Some people believe that space exploration is a necessary investment in humanity's future. Others regard it as a luxury the world cannot justify.

Governments spend billions of dollars on space programmes every year. Some people believe this is necessary for the future of humanity, while others think this money should solve problems on Earth. In my opinion, space exploration is useful and should continue.

On the one hand, our planet has very serious problems. Millions of people do not have clean water, hospitals need equipment, and many children cannot go to school. When people hear that a rocket costs billions of dollars, they think this money could save many lives immediately, and this opinion is easy to understand.

On the other hand, space technology gives us many things that we use every day. Satellites give us weather forecasts, television, GPS navigation in our cars and telephones, and they also help scientists to see pollution and forest fires from above. Many inventions, for example solar panels and some medical equipment, were first created for space programmes.

In addition, space research helps us to understand our own planet. Satellites show how the ice is melting and how the climate is changing, and without this information governments cannot make good decisions.

In conclusion, although the problems on Earth are very important, I believe that space exploration is not a waste of money, because it gives practical benefits to ordinary people and helps us protect our own planet.

Space programmes are defended as essential to humanity's future and attacked as an indulgence while urgent problems remain unsolved on Earth. My view is that the objection is weaker than it appears, largely because of the sums actually involved.

The case against deserves a fair hearing. Public money is finite, and any large scientific project competes with health, housing and education. There is also a legitimate complaint about how funding decisions are made: ambitious, visible projects attract political support far more easily than unglamorous necessities such as maintaining water systems or paying carers properly. Anyone who has watched a spectacular launch while a local hospital struggles has grounds for irritation.

The difficulty is that the numbers do not support the implied trade-off. Space agencies typically receive well under one per cent of national budgets, so cancelling them entirely would make almost no difference to health or welfare spending, and the persistence of those problems clearly has other causes. Meanwhile the practical returns are considerable and mostly invisible because they are so familiar. Satellites underpin navigation, telecommunications, weather forecasting, agricultural planning and disaster response, and the climate data governments rely on comes overwhelmingly from orbit. This is infrastructure rather than adventure, and no serious critic proposes abandoning it.

In conclusion, I do not regard space spending as wasteful. Most of it is applied technology already embedded in daily life, and the exploratory remainder is too small a fraction of public expenditure for its cancellation to relieve any of the problems raised against it.

The charge against space exploration is that it diverts money from urgent needs. It is worth testing that claim before arguing about values, because it contains an empirical assumption — that the sums are large enough to matter elsewhere. They are not: space agencies generally receive a fraction of one per cent of national expenditure, so abolishing them would leave health and welfare budgets essentially unchanged. Whatever explains persistent poverty, it is not the money spent on rockets.

That is not a complete answer, though, and treating it as one would be evasive. The objection contains a fair point about how public priorities are set: visible, ambitious projects attract political enthusiasm that unglamorous maintenance never does, and a government can find funding for a launch more easily than for social care. That is a genuine criticism of decision-making, even if it does not establish that the specific spending is wasted.

The stronger move is to notice that "space" bundles two very different activities. The overwhelming majority is orbital infrastructure — navigation, telecommunications, weather forecasting, crop monitoring, disaster response and the climate observation on which environmental policy entirely depends. None of this is exploration in any meaningful sense; it is utility provision that happens to be located above the atmosphere, and it is so thoroughly embedded in ordinary life that people arguing against space budgets are generally using several of its outputs while doing so.

Exploration proper is the smaller and more contested part, and it should be defended honestly. The argument that humanity must become multi-planetary to survive is the one most often advanced and the least persuasive: any planet we could reach is far more hostile than the worst plausible version of this one, and the engineering required to live on Mars would be better spent making Earth habitable. The credible justification is capability. Difficult objectives with hard deadlines force the development of technologies that incremental research does not produce, and the spillovers — in materials, imaging, power systems and computing — have historically been substantial and unpredictable in advance.

My position, then, is that this spending is justified, but on considerably more modest grounds than its advocates usually claim. It is not securing the future of the species; it is maintaining infrastructure society already depends on and buying technical capability that has repeatedly proved useful. Both are ordinary reasons, and ordinary reasons are enough at these sums.