Space Sunday: rockets, water and spaceplanes

After a build-up of excitement around a potential start-of-year flight for SpaceX Starship prototype SN9, things has slowed down somewhat – but the vehicle may now be on the brink of making its 12.5 km ascent to altitude and an attempt to land successfully after an unpowered “skydive” back towards Earth.

As I noted in my January 10th Space Sunday report, SpaceX had managed to accelerate the processing of SN9 in comparison to SN8 to a point where the majority of pre-flight checks for the vehicle – including a static fire test of the engines on January 6th –  had been completed in just a 2-week period following its delivery to the launch stand on December 22nd, compared to 2 months taken for prototype SN8 to reach the same point.

However, as I noted at the time, that static fire test was far shorter than had been expected – just 2 second in length, signifying a possible issue. This appeared to be confirmed when SpaceX attempted further engine tests between January 8th and January 12th, of of which had to be scrubbed for various reasons (including weather), before a further test was made on Wednesday, January 13th – and things took an unexpected turn: after the first brief test, two further tests took place within a 2-hour period for all three tests.

The three firings were apparently “test starts” of the three Raptor motors, rather than a full pre-flight static fire test of all three simultaneously. Following them, and a successful de-tanking of excess fuel, inspections of the motors revealed that two needed slight repairs, causing the company to swap them out for other units.

As part of streamlining starship operations, SpaceX have refined the processes related to engine swap-outs to a point where they can effectively be achieved within days rather than weeks, depending on the availability of replacement motor units – the actual physical removal of an engine can be completed in hours, as can the installation of a replacement. In this case, the work was done over a couple of days, the engines requiring replacement being removed from the vehicle and shipped out of Boca Chica before the replacements were delivered and installed, clearing the way for a final engine test.

This took place on Friday, January 22nd, when all three engines were ignited for several seconds before shutting down.

Outside of SN9, it appears work at Boca Chica has commenced on starship prototypes SN17 and SN18, and on the second Super Heavy booster prototype. Also, in my January 10th Space Sunday update, I noted that work had been discontinued on starship prototypes SN12 through SN14. Work has now commenced in dismantling those parts of SN12 that had been fabricated. This is likely due to the fact that SpaceX are iterating the design and construction of the prototypes so fast, SN12 had become effectively obsolete due to the materials used.

The rapid rate of iteration is also reflected in the move of a new fuel tank section – SN7.2 -, which has been moved to a test stand where it will  be pressurised to destruction in a similar manner to the SN7 and SN7.1, each of which also saw iterations in the basic tank design. SN7.2 in particular is built using 3 mm aluminium rather that the current 4 mm material in an attempt to reduce the overall “dry” mass of the vehicle.

In 2020, Musk raised the idea of launching starship / Super Heavy vehicle from sea platforms, suggesting this could be used for vehicles intended to reach orbit or in passenger-carrying sub-orbital transcontinental flights.. While passenger carrying point-to-point will not happen (for reasons I will explain at some point), evidence has emerged that SpaceX are planning to make sea launches a thing, and is in the process of converting two former offshore drilling platforms for use as floating launch platforms.

Aerospace Photographer Jack Beyer was the first to bring the news to the public eye after exploring the port of Brownsville, Texas, not far from the SpaceX facilities at Boca Chica whilst waiting for the SN9 static fire tests to resume. In particular, he spotted an oil platform apparently called Deimos (“dread”) undergoing extensive refit work. Not long after, a image captured over the port of Galveston, Texas, and dated January 13th revealed another rig with the name Phobos (“fear”), and which was later moved to Pascagoula, Mississippi, between January 17th and 22nd.

Phobos and Deimos are, of course, the names given to the captured moons of Mars, and the discovery of the two rigs sparked speculation that the platforms had been purchased by SpaceX.

Michael Baylor from NASAspaceflight.com started digging into things using further images captured by Jack Beyer, and discovered that the two rigs in question were originally owned by the world’s largest offshore drilling / well drilling company: UK-registered and Texas-based Valaris plc (formerly ENSCO-Rowan).

Originally constructed in Singapore in 2008, the two rigs were originally called ENSCO 8500 (later Valaris 8500 and now Deimos), and ENSCO 8501 (later Valaris 8501 and now Phobos). However, following the company declaring bankruptcy, the company offered the platforms for sale and US 3.5 million apiece. The purchaser was company called Lone Star Mineral Development LLC, which had only formed in June 2020. Further digging revealed that one of the principals for Lone Star Mineral Development is none other than SpaceX Chief Financial Officer (CFO), who is also the head of the company’s Strategic Acquisitions Group, Bret Johnsen.

Both platforms are classified as “semi-submersible”, meaning they float on large pontoons that can be filled with water ballast that both settles them in the water to stabilise them while dynamic positioning water thrusters hold them in a precise location, making them an ideal launch platform, as does their deck loading of around 8,000 tonnes, means that are more than capable of supporting a Super Heavy  / starship combination and their fuel loads.

The work to convert the two platforms to support fuelling, payload integration, launch, and landing operations is extensive. As such neither is likely to be ready for use in 2021. However, once operational, they will effectively double the number of Super Heavy / starship launch facilities – SpaceX is currently building the first Super Heavy platform at Boca Chica, and have plans for a second. Multiple launch facilities will be essential in the future if SpaceX is to start to build towards the planned number of launches for the system..

A New Dawn for Launches?

A New Zealand-based company has received approval to fly a suborbital space plane from a conventional airport.

Dawn Aerospace has received the go-head from the country’s Civil Aviation Authority (CAA) to commence flights of their Aurora Mk-II vehicle from an undisclosed airport on New Zealand’s south Island. If successful, these flights could see Dawn Aerospace offer launch services from anywhere in the world.

Measuring just under 5 metres, the Aurora Mk II will be able to carry science payloads to altitudes of up to 100 km altitude, and be able to maintain a flight altitude of 50-80km over extended distances. It is designed to be maintained and operated in a similar manner to a conventional aircraft, potentially able to make multiple flights per day.

To achieve this, Dawn Aerospace has been working in partnership with the (CAA) for 18 months to design flight procedures and systems that would allow Aurora aircraft to operate alongside commercial passenger and freight aircraft at airports around the world without interruption normal flight operations.

Once the Mk II craft has proven its viability, Dawn Aerospace plan to introduce a large Mk III vehicle.  This will be more than three times the length of the MK II. This will be capable of carrying and launching a second stage rocket that will be ableto deliver satellite payloads of up  to 100 Kg to orbit.

The challenge of getting to space is equal parts the vehicle, the launch infrastructure and the regulation. We have made great strides in revolutionizing the hardware. Today is a significant step towards the rest; showing we can fly from one of the thousands of civilian airports around the world, and do so without kicking other aircraft out of their airspace. This is the key to rapid, reusable and sustainable space flight.

– Stefan Powell, Dawn Aerospace CTO

Dawn believe that by offering the means for customers to use their services from almost any airport in the world, they will be able to offer a launch service at a highly competitive price that will be very attractive to the small satellite market.

NASA Scraps Historic Launch Platform

In the 1960s, NASA required the development of three huge mobile launch platforms to support the launch of the agency’s massive Saturn 1B and Saturn V rockets. In all, three of these platforms, measuring 50 metres in length, 40 metres in width and some 8 metres tall and weighing 3,733 tonnes, were built and saw service in both the the Apollo and shuttle programmes.

With the space shuttle’s retirement, Mobile Launch Platform-3 (MLP-3) was earmarked for use to transport / launch the OmegA medium-launch vehicle under development by Northrop Grumman, undergoing conversion to support that rocket. However, when OmegA was cancelled in 2020, work on MLP-3 was stopped, and the fate of the platform remains uncertain.

Of the remaining two platforms, MLP-2 notably supported the launch of the Skylab orbital laboratory, every shuttle orbiter vehicle maiden flight (with the exception of the Columbia), and the launch of STS 51L that resulted in the loss of the Challenger. As such, it might be imagined that MLP-2 would be preserved as a monument to the shuttle and Apollo programmes, particularly given MLP-1 was extensively damaged following the first and only flight of an Ares 1 rocket in 2009. But instead, this week saw a salvage company started work on dismantling the platform. The reason? “lack of parking space”.

Simply put, with the construction of the new launch platforms required for the space Launch System (the MLPs, as massive as they are, cannot support a fully laden SLS and its supporting launch tower) coupled with having three MLPs on-site means that the agency has “run out of room” to park such huge structures at Kennedy Space Centre. and so it is, MLP-2 is being torn apart by excavators and hydraulic sheers in a demolition expected to take several days.

Defending the decision to scrap the platform, NASA indicated that they had put out a call to museums  like the Smithsonian to see if any would be interested in taking all or part of the platform for preservation, but nothing was heard in reply.

In the meantime, MLP-1 remains operational  for the time being. Loaded with concrete blocks to simulate the mass of a SLS rocket and and its launch tower, and mounted on the back of one of NASA’s two iconic Crawler Transporters – the massive tracked vehicles that transferred the MLPs to and from the pads at Launch complex 39, it is being used to “condition” the crawlerway connecting Pad 39B – the future launch site for SLS – and the Vehicle Assembly Building two ensure the gravel trackway is compacted and capable of supporting the weight of the new rocket and its launch tower. Like MLP-3, the long-term future of MLP-1 has yet to be decided.