Czech high frequency laser could help space exploration

25-09-2019

Influential scientists gathered in Prague this week to discuss the possibility of constructing a very powerful laser that would be used to propel probes to distant solar systems at extremely high speeds. Hopes are that the advanced technology developed in the HiLase laboratory in the Central Bohemian village of Dolní Břežany could be used in constructing the laser.

Photo: archive of Breakthrough InitiativesPhoto: archive of Breakthrough Initiatives Four years ago physicist Stephen Hawking announced the creation of Breakthrough Initiatives, a 100 million dollar science-based program whose aim it is to search for extra-terrestrial intelligence.

The programme’s executive director, Pete Worden, is perhaps the most important representative at this week’s talks with Czech scientists.

At a press conference on Monday, he explained that one of the main goals of the programme is to send probes to distant solar systems with the help of powerful lasers.

“Fundamentally the idea is that if you can build a really small, sub-gram spacecraft, we call it a ‘starchip’, you can get it to reach a velocity of up to 20 percent the speed of light if you attach it to what we call a ‘light-sail’. The light-sail is about four to five meters large and made out of a very thin material. The whole system would only weigh a few grams at most.

“We would put these deep into space and then hit them with a very powerful 100 billion Watt laser, which would be capable producing a square kilometre of laser beams or more. The laser, which would be situated on the ground could shoot its beam at the light-sail and accelerate it to the necessary speed in a matter of a few minutes.”

Mr. Worden, who was the director of NASA's Ames Research Center before taking over the leadership of Breakthrough Initiatives, says that the expertise of scientists based in the European Union’s HiLASE laser facility in Dolní Břežany, could be very valuable to the project.

“There are probably only eight or 10 places in the world where there are significant areas of expertise in this field and one of them is here in Prague. They have very good expertise in shorter wavelengths.

“Fundamentally the idea is that if you can build a really small, sub-gram spacecraft, we call it a ‘starchip’, you can get it to reach a velocity of up to 20 percent the speed of light if you attach it to what we call a ‘light-sail’.”

“The advantage in using shorter wavelengths is that the size of the optical system you need is correspondingly smaller to get the same performance. Therefore, if we can figure out how to use the shorter wavelength, the laser does not have to be two kilometres long but just one kilometre.”

The director of HiLase Tomáš Mocek agrees that his centre can offer expertise that could lead to a more scalable solution for the proposed laser.

HiLase possesses some of the most powerful lasers in the world, but these are only at kilowatt level thus far.

However, the centre’s technology is very scalable and HiLase has come up with some concepts on how to ramp up the power by at least one order of magnitude, bringing it closer to the gigawatt power required for accelerating the light-sail.

Protecting the earth and exploring the origins of life

Tomáš Mocek, photo: archive of HiLASETomáš Mocek, photo: archive of HiLASE When it comes to practical uses in space, Mr. Mocek also sees another possible task for the type of high frequency lasers his centre specialises in.

“I think that our high pulse repetition rate will be needed if you want to use a laser not for such a star-shot, but for space debris removal for example. Because in that case one shot would not be enough to remove an asteroid from its trajectory.”

Furthermore, it seems that such technology may not only be used to potentially save life on earth, but also to discover how it developed in the first place.

This is the hope of Martin Ferus the head of the Department of Spectroscopy at the Jaroslav Heyrovský Institute of Physical Chemistry.

“The origin of life is a great enigma and to study it on earth is a great problem because we have a lack of evidence concerning the materials that the early earth was made up of. Simple questions, such as what was the composition of the earth’s atmosphere, are very difficult to answer.

“In each early planetary system you still have waste remaining after the formation of the planets, a lot of asteroids and comets. These of course fall on the planets and influence their chemical compositions and that could potentially be a cause for the origin of life.

“There are probably only eight or 10 places in the world where there are significant areas of expertise in this area and one of them is here in Prague. They have very good expertise in shorter wavelengths.”

“You need laboratory experiments and you have to find some system of how to study the processes connected to impacts. Large laser infrastructures are among only a few systems able to simulate such harsh conditions such as the impact of an extra-terrestrial body on the atmosphere.”

The Czech government recently identified laser technology as one of the key intersections between research excellence, business potential and future technological trends in the country.

In what it calls its ‘Smart Specialisation Strategies’, laser research and its applicability in the private sphere has been selected as a high priority in the government’s innovation strategy for the next 11 years.

HiLase director Tomáš Mocek says that it is mainly thanks to big investments over the past 10 years into research and development infrastructure from EU cohesion funds, that the Czech Republic is now in a position where it has cutting edge laser technologies.

Although the result of international public sector financing, the facility is now trying to stand on its own legs, says the director.

“We are trying to reorganise our services and technologies portfolio in order to reinforce the amount of contract services we provide for companies. This is because we do not want to be too dependent on public funding.”

HiLASE laboratory, photo: archive of HiLASEHiLASE laboratory, photo: archive of HiLASE He believes that the high pulse repetition rate lasers that HiLase specialises have a lot of potential for making production more efficient.

“It can be applied in the space industry for example. There you often have to drill a certain number of extremely small, but very precise holes in some materials. There are technologies with which to do this by shooting one [laser] shot after another.

“You can make 100 or 1,000 holes, but what if the customer comes to you and says that he needs a reliable technology to shoot 100,000 holes and ideally in a couple of shots? That is when you need the high average power [we provide]. High average power is key for the practical application in industry, when you want things done repeatedly, but also robustly and reliably.”

Establishing international oversight

The lasers in Dolní Břežany could also serve a positive political purpose. Those are the hopes of Nikola Schmidt from the Institute of Political Studies.

“We feel that this is a big opportunity for a small state to further its inclusive cosmopolitan foreign policy, which would spread these ideas among other small states.”

He is currently in charge of devising the country’s national strategy for planetary defence and says lasers are a great alternative to nuclear warheads if we ever had to stop an asteroid from hitting the earth.

“We feel that this is a big opportunity for a small state to further its inclusive cosmopolitan foreign policy, which would spread these ideas among other small states. These could then become initiators of a research consortium that could agree on the reform of some international organisation such as the International Telecommunication Union. On this basis one could establish an international regime that would supervise that these sorts of systems are used for civilian and scientific purposes rather than weaponizing them.”

Whether these are idealist thoughts or not, Nikola Schmidt is discussing this topic with Pete Warren this week both at a special symposium organised at the Ministry of Foreign Affairs and at the Prague SpaceApps Laser Workshop organised by the Faculty of Social Sciences at Charles University, HiLase and Prague’s Institute of International Relations.

25-09-2019