Safe landing: SpaceX's new capability to improve space exploration

SpaceX on Sunday performed a brief but stunning eight-minute demonstration of a new capability, which has the potential to vastly improve the efficiency of space flight and exploration. The company launched its Starship spacecraft from its facility in Boca Chica, Texas, and after the detachment of the payload spacecraft module, the first-stage “Super Heavy” booster was returned to the launch pad and captured by mechanical arms. The demonstration is conceptually simple: Launch a multi-stage vehicle, and retrieve the first-stage booster after detachment. The booster can then be refuelled and reused. Indeed, SpaceX has been doing this for almost 15 years with its earlier series of Falcon rockets, which are used to ferry goods and passengers to the International Space Station  (ISS) using a reusable first stage.

The big deal was the mode of capture. The Super Heavy returned to the launch pad itself and, after capture, it could be re-launched in a quick turnaround after refuelling, running repairs and maintenance. Booster recaptures of the Falcons have always been done on floating launch pads, or on specially prepared concrete pads, where the booster has inevitably suffered significant damage upon landing, requiring extensive repairs after return to the space facility. This time, the booster was captured by a pair of mechanical arms (nicknamed chopsticks), which lowered it gently. The damage was minimal, according to the company. Moreover, a fully loaded Starship is much larger and heavier, at a height of 121 metres, than the Falcon-9, which is 70 metres. After the detachment of the spacecraft module, the booster which was captured was around 71 metres tall, and weighed over 275 tonnes. The Super Heavy booster contains 33 rockets powered by methane-oxygen mixes. These are used in various combinations to push the two-stage Starship into flight, and then guide the booster back.

The second stage of the Starship, which contains the payload, detaches at a suitable point in the flight. In this case, it was allowed to fall into the Indian Ocean, where it sank. The Starship second stage has its own array of rockets, which may offer it the capability to fly out and reattach to a Super Heavy booster. A variant includes a Human Landing System, which could land on the moon or Mars. As conceptualised, the Starship could contain a crew of up to 100 persons riding in the second stage and it would eventually be used to deliver humans and supplies to Mars. The first stage Super Heavy booster would perform its task, and be recaptured at the launch pad, and, if necessary, be re-launched almost immediately.

This is the fifth test flight of the Starship and the first four did not involve recapture of the booster by chopsticks, due to various technical snags. The booster was destroyed or it sank in the ocean in those tests. Assuming the technology can be stabilised, the booster could be re-launched within an hour, according to the chief executive of SpaceX, Elon Musk. This could potentially save millions of dollars on every launch. The Starship and the Human Landing System are being designed to be used in a moon-landing mission by the National Aeronautics and Space Administration, for which SpaceX has been awarded a contract worth $4 billion. However, Mr Musk’s oft-stated ambition is to set up a manned mission to Mars, which will eventually lead to the establishment of colonies on the red planet. Chopsticks bring that goal a little closer.