Starship I: A Revolutionary Rocket
Starship I: A Revolutionary Rocket
SpaceX has come to dominate the American space industry. Now they are dreaming bigger.
This is the first in a series of articles covering the exciting potential of Starship. For the first time I will initially be making parts of this series available to paying subscribers only. For those who are not already full subscribers, you can get your first two months of subscription for free by taking advantage of this special offer.
Elon Musk has never been one to hide his ambition. In 2005, a year before SpaceX would launch its first rocket, he was already hinting at plans to build a spacecraft more powerful than had ever flown before. The BFR - officially the Big Falcon Rocket, though the F sometimes stood for something else - would, in his imagination, carry more than one hundred tons into orbit, open the doors to Mars and let humanity blossom out across the Solar System.
It was a heady vision, and one that looked rather ambitious. Just a year later SpaceX would see its first attempt at launching a rocket - the Falcon 1 - spin out of control and crash back to Earth. By 2008, after two more failures, Elon Musk and SpaceX were running short on cash. Just one more failure, Musk later said, would have meant the end.
Fortunately for him, attempt number four was a success. On September 28, 2008, the Falcon 1 reached an altitude of four hundred miles, fired its engines to circularise its orbit, and deployed a lump of aluminium into orbit. It was SpaceX’s first real success; a victory that proved they really could fly rockets.
Even so, the idea of the BFR - capable of carrying two hundred times more mass to orbit than the Falcon 1 - still looked faintly ridiculous. SpaceX had put a grand total of 345kg into orbit by the start of 2010, a puny amount by any measure. To go further they would need a bigger rocket - and, to make it cheap, they’d have to learn to land it.
From the beginning the Falcon 9 was designed to be that reusable rocket. That, at the time, was something novel. True, the Space Shuttle had been partially reusable, and even featured two reusable boosters; but the technology had failed to lower costs as expected. By 2010, when SpaceX was working on the Falcon 9, the Space Shuttle was anyway on the edge of retirement; considered too dangerous for further use.
Many rocket engineers, back then, considered the idea of reusable rockets uneconomic. In a paper that formed part of the introduction to Space Mission Analysis and Design, one of the pre-eminent texts of the field, James Wertz skewered the idea. Reusable rockets, he concluded, would be uneconomical, unreliable and difficult to upgrade.
Musk begged to differ, and within a decade he was proven right. The Falcon 9 has cut the cost of spaceflight dramatically, flown astronauts to the International Space Station and launched thousands of satellites. It is an unquestionable success; a rocket so versatile and cheap it has come to dominate the American space industry.
In 2022, SpaceX lofted hundreds of tonnes into orbit over sixty-one launches. This year they have done even more, with the Falcon 9 reaching orbit on more than eighty different occasions. Yet the company is beginning to hit the limits of what they can do with their flagship rocket. To go further, they’ll need something ambitious, something capable of lifting hundreds of tonnes into space at once. Something, indeed, that looks a lot like the BFR.
I. The Last Super Heavy
Four hundred miles east of Florida, and three miles under the sea, lie a set of rocket engines. Each is enormous, capable of burning six thousand pounds of fuel in a second and of outputting one and a half million pounds of thrust. They sustained this for a little less than three minutes; five of them working together to power the mighty Saturn V rocket into orbit. Then, job done, they were discarded, left to plunge into the frigid depths of the ocean.
The Saturn V, Apollo’s super heavy moon rocket, was a thing of staggering beauty and power. It could lift one hundred and forty tons to low Earth orbit, and send more than forty of them to the surface of the Moon. Just fifteen were ever built, at a cost of a billion dollars (in today’s money) each. Thirteen of them flew, carrying astronauts to the Moon and lofting the Skylab space station into orbit.
The rocket’s designer, the former Nazi Wernher von Braun, had bold plans for the rocket. To him, the Moon landings were just the beginning. Equipped with another set of Saturn Vs - or an even bigger rocket - America could reach out across the Solar System, send astronauts to explore Mars and build a long-term base on the Moon.
Political reality soon intervened. The cost of the Saturn V might have been justifiable as a matter of national prestige, when America was racing to beat the Soviets to the Moon, but after, with the race over, the money dried up. No second set of Saturn Vs was ever made, and those that remained were given to museums.
The age of the super heavy rocket came to a close in 1973, with the launch of Skylab. Nothing so powerful would fly again for fifty years, and no human has since ventured more than four hundred miles from the Earth. Instead of the Moon and Mars, space agencies focused on space stations and satellites, sending robots to explore the Solar System instead of humans.
Cost was the main reason for all this. Going back to the Moon or on to Mars has been on the wishlist of many American presidents, but it has always run up against the fantastic price tags involved. Only in recent years, with the development of NASA’s new SLS super heavy rocket, have things looked likely to change. But even here the sums are plainly unsustainable: each flight of the SLS burns no less than four billion dollars.
II. Starship
Over the years, SpaceX’s commitment to building a cheap super heavy rocket has rarely wavered. In 2014, the company revealed it had started work on a new rocket engine, capable of powering spacecraft to Mars. By 2016, Musk was talking of putting three hundred tons into orbit, and of sending one hundred people to Mars. In 2019 the BFR finally took on its current incarnation: a stainless steel behemoth capable of lifting at least a hundred tonnes into orbit, and of one day landing humans on Mars.
Crucially, the rocket is designed to be fully reusable. Unlike the Falcon 9 - for which the second stage is still discarded - SpaceX hopes to return both the booster and upper stage to Earth after each flight. After refurbishment, checks and refuelling, both could then fly again.
In principle that could dramatically lower costs. Certainly it should allow the rocket to fly more often. The SLS, the only other super heavy rocket currently in existence, can fly at most once a year; limited by the ability to produce each booster. For Starship, however, the frequency will be limited only by the time needed to refurbish the rocket. Musk, ambitious as always, reckons that could see each rocket flying several times per day. Perhaps the Falcon 9 is a better guide: the gap between landing and launching is now about three weeks.
Exactly how much each launch will cost is hard to say, and depends on a lot of variables. Musk has quoted prices as low as a million dollars per launch, which seems optimistic, to put it mildly. Right now a launch of the Falcon 9 seems to cost SpaceX about twenty million dollars. Starship, even if it is fully reusable, is unlikely to approach that number for some time. Estimates of fifty to a hundred million per launch seem far more likely.
Even if Starship comes in at a hundred million per flight, it is still an order of magnitude better than the Saturn V or the SLS. In today’s money the Saturn V cost about $7000 for every kilogram of mass it carried to orbit. The SLS costs a ridiculous $40,000 per kilogram. The Falcon Heavy is much better, coming in at $1500/kg. Starship, though, beats them all, costing $1000/kg at most, and as little as $300/kg under more optimistic estimates.
When Starship flies it promises to be revolutionary. The impact of frequent low-cost flights into orbit should not be underestimated: they will open up space in a way that has hitherto been impossible. The arrival of the reusable super heavy will be a watershed in human history; the beginning of an era in which our species truly begins to expand beyond the Earth.
III. Getting it to Fly
Before the revolution can begin, SpaceX first needs to get Starship to fly. More, they need to perfect a whole set of technologies that come with it, from landing the spacecraft and its booster to refuelling Starship in orbit. Even with all that done, prices will only come down if they can start flying it regularly.
The challenge involved should not be underestimated. SpaceX is trying to do many things here that have never been seriously attempted before. No one has ever tried to re-enter and land a spacecraft as big as Starship, or attempted to refuel spacecraft in orbit on the kind of scale that will be needed.
These are big technical challenges, but it is likely SpaceX has the will and money to see them through. Crucially the company seems able to produce hardware fast, meaning they can launch test flights frequently. That should make it easier to test new approaches to hard problems - and mean they worry less about the kinds of failure we saw over the last year.
In this Starship is a striking contrast to the SLS. Since each SLS rocket takes years to build and prepare, failure is not an option. The rocket must be designed to work perfectly every time - and that, naturally, encourages designers to be cautious. As a result, the SLS is stuck using technology developed decades ago, and still comes with an enormous price tag.
Over the next year Starship is likely to fly several times. The initial goal, to complete a suborbital flight and splashdown in the ocean, will occupy the next few flights at least. But after, once the basic concept of operations are resolved, the rocket will begin to target orbit and the more challenging tasks of refuelling and reusability.
In theory, Starship is scheduled to participate in a Moon landing as soon as 2025. In reality, and outside the optimistic projections of Musk, it is unlikely to reach that deadline. A backup date of 2028 seems more realistic, and also looks like a good marker for the project as a whole. By the end of the decade, certainly, the Starship revolution should be upon us.
When it does come, Starship will change the way we think about space. It will allow humans to once again venture to the surface of the Moon. It will put Mars, and perhaps beyond, in reach. It will allow new space stations, space telescopes of magnificent power, and put spaceflight within the reach of millions. That is insanely exciting, and nothing short of revolutionary.
This is the first in a series of articles covering the exciting potential of Starship. For the first time I will initially be making parts of this series available to paying subscribers only. For those who are not already full subscribers, you can get your first two months of subscription for free by taking advantage of this special offer.