James Webb Space Telescope hasn't even launched yet and NASA is already looking for a successor.
Could the LUVOIR mission be the answer?
NASA is faced with a difficult decision of which instrument will shape scientists' research
in the 2040s as the agency's next major space telescope.
Although the answer is still years away, NASA has financed extensive evaluations of four
potential projects to understand better the risks and opportunities associated with each
proposal.
One of such mission concepts is called the Large UV/Optical/IR Surveyor (LUVOIR), a concept
for a highly capable, multi-wavelength space observatory with ambitious science objectives.
The team behind LUVOIR has proposed a launch date in the mid-2030s.
NASA's Goddard Space Flight Center Conceptual Image Lab
The space telescope includes upgradeable modern instruments and would reside at Earth-Sun's
second Lagrange point, or L2 point.
The state-of-the-art observatory would be able to observe ultraviolet, visible, and
near-infrared wavelengths of light.
The LUVOIR study team is considering two designs.
One with a 15-meter mirror, known as Architecture A, that would use the Space Launch System
(SLS).
And another design, Architecture B, with a mirror 8 meters across, which could launch
on a heavy lift vehicle like the Falcon Heavy.
The 15-meter mirror would be 50% bigger than the biggest Earth-based telescope.
This mission would enable significant advances in a wide range of science, from the age of
re-ionization to galaxy formation and evolution, star and planet formation, and solar system
remote sensing.
The main purpose of LUVOIR is to characterize a wide spectrum of exoplanets, including those
that could be habitable or possibly inhabitable.
If LUVOIR is built, its primary contribution to the field will be to provide a detailed
image of planets that now meet scientists' bare-bones criteria for Earth-like planets.
These planets resemble our planet in terms of size, mass, and orbit.
To us, extrasolar planets are little black shadows, not pale blue spots.
A mission like LUVOIR would change that by collecting enough data for scientists to begin
studying so-called Earth-like exoplanets in a statistical, population-wide manner.
That's similar to what the Kepler Space Telescope did for exoplanets in general: it discovered
so many new worlds that astronomers were able to begin to understand the relative quantity
of massive planets orbiting very close to their stars versus small, rocky worlds.
LUVOIR would zoom in on such small, rocky worlds and tell scientists what percentage
of planets that appear to be Earth-like have surface water, an atmosphere, and growing
organisms.
It would be able to detect the structure and composition of exoplanet atmospheres and surfaces.
It could also identify biosignatures produced by life in the atmosphere of a faraway exoplanet.
Biosignatures of interest in the atmosphere include carbon dioxide, carbon monoxide, molecular
oxygen, ozone, and water.
LUVOIR would not produce images but spectra: breakdowns of the amount of light of various
wavelengths originating from each of the worlds it investigates.
These spectra would allow scientists to identify the compounds on that world, offering further
information about what's happening on the surface.
According to the LUVOIR team, if scientists can do these investigations on at least 28
small, rocky worlds that turn out to have atmospheres but show no signs of life, they
should be able to conclude that less than 10% of planets with the same size and orbital
characteristics as Earth contain life.
If such an analysis succeeds in identifying life, scientists can move on to a more difficult
problem like understanding the laws of life.
There are undoubtedly more, but we'll never know what they are till we have more examples
of independent evolution.
The major goal of LUVOIR would be to detect and study alien planets to understand the
universality of life better.
Still, the telescope would also find lots of other worlds.
However, investigating exoplanets alone will not be enough to make LUVOIR a flagship mission
concept.
The LUVOIR team must also make the telescope's architecture relevant to a variety of astrophysics
subfields.
As a result, the team had to refine the suggested instrument suite to be as flexible as possible.
The mission concept team also designed a dozen sample science projects spanning the scale
of the universe to be included in the mission concept spanning the scale of the universe.
The team wanted to show off the work the telescope could do, from studying the dark matter to
showing how galaxies work to monitoring icy moons in the outer solar system for plumes
of water gushing out through their frozen shells.
LUVOIR would be able to observe objects within the Solar System better than anything else.
For example, here’s a view of Enceladus from Hubble, compared to the view from LUVOIR.
If NASA chooses LUVOIR as its next massive space telescope project, it will culminate
a long line of ideas.
Its predecessor, the Nancy Grace Roman Space Telescope (Roman), previously known as the
Wide-Field Infrared Survey Telescope (WFIRST), was repeatedly canceled in budget requests
by President Donald Trump's administration, only to be revived by Congress.
Another predecessor, the James Webb Space Telescope, is well behind schedule and over
budget, with a launch date of December 2021 at best.
LUVOIR's scientists and engineers have turned that experience with Webb into a list of ten
recommendations that they feel will keep their project on track.
Not all the strategies are under the team's control; others would require a review of
NASA's policy.
If NASA chooses the project, the LUVOIR team believes the recommendations will help them
avoid a similar fate as Webb.