SpaceX has been stepping up the pace of work at its Boca Chica Starbase facility, home of the Starship and Super Heavy booster development, in recent weeks.
Towards the end of July, the company started transferring personnel from its headquarters in Hawthorne, California to Starbase in what was seen as a start of gearing-up for flight activities out of Boca Chica. This operation came alongside continuing construction work at Starbase and the initial testing of the prototype B3 Super Heavy booster, which included a static-fire test of three Raptor sea-level engines. Since then, the pace of developments at Boca Chica has been dramatic – particularly in the last week and a half.
In that time, the first flight-capable Super Heavy booster was moved down to the launch facilities, whilst Starship 20, the vehicle that will will fly within it in an attempt to reach orbit later this year, completed its major assembly, stacking the two cylindrical tank sections one atop the other an onto the vehicle’s engine skirt, and then adding the upper ring sections and nose cone.
This work included the installation of two of the news aft aerodynamic fins that are around 20% smaller than those used on earlier test vehicles, offering a reduction in mass, and the installation of six Raptor motors – 3 sea-level engines (believed to be the three motors used in the Booster 3 static fire test) and three fixed vacuum engines – although all six may have only been installed for testing purposes.
At the same time, the massive 370-tonne launch table – the ring of hydraulic clamps, actuators, bolt mounts, etc., that will hold a Super Heavy / Starship combination securely on the launch pad, was hoisted up on to the ring of the launch platform’s legs and installed. This paved the way for the 70-metre tall, 9-metre wide Booster 4, complete with a contingent of 29 Raptor motors – 20 fixed in a ring around the rocket’s circumference, and 9 centre motors that can be gimballed to provide directional thrust – to be hoisted up onto the launch platform and secured into the launch table.
Then, on Thursday, August 5th, in a move that almost caught people off-guard, SpaceX proceeded to roll-out Starship 20 (formerly prototype SN20, SpaceX now apparently having dropped the “SN” designation from the vehicles) from the production site and transport it to the launch facilities.
The roll-out of Starship 20 prompted a lot of speculation that the launch could be coming in days. However, the fact that the vehicle was lacking a full covering of thermal protection tiles coupled with the fact that the fuel farm that is vital in providing Super Heavy and Starship with the propellants they’ll need to power their way to orbit is still very much under construction (as evidenced by GSE tank 3 joining S20 on its journey to the launch facilities, ready to be installed at the farm), are the clearest indicators that any launch is still a good several weeks away at best.
Once at the launch facilities, plans to carry out a “test stacking” of S20 in top of B4 were scrapped for the day due strong wind gusts. Instead, attention turned to mounting more of the black tiles of the vehicle’s thermal protection system (TPS) that will protect it during entry back into the denser part of Earth’s atmosphere, to the more obvious parts of the hull where they had been absent.
Work on the stack then paused while, close by, GSE tank 3 was also hoisted aloft and moved into position on its mounting ring at the tank farm, where it will later be sheathed by a grey cryogenic cooling sleeve. With this work done, the massive “Frankencrane” that is being used in the construction of the launch support tower as a temporary means of stacking Super Heavy and Starship on the pad, once more lifted S20 aloft and then lowered it back onto its autonomous transport so it could be rolled back to the production facilities to undergo further work in readiness for its flight.
This cleared the way for work to resume on other aspects of the orbital facilities build-out which, although they will not feature in the initial flight(s) for Super Heavy and Starship, are vital to long-term operations. These include the fabrication of a prototype “capture mechanism” that will eventually be used to “grab” a returning Super Heavy Booster post-flight (yes, seriously), and the construction of the hard stands that will support both a Super Heavy and a Starship for final check-outs prior to stacking on the launch platform ready for flight.
Starliner: No Go for Launch
The long-awaited launch of the Boeing CST-100 Starliner vehicle on its uncrewed second Orbital Flight Test (OFT-2) has been indefinitely delayed n a further blow to the troubled programme.
Scheduled to lift-off on Tuesday, August 3rd, the launch was scrubbed after the Boeing launch team received warning of “unexpected valve position indications” within the capsule’s propulsion system. Initially, it had been hoped that a further attempt could be made on Wednesday, August 4th. However, Further checks on the vehicle, Boeing announced a suspension of all launch attempts, and that the vehicle would be rolled back to its service structure to allow further checks to be made on the vehicle.
Designed to partner the SpaceX Crew Dragon – already operational – in ferrying crews to and from the International Space Station (ISS), Starliner first flew on an uncrewed mission in December 2019 in what was supposed to be a final check-out prior to commencing crewed operations. However shortly after the vehicle reached orbit it suffered a software glitch that caused repeated incorrect firings of its manoeuvring motors, leaving it with insufficient fuel to make a rendezvous and docking with the ISS. Hence the need for the OFT-2 flight.
That this has now been postponed following 18 months of reviews and changes to both systems on the vehicle and the procedures used in readying it for flight, is nothing short of embarrassing for Boeing and NASA alike – the CST-100 contract being the most expensive in the Commercial Crew Programme.
Continue reading “Space Sunday: the ups and downs of vehicle development”
