Starship’s unusual descent profile, they act more like the hands and legs of a skydiver (particularly one in a wingsuit), allowing ships to control their pitch, attitude, and roll while freefalling belly-down to the ground. In theory, that allows Starship to gain practically all of the benefit of a structural wing like that on the Space Shuttle but for a far lower mass penalty.

Instead of elegantly slowing down with wings, Starship uses its flaps to create as much drag as possible during descent, slowing down to a terminal velocity around 100 m/s (~225 mph) or less. Using a freefall trajectory and flaps incapable of generating lift does likely come at the cost of “crossrange performance,” referring to how far Starship can travel horizontally in Earth’s atmosphere after reentry. However, significant crossrange performance is almost entirely irrelevant outside of Cold War paranoia like the kind that NASA let influence the Shuttle’s design to an ultimately catastrophic degree. Landing vertically also precludes the need for exceptionally long, expensive runways like those the Shuttle needed.

Aside from allowing it to navigate to a small vertical landing pad (or massive ‘Mechazilla’ catch tower), Starship’s flaps are also important for controlling vehicle orientation and heading during reentry itself. To fill that role, those flaps will have to be able to actuate across their full range of motion duringreentry, as Starship’s hypersonic assault against the thin upper atmosphere creates a flood of superheated plasma that wants nothing more to find the gaps in its heat shield. Shuttle engineers had to deal with the same issue, ultimately designing complex seals that would allow the vehicle’s wing and body flaps to actuate during reentry without allowing superheated plasma to leak inside and damage their fragile mechanisms or structure.

Although Starship does have the benefit of relying on steel – not aluminum – for almost all of its structures, it still has to grapple with the same challenges of shielding sensitive electronics, actuators, motors, and more from the reentry onslaught that its heat shield and steel structure are designed to survive.

(NASASpaceflight – bocachicagal)

Half-covered in heat shield tiles, it’s not clear how SpaceX plans to seal off the more sensitive, exposed components of each flap’s actuation mechanism – including motors, cabling, and the hinge itself. Based on what’s visible, Starship’s flaps and the cradle-like ‘aerosurfaces’ they slot into do have very tight tolerances and may rely on some felt-like ceramic wool or TPS blanket to seal the tiny remaining gaps. With small enough gaps, a hypersonic airstream can behave as if there are no gaps at all, suggesting that that might be SpaceX’s preferred approach to sealing Starship flaps.

Up next on Starship S20’s path to launch is the reinstallation of 3-6 Raptor engines (for the third time) ahead of a crucial static fire test campaign that could begin as early as Thursday, October 7th. Likely beginning with 1-3 Raptors, SpaceX will perform an unknown number of static fire tests, ultimately culminating in the first ignition of 4, 5, and 6 engines on any Starship prototype. If all goes well, that testing will also mark the first time Raptor Vacuum has been ignited on a Starship prototype and the first time SpaceX has ignited multiple Raptor variants (sea level and vacuum, in this case) on the same vehicle. Stay tuned for updates on engine installation.

Quelle: TESLARATI

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Update: 12.10.2021

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SpaceX installing Raptors on first orbital-class Starship – third time’s the charm?

For the third time in two months, SpaceX has begun installing Raptor engines on its first orbital-class Starship prototype – hopefully for good.

In no uncertain terms, Starship 20’s (S20) path to what could be its last Raptor installations has been about as windy and mysterious as they come. Starship 20 (S20) left the Starbase factory floor for the first time in early August – all six Raptors installed in another program first – for a brief fit check and photo op. After spending about an hour installed on top of Super Heavy Booster 4 (B4), Ship 20 was removed and returned to the build site, where teams removed all six engines and finished wiring and plumbing the vehicle.

Days before the ship’s long-anticipated trip to Starbase’s suborbital launch site for qualification testing, the mount SpaceX prepared for the process quickly had hydraulic rams – used to safely simulate Raptor thrust – were abruptly removed. Starship S20 was then installed on the Pad B mount, where SpaceX proceeded to reinstall six Raptors. Weeks later, after slow heat shield repairs neared completion, SpaceX again removed Ship 20’s Raptors and reinstalled the hydraulic rams it had removed – unused – the month prior. Finally, on September 30th, some seven weeks after the prototype arrived at the suborbital launch site, SpaceX put Starship S20 through its first major test – a lengthy ‘cryoproof’.

Now, ten days after completing a seemingly flawless cryoproof test on its first try, SpaceX has once again trucked multiple Raptors – at least one sea level and one vacuum engine – from the Starbase build site to Starship S20’s suborbital test stand. From the outside looking in, it’s hard not to view the contradictory path S20 took to its first tests – and is still taking to its first static fire(s) – as an unusually visible sign of some kind of internal tug of war or major communication failure between different SpaceX groups or executives.

It’s impossible to determine anything specific beyond the apparent fact that several of the steps taken from Ship 20’s first factory departure to its first cryoproof and static fire tests could have probably been deleted entirely with no harm done and many dozens of hours of work saved. At the end of the day, Starship S20 completed cryoproof testing without issue on the first try and is now seemingly on track to begin its first static fire test campaign later this month.

SpaceX reveals first orbital Starship with six Raptor engines

At the moment, SpaceX has three possible static fire test windows scheduled from 5pm to midnight CDT on Tuesday, Wednesday, and Thursday (Oct 12-14). A similar Monday window was canceled days ago on October 7th, suggesting that more cancellations are probably on the horizon. For now, there’s a chance that Starship S20 – with anywhere from two to all six Raptor engines installed – will fire up for the first time before next weekend. It’s hard to say how exactly SpaceX will proceed. It’s not inconceivable that SpaceX will install all six engines and gradually ramp up to a full six-engine static fire over several tests.

Given that SpaceX has already static fired three Raptor Center (RC) engines on multiple Starship and Super Heavy prototypes, odds are good that Starship S20’s test campaign will be similar – beginning with a three-Raptor static fire, in other words. SpaceX could then add one, two, or all three Raptor Vacuum engines into the fray for one or more additional tests with 4-6 engines total. It’s also possible that suborbital launch mount and pad limitations will prevent more than three engines from firing at once, in which case SpaceX would presumably perform two separate tests of Ship 20’s Raptor Center and Raptor Vacuum engines.

Given that two Raptor variants have never been static fired simultaneously on the same vehicle, it’s hard to imagine that SpaceX won’t also want to perform one or several combined static fires with Raptor Vacuum and Raptor Center engines on Ship 20.

Quelle: TESLARATI