Tag: astronomy

Webb’s primary mirror successfully deployed

2:54 pm

Today engineers successfully completed the unfolding of the primary mirror on the James Webb Space Telescope.

The two wings of Webb’s primary mirror had been folded to fit inside the nose cone of an Arianespace Ariane 5 rocket prior to launch. After more than a week of other critical spacecraft deployments, the Webb team began remotely unfolding the hexagonal segments of the primary mirror, the largest ever launched into space. This was a multi-day process, with the first side deployed Jan. 7 and the second Jan. 8.

Mission Operations Center ground control at the Space Telescope Science Institute in Baltimore began deploying the second side panel of the mirror at 8:53 a.m. EST. Once it extended and latched into position at 1:17 p.m. EST, the team declared all major deployments successfully completed.

Next step over the next few months will be aligning the primary mirrors 18 segments with each other as well as the secondary mirror. First science images are expected during the summer, but do not be surprised if NASA releases some test images before then, should all be well and it obtains some eye candy.

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The very first observations of dying star before, during, and after it goes supernova

9:43 am

Astronomers have, for the very first time, observed in real time a dying red supergiant star prior to, during, and after it exploded as a supernova, thus destroying itself and collapsing into either a neutron star or a black hole.

This discovery is unprecedented because previous observations of the star prior to its explosion were discovered post-supernova, when astronomers went back and found it in archival footage. In this case the astronomers were studying the star before it exploded, and thus got a far more detailed look at its behavior.

Prior to this, all red supergiants observed before exploding were relatively quiescent: they showed no evidence of violent eruptions or luminous emission, as was observed prior to SN 2020tlf. However, this novel detection of bright radiation coming from a red supergiant in the final year before exploding suggests that at least some of these stars must undergo significant changes in their internal structure that then results in the tumultuous ejection of gas moments before they collapse.

This data will require the computer modelers and theorists to completely revise their computer models and theories for explaining the ignition of a supernova.

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Webb deploys heat radiator

8:57 am

Engineers today successfully deployed the heat radiator on the James Webb Space Telescope, allowing for unfolding of its 21-foot-diameter primary mirror over the next two days, the final step in the telescope’s deployment.

At about 8:48 a.m. EST, a specialized radiator assembly necessary for Webb’s science instruments to reach their required low and stable operating temperatures deployed successfully. The Aft Deployable Instrument Radiator, or ADIR, is a large, rectangular, 4 by 8-foot panel, consisting of high-purity aluminum subpanels covered in painted honeycomb cells to create an ultra-black surface. The ADIR, which swings away from the backside of the telescope like a trap door on hinges, is connected to the instruments via flexible straps made of high-purity aluminum foil. The radiator draws heat out of the instruments and dumps it overboard to the extreme cold background of deep space.

The whole operation took fifteen minutes.

If all goes well, by Saturday night (January 8th) engineers and scientists will have in their hands the world’s largest infrared telescope, and it will be operating in space. Actual scientific observations however will not begin immediately. It will still take several weeks for the telescope to cool down to the very cold temperatures it needs to see faint infrared objects, and then about five more months of additional testing to precisely align the mirrors while figuring out how the telescope itself operates in space.

We should expect the first raw and unaligned infrared images in about a month, with the first official observations released sometime in the very early summer.

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Webb engineers successfully deploy the telescope’s secondary mirror

2:50 pm

Engineers today confirmed that the secondary mirror for the James Webb Space Telescope has successfully deployed, its tripod structure unfolding and locking into place.

In addition the cover protecting the Mid-Infrared Instrument (MIRI) was successfully unlocked. The instrument’s science team did not open the cover yet because the telescope hasn’t yet cooled enough, its sun shield only in place for a day or so.

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Webb: Sun shield deployment completed

3:32 pm

Engineers today successfully completed the full deployment of the sun shield of the James Webb Space Telescope.

The unfolding and tensioning of the sunshield involved 139 of Webb’s 178 release mechanisms, 70 hinge assemblies, eight deployment motors, roughly 400 pulleys, and 90 individual cables totaling roughly one quarter of a mile in length. The team also paused deployment operations for a day to work on optimizing Webb’s power systems and tensioning motors, to ensure Webb was in prime condition before beginning the major work of sunshield tensioning.

The process took eight days, and was by far the most complex such remote deployment ever attempted by an unmanned spacecraft. The shield is now in place to shade Webb from sunlight and heat and thus allow it to observe very faint infrared objects billions of light years away.

Next comes the deployment of Webb’s secondary mirror, followed by the unfolding of its main mirror.

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Webb deployment resumes, with continuing success

9:50 am

After a day delay to assess the telescope’s earlier operation in space, engineers yesterday resumed the deployment of the James Webb Space Telescope’s sun shield.

First they began tensioning the shield’s first of five layers, completing that operation in about five and a half hours.

Next the engineers proceeded to tighten layers two and three, completing that task in about three hours.

Today they have begun tightening the last two layers. A live stream of this slow and relatively unexciting process (as long as nothing goes wrong) is available from NASA here.

Based on what has been done so far, it appears that the deployment of the sun shield, considered the most challenging part of Webb’s deployment, is going to complete successfully. While the unfolding and deployment of the mirror still must be done, getting the sun shield deployed eliminates one of the great concerns that has kept both astronomers and engineers awake nights for decades.

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The unfurling of Webb’s sun shield begins

5:18 pm

Engineers have begun the multi-day unfurling and deployment of the sun shield on the James Webb Space Telescope.

The first step is to deploy two booms on each side of the telescope that draw the shield itself outward.

The deployment of the first boom was held up several hours to give engineers time to make sure the protective covers had, in fact, rolled off to the side of the sunshade pallets as required.

“Switches that should have indicated that the cover rolled up did not trigger when they were supposed to,” NASA said in a blog post. “However, secondary and tertiary sources offered confirmation that it had.”

“The deployment of the five telescoping segments of the motor-driven mid-boom began around 1:30 p.m., and the arm extended smoothly until it reached full deployment,” NASA said.

Engineers then sent commands to deploy the second sunshade boom, which extended smoothly and locked in place at 10:13 p.m., finally giving Webb its iconic kite-like shape.

Next the shield has to be tightened in place, which will also separate and tighten in place the shield’s five layers. According to the schedule, the four layers will be tensioned today, with the fifth tomorrow.

The step-by-step deployment is outlined in detail here, and updates to the most recently completed step after it is finished.

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1st stage of Webb sun shield deployment completed

9:29 am

The deployment of the forward and aft pallets required to support the sun shield for the James Webb Space Telescope has apparently been successfully completed.

The link takes you to the website that outlines each step in Webb’s entire 30-day deployment sequence, and is updated to show you the next required step as the process continues. Though I have yet to see any official announcement, this page now shows that both pallets have successfully unfolded and that the next step is removal of the covers that have protected the sun shield membrene during assembly and launch.

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Deployment of Webb’s critical sunshield has begun

9:03 am

The deployment of the complex sunshield for the James Webb Space Telescope has successfully begun, and if all continues as planned, will continue for the next five days.

Early this afternoon the Webb mission operations team concluded the deployment of the first of two structures that hold within them Webb’s most unpredictable and in many ways complicated component: the sunshield.

The structures – called the Forward and Aft Unitized Pallet Structures – contain the five carefully folded sunshield membranes, plus the cables, pulleys, and release mechanisms that make up Webb’s sunshield. The team completed the deployment of the forward pallet at approximately 1:21 p.m. EST, after beginning the entire process about four hours earlier. The team will now move on to the aft pallet deployment.

Over the next five days the aft pallet must be deployed, along with a tower assembly that will raise the telescope itself away from the sunshield to better keep Webb cold. After this the deployment of the many additional parts of the shield will take place, a process that is probably the most complex in-space spacecraft deployment ever.

It is good news that so far all is proceeding as planned, and gives hope that all will continue to do so.

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Webb: Course correction burn and main antenna deployment both a success

2:11 pm

Over the weekend engineers for the James Webb Space Telescope successfully completed a course correction burn that put the telescope on route to is planned location a million miles from Earth.

They also successfully deployed the telescope’s main antenna.

Other steps completed on Webb’s first full day in space included the switch-on of temperature sensors and strain gauges on the telescope, used for monitoring Webb’s thermal and structural parameters, NASA said. The antenna release and first mid-course correction burn set the stage for the next step of Webb’s post-launch commissioning — the deployment and tensioning of the observatory’s tennis court-sized sunshield.

These next steps are likely the most risky part of the telescope’s deployment, as it involves the most moving parts and is the most complex. While similar such unfoldings have been done successfully many times before, they have also been the very prone to failure.

The sunshield must work however for Webb to operate. As an infrared telescope, it essentially detects heat, and if it is not well shielded from sunlight its images will be fogged.

The deployment is presently set to begin tomorrow.

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Webb successfully launched

8:13 am

Early this morning an Ariane 5 rocket successfully launched the James Webb Space Telescope from French Guiana.

The key moment that indicated the launch was success was, after Webb was deployed from the rocket’s upper stage, its solar panels deployed and the telescope began receiving power from them.

The launch itself was something that has been done by the Ariane 5 rocket many many times, without failure. Now comes the part of this operation that has never been done before.

Now “30 days of terror” begin, as JWST starts its career in space. First, it will take the space telescope 30 days to reach the start of its halo orbit at L2. On its way, the telescope must unfurl its 18 gold-plated beryllium mirror segments using 132 actuators. It will also have to deploy its five-layer, origami sunshield and cool down to below 50K (-223°C or -370°F) to begin the start of science operations in 2022.

NASA has a webpage that shows the step-by-step deployment, and allows you to see the status at any time during the next 30 days.

After almost twenty years of development and a budget that went 20x over its original estimate, let’s us all hope that Webb deploys properly and begins collecting data as intended. If it does, it will allow astronomers to make ground-breaking discoveries, and we shall gain a better idea of what lies hidden behind that black sky that surrounds us.

As for the 2021 launch race, this is the updated leader board:

49 China
31 SpaceX
22 Russia
7 Europe (Arianespace)

China will likely be the winner in the national rankings, 49 to 48 over the U.S. This was the 130th successful launch in 2021, only the second time in the history of space exploration that the world reached that number of launches in a single year.

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Webb telescope reaches launchpad on Ariane 5 + how to watch launch

9:14 am

The James Webb Space Telescope, stacked on top of Arianespace’s Ariane 5 rocket, has finally reached its launchpad in French Guiana after twenty years of development costing 20 times its original budget.

The launch itself is now scheduled for December 25, 2021 at 7:20 am (Eastern). It will be live streamed by both NASA (in English) and Arianespace (with options in English, French, or Spanish).

I have embedded below NASA’s feed. As always, expect NASA to pump you with lots of propaganda during its live stream.

When all is said and done, Webb has the chance to show us things about the universe we’ve never seen before. Optimized for deep space cosmology, it will provide us a window into the earliest moments of the universe’s existence. And is infrared capabilities will allow it to peer into many nearer places obscured by dust with a resolution unmatched by previous telescopes.

Keep your fingers crossed all goes as planned.
» Read more

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Astronomers detect 70 to 170 free floating exoplanets

11:03 am

The uncertainty of science: Astronomers today announced that they think they have detected from 70 to 170 exoplanets in a nearby star-forming region that are apparently free-floating, unattached to any star or solar system.

The astronomers also combined the vast number of images available in public astronomical archives with the new deep wide-field observations obtained with the best infrared and optical telescopes on the ground and in space. Using over 80,000 wide-field images adding up to around 100 terabytes and spanning 20 years, they identified at least 70, and up to as many as 170 of these Jupiter-sized planets, as members of the Upper Scorpius association among the background stars and galaxies.

If confirmed, this discovery more than doubles the number of free-floating planets known.

The discovery was made by first using the motion of the stars to pinpoint which ones belonged to the Upper Scorpius star-forming region. The astronomers then compared this data with past archival telescopic images.

Though intriguing, a great deal of skepticism of this discovery is required. The press release is very vague about some points. For example, no explanation is given on how they measured the mass of these objects to determine they were Jupiter-sized.

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ESA delays Webb launch one day due to weather

8:41 am

The European Space Agency (ESA) announced late yesterday that, due to “adverse weather conditions” in French Guiana, it has delayed the launch of the James Webb Space Telescope on an Ariane 5 rocket one day to December 25th.

The announcement also stated that the final launch readiness review also approved the launch, though no update has yet been issued on the ground control communications problem that had caused a two day delay last week.

Meanwhile, this story and its headline encapsulates the terror I think many astronomers presently feel about this telescope:

Why Astronomers Are “Crying and Throwing Up Everywhere” Over the Upcoming Telescope Launch

The sense is one of helpless panic among astronomers who want to use Webb. They know it will do really cutting edge science, but they also know that many things can go wrong, and the history of the telescope (ten years late and 20x overbudget) will likely make replacing it impossible.

And many things can go wrong. Below is NASA’s video showing the telescope’s complex unfolding, step-by-step, after launch.
» Read more

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Webb launch confirmed for December 24, 2021

9:01 am

Ten years late and twenty times over budget the European Space Agency (ESA) yesterday confirmed that the launch of NASA’s infrared James Webb Space Telescope is now scheduled for December 24, 2021.

The ESA announcement is only a couple of sentences long, and does not mention if engineers had solved the intermittent ground communications issue with the telescope. Further tweets from ESA and NASA also said nothing about the communication issue.

A final readiness review is set for December 21st where a final launch decision will be made.

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Webb launch delayed two days because of ground equipment issue

9:42 pm

After engineers at Arianespace’s French Guiana launch facility found an intermittent issue with ground equipment related to the Ariane 5 rocket launching the James Webb Space Telescope, it was decided to delay the launch two days to make sure the problem was resolved.

n a brief statement, NASA wrote on its website late Tuesday that the Webb team is “working a communications issue between the observatory and the launch vehicle system.”

Thomas Zurbuchen, associate administrator for NASA’s science mission directorate, said Tuesday that engineers found an “interface problem” in a system that communicates with Webb while it’s on top of the Ariane 5 rocket. “The way to think about it is it’s a ground support equipment thing,” Zurbuchen said Tuesday night in an interview with Spaceflight Now. “Basically, the data cables are dropping some frames.”

Technicians inside the Ariane 5 rocket’s final assembly building in Kourou have tried to diagnose the problem, but so far, haven’t been able to resolve it.

The December 24th target day date remains tentative, and could slip to December 25th, or even later, depending on how successful engineers are at fixing the issue.

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99.9% of all mass at center of Milky Way is found in central black hole

10:46 am

New measurements of the orbits of several stars circling the Milky Way’s central supermassive black hole, Sagittarius A* (pronounced A-star), have confirmed that 99.9% of all mass at the galaxy’s center is concentrated in that black hole.

Astronomers have measured more precisely than ever before the position and velocity of four stars in the immediate vicinity of the supermassive black hole that lurks at the center of the Milky Way, known as Sagittarius A* (Sgr A*) [1]. These stars — called S2, S29, S38, and S55 — were found to be moving in a way that shows that the mass in the center of the Milky Way is almost entirely due to the Sgr A* black hole, leaving very little room for anything else.

The measurements, which further refine the mass of Sagittarius A* as 4.3 million times the mass of the Sun, show that very little of this mass is found in the surrounding space as gas or dark matter. It is all in the black hole, which might also help explain why the Milky Way’s central black hole is so quiescent. It has very little gas or other stars to feed it and thus produce emissions.

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Conflict in Hubble constant continues to confound astronomers

9:56 am

The uncertainty of science: In reviewing their measurements of the Hubble constant using a variety of proxy distance tools, such as distant supernovae, astronomers recently announced that their numbers must be right, even though those numbers do not match the Hubble constant measured using completely different tools.

Most measurements of the current acceleration of the universe (called the Hubble constant, or H0) based on stars and other objects relatively close to Earth give a rate of 73 km/s/Mpc. These are referred to as “late-time” measurements [the same as confirmed by the astronomers in the above report]. On the other hand, early-time measurements, which are based on the cosmic microwave background emitted just 380,000 years after the Big Bang, give a smaller rate of 68 km/s/Mpc.

They can’t both be right. Either something is wrong with the standard cosmological model for our universe’s evolution, upon which the early-time measurements rest, or something is wrong with the way scientists are working with late-time observations.

The astronomers are now claiming that their late-time observations must be right, which really means there is either something about the present theories about the Big Bang that are fundamentally wrong and that our understanding of early cosmology is very incomplete, or the measurements by everyone are faulty.

Based on the number of assumptions used with both measurements, it is not surprising the results don’t match. Some of those assumptions are certainly wrong, but to correct the error will require a lot more data that will only become available when astronomers have much bigger telescopes of all kinds, in space and above the atmosphere. Their present tools on Earth are insufficient for untangling this mystery.

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SpaceX launches NASA X-ray telescope

9:17 am

Capitalism in space: SpaceX early this morning successfully launched NASA’s Imaging X-ray Polarimetry Explorer (IXPE), a small X-ray telescope designed to black holes and neutron stars.

The first stage, making its fifth flight, successfully landed on a drone ship in the Atlantic.

This launch, SpaceX’s 28th for 2021, extends once again the company’s all time record for the most launches in a year by a private company.

The leaders in the 2021 launch race:

46 China
28 SpaceX
21 Russia
6 Europe (Arianespace)
5 ULA
5 Rocket Lab

China’s lead over the U.S, in the national rankings has now shrunk to 46 to 45. The launch was the 121st in 2021, making this year tied as the seventh most active year in the history of space, a ranking that is sure to go up before the end of the year.

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Hubble resumes full science operations

2:35 pm

Engineers have now successfully reactivated the Hubble Space Telescope’s second spectrograph, so that the telescope is now fully operational for the first time since it went into safe mode on October 25th.

NASA’s Hubble Space Telescope team recovered the Space Telescope Imaging Spectrograph on Monday, Dec. 6, and is now operating with all four active instruments collecting science. The team has still not detected any further synchronization message issues since monitoring began Nov. 1.

The team will continue work on developing and testing changes to instrument software that would allow them to conduct science operations even if they encounter several lost synchronization messages in the future. The first of these changes is scheduled to be installed on the Cosmic Origins Spectrograph in mid-December. The other instruments will receive similar updates in the coming months.

Essentially, they are modifying the telescope’s software so that it will not shut down should it “encounter several lost synchronization messages.” As the engineers have never fully explained this issue, I suspect this is a work-around to ignore an issue that in the past they would have taken more seriously. Now they are doing a cost-benefit analysis, and have decided that ignoring some of these messages is better than fixing them. It might even be impossible to do so.

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