Nibbles in Space Malcolm Macdonald || SpaceProf

Lidar technology, which uses a laser to measure the distance to a target, was first developed to help track spacecraft, and to help them autonomously rendezvous; a lot of spin-off technologies from human spaceflight, due to the challenges of trying to live in space; knowhow gained from wearable sensors developed to study astronauts has been applied to baby-monitors that can alert to the risk of sudden infant death syndrome; technology developed to land a spacecraft has been applied to the packaging of potato crisps to increase packing speed.

By the late 1970’s engineers were starting to grasp the risk of the ever-growing space debris population; we have best-practise guidance in place to help avoid the creation of more debris; space debris, much like pollution on Earth is a negative externality; no meaningful space debris legislation, nor enforcement.

Issues relating to the use of space have been dealt with through the United Nations Committee on the Peaceful Uses of Outer Space; five UN Treaties between 1967 and 1979; the Moon and other bodies be used “exclusively for peaceful purposes” but this does not apply to space itself; as we look forward it’s likely that further agreements are required.

Space sickness is experienced by as many as half of people as they adapt to weightlessness; just like on ground, exercise and health checks are vital; as water is the most heavily consumed item for life support it’s vital that as much be recycled as possible; to help reduce the risk of cancer, spacecraft will have areas with increased shielding against space radiation.

The only external source of energy available to a spacecraft with reasonable flight heritage is solar radiation; the use of unfolding solar arrays is common; in a fuel cell, hydrogen and oxygen, or a similar combination, are combined to produce electricity and water; Radioisotope Thermoelectric Generators, or RTGs, convert heat released from the decay of radioactive material into electricity.

The main way of changing the velocity of a spacecraft is to take part of the mass of the spacecraft, and eject it; anything but small plane changes require a lot of energy, which can make such manoeuvres prohibitive; the Earth’s diameter is almost 43km more at the equator than between the poles; Sun-synchronous orbits are used in Earth observation missions to maintain consistent illumination of the ground throughout the year.