Launching satellites and rockets from high altitudes not only reduces drag but furthers the efficiency of the launch. For this reason, researchers from the Finnish Meteorology Institute have been investigating the use of steam balloons in order to facilitate satellite launches.
If the booster rocket is first lifted to high altitudes, where the air is a lot thinner, it becomes considerably easier to launch a satellite. In the past, small rockets have been launched from aircrafts and balloons filled with hydrogen or helium. However, this has huge drawbacks due to cost and the flammability of hydrogen.
A recent study conducted by the Finnish Meteorological Institute proposes the use of hot steam balloons in the launch of rockets and satellites.
Pekka Janhunen is the lead author of the study conducted by the Finnish Meteorology Institute.
Janhunen said: “The balloon is filled by hot steam on ground and released. As the balloon ascends, part of the water vapour condenses. The condensation releases a lot of latent heat, which slows down the cooling and helps maintain the remaining vapour in gaseous state…After reaching sufficiently high altitude, the rocket is released, it ignites and flies into space. The balloon is emptied of vapour, it descends and may be collected for reuse.”
Researchers used a computer model in order to simulate the steam balloon’s ability to launch the rocket. The simulation also demonstrated to associated cooling of the steam at around 18 kilometres altitude. However, the weight of the rocket can vary which may have implications for the launch. The simulated weight was 10 tonnes which is around the weight of the rockets used to launch satellites.
Steam balloons are a cost-effective way of lifting a rocket into the stratosphere. The method is considered to be safe as well as reducing the carbon footprint of future rocket launches, where as in the past the emissions alone had terrible implications for the climate.