The Week in Space and Physics
On astronomy's future, Project Kuiper, the next Moon lander and reionization
Just over a month from now the James Webb Space Telescope will head skyward, unfurl its giant mirror and begin scanning the cosmos in unprecedented detail. That moment, if all goes according to plan, will be a triumph for American astronomy: the result of decades of work and billions of dollars, all leading to a new understanding of our universe.
Still, the James Webb has come at a high price. Its huge budgets and shifting deadlines ate up funds which astronomers could have directed elsewhere. Much of American astronomy is now on the edge of crisis – a state of affairs shown most dramatically by the collapse of Arecibo last year. The launch of the James Webb could, then, be a chance to rethink priorities; an opportunity to spread funds to long forsaken fields.
The release of an important new report this week – the Decadal Survey – shows that astronomers are indeed hoping to do that. It recommends building three new great observatories in space, fully funding two massive telescopes on the ground and paying to upgrade existing facilities.
Conscious, however, that recent astronomical projects have badly overshot their budgets, the report suggests a new way to manage big, expensive telescopes. More effort, it says, should be put into the early stages of projects. Astronomers must ensure technologies and concepts are ready and well thought out before they ask for large sums of money.
This, the authors think, can help their flagship recommendation – a 6-metre orbital telescope – launch on time and budget. Perhaps not fully convinced of this, however, they allocate an enormous $11 billion towards building the telescope. It could, they also suggest, take more than two decades to complete.
The result of all that time and money would be an extraordinarily powerful telescope; one that could even pick out signs of life on distant planets. The report proposes building two other telescopes: one X-ray and the other infra-red. Both projects are smaller. Each should cost less than $5 billion, and each would require years of detailed study before engineers start work.
Putting telescopes in space is hard and expensive. Those that stay on Earth can be made far bigger and, though they must deal with the effects of the atmosphere, they, too, can do advanced astronomy. The Decadal Survey, therefore, suggests that astronomers commit to a pair of big telescopes: the Giant Magellan Telescope and the Thirty Meter Telescope.
Work on both telescopes is already underway. But, as funding was not certain, astronomers feared that one, or perhaps both, telescopes would be cancelled. That would leave America trailing behind Europe, which is already building its own giant telescope in Chile. Even though funding now seems more likely, all three big telescopes will have to deal with the growing horde of satellites orbiting the Earth. There is still no clear solution to that problem.
In all, the Decadal Report is ambitious, painting an exciting path forwards after the James Webb. But it may be too ambitious – all that astronomy will cost money, and NASA and Congress will need to pay up. That, astronomers may find, could be easier said than done
Amazon Tiptoes Towards a Mega-Constellation
Amazon’s plans for a constellation of thousands of satellites took a step forward this week, as the company signed a deal to launch two prototypes. The satellites – KuiperSat 1 and 2 – should be in orbit by the end of next year, allowing the company to start testing its concept for satellite internet.
Amazon might have been expected to prefer Blue Origin – a company owned by Amazon founder Jeff Bezos – for their launches. And, indeed, Blue Origin will soon have a rocket that should, on the face of it, be suitable for two prototype satellites. New Glenn, their new orbital rocket, is currently scheduled for a test flight at the end of next year.
Instead Amazon has signed a contract with ABL Space Systems, a start-up that has yet to try launching anything at all. It is an interesting and risky choice, one that faces a high chance of delay or failure, and is – indeed – hardly a vote of confidence in Blue Origin.
Blue Origin Finally Give Up
After six months of legal battles, SpaceX can finally start building NASA’s new moon lander. When SpaceX won the contract in April, Blue Origin – a rival bidder – called foul, saying that NASA had changed the rules of the contest at the last minute. Months of legal appeals and court cases followed, each of which prevented SpaceX and NASA from starting work.
Though the arguments pursued by Blue Origin have shifted over time, the crux of the matter lies in their frustration that SpaceX won the contract – and billions of dollars of NASA funds – while Blue Origin missed out. Jeff Bezos – the billionaire founder of Amazon and Blue Origin – has tried for months to reverse the decision. At one point he even offered NASA billions of dollars in discounts if they selected his design for a lunar lander.
Now, at last, the legal fight seems to be over. Last week a federal court ruled against Blue Origin’s lawsuit and, soon after, Jeff Bezos signalled that the matter would, for now, be closed. That means that SpaceX can finally start working towards two planned missions to the lunar surface.
The first mission will be a test run. SpaceX will send an uncrewed version of the lander to touch down on the Moon’s surface. If that goes well, a human mission would follow a few months later: the first human mission to the Moon in more than fifty years.
The Science of the James Webb: Reionization
Over the next few years, the term “reionization” is likely to feature more and more in scientific articles. That’s mostly because the James Webb telescope – the biggest new observatory in decades – will study this reionization in detail. What, though, is reionization? And why is it at all interesting?
The answers lie in the early Universe. Back then, just after the Big Bang, the cosmos remained far too hot for atoms to form. Their constituents – mostly electrons and protons – instead filled the Universe with a kind of fog; one that light could not easily penetrate.
Over time, as the universe cooled and electrons and protons came together to form the first atoms, this fog gradually lifted. As they formed, those new atoms released a faint glow. Aeons later our telescopes would pick that glow up - we now call it the cosmic microwave background, the oldest known trace of our universe.
That was the first light the cosmos ever saw, but, as no stars or galaxies yet existed, it did not last long. A deep and profound darkness settled over the universe, one that must have lasted millions of years. Over countless millennia, however, swirling clouds of hydrogen and helium gradually coalesced, until enough gathered to ignite the first stars.
Those stars, as they flickered into existence, started to blast the cosmos with a new form of radiation. That, once again, stripped electrons from atoms: a process known as reionization. Why? Because an atom stripped of electrons is known as an ion, and this process was, in a sense, restoring the original ions to the universe: reionizing it.
The catch, of course, is this happened a very long time ago. The light from those original stars has long since been stretched and red-shifted by the expansion of the Universe. When it reaches us – as it does after billions of years of travelling through space – it appears strongest in the infra-red frequencies. To pick them out – since almost no light at all from them still reaches us – we need a powerful infra-red telescope - exactly what the James Webb promises to be.
When astronomers talk about reionization, then, they are referring to this period of the early universe. It was, indeed, a fascinating time: the moment when stars and galaxies first came into being; when the modern universe started to take shape. But it is also, until now, a relatively unknown period. The James Webb will, hopefully, change that.