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| SpaceX's BFR/BFS at launch. Source: Teslarati. |
Until Spacex's BFR/BFS is operating, the only rocket which can lift more than 20 tonnes (20,000 kgs, 44,000 pounds) into low earth orbit (LEO) is SpaceX's Falcon heavy, and it is at yet untested. There was a test launch, when it famously put Elon Musk's old Tesla Roadster on a flight towards Mars, but it hasn't actually launched a "real" cargo to space. But before the development of the BFR/BFS combo, SpaceX planned to use the Falcon Heavy to get to Mars.
How quickly we forget the technological advances mankind makes: it now seems normal and routine for rocket boosters to land after use, and to then be re-used. Yet just 3 years ago, it had never been done. Because the Falcon Heavy has three first stages "bolted" together, all of which are re-usable, it has a higher percentage of re-usable components than the Falcon 9, and because there are economies of scale with respect to the size of a rocket and its launch capability, the cost per tonne launched by the Falcon Heavy should be way below that of its competitors'. To show the economies of scale, the Falcon 9 can lift 23 tonnes to LEO, and costs $62 million per launch ($2.7 million/tonne), while the Falcon heavy can lift 64 tonnes, and will cost $90 million ($1.4 million/tonne). Though it consists of three of the tried-and-tested Falcon 9s bolted together, it is still new, and you can understand the reluctance of companies launching satellites to use it, even though it's cheaper.
It's easy to forget, with all the attention being paid to the BFR/BFS and SpaceX's mission to Mars that in fact SpaceX will have to go on making money until the BFR/BFS is working--which is a good 2 years away. So it's good news that SpaceX is getting contracts to launch satellites using the Falcon Heavy.
From Teslarati:
Major broadband satellite operator Viasat has officially committed to launching one of its powerful next-generation Viasat-3 satellites on a SpaceX Falcon Heavy rocket, set to occur sometime between 2020 and 2022.
Nine days after Swedish satellite communications company OvZon made its own announcement of a Falcon Heavy launch contract, Viasat’s Falcon Heavy selection marks SpaceX’s third commercial launch contracted on the nascent heavy-lift rocket.
During Falcon Heavy’s maiden launch, SpaceX took it upon itself to use the unique opportunity – a mission where the only payload at risk was functionally worthless – to test a number of technologies that the company had yet to personally [sic] prove out. In order to place certain payloads in orbits as convenient, efficient, and high-energy as possible, rocket upper stages can sometimes be required to spend hours orbiting Earth between two or more engine ignitions and burns.
Once successfully in orbit, the performance potential of upper stages grows dramatically thanks to the increased efficiency of vacuum-optimized rocket engines and major improvements in thrust-to-weight ratios, having already consumed a majority of the fuel and oxidizer loaded prior to launch. The problem is that keeping a large upper stage alive in orbit – while preserving enough liquid propellant to perform its job – is extraordinarily difficult. Notably, the thermodynamic environment alone is a massive hurdle – aside from expanded power supplies, radiation-hardened or resilient avionics, and multi-engine-restart capabilities, some combination of coolers, insulation, and/or tank stirrers must be involved to prevent SpaceX’s already-supercooled liquid oxygen and kerosene (RP-1) from changing phases into a solid or a gas.
During Falcon Heavy’s debut, SpaceX demonstrated what must have been a nearly flawless six-hour coast of the rocket’s Falcon 9 upper stage – in the last four months alone, SpaceX has officially received three new Falcon Heavy contracts all hoping to take advantage of that long-coast capability. Critically, this allows SpaceX to send large satellites directly or almost directly to geostationary orbits (GEO) instead of a more common transfer orbit (GTO), saving satellites from spending weeks or months completing their own orbit-raising maneuvers and the hundreds or thousands of kilograms of propellant they require.
[Read more here]
Meanwhile, progress on the BFR/BFS continues, with SpaceX confirming that the works at Boca Chica are for tests of the BFS.
Unlike Falcon 9’s Grasshopper and F9R reusability development programs, SpaceX’s BFS hop test campaign is likely going to be much more aggressive in order to gather real flight-test data on new technologies ranging from unfamiliar aerodynamic control surfaces (wings & fins vs. grid fins), all-composite propellant tanks (Falcon uses aluminum-lithium), a 9m-diameter vehicle versus Falcon’s 3.7m, a massive tiled heat-shield likely to require new forms of thermal protection, and entirely new regimes of flight (falling like a skydiver rather than Falcon 9’s javelin-style attitude) – to name just a handful.
To fully prove out or at least demonstrate those new technologies, BFS hop testing is likely to be better described as “flight testing”, whereby the spaceship launches vertically but focused primarily on regimes where horizontal velocity is far more important than vertical velocity.
“But by ‘hopper test,’ I mean it’ll go up several miles and then come down. The ship will – the ship is capable of a single stage to orbit if you fully load the tanks. So we’ll do flights of increasing complexity. We really want to test the heat shield material. So I think we’ll fly out, turn around, accelerate back real hard and come in hot to test the heat shield because we want to have a highly reusable heat shield that’s capable of absorbing the heat from interplanetary entry velocities, which is really tricky.” – CEO Elon Musk, October 2017
SpaceX does has significant familiarity with the general style of testing expected to be used to prove out its next-gen spaceship, a major department from anything the company has yet built or flown. Updated in September 2018 by CEO Elon Musk, the craft’s most recent design iteration is reportedly quite close to being finalized. That near-final design prominently features a trio of new aft fins (two able to actuate as control surfaces), two forward canards, and an updated layout of seven Raptor engines.
Critically, SpaceX has decided to commonize BFR’s main propulsion, choosing to skip the performance benefits of a vacuum-optimized Raptor variant for the simplicity and expediency of exclusively using sea level Raptors on both the booster and spaceship. This decision is ultimately strategic and well-placed: rather than concerning early-stage development with the inclusion of a second major branch of onboard propulsion, the company’s engineers and technicians can place their focus almost entirely on a one-size-fits-all version of BFR with plenty of room for upgrades down the road.
With a rocket as large as BFR and a sea level engine already as efficient as Raptor, the performance downgrade wrought by the initial removal of Raptor Vacuum (RVac) is scarcely more than a theoretical diversion. The specific performance numbers remain to be seen but will likely be greater than 100 metric tons (~220,000 lbs) to low Earth orbit (LEO). Past a certain point, however, the actual performance to LEO and beyond is almost irrelevant, at least from a perspective of individual launches. The paradigm SpaceX is clearly already interrogating is one where the cost of individual launches is so low relative to today’s expendable launch pricing ($5,000-20,000/kg to LEO) that it will almost be anachronistic to design or work with a single-launch-limit in mind, a limit that is just shy of a natural law in the spaceflight industries of today.
In 2016, Musk pegged SpaceX’s cost goals for a BFR-style fully-reusable rocket at less than $1M per launch for booster and spaceship maintenance alone, or $3.3M per launch with amortization (paying for the debt/investment incurred to fund BFR’s development) and propellant estimates included. To realize those ambitious costs, SpaceX will effectively have to beat the expendable but similarly-sized Saturn V’s per-launch costs (~$700M) by a factor of 100 to 200 – more than two orders of magnitude – and SpaceX’s own Falcon 9 and Heavy launch costs (~$55M to $130M) by 20-50X.
To even approach those targets, SpaceX will need to learn how to launch Falcon and BFR near-autonomously with near-total and refurbishment-free reusability, while also developing and demonstrating orbital refueling capabilities that do not currently exist and rapidly maturing large-scale composite tankage and structures. None of those things require Raptor Vacuum.
[Read more here]
The 2022/25 Mars timetable is probably not attainable, but 2025/27 looks as if it will happen (2025 for unmanned cargo missions, 2027 for the first settlers.) The circumlunar expedition with Yusaku Maezawa is planned for 2023. There will likely be several unmanned test missions around the moon before that, to test life support systems and re-entry. That will give SpaceX the knowhow to do the first Mars launches in 2025. It is possible that SpaceX could launch cargo missions to Mars in 2022 to test the BFS's ability to land on the red planet.
Meanwhile, SpaceX will continue to lead the space industry.
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