OPENSPACE 24: The Future of Space Exploration | Page 44

LISA will
consist of three
spacecraft
following Earth
in its orbit
around the Sun,
separated by
2.5 million km.
quantum world using LISA Pathfinder as the much of the technology already,” stated
platform to perform experiments. “You need an McNamara.
extremely precise orbiting laboratory to study In order to be able to detect gravitational
the quantum effects, and LISA Pathfinder would waves, LISA will consist of not one but three
be the perfect laboratory for these quantum- spacecraft following Earth in its orbit around
like measurements,” stated McNamara. the Sun. In LISA Pathfinder, there were two
The first detection of gravitational waves platinum cubes on the spacecraft separated
and the success of LISA Pathfinder have by about 40 cm. In LISA, the little cubes are
encouraged ESA to give the green light to LISA separated by 2.5 million km—six times the
to continue the journey in search of the origins distance to the Moon. “We need to make
of the universe. According to McNamara, the sure that all three s atellites are perfect because
mission will be an international effort, with the they act as a single instrument. That will be a
involvement of NASA in about 20 percent of challenge, to maintain the rigor in building and
the mission. testing all three satellites,” said McNamara.
Now that the mission has been approved, However, the main challenge for LISA is not
the next step will be to undertake a new design how to build the gravitational wave detector
study to determine the mission’s science but how to achieve the high level of precision
requirements based on the technology already needed to detect gravitational waves, which
demonstrated by LISA Pathfinder in order have an amplitude of a few millionths of a
to submit them to industry and kick off the millionth of a meter over a distance of 1 million
mission. “In terms of the technology, we are km. Any large movement of the test masses
pretty much there. Pathfinder demonstrated would mask the gravitational wave. “The
instrument is extremely sensitive. With LISA
Pathfinder we noticed that any small change,
even the switch-on of the star tracker, added
noise to the instrument, which means that it
will take you a week to get back to operational
mode,” said McNamara.
When complete, the new LISA mission will
look at a new part of the spectrum. “We will
be able to observe the entire universe over the
universe’s history. We will be able to build up
the scenario about how the universe came to
be the way it is today, how the galaxies formed,
how the super massive black holes appear in
the center of galaxies. So it is a whole new way
of doing astronomy. We are doing astronomy
right back to the very first objects that appeared
in the universe,” said McNamara.
None of that would have been possible
without LISA Pathfinder.
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