From the human perspective, the universe is ancient. 13.8 billion years, to be precise. Despite this, we can use sophisticated equipment to unravel what went on long ago. Niels Vertegaal, a researcher at Eindhoven University of Technology (TU/e), has developed an inflatable telescope that provides a glimpse of the ‘beginning of time’. Recently, this telescope underwent its first test in space.
Why you need to know this:
Understanding the origin of the universe and the events that took place billions of years ago is crucial to understanding our place in the universe.
Although the origin of the universe is still a mystery, more and more puzzle pieces are falling into place. Most astronomers agree that the universe was created by the big bang, also known as big bang. Although the theory is solidly based, including evidence of cosmic background radiation, there remains a need for additional evidence about the details and conditions of 14 billion years ago.
Vertegaal, who is in the final stages of his PhD research, knows that evidence can manifest itself in the form of signals. “Signals that we can still pick up today with my inflatable antenna,” explains the researcher. Why inflatable? “Because the device has to fit in a rocket. At the same time, it has to pick up enormously weak signals. For that, we need large sensitive antennas. We put the antenna in a ten-by-ten-centimetre box during launch.” The proof of concept version folds out to about a square metre. “But the final version to about ten square metres.” On Wednesday 6 December, the PhD student sent his radio telescope to an altitude of about thirty kilometres using a weather balloon. The instrument was launched into the stratosphere by the British space agency Sent Into Space. The antenna unfurled correctly, although a little later than expected. Mission accomplished.
During the experiment, Vertegaal worked with signals he generated himself. This allowed him to test whether the antenna is doing its job properly. But if the telescope is actually deployed during a space mission, it will start picking up signals from hydrogen molecules. Vertegaal: “In the beginning, the universe consisted mainly of hydrogen molecules emitting signals at a specific frequency. Due to the continuous expansion of the universe, these signals are ‘stretched’ further and further, so to speak. They get weaker and weaker as time passes. At some point, you will need more antennas to get the same “signal strength”. But they can still be measured now with a single, sensitive telescope.”
Just like a flat tyre
The project had its bumps. For the inflation technique, the researcher used an extremely thin film, only a quarter of the thickness of human hair. “You probably expect it: cracks and holes soon appear in that. We had to stick the foil regularly with special tape, just like a flat bicycle tyre,” Vertegaal says, laughing. In the end, fortunately, all that tyre sticking was not in vain. “But as you will understand, I was sweating profusely when the device was launched.”
On or behind the moon?
Currently, researchers from TU/e and others are considering two different concepts of the inflatable telescope. The first concept involves a constellation of several satellites with antennas, which together form a large network. They will be placed behind the moon. A relatively quiet environment where they are protected from radiation from Earth.
The second concept, soon to be sent to the European Space Agency (ESA) for review, envisages the construction of a radio telescope directly on the surface of the moon. “The idea is that the telescope picks up signals on the other side of the moon. This version of the device looks like a kind of inflatable mattress on which there are more than a thousand antennas.
The sooner, the better
The dissertation Vertegaal has been working on for the past five years is currently with the doctoral committee. The defence will take place in early May. As with any space project, it will be some time before there is actually an inflatable antenna on the moon. “I expect it to happen within ten years. Meanwhile, the universe keeps expanding and the signals we want to capture are getting weaker and weaker. The sooner we start, the better.”