Starship reaches orbit with 26 Starlink satellites, but SpaceX steers its new booster into the sea instead of catching it

The stories

16 on this beat today.

Every story told the same way: what happened, who is involved, why it matters, how it works, the truth and the good news.

1. 01

   Starship reaches orbit with 26 Starlink satellites, but SpaceX steers its new booster into the sea instead of catching it

   26

   Starlink satellites the Ship released in orbit

   over 42 minutes, starting 35 minutes after launch [1]

   22.5 hours

   planned length of the flight, from launch to catch

   the Ship circles Earth 14 times first [4]

   3

   boosters SpaceX has caught, all of an older version

   it has flown 2 of them again [1]

   10,000

   Starship launches a year Musk is aiming for by 2030

   Starship flew 5 times in all of 2025 [9]

   What happened

   • SpaceX launched the 15th test flight of Starship from Texas at 22:47 UTC on Friday. [1] Starship is the biggest rocket ever built. [8]
   • Its top half, called the Ship, reached orbit and let go of 26 Starlink internet satellites. [1]
   • SpaceX had planned to catch the bottom half, the Super Heavy booster, with arms on its launch tower. [4]
   • Instead the booster was steered out to sea, and it burst into flames as it came down. [4]
   • SpaceX will decide in orbit whether to try to catch the Ship itself on Saturday, something it has never done. [4]
   • The Ship's engines parked it in orbit about 275 km up, 26 minutes after launch. [1]
   • It is only the second Starship to reach orbit, after Flight 14 on 28 September. [1]
   • Some of the satellites carry cameras to photograph the Ship's heat shield. [1] Those pictures help SpaceX decide whether the Ship can come home to Texas. [1]
   • SpaceX has caught 3 boosters before, all of an older version, but never one of the new, bigger kind. [1]
   • Of the new kind, Flight 12's booster was lost, Flight 13's exploded and Flight 14's was destroyed on purpose. [2]
   • 'Not sure right now why we weren't able to bring it back,' SpaceX's Dan Huot said. [12]
   • A SpaceX spokesperson said safety comes first while the company tests moves it has never done before. [4]
   • The Ship is due to circle Earth 14 times and return to the tower 22.5 hours after launch. [4]
   • SpaceX built in 3 checkpoints where it can end the flight early. [1] Those would bring the Ship down off Hawaii or Chile. [13]
   • To get home, the Ship must fly over northern Mexico and southern Texas, its first return over inhabited land. [9]
   • Its flaps steer it away from bigger towns. [2] As a last resort, controllers can tumble it so it breaks up and burns up. [2]
   • Falcon 9 already lands and reuses its bottom stage, and that has cut the cost of launching sharply. [4]
   • 'We still throw that second stage away every single flight,' said Kiko Dontchev, SpaceX's vice president of launch. [11]
   • Catching both halves would be the first full recovery of a rocket that reaches orbit, SpaceX says. [9]

   Who is involved

   SpaceX, Elon Musk's rocket company, flew 165 Falcon 9 rockets in 2025. [9] That was about half of the world's orbital flights. [9]

   NASA, the US space agency, is paying SpaceX billions of dollars to land astronauts on the Moon with Starships. [11]

   The FAA, the US aviation regulator, issued the launch licence only hours before liftoff. [7]

   • NASA the US space agency; it is paying SpaceX billions to land astronauts on the Moon with Starship
   • SpaceX Elon Musk's rocket company, which builds Starship and runs Starlink; it flew Flight 15
   • The FAA the US aviation regulator; it approved the launch a few hours before liftoff
   • Blue Origin Jeff Bezos's rocket company, NASA's other Moon-lander maker; its rocket's return is delayed to early 2027

   How it unfolded

   1. Friday launch, booster lost
   2. Saturday a first try to catch the Ship
   3. 28 Sep Flight 14 becomes the first Starship to reach orbit [1]
   4. Friday Flight 15 reaches orbit
   5. Flight 12 booster lost
   6. Flight 13 booster explodes
   7. Flight 14 booster destroyed on purpose
   8. Saturday last checks in orbit
   9. Sat 21:15 UTC planned try to catch the Ship at the tower [3]
   10. Fri 22:47 UTC Flight 15 lifts off from Starbase, Texas [1]
   11. 6.5 min later the booster splashes down in the Gulf instead of being caught [1]

   Why it matters

   Astronauts on NASA's Artemis III flight are due to practise docking with a Starship in Earth orbit next summer. [11]

   A Moon landing by astronauts could follow as early as 2028. [11]

   Starship is also how SpaceX plans to launch its new Starlink satellites. [9] They are too big to fly well on Falcon 9. [9]

   Think it through

   1. 1

      Why go to the trouble of catching a rocket?

      Catching both halves at the launch mount cuts the time to check, repair and fly them again, SpaceX says. [10]

      Catch at the pad→Quick checks and repairs→Fly again sooner
   2. 2

      Who needs that many launches?

      SpaceX itself: Musk says it is aiming for about 10,000 Starship launches a year by 2030. [1] It wants them to build giant fleets of its own satellites. [9]

      10,000Starship launches a year Musk is aiming for

   3. 3

      How far is it from that today?

      Starship flew 4 times in 2024 and 5 times in 2025. [9] Its Texas site is allowed 25 launches a year. [9]

      Flights in 20244 launches

      Flights in 20255 launches

      Allowed each year in Texas25 launches
   4. 4

      Who is paying for all this?

      SpaceX has put in at least $15 billion of its own. [12] NASA is paying it billions more for the Moon landings. [11]

      SpaceX's own money$15 billion+

      ++

      NASA's lander dealbillions more
   5. 5

      So was losing the booster a failure?

      Not for the flight's main job: all 26 satellites reached orbit. [3] It was a miss for reuse, the thing SpaceX most needs to show next. [3]

      Main job26 of 26 delivered

      vsvs

      Reusebooster lost
   6. 6

      Who else is building a fleet like Starlink?

      Amazon is, with its Leo network. [16] A Vulcan rocket is due to launch 40 more of its satellites on Saturday. [16]

   7. 7

      So what is really going on?

      NASA has tied its 2028 Moon landing to Starship and to Blue Origin's lander. [4] So how fast Starship's tests go bears directly on NASA's Moon plans. [4]

      Starship testsset the pace

      ↓→

      NASA's Moon landing2028 at the earliest

   How it works

   Engineers call hot gas leaking into the gaps between heat-shield tiles heat incursion. [3]

   Flat tiles on a round hull leave corners and gaps where hot gas gets in. [2] The Ship's curved tiles follow the hull and seal those gaps. [2]

   Seen it before

   Tiles laid on a bumpy floor leave gaps, and water from a spill seeps in underneath.

   The truth

   • What is really going on Starship can now reach orbit and deliver a load of satellites. [3]What SpaceX's plans need next, a new booster caught and flown again, has not happened yet, and SpaceX had not said why this one went into the sea. [1][6]
   • Musk told investors success on this flight was 'more likely than not'. [9] No Ship has ever been caught to check that against. [10]
   • SpaceX had not said why it sent the booster to sea, though it usually explains quickly. [6]
   • Who pays People in the Rio Grande Valley in south Texas — They will hear a sonic boom as the Ship slows below the speed of sound over them on its way home. [2]
   • Who pays Air travellers between Hawaii and the US west coast — Their flights were briefly paused on Friday because of debris from the launch, Hawaii's transport agency said. [5]
   • Nobody knows yet

     Whether SpaceX tries to catch the Ship on Saturday, and whether it works.

     The last go or no-go point comes about 20 hours and 41 minutes into the flight, after this edition was written. [2]

   What comes next

   If all goes well, the Ship returns to the tower at about 21:15 UTC on Saturday. [3]

1. 02

   Vulcan's return slips a day

   What happened

   • United Launch Alliance (ULA), a US rocket company, put off its Vulcan rocket's return to flight by one day. [16] Vulcan replaces ULA's older Atlas V rocket. [17]
   • A power cut at an Air Liquide nitrogen plant knocked out the pumps that supply the launch site. [16]
   • Vulcan has not flown for 9 months. [16] A booster nozzle failed on 2 of its first 4 flights. [16]
   • After the second failure, the US Space Force stopped flying its own missions on Vulcan. [16]
   • This flight carries 40 satellites for Leo, Amazon's internet network, the first of 38 Vulcan launches Amazon has bought. [16]

   How it unfolded

   1. Friday scrubbed by the power cut
   2. Sat 17:32 UTC the next try

   Why it matters

   The Space Force wants to see this flight's data before it decides whether to fly Vulcan again. [16]

   Think it through

   1. 1

      Why does Amazon need Vulcan so badly?

      Amazon has about 400 Leo satellites in orbit. [16] SpaceX has more than 11,000 Starlinks. [16]

      Satellites in orbit

      Amazon Leo400

      SpaceX Starlink11,000
   2. 2

      Has the nozzle fault been fixed?

      ULA found 3 possible causes and changed how the nozzle is designed and built. [16]

      3 of 3

      possible causes found

   3. 3

      Why fly before the investigation ends?

      'Every flight generates data and every flight teaches us something,' said Mark Peller, who runs ULA. [16]

   How it works

   Rocket engineers call a gas that flushes and fills a rocket's pipes before launch a purge gas.

   At Vulcan's pad, nitrogen purges and pressurises the rocket's systems. [16] Without a steady supply confirmed, the team moved to the backup day. [16]

   Seen it before

   A car wash cannot open when its water is cut off, however ready the cars are.

   Why a rocket's success rate means little until it has flown many times

   Statisticians call it sample size: a success rate worked out from a few flights can swing a long way on a single result.

   The twist

   With only 4 flights, one failure cuts a rocket's success rate by a quarter, so a single test, good or bad, says little about the next one.

   The picture

   Electron99 launches

   Vulcan4 launches

   Step by step

   1. 1 Count the flights that worked
   2. 2 Divide by all the flights so far
   3. 3 With 4 flights, one failure moves the rate by a quarter
   4. 4 With 99 flights, one failure barely moves it
   5. 5 So a success rate earns trust as the count grows

   The same force, elsewhere today

   Where this chain is also running, in today's other stories.

   • Vulcan's return slips a day

     booster nozzles failed on 2 of Vulcan's first 4 flights, too short a record to show a fix works, so the Space Force waits for this flight's data

   • Rocket Lab's small rocket flies its 100th time

     Rocket Lab quotes 96% across 99 launches, a count long enough that one more result barely moves the rate

   • Crowded galaxies run short of star fuel

     the gas shortage was measured in one group of galaxies, and the authors say only more groups will show whether it is typical

   Where you've seen this

   Car insurance

   new drivers pay more, because a few months of driving says little about how safe someone is

   Online reviews

   five stars from 3 buyers can be luck, while 4.6 stars from 2,000 buyers is a record

   Football

   a striker who scores in his first 2 games has not yet shown he will score all season

   Medicine trials

   a new drug is tested on thousands of people, so one lucky recovery cannot pass for a cure

   The catch

   A long record only counts while the rocket stays the same: Starship's new, bigger booster started its count of catches again from nothing.

   And the whole of it

   NASA, Amazon and the radar-satellite companies all plan years ahead on rockets with only a few flights behind them. So does anyone whose internet or satellite pictures come from those launches, usually without ever seeing the count.

   The truth

   • 'What we do here is not without risk,' Peller said this month. [16]
   • Nobody knows yet

     Whether Vulcan's new booster nozzle fixes the fault.

     ULA has not named the 3 possible causes it found, and the investigation stays open after this flight. [16]

   What comes next

   The new launch time is 17:32 UTC on Saturday 14 November. [16]

1. 03

   Senators tell Musk to keep his Starshield records

   What happened

   • Two Democratic US senators, Jeanne Shaheen and Chris Coons, wrote to Elon Musk. [28] They told him to keep every record on SpaceX's limits on Ukraine's service. [28]
   • Starshield is the military version of SpaceX's Starlink internet service. [28] Ukraine's forces rely on it for frontline communications and drones. [28]
   • Ukraine's president, Volodymyr Zelenskiy, said on Thursday 12 November that the disruptions were back. [28]
   • The senators want SpaceX's records since 1 September, including its messages with the Trump administration and the US military. [28]

   Who is involved

   • Shaheen and Coons senators asking for records
   • Elon Musk runs SpaceX

   How it unfolded

   Ukrainian officials say the service was slowed without warning in mid-October. [28]

   1. Mid-Oct service slowed without warning
   2. 12 Nov disruptions reported again

   Why it matters

   The senators say the limits raise 'serious questions' about SpaceX's control of systems vital to US security. [28]

   Think it through

   1. 1

      Why does a slower signal matter in a war?

      Ukrainian officials say the limits slowed the interceptor drones they use to shoot down Russian attack drones. [28]

      Service slowed→Interceptor drones slower→Harder to stop attack drones
   2. 2

      Is Ukraine the only one relying on it?

      No: the senators warn the same weak points may exist in systems the US government itself relies on. [28]

   The truth

   • Nobody knows yet

     Who ordered the slowdown of Starshield in Ukraine.

     Reuters reported the order came from inside the Trump administration. Marco Rubio, the US secretary of state, said the decision was SpaceX's. [28]

   What comes next

   Musk has until 30 November to confirm in writing that the records are being kept. [28]

2. 04

   Rocket Lab's small rocket flies its 100th time

   What happened

   • Rocket Lab's small Electron rocket made its 100th launch at 05:30 UTC on Saturday, from New Zealand. [15]
   • Its founder, Peter Beck, says no rocket built by a company reached 100 launches faster, not even Falcon 9. [15]
   • Beck told investors on 9 November that Electron had worked on 96% of its 99 launches so far. [15]
   • Saturday's rocket carried a radar satellite for iQPS, a Japanese company, its 11th launch for that customer. [15]
   • iQPS is building a fleet of about three dozen radar satellites, which can see through cloud and at night. [15]

   How it unfolded

   Electron's first launch, in May 2017, failed. [15] Its second, in January 2018, reached orbit. [15]

   1. May 2017 first launch fails
   2. Jan 2018 first to reach orbit
   3. Saturday 100th launch

   Why it matters

   Electron has become one of the busiest and most reliable rockets for small satellites. [15]

   Think it through

   1. 1

      Are all 100 launches trips to orbit?

      No: 9 were HASTE flights, a version that stays below orbit so customers can test very fast flight. [15]

      9HASTE flights, which stay below orbit

   2. 2

      Does Rocket Lab have rivals for these customers?

      Yes: Firefly has just signed up to 10 launches for Synspective, a radar company that also flies on Electron. [18]

   How it works

   Rocket Lab quotes 96% across 99 launches, a count long enough that one more result barely moves the rate

   The idea, in story 02: Why a rocket's success rate means little until it has flown many times →

   The truth

   • The 96% is Rocket Lab's own count, given to investors by its founder. [15]

   Good news

   • Rocket Lab's small Electron rocket made its 100th launch on Saturday, after a first flight in 2017 that failed.
3. 05

   Firefly signs 10 launches for a Japanese radar fleet

   What happened

   • Firefly Aerospace, a US rocket company, signed up to 10 launches for Synspective through 2030. [18] It announced the deal on 10 November. [18]
   • Each flight on Firefly's small Alpha rocket will carry 2 of its satellites, so up to 20 in all. [14]
   • Alpha can lift about 1,000 kg to low orbit. [14]
   • The flights will leave from 2 pads: Wallops in Virginia and Vandenberg in California. [18]

   Who is involved

   Synspective is a Japanese company building StriX, a fleet of radar satellites. [18]

   Why it matters

   Synspective's founder, Motoyuki Arai, said the 2 coasts give it 'valuable flexibility' in the orbits it can reach. [18]

   Think it through

   1. 1

      Why add a second rocket company?

      Synspective flew much of its fleet on Rocket Lab's Electron, and has bought 47 Electron launches in all. [18]

      Electron launches bought47 launches

      Alpha launches signed10 launches
   2. 2

      So is Rocket Lab losing the customer?

      No: in September Synspective signed with Rocket Lab for Electron to launch 20 more satellites from 2028 to 2031. [18]

   How it works

   Supply managers call buying the same thing from two firms dual sourcing.

   Synspective now has 2 rocket makers, Rocket Lab and Firefly, signed up. [18] So a hold-up at one need not stop its launches. [18]

   Seen it before

   A school that buys bread from two bakeries still serves lunch when one oven breaks.

4. 06

   Canada shrinks its Moon rover to fly years sooner

   What happened

   • Canada's space agency, the CSA, wants a smaller Moon rover that can be ready years sooner. [21]
   • The CSA wants a robot rover about the size of 2 pickup trucks side by side. [21]

   Who is involved

   Three companies, Canadensys, MDA Space and Mission Control, shared 14.6 million Canadian dollars for a first study in July 2025. [21]

   • Canadensys rover maker
   • MDA Space also builds Canadarm3
   • Mission Control Moon software and instruments

   How it unfolded

   1. Within days a new call for bids
   2. 2027 2 firms keep building

   Why it matters

   NASA's planned Moon Base will need big rovers as part of its transport. [21] The CSA is expected to spend more on rovers as a result. [21]

   Think it through

   1. 1

      Why not wait for the bigger rover?

      Waiting until 2034 risked the design going 'obsolete', said Ewan Reid of Mission Control. [21]

   2. 2

      Does a company lose out if its design is not picked?

      The companies say their rover work can go into other Moon projects, for the US and Europe. [21]

   How it works

   Project managers call this trading scope for time: doing less, so it is done sooner.

   The CSA swapped a 4-ton rover planned for 2034 for a 2-ton one. [21] That should ship about 3 to 4 years sooner. [21]

   Seen it before

   A short school project gets handed in sooner, even if it covers less.

   What comes next

   That study is almost done. [21] A new call for bids, due within days, will pick 2 firms to keep building in 2027. [21]

5. 07

   Stoke signs Planet for its new rocket

   What happened

   • Stoke Space, a US rocket start-up, signed a deal on Monday to launch satellites for Planet Labs. [14]
   • 'We need launch partners who move as quickly as we do,' said Planet's chief, Will Marshall. [14]
   • Stoke says its Nova rockets are built for operators who launch again and again to grow and replace their fleets. [14]

   Who is involved

   Planet runs the biggest fleet of Earth-imaging satellites in orbit. [14] It photographs all of Earth's land every day. [14]

   • Stoke Space sells the rides
   • Planet Labs buys them

   Why it matters

   Planet must keep launching to replace its fleet, so it needs rockets that can keep up, its chief says. [14]

   Think it through

   1. 1

      Why are buyers signing with new rockets now?

      SpaceX is winding down its Transporter shared rides, and that is pushing buyers to new rockets, Ars Technica reports. [14]

      SpaceX ends shared rides→Fewer seats to orbit→Buyers sign with new rockets
   2. 2

      Who else thinks rides will stay short?

      Sagittarius, a new Colorado start-up, is betting that demand for launches keeps outrunning supply for years. [19]

   The truth

   • Neither company said how many launches the deal covers. [14] Ars Technica reads it as possibly open-ended. [14]
   • Nobody knows yet

     How many launches Planet bought from Stoke, and what it paid for them.

     Neither company announced the terms. [14]

6. 08

   Ex-Masten team raises $1.2 million for inland launches

   What happened

   • Sagittarius Logistics, a Colorado start-up, raised $1.2 million to start building reusable rockets. [19]
   • It plans to launch from inland sites it controls, away from the coast. [19]
   • Its rockets are designed to abort mid-flight without exploding over towns. [19]
   • In an abort, both stages would separate and land, says its chief, Jonathan Slavik. [19]
   • Its first test rocket, Yellowstone, is meant to fly below orbit in mid-2027. [19]

   How it unfolded

   Its founders include David Masten, whose company Masten Space Systems went bankrupt in 2022 after overspending on a Moon lander. [19]

   1. 2022 Masten goes bankrupt
   2. Last year Sagittarius founded
   3. Now $1.2 million raised

   Why it matters

   Sagittarius is built on the idea that demand for launches will outrun supply for years to come. [19]

   Think it through

   1. 1

      Why launch from inland at all?

      To book launches faster from its own sites, instead of competing for slots at Florida's Cape, Slavik says. [19]

   2. 2

      What does safety over land have to do with it?

      Slavik says safe aborts let it meet much stricter safety rules for flying over land. [19]

      Safe abort→Stricter rules met→Flights over land allowed

   How it works

   Safety regulators call flying over towns and roads overflight.

   An inland rocket always flies over land. [19] So Sagittarius designs both stages to land after an abort, to meet overflight rules. [19]

   The truth

   • Slavik says the 3 rockets will need more than $1 billion in all. [19]

   What comes next

   A first orbital rocket, Sequoia, would carry 4 tons to low orbit in the early 2030s. [19]

7. 09

   French start-up raises 15 million euros for solar wings

   What happened

   • Gama, a French start-up, raised 15 million euros to build light solar panels that unfold in space. [20]
   • The money pays for a factory outside Paris that can make 100 megawatts of solar arrays a year. [20]
   • Almost every spacecraft runs on solar panels. [20] Their cells come from a few makers, with waits of a year or more. [20]
   • Gama aims to sell its arrays at $10 a watt. [20]

   How it unfolded

   Gama started out on solar sails, which use sunlight to push a spacecraft. [20]

   Why it matters

   Gama's chief, Andrew Nutter, says pooling orders from many satellite builders lets it offer cheaper prices. [20]

   Think it through

   1. 1

      Is this a big first round?

      Payload, a space news site, calls it one of Europe's largest space seed rounds in recent years. [20]

   2. 2

      How does it compare with SpaceX's own solar plans?

      SpaceX ordered a factory line for 100 gigawatts of solar cells a year, far more than Gama's 100 megawatts. [9]

      100 megawattsGama's factory

      vsvs

      100 gigawattsSpaceX's order

   How it works

   Engineers call a structure's resistance to bending its stiffness.

   As arrays grow, they get floppy and catch sunlight less well. [20] Gama uses software to point the whole spacecraft better, instead of adding weight. [20]

   Seen it before

   A long fishing rod wobbles more than a short one, so you hold it steadier.

   What comes next

   Its first units, called Wings, should come off the line next year. [20]

8. 10

   Giant early black holes ruled out as dark matter

   What happened

   • Physicists have ruled out one idea for dark matter: giant black holes formed just after the Big Bang. [24]
   • Nobody yet knows what dark matter is, so scientists are crossing ideas off one by one. [24]
   • These 'stupendously large black holes' would weigh up to 10 billion billion times as much as the Sun. [24]
   • If many existed, they would have left the universe's oldest light looking grainy. [24]
   • Maps from Planck, a European satellite switched off in 2013, show no such grain. [24]
   • The study, led by Christopher Gerlach of Mainz university in Germany, is in Physical Review Letters. [24]

   How it unfolded

   That light, the cosmic microwave background, was released about 380,000 years after the Big Bang. [24]

   Why it matters

   It also weakens one idea for why the Webb space telescope saw such big galaxies so early. [24]

   Think it through

   1. 1

      Why use a satellite switched off 13 years ago?

      Better computers and new data to compare it with keep turning up new results in Planck's maps. [24]

      Old Planck maps→More computing, new data→New results
   2. 2

      So is dark matter not black holes at all?

      Earlier work had already all but ruled out smaller early black holes as the whole of it. [24]

   How it works

   Scientists call this a process of elimination. [24]

   Each idea for dark matter predicts a mark in the data. [24] This one predicted grain, Planck found none, so it is out. [24]

   Seen it before

   A detective crosses a suspect off once the suspect was seen across town at the time.

   Good news

   • Physicists crossed one suspect off the dark-matter list using maps from Planck, a European satellite switched off 13 years ago.
9. 11

   A dead star's radio pulses traced

   What happened

   • Astronomers traced a strange radio signal to a white dwarf, a dead star, circling a star like the Sun. [22]
   • The pair is about 5,000 light-years away. [22]
   • The white dwarf spins once every 8 minutes, sending out radio pulses. [22]
   • It belongs to a rare group called long-period transients: radio sources that switch on and off over minutes or hours. [22]
   • The pulses were clear enough to show the white dwarf moving in its orbit. [22] So the signal comes from close to the white dwarf. [22]
   • The team used telescopes in Australia and South Africa, and published in Nature Astronomy on Thursday. [22]

   How it unfolded

   About a dozen have been found since the first in 2021. [22]

   1. 2021 the first one found
   2. Now about a dozen known

   Why it matters

   In earlier pairs it was unclear which of the two stars made the pulses. [22] Now one case has an answer. [22]

   Think it through

   1. 1

      What else did the pulses show?

      They also caught flares bursting from the Sun-like star, seen from Earth by radio. [22]

   2. 2

      How sure are they about the partner?

      Light seen by the Keck telescope in Hawaii confirmed the partner is a star like the Sun. [22]

   The truth

   • What makes these pulses is still not known, and this finding may be one step toward it. [22]
10. 12

    The sharpest low-frequency radio map yet

    What happened

    • A team led by Leiden University made the deepest, sharpest picture yet of the sky in low-frequency radio. [23]
    • The picture holds 63,000 radio sources, including young galaxies busy making stars. [23]
    • It took 200 hours of watching and filled 400 terabytes, an 8-billion-pixel image. [23]
    • A computer system called Spider, with better methods, cut the processing time to a tenth. [23]

    Who is involved

    It used LOFAR, a radio telescope whose central part sits near Exloo in the Netherlands. [23]

    • Leiden team made the picture
    • LOFAR the radio telescope

    Why it matters

    Radio waves pass through the dust that hides young stars from other telescopes. [23] So astronomers can watch how early galaxies grew. [23]

    Think it through

    1. 1

       What is still missing from the picture?

       How far away each source is: that needs pictures of the same patch at other kinds of light. [23]

    2. 2

       What links this to the white dwarf found today?

       Both lead toward the Square Kilometre Array, the world's biggest radio telescope project. [22][23]

    How it works

    Radio astronomers call it interferometry: combining signals from many antennas into one clearer picture. [23]

    Better ways of combining LOFAR's antennas made this picture 20 times sharper than its last one. [23]

    Seen it before

    Two ears tell you where a sound comes from better than one ear does.

    Good news

    • A team led by Leiden University made the sharpest map yet of the low-frequency radio sky, with 63,000 radio sources in it.
11. 13

    Crowded galaxies run short of star fuel

    What happened

    • Galaxies in a crowded group hold only 20% to 40% of the star-making gas ordinary galaxies have. [25]
    • The group, COSMOS-Gr30, sits billions of light-years away. [25]
    • Gas pushed out of the group's galaxies hangs between them. [25] Less than a third of it is cold enough to make stars. [25]
    • The study, led by Jonathan Freundlich of the University of Strasbourg, will appear in Astronomy and Astrophysics. [25]

    Who is involved

    • Jonathan Freundlich led the study, Strasbourg

    How it unfolded

    Across the universe, star-making has fallen by about 97% since a peak about 10 billion years ago. [25]

    The Milky Way, the galaxy Earth is in, now makes only about 6 or 7 new stars a year. [25]

    Why it matters

    Most galaxies live in groups, so what happens in groups shapes how fast the universe makes stars. [25]

    Think it through

    1. 1

       Is one group enough to be sure?

       No: the authors say larger samples of groups are needed to see how much groups differ. [25]

    2. 2

       What will check it?

       ALMA, an array of 66 radio dishes, will make further measurements of the group. [25]

       66dishes in ALMA

    How it works

    Astronomers call it environmental quenching: a galaxy's neighbours shut down its star-making. [25]

    Here, gas was pushed out by the galaxies' own stars and black holes, and by brushes with neighbours. [25]

    Seen it before

    A campfire in the wind burns out faster than one in a sheltered pit.

    the gas shortage was measured in one group of galaxies, and the authors say only more groups will show whether it is typical

    The idea, in story 02: Why a rocket's success rate means little until it has flown many times →
12. 14

    New US stealth bomber drops its first weapon

    What happened

    • The B-21 Raider, a new US stealth bomber, released a weapon for the first time in a test this month. [27]
    • It took off from Edwards Air Force Base in California in early November and dropped a conventional weapon. [27]
    • It can carry conventional or nuclear weapons over long distances. [27]
    • Northrop is also building a 1 million square foot assembly line in Palmdale, California. [27]

    Who is involved

    Northrop Grumman builds it, and it is the US Air Force's first new bomber in more than three decades. [27]

    • Northrop Grumman builds the B-21
    • US Air Force buys it

    How it unfolded

    1. Early Nov first weapon released
    2. 2027 first B-21 reaches Ellsworth

    Why it matters

    The Air Force says the B-21 will become the backbone of the US bomber fleet. [27]

    Think it through

    1. 1

       What does the Air Force say it is for?

       To 'hold any target at risk if deterrence fails', said Troy Meink, the US Air Force secretary. [27]

    2. 2

       Who gains from building it faster?

       Northrop Grumman, which says it is moving fast to meet an Air Force order to speed up production. [27]

       Air Force: build faster→New factories→More B-21s sooner

    How it works

    Engineers call a computer copy of a machine a digital twin. [27]

    The B-21 team ran thousands of hours on its digital twin. [27] That let them predict the weapon's path before the plane left the ground. [27]

    Seen it before

    Racing drivers learn a new track on a simulator before they ever drive it.

    What comes next

    The first B-21 for an operational unit is due at Ellsworth Air Force Base, South Dakota, in 2027. [27]

13. 15

    A way to look for gravity waves in the tides

    What happened

    • A mathematician in Berlin has shown how to look for gravitational waves in Earth's tides. [26]
    • Gravitational waves are ripples in space and time, predicted by Albert Einstein's theory of gravity. [26]
    • Thousands have been detected, most of them from black holes or neutron stars crashing together. [26]
    • Muhittin Cenk Eser, of the Free University of Berlin, put both into one model of the Moon's tides. [26]

    Who is involved

    • Muhittin Cenk Eser built the model

    How it unfolded

    Isaac Newton's theory, published in 1687, already predicts the tides very well. [26]

    1. 1687 Newton explains the tides
    2. Now tides plus Einstein's waves

    Why it matters

    The Earth and Moon's tides are already measured very precisely, so a tiny extra signal could show up there. [26]

    Think it through

    1. 1

       So has anyone found the waves in the tides?

       'We are not claiming to have discovered a new gravitational effect,' Eser said. [26]

    2. 2

       What makes the search hard?

       Measuring errors, the choice of reference point and doubt over the Sun's and Moon's exact positions. [26]

       Measuring errorsnoise

       ++

       Reference pointa choice

       ++

       Positionssmall doubts

    How it works

    Physicists call it pulling a signal out of noise: finding a tiny real effect among bigger errors.

    Eser lists what must be allowed for first. [26] Then a real signal could be told apart from the errors. [26]

    Seen it before

    Hearing a friend's voice in a noisy room means tuning out everything else.

14. 16

    China tests 3 new solar panels in orbit

    What happened

    • Yanhe Technology, a Chinese company, put 3 new kinds of solar panel into orbit to test them. [29]
    • They launched on 7 November on a Ceres-2 rocket, built by Galactic Energy, from the Jiuquan launch centre. [29]
    • The panels went into an orbit 535 km above Earth. [29]
    • All 3 use perovskite, a newer solar material. [29] It could give more power for its weight than today's space cells, from cheaper materials. [29]
    • Yanhe calls it China's first test of three perovskite designs in orbit at once. [29]

    Who is involved

    Two sit on the North University of China-1 satellite, and a bendable one on Yunyao-1 28. [29]

    • North University of China-1 carries 2 panels
    • Yunyao-1 28 carries the bendable one

    Why it matters

    Yanhe is aiming at the fast-growing fleets of satellites in low orbit. [29]

    Think it through

    1. 1

       Why test them in orbit at all?

       Whether perovskite keeps working through years of radiation and heating and cooling is still the big question. [29]

       Radiation and hot-cold cycles→Panels may wear down→Only orbit shows how fast
    2. 2

       Is anyone else chasing lighter space solar panels?

       Yes: Gama, a French start-up, raised 15 million euros this week to make light solar arrays for satellites. [20]

    How it works

    Engineers call the power a solar cell gives for each kilo its specific power. [29]

    Lighter panels mean less weight to launch. [29] A solar news site, pv magazine, says that could help cut launch costs. [29]

    Seen it before

    A lighter backpack lets you walk further on the same lunch.

    The truth

    • Yanhe has not said how efficient or how powerful the panels are. [29]