Tuesday , January 18 2022

Smallsats as a guide for large space telescopes


There are more than 3,900 planet beyond the Solar System. Most of them have been detected as "transitions"; when a planet passes through a star when a moment blocks its light.

The brightness of the stars astronomers tell you a little bit about the size of the planet and the distance from the star.

But knowing more about this planet, whether it's between oxygen, water, and other life signs, requires powerful tools. Ideally, they would be larger telescopes in space, which contain clear mirrors with the highest viewing points. NASA engineers are developing designs for the next generation of space telescopes, including "segmented" telescopes, to build a small space in order to build and deploy a large telescope once in the mirror.

NASA's next James Webb space telescope is an example segmented mirror with a diameter of 6.5 meters and 18 segment hexagons. Next-generation space telescopes will be more than 15 meters in length, with more than 100 mirror segments.

The challenge of segmented space telescopes is how to maintain stable mirror segments and point collectively towards an exoplanetary system. Such telescopes would be equipped with coronographs – sufficiently sensitive to the distinction between clear light emitted by a star-emitted light and the planet's orbit. But the slightest change in each section of the telescope can lead to coronary measures and may stop the measurement of oxygen, water or other planetary features.

Now, MIT engineers suggest that large spacecraft with laser lasers fly far away from the large space telescopes and act as a "guide-star", providing clear and clear light next to the telescope target system. Use it as a reference in space to stay stable.

In a paper published in the Astronomy Magazine, researchers show that designing the laser's star screen is today feasible with today's technology. The researchers say that the laser light does not allow the second probes to stabilize the system, reduces the accuracy of demand for a large segmented telescope, saves time and money and allows flexible telescopes designs.

"This article suggests that in the future it is capable of building a slightly soluble telescope, a little less stable, but a bright source can be used to maintain stability," says Ewan Douglas. MIT's Aeronautics and Astronautics Department and main paper co-author.

In addition, Kerri Cahoy, along with Assistant Professor of Aeronautics and Astronautics at MIT, James Clark and Weston Marlow, MIT and Jared Males, Olivier Guyon and Jennifer Lumbres, from Arizona University.

In the Red Cross

In more than a century, astronomers use real stars to "stabilize ground-based telescopes".

"If the telescope's motors or gear fail to make the telescope a little faster or slower, you can see a star on your guide with the look of the cross and slowly focus on taking a long exposure," says Douglas.

In the 1990's, scientists began to use serums as a laser star on the ground, and the lasers entered the sky around 40 kilometers of light. The astronomers could have a telescope that allows the telescope to point to the telescope.

"Now we are spreading this idea, rather than pointing a laser on space in the ground, we are shining a telescope in space," says Douglas. The lower telescope requires a coordinate guide to control the effects of the atmosphere, but the space telescopes in exoplanet images must contrast the modifications and minor changes in the system temperature.

Space based laser guide star idea was created by a NASA-funded project. The Agency has designed large and segmented telescopes in space and is aimed at researchers looking to reduce the cost of massive observers.

"This reason is right now to be decided by NASA next year, the large space telescopes will have our priority over the next few decades," says Douglas. "At the time of this decision, the Hubble Space Telescope took its decision in the 1960s, but it was not started in the 1990s."

Star Fleet

The Cahoy Laboratory develops laser communications for use in CubeSats, which can be built in space at a cost of conventional spacecraft and use shoebox-sized satellites in the space.

For this new research, researchers could use a laser-embedded CubeSat or SmallSat lesser than the stability of a large and segmented space telescope for the NASA LUVOIR (UV Optical Infrared Surveyor) after a conceptual design that includes a lot of mirrors that would be mounted in space.

Researchers believe that this telescope must still be still for 10 minutes (with a quarter of a hydrogen atom diameter), an internal coronation must take measures to measure the light of a planet, apart from the star.

"As regards the space field, like a small change in the sun's angle or a part of the change in the number of heat dissipated around the nuclear one, it will cause small structural expansion or contraction," Douglas says. "If you get abuse of around 10 picometers, you start changing the starlight model within the telescope and you can not completely change the changes to reflect the planet's reflective light."

The team created the laser scintillator with a global design that would be far away from a telescope, like a fixed star, about ten miles, which would go back and send the light to the telescope mirrors, each of which would reflect light laser for the camera's embroidering. This camera should reflect the phase of the reflected light over time. The change in 10 picometers or more indicates the commitment to telescope stability. In this way, they can be straightened directly onto the actuators.

In order to see Laser's guide-star design via today's laser technology, Douglas and Cahoy collaborated with United States colleagues with various brightness sources, for example, how bright the laser can provide a specific information on a telescope position or provide stability to the space's large telescopes Using Stability Segment Models. They created some laser transmitter sets and calculated that Laser should be more stable, stable and powerful laser, to act as a trusted driver.

In general, laser-based star designs have been found to exist because of the existence of technology, and the system incorporates SmallSat into a very small capsule footer. As Douglas says, the only driver could follow the "look" of the telescope, while traveling from one star to another, the telescope changes its observational goals. However, a smaller spacecraft would need to travel hundreds of thousands of miles away from the remote telescope when the telescope looks at other stars.

Instead, Douglas could open a small manual fleet for something, because, to stabilize television, it helps you to survey multiple exoplanetary systems. Cahoy has said that the ultimate success of NASA's MarCo CubeSats success, as Mars Knowledge Cape, is evidence of CubeSats's propulsion systems working in interplanetary space, long periods and long distances.

"We are currently looking at existing propulsion systems to correctly calculate it, and how many vessels would be leapfrogging in space," says Douglas. "After all, we believe it is a way to avoid the cost of large space telescopes and the cost of these segments."

Reference: "Laser guide star for segment segments for wide space telescopes I. Implantación de exoplaneo terrestre de detección y observatorio de estabilidad", E. S. Douglas et al., 2019, January 4, Astronomical Magazine. [http://iopscience.iop.org/article/10.3847/1538-3881/aaf385, preprint: https://arxiv.org/abs/1811.05309].

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