[ad_1]
NASA's Hubble Space Telescope, famous for its brilliant images of the cosmos, has problems in orbit around the Earth. Friday, an important mechanism on the spaceship failed – a necessary tool to reorient the observatory in the space and keep it oriented to parts of the sky for long periods. Now, Hubble is in safe mode while the engineers are trying to solve the problem.
The broken mechanism on Hubble is a gyroscope or a gyroscope. It is a device that many spacecraft use to change their orientation in space. Gyroscopes are basically wheels inside the vehicle that rotate, which changes the position of the spacecraft. It is an essential tool that Hubble uses to change direction and look at different places in the Universe, to observe stars, exoplanets, supernovae, etc.
Hubble, which was launched in 1990, was originally built with six gyroscopes. At least three of these spacecraft must function to function effectively. Over the years, Hubble's gyroscopes have run into problems and many have failed. At one point, in 1999, there were so many that the telescope could no longer make scientific observations for a few weeks. But during the space shuttle program, astronaut crews were able to visit Hubble periodically and replace the gyroscopes. The last Hubble maintenance mission took place in May 2009, during which time the six gyroscopes were replaced.
Before Friday's failure, Hubble still had four gyroscopes in motion, confirmed NASA The edge. But after the latest, the Hubble team tried to put back one of the four, which had been out of order for a while, according to a series of tweets by Rachel Osten, Hubble at the Space's Assistant Chef de Mission. . Institute of Telescope Sciences. However, this other gyro turns out "problematic," she says. If it can not come back online, it means that Hubble has more than two gyroscopes in operation. It's not ideal.
It's not a difficult decision, @astrogrant: the plan has always been to switch to 1 gyroscope mode when there are two left. There is not much difference between 2 and 1, and it saves a lot of observation time. What the astro community desperately wants.
– Dr. Rachel Osten (@ rachelosten) October 8, 2018
The situation is not a cause of despair for the moment. Previously, Hubble engineers had imagined a way to run the spacecraft with only two gyroscopes to extend Hubble's life. In addition, NASA says the Hubble team expected this gyroscope to fail for about a year. If the problem gyro does not come back online, the engineers have a plan that will allow the Hubble to operate with at least one gyroscope. She says that there is not much difference between operating with two gyroscopes and a gyroscope; both modes can still allow astronomers to observe the sky and do valuable scientific work.
In the end, putting this gyroscope into service would be the best scenario. And time is crucial, because Hubble can not do any science in safe mode. Meanwhile, all the instruments of the spacecraft are stopped, while only the most essential systems for the proper functioning of the vehicle remain activated.
To repair Hubble, you need a repair team trained in a mid-level LEO with a spaceship having two weeks + flight duration, numerous tool docking, airlock, robotic arm . We had a few but none now or on the horizon. #saveHST
– Wayne Hale (@waynehale) October 8, 2018
Still, this is not the end for Hubble yet. This spaceship overcame worse situations in the past; When the observatory was launched for the first time, the engineers quickly realized that the main mirror of the spacecraft had a defect that prevented the telescope from getting the sharp images for which it was designed. Although the mirror was eventually replaced, Hubble failed for three years to capture the sharp and astonishing images for which he is now known.
Today, there is no option to replace the failed hardware on Hubble. The telescope was designed to be serviced by space shuttle crews. There is currently no vehicle to bring astronauts to the observatory and repair it in orbit. Some considered sending a robotic spacecraft to Hubble's service, but none succeeded, with some plans deemed unachievable. Last year, the the Wall Street newspaper announced that the Trump administration was planning to send a crew to Hubble aboard a commercial spacecraft called Dream Chaser, developed by the Sierra Nevada Corporation. However, such a flight has not been officially recognized and no updates have been made since the first flight. WSJ report.
Unless a concrete plan is established to send a new spacecraft to Hubble for repair, the telescope will eventually become unusable if all its gyroscopes fail. And even if they stay active, Hubble will eventually fall. The telescope is in orbit, about 350 km, but its trajectory decays with time, thanks to the small particles coming from the upper Earth's atmosphere that bombard the spacecraft and pull it towards our planet. In addition, Hubble also has no onboard thrusters, so it can not propel itself into a higher orbit. According to Space.com, most models show that Hubble will naturally come back to Earth in the 2030s. This is a bit worrisome because its primary mirror could survive the fall, even though most of them will probably burn so much. harmless.
But rather than dropping it by itself, NASA has the opportunity to guide Hubble's descent into a safe zone on Earth – perhaps on the ocean. During the last Hubble maintenance mission, the astronauts installed a mechanism on the spacecraft that could allow future vehicles, whether equipped or unarmed, to end up with the telescope and be moored at the port. These vehicles could then potentially drag Hubble out of his orbit, sending him into a fiery dive into the Earth's atmosphere where he has no chance to hurt anyone. However, no plan has been planned for this desorbite.
As Hubble approaches the end of its life, NASA is working to send the successor of the telescope into space. In 2021, the space agency plans to launch a new giant observatory called James Webb Space Telescope. While the spacecraft has suffered many delays and cost overruns, the JWST will be even more powerful than Hubble at launch, able to observe galaxies and stars formed shortly after the Big Bang. However, JWST will remain about 1 million miles from Earth and there is no plan to repair the telescope once in space. If something breaks on JWST, engineers will have to repair it from Earth (if possible).
Meanwhile, Hubble should still have a valuable observation time. The telescope is known for many revolutionary discoveries. He helped astronomers understand how fast our universe grew and captured images of planets outside our solar system. I hope Hubble will still have a little more science once it will come out of safe mode.
[ad_2]
Source link