SpaceX’s Starship completes critical test flight: Everything you need to know about the world’s largest rocket

The success of Flight 10 is likely to have come as a relief for both SpaceX and the National Aeronautics and Space Administration (NASA), which plans to use Starship to put its astronauts back on the Moon in the coming years.

SpaceX aims to make Starship a fully and rapidly reusable rocket system, which can take people to Mars. Once entirely operational, Starship can redefine space travel and exploration for the benefit of astronomy and planetary science. Here is how.

But first, what is Starship?

Starship is a two-stage heavy lift-off vehicle designed to carry crew or/and cargo to Earth orbit, the Moon, Mars, and beyond. Put together, the rocket system is nearly 120 metres tall, making it the largest rocket ever flown — taller than even the Saturn V (111 m), which took Neil Armstrong to the Moon. For perspective, the Qutab Minar is 72.5 m tall.

The Super Heavy booster consists of 33 Raptor engines that can produce 74 meganewtons of thrust. NASA’s biggest currently-operational rocket, the Space Launch System (SLS), generates 39 meganewtons off the pad. Saturn V delivered some 35 meganewtons of thrust off the pad. These Raptor engines use a 3.6:1 ratio of liquid oxygen (the oxidiser, a chemical which reacts with the fuel to cause combustion) and liquid methane (the fuel).

According to SpaceX, upon the project’s completion, the Super Heavy will be fully reusable, and capable of re-entering Earth’s atmosphere after a mission to land at the launch site. The Starship spacecraft, comprising six Raptor engines and four landing fins, will also be fully reusable.

Note that SpaceX plans to retire the current version of Starship, which has faced several issues in recent months. The company’s owner, Elon Musk, has already begun to tease plans for larger, more ambitious iterations of the vehicle that would stretch even taller and carry more propellant.

How can Starship reduce the cost of space travel?

One of Starship’s biggest selling points is that it will drastically bring down the cost of space travel. Three main features will allow this.
First, the Starship is eventually expected to be able to carry up to 150 tonnes of payload to low-Earth orbit, and at least 100 tonnes to the Moon and Mars. This is more mass than humankind has collectively soft-landed on the lunar surface so far.

Two, SpaceX is developing the Starship’s upper stage in such a way that it can be refuelled in Earth orbit by other Starships. In theory, this will allow it to operate like an aeroplane that can be refuelled and put into the air quickly.

“With refuelling, spacecraft can instead be designed for increased payload capacity and more capable scientific instruments, thereby fundamentally increasing their value-generating potential,” according to a report by The Space Review, an online publication.

Three, the Starship rocket system is designed to be entirely, and rapidly reusable. Unlike in the case of other launch systems, Starship’s principal hardware elements are not discarded — either by being dropped in the ocean or allowed to burn up — but rather brought back to the ground so that they can be used again.

Even NASA’s reusable Space Shuttle spacecraft used a disposable external fuel tank and reusable thrusters, which had to be recovered from the sea, examined, and refurbished after every use. Even the shuttle itself often took months to get running again.

According to some estimates, the Starship will be able to deliver cargo up to 100 tonnes to Mars for just $50 million. The Space Shuttle, which was retired in 2011, used to cost $1.5 billion to lift only about one-quarter of what Starship will, and only into low Earth orbit, according to a report by ABC News.

How does this benefit science?

Over the years, the biggest hurdle to space exploration, and the commercialisation of space travel has been the inability of launch vehicles to carry heavy payloads. This requires carrying lots of fuel (hence a bigger rocket), and is a very expensive endeavour.

Starship’s capability to carry heavy payloads, while being extremely cost-effective, promises to change that. For instance, scientists will be able to launch much larger space telescopes, which could be built out of cheaper but heavier materials. They will also be able to send bigger equipment in future Moon and Mars missions, such as a full-sized drilling rig, which can drill up to a kilometre. This will give scientists unprecedented access to the interior of the Moon and Mars, where useful resources are believed to be present. The Apollo Missions, in contrast, were able to carry only smaller equipment to the Moon.

Speaking to the journal Science, Philip Metzger, a physicist and space technologist at the University of Central Florida, said: “If the mass and the volume of the payload are larger, then we can imagine other capabilities in space that we’ve never even done”.

As Starship is capable of returning to Earth, it would also be able to bring back huge amounts of samples from the Moon and other planets, which could help scientists unlock numerous mysteries about our solar system and the origin of life.

The rocket system is central to NASA’s Artemis program, which aims to put astronauts back on the Moon in the coming years. It is also supposed to take astronauts to Mars before the end of the next decade.

What are the challenges?

But before these ‘benefits’ can be actualised, SpaceX needs to prove that Starship is safe and reliable, while keeping costs low, as per its promise. Historically, this has been a major challenge for space flight programmes.

For example, the major criticism of NASA’s Space Shuttle programme was that the incremental cost of its reusable space shuttles turned out to be much more expensive than expendable rockets, despite the latter not being reusable. Moreover, despite the rapid development of Starship in comparison to other launch vehicles, the progress has been slower than Musk talked about. And it has come at a cost.

Last year, a Reuters investigation found that in a bid to quickly develop Starship, Musk endangered SpaceX workers in Texas and California. The news agency documented at least 600 previously unreported workplace injuries at SpaceX. The company’s employees said: “They are paying the price for the billionaire’s push to colonise space at breakneck speed”.