The Evolution of the Big Falcon Rocket


The updated Spaceship stage would mass up to 1,335 tonnes at launch, carry up to 1,100 tonnes of propellant, and have a modest dry mass of 85 tonnes. Its design featured a side-mounted docking station along with two large windows in place of the ITS Spaceship’s massive main window.

Although much smaller than before, it still boasted 825 cubic meters (29,134.6 cubic feet) of pressurized space, only 9.9% less than the International Space Station (915.6 cubic meters/32,334.1 cubic feet) but not in fact more than the 2,100 cubic meters (74,160.8 cubic feet) of an Airbus A380 as SpaceX claimed.

Internally, it would have 40 cabins housing up to 100 passengers, space toilets, a galley, large common spaces and even a solar storm shelter to address radiation concerns.

BFS docked to the ISS – SpaceX

It would be refueled in orbit by an equally large BFR Tanker via milli-gravity acceleration achieved via control thrusters and propellant tank rotation.

The third version of the upper stage was a modified carrier rocket stage which would enable the design to launch commercial satellites.  It housed a massive payload bay, which would open and close via a hinged door.

This would be mounted on only one side of the vehicle, with the ventral side protected by the integrated heat shield.

Deploy render – via SpaceX

All three variants would mass up to 4,400 tonnes and stand 106 meters (347.8 feet) tall on the pad. The BFR would have a payload capacity of up to 250 tonnes for an expendable launch and 150 tonnes for a fully reusable launch. This capacity would make the BFR system the world’s most efficient LEO launch system ever built, with over 5.68% of launch mass making it to orbit if figures are accurate. That would make the BFR some 26.5% more efficient at launching its mass into Low Earth Orbit than the current record-holder, SpaceX’s Falcon Heavy (4.49%).

The three upper stage variants would enable the BFR system to support commercial Earth orbit satellite launches, Earth and beyond Earth orbit spaceflight, and missions to the Moon, Mars and beyond via refueling of the BFR Spaceship. In addition, Musk revealed SpaceX’s plans for using the BFR to enable traveling between any two cities on Earth in under an hour. Eventually, this enormous rocket system would even replace SpaceX’s Falcon 9 rocket family and potentially bring costs down radically thanks to full reusability.

Somewhat ironically, the trimming of the vehicle’s size from 10,500 tonnes to 4,400 tonnes was what enabled the BFR’s uses to expand so dramatically. It also alleviated the most pressing design concerns over development cost, exclusion zones, and launch pads.  In the months that have followed, SpaceX has updated the design to include a third sea level Raptor engine on the upper stage to enable “airline levels” of safety via an engine-out capability.  Whether this is possible in rocketry when 2-6% of orbital rocket flights fail every year remains to be seen.

At IAC 2017 in September, Musk also announced that the firm had already ordered the tooling for the BFR’s main tanks and begun construction on the factory, with production of the first BFR to nominally start in the second quarter of 2018. The first two cargo flights to Mars would nominally be in 2022 to prepare a long-term Martian base and eventually a colony. As always with Musk, he has set SpaceX an ambitious schedule of development and flights for the new BFR. It is unlikely Musk’s firm will achieve the schedule, but SpaceX does have a track record of accomplishing its goals eventually.

At a news conference for the first launch of SpaceX’s new Falcon Heavy rocket on February 6th, Musk mentioned tests the firm hoped to do with the BFR Spaceship. “If we get lucky, we’ll be able to do short hopper flights with the spaceship part of BFR maybe next year,” Musk said. These would follow those of the Grasshopper prototypes, and testing would take place either at its South Texas launch site, nearby, or from ship-to-ship. Further mentions of the BFR’s evolution were made the next month by Musk.

On March 8th, 2018, Elon Musk tweeted the first image of the tooling for the BFR’s main body, which dwarfed a Tesla Model 3 parked next to it.

Later on March 11th, 2018, while at South by Southwest, Musk noted that the design was “evolving rapidly” and the construction of the second stage Spaceship was proceeding.

He mentioned one goal of the BFR, the colonization of Mars, might enable humanity to survive a nuclear war on Earth. The BFR’s development would be paid for, in part, by SpaceX’s upcoming Starlink broadband internet satellite constellation, which would contain as many as 10,000 small satellites.

Later in March, documents emerged that a company called WW Marine Composites LLC had applied to repair a vacant lot at Berth 240 on Terminal Island, Los Angeles, which had been approved by the Board of Harbor Commission.

Teslarati photographer Pauline Acalin (@w00ki33) photo of the facility

Eric Berger of Ars Technica noted that the firm appeared to be a subsidiary of SpaceX, with an anonymous source confirming that the site was intended for the BFR’s manufacture. SpaceX Spokeswoman Eva Behrend confirmed some of this to the Los Angeles Times, saying that the company was in talks with the Port of Los Angeles regarding the “potential of leasing additional land for operations”, which other documents confirmed were rocket-related.

With the BFR’s factory shifting to the Port of Los Angeles, that would not only ease transportation issues for SpaceX, but also potentially allow it to build the BFR with a diameter greater than 9 meters, allowing further improvement of the rocket’s potentially record-breaking efficiency.

The ambitious plans presented by Musk represented the culmination of a lifelong passion. It was that passionate interest in space that brought him into contact with prior Mars visionary Robert Zubrin, whose Translife Mission ultimately inspired Musk towards an even grander vision.

When Russian engineers thwarted Musk’s early goals in space, he instead gambled his fortune on SpaceX. Thanks to finally achieving orbit with the Falcon 1 rocket, Musk’s dreams of Mars colonization was ultimately saved in December 2008. Since that time, Musk’s vision has matured and grown alongside SpaceX.

The firm’s development of the Falcon 9 into the world’s first partially reusable launch vehicle – past the Space Shuttle – and the most efficient rocket ever heavily shaped the Big Falcon Rocket.

Much like the Falcon 9, since it was first conceived the BFR has more than doubled in thrust and payload, while also becoming more efficient by adapting all carbon fiber construction. The result was nothing less than a fully reusable launch vehicle system that would be unprecedented in capabilities and technology.

Musk’s presentations showed that SpaceX would like to be the transportation company enabling the colonization of Mars, reducing the firm’s expenses and risk. This, however, will mean that it must rely upon third parties to figure out the difficult logistics of creating and growing a colony on Mars. However, this may change as Musk has been noted in the past to grow impatient with the slow progress of others, and to undertake the tasks he sees as required himself.

Elon’s envisioning of a Mars base – via SpaceX

Although these second sets of plans presented by Musk were extensive, and in some ways less ambitious than the 2016 designs, they were not comprehensive.

There remain concerns with the scope of ambitions, getting to Mars and back, the financing of the BFR, and even with the vehicle’s design. Left out are details like the design of the Mars propellant production system, the building of the first Mars base, and the nuclear reactors with which SpaceX originally hoped to power the colony. There even remain questions about the BFR design, from its lack of a launch abort system, its non-redundant landing leg setup, and how its life support system would work over a Martian round-trip.

Will SpaceX’s Starlink Constellation actually finance the BFR’s creation, or will it lead to financial problems, as Iridium, the world’s only global satellite phone constellation, did for Motorola? Success in creating Starlink, let alone the BFR, is far from guaranteed. Will the US government help fund a 100 passenger rocket design that doesn’t feature a launch abort system? Can the vehicle minimize the radiation exposure of its passengers to NASA acceptable levels on the multi-month trip to Mars? How will the colonists on Mars survive? If the current primary energy source of solar panels proves inadequate, does SpaceX plan on launching nuclear reactors to Mars to provide part of the colony’s power as it originally intended to?

As to when the next update is expected, it could be soon.

Based on the rapid evolution of the design, with an additional engine added just a few weeks after the 2017 presentation, we can expect the BFR to be further refined.

Musk and SpaceX have accustomed us to a continuous iterative design process, as seen with the evolution of the Falcon 9 rocket.

Even in its current unfinished state, the SpaceX plan is unquestionably the most ambitious Mars colonization vision ever presented.

(This feature article was the result of months of evaluations into public and envisioned information and community edited via a draft process in this L2 thread)