Impact of space station spin requires study, official says

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New York Post 04 August, 2021 - 02:10pm 75 views

Moment Russia's Pirs module breaks up the atmosphere after leaving ISS

Daily Mail 04 August, 2021 - 08:43am

Astronaut Thomas Pesquet watched from the International Space Station as Russia's Pirs module was discarded on June 26 and raced towards its death in Earth's atmosphere.

The stunning video shows Pirs break up into a 'shooting star' and slowly disappearing into a sea of ominous clouds hanging over our planet.

'Atmospheric reentry without a heat shield results in a nice fireball,' Pesquet wrote in a Facebook post, which also included a French description.

'You clearly see smaller pieces of melting metal floating away and adding to the fireworks.'

Although the video was sped up, Pesquet and a few other crew members watched Pirs break up above the clouds for six minutes.

'Next time you see a shooting star, it might be our ISS trash getting burnt up… Not sure it will be granted in that case, but you never know, I'd still advise to go ahead and make a wish, Pesquet joked in the post.

Scroll down for video 

The 16-foot-long by 8-foot-diameter Pirs began its decent into Earth's atmosphere at 10am EST after 20 years of service on the ISS, Space.com reported.

The module provided the ISS with a docking port for spacecraft, along with an airlock for astronauts to conduct spacewalks.

The removal of the module was to make room for Russia's 22-ton Nauka Multipurpose Laboratory Module, or Nauka for short, which docked with the ISS on June 29. 

Nauka, which means 'science' in Russian' launched on July 21 atop a Russian Proton rocket. This rocket also carried the new European Robotic Arm, or ERA, a 16-foot-long two-handed robot that can move freely outside of the ISS.

After eight days in free-flight, the uncrewed 43-foot-long module linked up to the port on the Earth-facing Russian segment of the ISS.

Nauka will be a new science facility, docking port and spacewalk airlock for future operations, along with providing additional crew quarters, a galley and a toilet. 

However, the new module experienced a software glitch about three hours after docking, which inadvertently fired its thrusters about three hours after making contact with the massive ship.

NASA released new details today, saying the ISS backflipped and was left upside down when Nauka's jet thrusters misfired.

The American space agency had previously said the ISS had moved out of its attitude – its orientation in relation to its direction of travel – by 45 degrees, or one-eighth of a complete circle.

However, the flight director who was in charge at the time has since revealed this was 'a little incorrectly reported' and the actual figure was closer to 540 degrees.

This means the ISS performed 1.5 backflips when it was sent spinning and required a 180-degree forward flip to regain its original position.

The station's position is key for getting power from its solar panels.

If this was lost, the ISS would 'decay', meaning it would get closer and closer to Earth before it came crashing down.

EarthSky | The Nauka module mishap that sent ISS tumbling

EarthSky 04 August, 2021 - 07:45am

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The new Russian research module Nauka successfully docked with the International Space Station (ISS) late last week (July 29). But Nauka accidentally fired its thrusters, sending the space station into a spin. ISS briefly lost what pilots and engineers call attitude control. At first, NASA said on Twitter that ISS had tilted about 45 degrees. Later, it became clear the situation was more severe than NASA had initially reported. A NASA official told the New York Times on August 2:

That’s been a little incorrectly reported.

That statement came from Zebulon Scoville, the flight director who led NASA’s Mission Control center in Houston, Texas, during the July 29 tumbling event. In his Times interview, Scoville described how the ISS spun 1 1/2 revolutions – about 540 degrees – before coming to a stop upside down. The space station then did a 180-degree forward flip to get back to its original orientation.

NASA officials reportedly confirmed the accuracy of Scoville’s statements with Space.com. To provide insight into where “45 degrees” came from, one representative said:

The 45-degree number was initially offered in the first minutes after the event occurred by our guidance, navigation and control officer in Mission Control, but was later updated following an analysis of the actual divergence.

Nauka – which means “science” in Russian – is Russia’s Multipurpose Laboratory Module. The 23-ton module adds a laboratory, additional sleeping quarters and other capabilities to the Russian segment of ISS. Following its July 21 launch, it reportedly encountered some propulsion problems that Russian controllers were able to resolve ahead of its planned docking with ISS. Then came a successful docking, and all seemed well, until the unexpected thruster firing. In a July 30 statement, Roscosmos – Russia’s space agency – said that a software glitch on Nauka was at the heart of the problem. The glitch caused:

… a direct command was given to fire the module’s engines.

Zebulon Scoville told the New York Times that a caution warning came soon after Nauka’s docking. It was 11:34 a.m. Houston time (16:34 UTC) on July 29. Initially, he thought that the prompt, just two lines of code, might have been a mistake. But NASA controllers quickly discovered that Nauka was doing more than firing. It was trying to pull away from the station it had docked with just moments ago.

Scoville said:

At first, I was like, ‘Oh, is this a false indication?’ And then I looked up at the video monitors and saw all the ice and thruster firings. This is no kidding. A real event. So let’s get to it.

The NASA team had no control over Russia’s Nauka module. The module can receive direct commands only from a ground station in Russia. And, in the moments after the unexpected thruster firing, the next pass over Russia was more than an hour away.

It took 45 minutes for mission controllers in Houston to get ISS back under control. They called on the seven astronauts aboard the station for help. Led by Scoville, the ISS astronauts and NASA ground controllers worked to counteract Nauka’s thrusters. To balance the tilt, they counter-fired thrusters on the Russian module Zvezda and the Progress cargo ship.

As it turned out, after about 15 minutes of fire, Nauka’s thrusters shut off. Scoville says he doesn’t know why they shut off. But it was NASA’s countermeasures that enabled the station to return to a stable orientation.

Scoville added:

After doing that backflip 1 1/2 times around, it stopped and then went back the other way.

NASA held a news conference following the dramatic event to discuss what happened. According to Scoville, the ISS reached a maximum rotation rate of 0.56 degrees per second. The crew members on board, space station manager Joel Montalbano said, were never in any immediate danger during any time of the lost attitude control:

Those numbers representing the change in attitude are correct. We’d reiterate that the maximum rate at which the change occurred was slow enough to go unnoticed by the crew members on board, and all other station systems operated nominally during the entire event.

Scoville has echoed this same testimony and agreed that the safety of the astronauts was never at risk. Moreover, despite the unexpected scare Nauka caused, he wanted to reaffirm his faith in NASA’s partnership with its Russian colleagues. Specifically, he told the New York Times:

I have complete confidence in the Russians. They are a fantastic partnership with NASA and the entire International Space Station program.

Bottom line: Shortly after docking with the International Space Station on July 29, Russia’s new Nauka module accidentally fired its thrusters, sending the space station into a spin.

Impact of space station spin requires study, official says

Gizmodo 04 August, 2021 - 06:15am

MOSCOW (AP) — Space engineers will analyze whether a glitch that caused the International Space Station to spin out of its normal orientation could have impacted any of its systems, a Russian space official said Wednesday.

Sergei Krikalev, the director of crewed space programs at the Russian space corporation Roscosmos, emphasized that last week’s incident did not inflict any observable damage to the space station but he said that experts would need to study its potential implications.

“It appears there is no damage,” Krikalev said in an interview broadcast by Russian state television. “But it’s up to specialists to assess how we have stressed the station and what the consequences are.”

NASA emphasized Wednesday that the station was operating normally and noted that the spin was within safety limits for its systems.

Thrusters on Russia’s Nauka laboratory module fired shortly after the module arrived at the International Space Station on Thursday, making the orbiting outpost slowly spin about one-and-a-half revolutions. Russia’s mission controllers fired thrusters on another Russian module and a Russian cargo ship attached to the space station to stop rotation and then push the station back to its normal position.

Both U.S. and Russian space officials said the station’s seven-person crew wasn’t in danger during the incident.

The station needs to be properly aligned to get the maximum power from solar panels and to maintain communications with space support teams back on Earth. The space station’s communications with ground controllers blipped out twice for a few minutes on Thursday.

NASA said in a tweet Tuesday that the station was 45 degrees out of alignment when Nauka’s thrusters were still firing and the loss of control was discussed with the crew. “Further analysis showed total attitude change before regaining normal attitude control was (tilde)540 degrees,” NASA said.

On Wednesday, NASA noted that “continued analysis following last week’s event with unplanned thruster firings on Nauka has shown the space station remains in good shape with systems performing normally.”

“Most importantly, the maximum rate and acceleration of the attitude change did not approach safety limits for station systems and normal operations resumed once attitude control was regained,” it said.

Roscosmos’ Krikalev, a veteran of six space missions who spent a total of 803 days in orbit, noted Wednesday that firing orientation engines created a dynamic load on the station’s components, making a thorough analysis of whether some of them could be overstressed necessary.

“The station is a rather delicate structure, and both the Russian and the U.S. segments are built as light as possible,” he said. “An additional load stresses the drivers of solar batteries and the frames they are mounted on. Specialists will analyze the consequences. It is too early to talk about how serious it was, but it was an unforeseen situation that requires a detailed study.”

Krikalev said Nauka’s engines fired because a glitch in the control system mistakenly assumed that the lab module hadn’t yet docked at the station and activated the thrusters to pull it away.

The launch of the 22-ton (20-metric-ton) module has been repeatedly delayed by technical problems. It was initially scheduled to go up in 2007, but funding problems pushed the launch back, and in 2013 experts found contamination in its fuel system, resulting in a long and costly replacement. Other Nauka systems also underwent modernization or repairs.

Nauka is the first new compartment for the Russian segment of the International Space Station since 2010, offering more space for scientific experiments and room for the crew. Russian crew members will have to conduct up to 11 spacewalks beginning in early September to prepare it for operation.

The space station is currently operated by NASA astronauts Mark Vande Hei, Shane Kimbrough and Megan McArthur; Oleg Novitsky and Pyotr Dubrov of Roscosmos; Japan Aerospace Exploration Agency astronaut Akihiko Hoshide and European Space Agency astronaut Thomas Pesquet.

In 1998, Russia launched the station’s first compartment, Zarya, which was followed in 2000 by another big piece, Zvezda, and three smaller modules in the following years. The last of them, Rassvet, arrived at the station in 2010.

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