"Celebrating Yuri’s Night" Niall Smith

Specifically for Teachers Nature of Science 1: “Appreciate how scientists work and how scientific ideas are modified over time“ Nature of Science 10: “Appreciate  the role of science in society; and its personal, social and global importance; and how society influences scientific research” Earth and Space 8: “Examine some of the current hazards and benefits of space exploration and discuss the future role and implications of space exploration in society”

Sputnik 1 - 1957

Yuri Gagarin - 12 April 1961

Observe and deduce

This is also true of asteroids Prevalence of Impacts Moon Mercury Moon and Mercury both show significant evidence of crater impact after they had become geologically inactive This is also true of asteroids This suggests that large bombardments occurred at some time in the PAST (since we don’t see them happening much today) (Moon and Mercury shown different scales) Mercury closeup Asteroid Phoebe closeup Moon closeup Credit: NASA

Theories of Lunar Formation Moon being a captured object Highly unlikely Spun-off by a rapidly rotating Earth Early Earth did not spin fast enough These theories don’t work As a result of a collision with a Mars-sized planet called THEIA “Giant Impact Theory”

Collisions in recent times

Threats from Space

Earth crossing NEOs Asteroids Earth crossing asteroids

Oumuamua – from beyond the Solar System

Earth Sterilizing Impacts are Possible Inevitable

Not all collisions are bad

Early earth – 4.5 billion years ago – was too hot to retain water So where did it come from? HADEAN EARTH

Asteroids may be responsible for much of Earth’s water – not comets!!

What is space junk? Orbital bits that do nothing useful: spent rockets; fragments splayed by collisions and degradation; old satellites no one cares about anymore In total, they amount to millions of pieces of debris And it's about to get worse: Thousands and thousands of satellites are set to launch to low-Earth orbit before 2025.

The key issue in a collision is energy This is determined by the Kinetic Energy in the interaction: K.E. = ½ . M. V2 (where M = mass of the debris and V = velocity between the debris and the target) Collision velocities can be as high as 8 km/s 18,000 mph 4 times faster than a bullet

Radar and optical track pieces in low-earth-orbit as small as 5-10cm For higher orbits its 30cm – 1m Debris of <1mm can be inferred from returned satellites and dedicated instruments on others Estimates >170 million pieces

ISS Impact Chip Quadruple glazing!

Sentinel 1A impact damage

Occasionally pieces of debris reach the ground

Some Impacts are Intentional … 2007 Feng Yun-1C Weather Satellite 3400 tracked fragments

Others are accidental … 10th Feb 2009 Iridium 33 2300 fragments Kosmos 2251

And Low-Earth-Orbit is increasingly tempting … Cubesats and Space 4.0 or New Space

Why is Low-Earth-Orbit of such interest? Requires the lowest amount of energy for satellite placement. It provides high bandwidth and low communication latency. Satellites and space stations in LEO are more accessible for crew and servicing. Satellite needs less powerful amplifiers for successful transmission - LEO is used for many communication applications, such as the Iridium phone system. “Disadvantages” Satellites in LEO have a small momentary field of view, only able to observe and communicate with a fraction of the Earth at a time, meaning a network (or "constellation") of satellites is required to in order to provide continuous coverage. Satellites in lower regions of LEO also suffer from fast orbital decay, requiring either periodic reboosting to maintain a stable orbit, or launching replacement satellites when old ones re-enter.

The “cubesat” is the new standard form LEO satellites “Sprites” Satellites are getting smaller, but impressively powerful, as technology advances “Cubesats”

New Space is Why? Rockets built by private companies Satellites built by private companies, universities and (increasingly) schools – with satellites becoming smaller and lighter Why? To provide information to people who live on the Earth that can’t be obtained in other ways THE USES FOR THESE SMALL SATELLITES IS LIMITED ONLY BY YOUR IMAGINATION!

New countries such as India are also getting involved .. 2017 31 payloads delivered by this Indian rocket

… or New Zealand … New Zealand are interested in building rockets for: Specific Tasks Specific Orbits New Zealand

Some big targets for New Space Connecting the 3.8 billion people not currently connected to the web (Even rural broadband in Ireland) Autonomous vehicles Earth observation Almost any application you can think of! Space Tourism Space Exploration The Moon Village Mars

Huge interest in Constellations of Satellites The company ONEWeb ultimately plan to launch 2417 satellites

People are also interested in ….

Restore-L NASA Mission People are also interested in …. ESA e.Deorbit mission Restore-L NASA Mission https://sspd.gsfc.nasa.gov/video/Restore-L_ConOps_27Oct2017.m4v

Or …. Ecologically friendly spacecraft

But Space 4.0 is here to stay

And there are always people with new ideas …

THANKYOU