Space Sunday: the ups and downs of vehicle development

SpaceX Boca Chica: A giant crane gets ready to lift Starship S20 some 90 metres into the air so it can be stacked onto Super Heavy Booster 4, Friday, August 6th. Credit: BocaChicaGal / NASASpaceflight.com

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.

Two shots of the 70-metre tall Booster 4 departing the SpaceX high bay on its way to the launch facilities. Note the fixed (non-folding) grid fins that will be used to steer operational Super Heavy boosters to back to Earth, and in the background of the picture on the left, the lower tank section of Starship S20. Credit: Elon Musk

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.

Starship S20 departs the Starbase production area en route to the launch facilities, GSE tank 3 following behind, destined for the fuel farm. Credit: BocaChicaGal / NASASpaceflight.com

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 base of Booster 4 showing the central cluster of 9 Raptor engines and the outer ring of 20. Credit: SpaceX

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.

The Starbase orbital facilities: to the top right: the orbital launch platform and support tower with Booster 4 and Starship S20 waiting to be lifted. Top lift, , the tank farm with the newly-delivered GSE 3 tank awaiting its turn to be lifted into place. Credit: RGV Aerial Photography
With the wind behaving itself on Friday, August 6th, Starship 20 was raised some 95 metres into the air and then gently lowered onto the reinforced interconnect at the top of the Super Heavy. In doing so, the combined Starship / Super Heavy became the largest launch system ever raise – 120 metres tall from engine bells to tip of the nose cone (that’s around 10ft shy of 400 ft). With the launch platform taken into account, the stack of vehicles rose some 140 metres above the ground.

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.

The OFT-2 Starliner capsule on its Atlas 5 booster prior to the mission being indefinitely postponed. Credit: NASA/Aubrey Gemignani

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.

ISS And Nauka: New Details as US and Russia Stress Relations are Still Good

In my previous Space Sunday update, I covered the “Nauka incident” on the ISS, when the newly-arrived 20-tonne Russian Nauka module unexpectedly fired its thrusters and attempted to pull away from the space station.

At that time, US officials reported that the accident took around 47 minutes to correct, during which the station rolled some 45º out of its correct orientation. However, new data reveals that in total, the station rotated a total of 540º (1.5 revolutions), but it did so very slowly and over such an extended period of time the crew barely noticed it, although it did finally come to rest “upside down” relative to its usual orbital orientation.

A Russian Progress resupply ship with the Pirs module, detached from the ISS to make way for the Nauka module, are caught on camera as they burn-up in the upper atmosphere over the south Pacific Ocean at an altitude of 430 km on July 26, 2021. Credit: Thomas Pesquet/ESA/NASA.

Despite Roscosmos stating the matter was “quickly” corrected it took the combined use of attitude control thrusters on bthe Zvezda module (to which Nauka was docked) and the remaining Progress resupply vehicle to halt the spin and then gently reverse it by 180º to get the station back into its correct orientation.

All of this likely placed a degree of stress on the station’s multiple parts, and as a result, mission teams in both the US and Russia are now checking through data received back from the station to check for any tell-tale signs that the incident may have given rise to issues. Nevertheless, despite the slightly differing reports on the matter that came out of the US and Russia, both NASA and Roscomos have been keen to state their partnership remains firm, and Roscosmos has announced a formal investigation into how Nauka was able to autonomously fire its thrusters post-docking.

Virgin Galactic: Ticket Price Hike

Sir Richard Branson’s Virgin Galactic is again courting controversy. In July, the company successfully completed the first fully-crewed flight of is sub-orbital tourist spaceplane,  VSS Unity, only to run into claims of “fakery” after admitting footage shown during the livestream of the flight that supposedly showed Sir Richard cycling through the pre-drawn light on the morning of the flight had actually been recorded days in advance.

Now the company has been criticised for “price hiking”, following an August 5th announcement that it is resuming sale of tickets for sub-orbital  trips – but at almost twice the original US $250,000 price tag.

Tickets for sub-orbital flights with Virgin Galactic just got a lot more expensive. Credit: Virgin Galactic

Those who put down a deposit prior to ticket sales being halted in December 2018 will apparently  see their ticket prices held at the US $250,000, but those booking after August 5th, 2021 will have to pay a minimum of US $450,000 for a ticket – and with no clear indication of when they’ll actually get to fly.

Following  the July 11th flight, it had been suggested that commercial flights might commence before the end of 2021. However, the company has now indicated that following a contract flight on behalf of the Italian Air Force in September, both VSS Unity and its carrier vehicle, MSS Eve will both undergo an extensive period of maintenance and upgrade that will run through until around mid-2022.

After this, Unity will have to undergo a further test flight before it can start flying fare-paying passengers. However, Eve will only be able to devote a part of its time to passenger operations, as it will also be required in flying the newer SpaceShip III craft VSS Imagine (almost ready to start flight tests), and VSS Inspire (currently being fabricated) through their flight test programmes. And those passenger flights that do take place will likely be for the estimated 600 who have either paid the original US $250,000 ticket fee in full or in part.

Nevertheless, with Blue Origin yet to publicly release the price of ticket on New Shepard, Virgin Galactic could end up seeing a lot more than the initial 600 lining up for a chance to fly with them…

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