Science & Technology

November Snapshots of Science History

This November we have focused on several space science and aerospace snapshots from science history.

First flight in a hot air balloon

Hot air balloons were humanities’ first experience of flight, it was the first time we left the ground to explore what is above us. In 1983 the first free flight with humans on board a hot air balloon took place. This followed on from a few months earlier where the first hot air balloon carrying animals was tested. This basket had on board a duck, a sheep, and a cockerel.  A range of animals was chosen, the duck could fly and was therefore unlikely to be affected by the altitude, whilst the rooster could not and would show any negative effects of the heights reached. The sheep was on board as it was thought that the psychology of sheep and humans were similar- and therefore would indicate the emotional effect of the flight.

On the 21st November it was time for two humans – de Rozier and the Marquis Francois d’Arlandes to board the balloon. The balloon diameter was nearly 50 feet and was powered by hot air created by burning hay and straw.  The balloon material was cloth that was lined by paper designed by the Montgolfier brothers.

During the flight -which lasted around 25 minutes-  the two passengers travelled over 5 miles. It would have been able to travel further if not for the embers, which were at risk of destroying the balloon.  As balloons developed, gas became more popular than lighting hay on board, due to the danger.

Hot air balloons paved the way for future flights and were the beginning of human exploration in space. They have been used not only for flights and weather observation, but also in military practices to observe the action on the ground. 

Launch of Mariner 10

Nearly 50 years ago on 3rd November the Mariner 10 spacecraft was launched. It was part of the Mariner program in which 10 probes were launched. This program is significant as it was a substantial exploration into the inner planets of our solar system. Between 1962-1973 probes designed by NASA’s Jet Propulsion Lab visited Mercury, Venus, and Mars. These were the first spacecrafts to visit Mercury and Venus.

Mariner 10 [credit: Smithsonian]

Mariner 10 was the last spacecraft in the Mariner program, setting out with the aim of observing Venus and Mercury. It was the first spacecraft to use the gravity of one planet to reach another, a technique known as a gravity assist. This way of travelling means that less fuel must be brought onboard, which reduces the cost of the spacecraft. Gravity assists are an effective way for spacecraft to travel and the current spacecraft to Mercury – Bepi Columbo- will complete nine flybys as part of its journey.

Several important discoveries were made because of the Mariner 10 observations. The spacecraft produced over 4,000 photos of Venus, and 2,700 photos of Mercury, covering nearly half of the planet’s surface. It revealed a magnetic field at Mercury that was not predicted. As a consequence of the data, it allowed scientists to discover the metallic core at Mercury, which makes up the majority of this planet’s mass.  This has led to developments about how Mercury could have formed at the beginning of the atmosphere and how its magnetic field works.

Overall, the Marnier program, including the Mariner 10 spacecraft, contributed significantly to our understanding of the inner solar system. The initial discoveries made by the Mariner 10 spacecraft have informed other missions’ objectives and left us with many unanswered questions.

Founding of the SETI institute

SETI stands for Search for Extra-terrestrial Intelligence. It was founded on the 20th November 1984, which is significant as it marks the date that humanities’ efforts to search for life beyond our planet was officially organised. Whilst projects had been previously undertaken before involving the examining signals from various sources, the founding of the institute gave a new level of recognition to this work.

This institute focuses on analysing signals from space to search for life. It looks for non-random patterns that could have been sent deliberately or accidentally by advanced life with technological capabilities. The research focuses on radio signals as well as wavelengths of visible life.

The SETI logo [credit: SETI]

SETI operates with three main centres: Carl Sagan Centre (which studies potential signs of life in the universe), Centre for Education, and the Centre for Public Outreach, administering more than a quarter of a billion dollars for research so far. The programs are not government run but privately funded. Over 700 people have been employed at the institute which has more than 100 employees now.

The SETI institute is a significant organisation as they are the only organisation in America which are dedicated to the search for life further out in the solar system. By focusing their research on this one area, they are the leading force examining signals from all over the solar system. Their work in education and public outreach is significant, as it encourages other people to consider the possibility of life outside of our planet.

Written by Louise Weightman