Largest rocket

The largest launch system to reach space is the SpaceX Starship/Super Heavy, which measures 121 m (396 ft) in height, 9 m (30 ft) in diameter and has a fueled mass of around 5,000 tonnes. The system's first launch attempt, which took place on 20 April 2023, was disrupted by the partial disintegration of the launchpad, which damaged the booster and prevented it from reaching full power. The rocket's first full-power launch was made during its second integrated flight test on 18 November 2023.

The Super Heavy booster, along with its Starship upper stage, has been in development in some form or other since around 2012. The project was initially known as the BFR (Big Falcon Rocket) and went through various name changes before settling on Starship (upper stage) and Super Heavy (booster stage). The basic architecture of the system has remained broadly consistent since the earliest publicly shown concepts – a massive booster that utilizes a large number of small engines instead of a few large ones, and a re-usable upper stage that can perform re-entry and vertical landing like a Falcon 9 booster.

Aside from this general outline, however, almost everything about the project has changed at least once. The most notable of these changes was the decision in 2019 to shift from carbon-fibre composite construction to stainless steel, which gave the rocket its distinctive gleaming appearance.

The 69-m-tall (226 ft) first stage is powered by three concentric rings of Raptor engines – 33 in all – which were developed in-house for this project. The Raptor is a closed-cycle methane-oxygen engine, meaning that it burns liquid methane and liquid oxygen, both chilled to cryogenic temperatures, in a series of staged combustion chambers that route all propellants and exhaust gases through the thrust nozzle.

The staged-combustion system squeezes more power from a given volume of propellant, and the choice of methane as a fuel – which burns much more cleanly than kerosene – should allow the rocket to be re-used many times without requiring extensive refurbishment. A single Raptor 2 engine generates 2,300 kN (570,000 lbf) at sea level, though this design is being continuously tweaked and revised by SpaceX engineers. The next-generation Raptor 3 will reportedly be capable of 2,690 kN (590,000 lbf), potentially increasing Super Heavy's power to around 90,000 kN.

All this power allows for the orbiter/upper stage (Starship) to be built on an unprecedented scale. Starship measures 9 m (30 ft) in diameter and is 50 m (164 ft) long. Around two-thirds of its internal volume is taken up by propellant tanks and other systems, but this still leaves a payload/crew compartment of around 1,000 m3 (35,000 cu ft). This means that Starship/Super Heavy can lift, in a single launch, a habitable space larger than the entire pressurized volume of the International Space Station.

In addition to SpaceX's continuous program of Starlink satellite launches, Starship/Super Heavy has already been booked for the private "Dear Moon" trans-lunar flight as well as NASA's Artemis Program, where Starship rockets will provide logistical support and landing capabilities for a future moon landing mission.