Rocket Lab launched New Zealand’s first rocket designed to reach space in 2009. Their goal to reach space was to develop and showcase innovative technology that would appeal to potential international aerospace companies.
Flight of the Ātea-1 rocket
Rocket Lab named their rocket Ātea-1 (Ātea is the Māori word for space). It was built to reach an altitude of up to 150 km (space officially begins at 100 km altitude above the Earth’s surface).
There were several launches of rockets in New Zealand to study the atmosphere in the 1960s. These rockets only reached altitudes between 60 and 80 kilometres. The Ātea-1 would be the first in New Zealand designed to reach space.
Ātea-1 was 6 metres long with a diameter of 15 cm – long and narrow. It was made of two sections. The larger section at the bottom contained all of the fuel and the rocket engine. The narrower 6 cm section contained the payload designed to reach space.
When the rocket launched on 30 November 2009, it accelerated upwards to reach a speed of Mach 5 (five times the speed of sound). At this stage, all of the fuel had been used up, and the two sections of the rocket then separated. This was designed as a smooth separation caused by the extra drag on the lower section.
The top section did not contain any rocket engine or fuel. It kept travelling upwards because of its momentum. Gravity and drag gradually slowed it down and it fell back to Earth.
Suborbital sounding rockets
Ātea-1 is classed as a suborbital sounding rocket. These rockets can make brief visits into space before falling back to Earth. Sounding rockets are used for scientific measurements, such as study of the atmosphere, and for experiments involving microgravity for up to 20 minutes. Some sounding rockets can travel as high as 950 km before falling back to Earth.
Suborbital rockets do not go into orbit around the Earth. For an object to remain in space at an altitude of 150 km, it also needs to be moving sideways at a great speed. For example, the International Space Station is at an altitude of 360 km and travels sideways at a speed of 28 000 km/h. Rockets designed to place satellites into orbit need to be much larger than suborbital rockets. This is because it takes about 30 times as much energy to give an object the sideways speed necessary to stay in orbit.
New technology developed for Ātea-1
Rocket Lab designed Ātea-1 to be one of the lightest sounding rockets ever to reach space. One reason was to push the limits of technology but also to develop a rocket that would be more affordable for future clients.
Several unique technologies and approaches were invented during its development:
- All carbon-fibre composite structure – this is much lighter than metal. The Ātea-1 launch mass was 60 kg.
- Liner-less pressure vessels – these contain the high-pressure gases. Pressure vessels are normally made of metal because gas escapes through tiny holes in a carbon-fibre structure. Rocket Lab developed a way to stop gases escaping without using metal. This reduced overall mass significantly.
- New heat-protective ablative material – Rocket Lab invented new ablative coating for heat protection at the nose conecombustion chamber and nozzle. This protects the structures from damage due to temperatures of around 2000 °C. It is also elastomeric (stretchy), which could make it suitable for use on inflatable re-entry systems.
- New propulsion fuels and systems – an entirely new fuel was developed. Rocket Lab also develops its own engines using liquid bipropellant, solid fuel or hybrid fuel. They use computer modelling to design an engine with the exact thrust required before making and testing it ready for use.
Rocket Lab’s innovative technology has already brought them several international contracts with organisations in the USA and Australia to further develop rocket propulsion technologies.
Nature of science
Solving challenges such as designing a rocket to reach space often leads to the development of new technologies such as new fuel systems and heat protection systems.