OrbitalHub

Photo: Thorsten Schumm for TU Wien, from the announcement.

In October 2026, two groups of physicists published a machine no clock had managed before: it keeps time with the nucleus of a single element rather than the electron cloud around it, and it steers itself. The Vienna prototype, built by Thorsten Schumm’s group at TU Wien with Ekkehard Peik’s group at PTB Braunschweig, held its frequency for a full day on its own feedback loop. A Chinese consortium at Tsinghua University and the Shanghai institutes of the Chinese Academy of Sciences published a rival system in the same issue of Nature (Schumm et al., Nature 658, 897-902, October 2026). What both machines lock a laser to is the low-lying isomer state of thorium-229, an excited nuclear level 8.4 electron volts above the ground state. No other nucleus has a gap that small, and that gap is the reason this clock can exist.

Getting to that number took fifty years of argument. A stream opened by Kroger and Reich in 1976 narrowed the energy from a guess of under 100 eV to minus 1 eV, then 3.5 eV, then 7.8 eV. Internal conversion proved the isomer existed in 2016 at 8.28 eV, and two years later its radiative decay was caught in the vacuum ultraviolet, fixing the value at 8.338(24) eV. In April 2024 the Vienna and Braunschweig teams excited the transition with a laser for the first time; by that autumn they were using the nuclei as a timekeeper, with the laser disciplined by an ordinary optical atomic clock. That arrangement borrowed stability from the electronic world. The new one does not.

The physics behind swapping atoms for nuclei is insensitivity. A nucleus is roughly 10,000 times smaller in linear size than the atom containing it and carries very little of the charge and magnetic moment that make electronic transitions so sensitive to stray fields, temperature and radiation. Peik and Tamm proposed in 2003 that this stubbornness could become a frequency standard. Doping micrograms of thorium-229 into a crystal gives you not one nucleus but around 10^15 of them, which buys signal and costs resolution: the solid broadens the resonance to about 100 kHz, against a potential quality factor of 10^19 for a bare nucleus whose excited state lives nearly an hour in vacuum.

Vienna’s clock begins with an external-cavity diode laser at 1,187 nm locked to a high-finesse optical cavity by the Pound-Drever-Hall method for short-term stability, plus a seed laser offset-locked to it that carries the readout modulation. The seed is frequency-quadrupled and then doubled in a strontium tetraborate crystal to reach 148 nm. The beam enters a vacuum chamber holding a thorium-doped calcium fluoride crystal and ends on a photomultiplier tube. The decisive choice was absorption instead of fluorescence: rather than waiting for a nucleus to decay and emit, the experiment counts the probe light the crystal removes. That yields three orders of magnitude more signal photons per second and lets the feedback loop close far faster than the ten-minute isomer lifetime (Morawetz et al., Nature, October 2026).

The numbers were modest but real. Sixty-five picowatts of 148-nm light reached the detector, the tube counted photons with 10 percent efficiency, the 5/2 to 3/2 transition absorbed 0.75 percent of them, and the signal-to-noise ratio reached 17 in one second of counting. The error signal came from modulating the probe by f_FWHM/sqrt(3) on either side of the line; inverting that curve gave the detuning, fed back to the electro-optical modulator in a step of about a second. Two modes were possible, correcting every 30 minutes or every 20 seconds, trading cavity drift against short-integration noise. Inside a run, fractional frequency instability sat in the low 1e-14 range and settled near 1e-15 over a day, an error of about one second in thirty million years (TU Wien, 8 October 2026). Reproducibility from one day to the next was far worse, around 5e-13. The Vienna team traced that to the crystal: shifting the beam across the sample by fractions of a millimetre moved the line centre by as much as 1.7 kHz, which they attribute to local strain.

The Chinese group solved the laser problem differently. Instead of crystal frequency doubling it used four-wave mixing in cadmium vapour, with two 375-nm photons driving a two-photon resonance in the metal and a 710-nm beam completing the sum-frequency process, yielding 10 microwatts of continuous 148.4-nm light with an estimated sub-Hertz linewidth (Huang et al., Nature, October 2026). Their crystal came from 1.4 micrograms of thorium-229, an activity of 10 kilobecquerels, grown in one run with a temperature-gradient technique that leaves the crucible stationary and the crystal bubble-free. The clock locked to the quadrupole component labelled line b, and the fractional frequency instability was 5e-13/sqrt(tau/s), with 15 percent of the cycle lost to feedback overhead. Two independently grown crystals and earlier comb measurements tested whether the transition frequency repeats from crystal to crystal, the question that decides whether a nuclear clock is a standard or a curiosity.

Why this matters beyond clockmaking comes from the origin of the small gap. The 8.4 eV separation is what remains when mega-electronvolt-scale Coulomb and nuclear contributions to the binding energies of the two states nearly cancel. Sensitive to what is left over means the transition frequency responds strongly to the constants that set that balance. The sensitivity factors for thorium-229 are roughly 10^3 for the fine-structure constant, 10^4 for the QCD scale and 10^5 for the quark masses, against about 1 for a ytterbium ion clock. Vienna’s team searched 23 hours of clock data with a Lomb-Scargle periodogram for the slow oscillation an ultralight scalar field would imprint on the ratio f_Th/f_Yb+, found nothing above its detection threshold, and set limits ten to a thousand times deeper into that parameter space than earlier atomic clock work. The floor is photon shot noise in the interrogation, which follows sigma_y(tau) = (Gamma/f_0)(1/SNR)(tau/s)^(-1/2), with Gamma near 100 kHz and f_0 = 2.0204 x 10^15 Hz. Better crystals and brighter lasers push it down.

For spaceflight the appeal is direct. Clocks in orbit run fast because gravity is weaker there, and a navigation satellite’s clock gains about 38 microseconds a day, 45 from the shallower potential and minus 7 from orbital speed (Ashby, Living Reviews in Relativity, 2003). ESA already flies a clock ensemble outside the International Space Station, where the Atomic Clock Ensemble in Space pairs a laser-cooled caesium clock with an active hydrogen maser on Columbus to test relativity, targeting an instability of 2 x 10^-16, about a second in 300 million years (ESA, ACES). A nuclear clock would suit that job better: a doped crystal tolerates vibration and temperature better than a magneto-optical trap, and the same frequency that keeps time also probes for new physics. That is a promise, not hardware: the lasers at 148 nm are still laboratory instruments, and the Vienna result loses to the best optical atomic clocks by orders of magnitude in instability.

What the two groups have built is a measurement chain with no weak link left to hide behind, and the remaining problems are materials problems: crystal growth has to become reproducible to a fraction of a kilohertz, dopant concentration has to rise without broadening the line, and the lasers have to get stronger. If that happens, the thorium nucleus stops being the most interesting part of a nuclear clock and becomes the part that makes it work. The end state is a time standard that no laboratory can argue with, running at room temperature, in a piece of crystal, on a wavelength that lies in the vacuum ultraviolet.

On a Saturday morning at the MAX POWER aerospace expo at NASA’s Kennedy Space Center, the agency handed out the paperwork for a supply chain. Almost none of what NASA announced was about a spacecraft that flies soon. Eight companies were put on a list to fly cargo to the lunar south pole. Six task orders were awarded for launches and orbital transfer vehicles, and one company took home $94 million to deliver a nuclear-powered rover that will drill into the Moon (NASA, November 2026). That rover is PROMISE, the Polar Rover for Observation, Mapping, and In-Situ Exploration. Everything else that day was about how that box gets there, and what happens to the power and spare parts after it lands.

The program itself is young. In March 2026, at an event NASA called Ignition, administrator Jared Isaacman laid out a Moon Base: humanity’s first outpost, assembled one mission at a time rather than in a single leap. “The moon base will not appear overnight,” he said at the time (CNN, March 2026). Eight months later the program is issuing contracts, and the shape of those contracts says what NASA thinks a base is. Not a habitat first. A logistics chain first, with the habitat waiting at the far end of it. NASA’s phased plan is blunt about it: Phase One, through 2029, is titled “Gain Reliable Access, Experiment, and Learn,” and every asset listed under it flies without a crew aboard.

Getting to the south pole is not mainly a distance problem. It is a problem of arriving with power and staying alive. The sun never climbs high there, so sunlight is weak and arrives at a grazing angle. Shadowed craters near Shackleton reach roughly -242 degrees Celsius, cold enough to freeze tanks and kill batteries. A lunar night lasts about 14 Earth days. And the polar ice that would make a base self-sufficient sits under meters of dust, findable only by drilling or by watching neutrons scatter off hydrogen. The hard part is not the pressure vessel. It is landing repeatedly at a named spot on a world with no roads and no rescue, using hardware somebody else owns.

That is where the November 7 announcements land. NASA’s new CLPS 2 on-ramp admits eight companies: Blue Origin, Firefly Aerospace, Intuitive Machines, ispace-US, Lockheed Martin Space, Northrop Grumman Space Systems, SpaceX and Voyager Technologies. They compete for lunar delivery missions under a ten-year multiple-award contract with a ceiling of $10 billion. NASA also raised the value of the original CLPS 1.0 vehicle from $2.6 billion to $4.2 billion for Phase One, while deliveries already awarded must finish by November 2033. The trade has changed: the company builds the lander, operates it and flies it, and NASA arrives with a payload and a delivery ticket.

The legs in between are covered by a second contract. NASA’s Venture-Class Acquisition of Dedicated and Rideshare vehicle is a ten-year indefinite-delivery contract with a $5 billion ceiling. Six task orders worth roughly $1.3 billion went to Arrow Science and Technology, Blue Origin and Impulse Space, in three shapes (NASA, November 2026). One carries CAPSTONE 02, a pair of small spacecraft, into deep space to rehearse rendezvous and navigation around the Moon. One sends JPL’s MoonFall drones to scout terrain before astronauts arrive. One tests commercial orbital transfer vehicles in cislunar orbits. Launches will ride New Glenn, Relativity’s Terran R and Falcon 9, with transfer vehicles from Blue Origin, Firefly, Impulse Space and Quantum Space. SpaceX, separately, won a cislunar communications demonstration that will put satellites on a Starship in 2028, and NASA will buy parts for miniCAST towers: solar arrays, batteries and wireless power transfer, assembled at Marshall.

And then there is the rover, where the engineering gets specific. Blue Origin will fly PROMISE to the surface on its Blue Moon Mark 1 lander, under the $94 million award and $140 million in options. The rover is six wheels on a Curiosity-derived chassis. JPL is building it from the electronics, body structure and mobility system of the duplicate Curiosity vehicle used as a test bed for the Mars mission, supplementing that with flight spares and test models left over from Curiosity and Perseverance. That shortens the path from a parts bin to a landing site. Power comes from a flight-spare Multi-Mission Radioisotope Thermoelectric Generator, a unit that supplies about 110 watts of electricity at the start of a mission (NASA Radioisotope Power Systems). A hundred watts looks trivial next to a solar array, but it does not stop at sunset, and at the pole there is always a sunset.

The payload surveys everything the base will need to know. A rotary percussive drill called TRIDENT, designed by Honeybee Robotics, a Blue Origin subsidiary, pulls regolith up from a meter down in 10-centimeter increments while measuring how strong and how warm the material is. A mass spectrometer at Kennedy and a near-infrared spectrometer at Ames read its chemistry. A Lockheed Martin neutron spectrometer looks for hydrogen. A radiometer built at Johns Hopkins, using technology from the Lunar Reconnaissance Orbiter’s Diviner instrument, measures temperatures down toward -242 degrees Celsius inside permanently shadowed terrain. Everything runs on NASA’s High Performance Spaceflight Computing, which NASA says delivers more than 100 times the capability of current space processors. With light taking about 1.3 seconds to cross the Earth-Moon distance each way, the rover has to decide things on its own.

That chain is worth the arithmetic, because NASA has split the old lunar lander into three or four separately purchased pieces. From low Earth orbit to the lunar surface is roughly 5.6 kilometers per second of delta-v: about 3.1 for translunar injection, 0.9 for lunar orbit insertion and 1.7 for the powered descent. Tsiolkovsky’s rocket equation, Δv = v_e * ln(m_0 / m_f), explains why nobody flies that whole profile as one vehicle. A chemical stage with an exhaust velocity near 3.5 kilometers per second needs a mass ratio above two just for the departure burn. A Hall thruster needs far less propellant, but it thrusts too low to sprint, and solar flux at the Moon is a twenty-third of Earth’s. Electric transfers pay off when the cargo can carry a huge array, which is why the chain is layered. Impulse Space’s two awards show the logic: Helios, a chemical kick stage, takes the expensive first leg, while Mira and a throttleable lander handle the maneuvers and the descent. Blue Origin’s Blue Moon Mark 1 is scheduled to attempt a landing at the Shackleton Connecting Ridge, with SCALPSS cameras watching how engine plumes scour the ground. A second lander is booked to carry NASA’s VIPER rover in late 2027.

What to watch is not any single mission but the order they arrive in. Blue Moon’s Endurance landing attempt and CAPSTONE 02 both fly in 2027, followed by VIPER’s delivery, then the MoonFall drones, then PROMISE in late 2028 with its eighteen-month campaign. Every one of those dates assumes commercial hardware shows up on a schedule NASA does not control, at a place NASA does not own. The contracts do not make that harder. They make it financeable. An indefinite-delivery vehicle with a $10 billion ceiling turns a program of bespoke government spacecraft into a market where a lander operator has to show up repeatedly, not once, and where a failed delivery is somebody else’s problem. Whether the Moon Base ends up a settlement or a very expensive parking lot will be settled by how those eight companies perform over the next three years, long before anyone has to live there.

On 18 November 2026, at 2:16 in the morning Pacific time, Voyager 1 will cross a line in space that no human-made object has ever reached. The probe will be 16.094 billion miles (25.902 billion kilometers) from Earth, which is the distance light covers in a single day. Getting there took 49 years, two months and 11 days of flight for a probe that has cruised at nearly 38,000 mph (61,000 kph) since leaving Cape Canaveral on a Titan-Centaur rocket in September 1977. Nothing on board will react to it: no instrument fires, and the space on either side of the marker looks the same. The significance is arithmetic. After nearly half a century of flying away, the distance to home is large enough that a radio exchange takes a full day each way.

That is a strange condition for a machine to be in. Light travels about 186,000 miles every second, so once the marker is passed it crosses the gap between Earth and Voyager 1 in exactly 24 hours. A command sent then would take a day to arrive, and the reply another day to come home. Suzanne Dodd, the Voyager project manager at NASA’s Jet Propulsion Laboratory, put it plainly: you send your message and then “you go home and you wait two days” before an answer arrives. Two days is not much for a person waiting on a colleague. It is a long time for a spacecraft with a power supply running down and a radio that has to keep its dish on target.

The light-day is a useful unit for a reason that has nothing to do with poetry. Nothing outruns light, so it is the one ruler that never stretches as you take it to larger distances. The same logic that lets astronomers quote the Sun as 8 light-minutes away and Andromeda at about 2.5 million light-years also puts the Moon at 1.3 light-seconds from here. Neptune sits about four light-hours and 10 light-minutes off, and Voyager 2 needed 12 years to get there. The nearest star, Proxima Centauri, is 4.24 light-years away. Voyager 1’s new marker falls between those scales, and the number makes the solar system look small: a neighborhood whose nearest house is a four-and-a-quarter-year walk away.

The spacecraft that reached that marker was never meant to get there. It was built for a five-year job involving flybys of Jupiter and Saturn, and nobody involved had any idea how far it would eventually go. Voyager 1 launched on 5 September 1977 with ten science instruments and weighing 1,592 pounds (721.9 kg). Its power came from three radioisotope thermoelectric generators, which turned the heat of decaying plutonium into about 158 watts each at launch. It took the faster of the two routes, past the asteroid belt ahead of its twin, and overtook Voyager 2 on 15 December 1977. The alignment of the four outer planets that made the mission possible occurs only about every 175 years, and the two Voyagers together cost about $865 million including their nuclear batteries.

What it found along the way is a long list. At Jupiter it found a thin ring and two new moons, Thebe and Metis. At Saturn it added five moons and a new ring called the G-ring. Another discovery came out of an image nobody was looking for, taken for navigation rather than science: four days after the Jupiter encounter, project astronomer Linda Morabito processed a picture of Io and noticed something protruding from the limb of the moon. It was a volcanic plume, the first sign of active volcanism seen beyond Earth, and it changed what people expected from a world that had seemed dead. Later, the spacecraft turned its cameras back toward the planets for a family portrait taken from 40 AU, and the small pale speck of Earth in one of those frames became the Pale Blue Dot, a phrase that Voyager science team member Carl Sagan made famous.

In December 2004 Voyager 1 crossed the termination shock, where the solar wind still dominates, and in August 2012 it became the first spacecraft to pass the heliopause into interstellar space. By then it was still working, and it is now one of only two objects ever to have operated outside the heliosphere. The probe has been sending back data from a region no other human-made object has ever occupied, doing it with a shrinking tool kit.

The instruments have been switched off in a planned order for years, one at a time, as the plutonium decays. Of the ten instrument sets the spacecraft carried, seven have been shut down. The cosmic ray telescope stopped on 25 February 2025, and the Low-energy Charged Particles experiment, which had run almost without interruption since launch and measured the density structure of the space beyond our heliosphere, was switched off on 17 April 2026. What remains on Voyager 1 are the magnetometer and the plasma wave instrument. Voyager 2, which flew the longer path to Uranus and Neptune and has stayed closer to Earth as a result, still runs three.

In September 2026 the team pulled off a maneuver they call the Big Bang. Engineers switched off three powered devices on Voyager 1 in one step and swapped in three lower-power alternatives. All six exist to keep the spacecraft warm enough to operate in the cold. The swap had to happen all at once, because the heat the old units put out only balances if all three change together. Without it, the mission would have had to shut off another instrument as early as summer 2027. The same swap, run on Voyager 2 a few weeks earlier, gave the twin’s three instruments more time too.

The thin margin showed in October. On 18 and 19 October, NASA’s Deep Space Network could not detect Voyager 1’s signal during two scheduled communications attempts 24 hours apart, and the probe reappeared on the 20th. Engineers have so far traced the loss to a group of thrusters going offline with the backups switching on automatically, a protective response built into the spacecraft that puts it into a safe state when something looks wrong. Nothing on board was permanently broken, and the team has kept talking to the spacecraft since. But a half-century-old probe deciding on its own to go quiet for two days, then coming back, is what happens when the margins are this thin.

Science, meanwhile, has not stopped. A paper by Jeewoo Park of NASA’s Goddard Space Flight Center and colleagues, published this year in The Astrophysical Journal, reports what Voyager 1’s magnetometer has seen since a pressure front in 2020 pushed the surrounding magnetic field up. The strength of that field has stayed elevated instead of settling back down, holding between 0.45 and 0.53 nanotesla, while the field’s orientation has kept rotating toward the nominal Parker spiral, the pattern the Sun’s own rotation would produce. Intermittent, spiky behavior has generally been easing off, though it flared up again in 2023 and 2024 before settling. The authors’ conclusion is careful but pointed: after all these years the spacecraft has not yet reached a pristine interstellar medium free of the Sun’s influence, so the boundary where the solar system ends looks less like an edge than a transition.

The milestone on 18 November is mostly bookkeeping rather than a change in the sky. It marks the point at which the distance to the nearest star takes more than a single day’s worth of light to cross. Voyager 2 will get its own light-day in November 2035. Both probes keep climbing away from the Sun on the power their plutonium still gives them, carrying a gold-plated copper record with greetings in 55 languages, whale song and ninety minutes of music toward a star more than 17 light-years off, AC +79 3888 (Gliese 445), which Voyager 1 should pass within about 1.7 light-years of in some 40,000 years. Nobody will be around to watch that happen, and the disk will still be there, waiting for whoever does arrive.

Phobos is a lumpy rock, 25.9 by 22.6 by 18.3 kilometres across, orbiting 9,375 kilometres from the centre of Mars where gravity is 0.0057 m/s², roughly one seventeen-hundredth of what a person feels standing on Earth. It has no air, reflects 7 percent of the light that strikes it, and orbits in 7 hours and 39 minutes, rising in the west and setting in the east twice per Martian day. On 19 October 2026 a Japanese H3-24L rocket lifted off from the Tanegashima Space Center carrying the Martian Moons eXploration spacecraft, MMX, assigned to land on that rock, collect at least ten grams of its dirt, and fly it home (ESA, October 2026; Wikipedia). No mission has ever done either half of that.

Two hypotheses compete for Phobos’s origin. Under the capture hypothesis it is a carbonaceous asteroid that Mars pulled in from elsewhere in the solar system; under the giant impact hypothesis it is debris thrown into orbit by a collision with young Mars, making it a piece of the planet itself. The gap between those stories is the gap between small bodies and planets. Phobos also wears a blanket of material blasted off Mars by impacts, and JAXA estimates it carries more than a hundred times as much Mars-derived material as Deimos (JAXA, October 2026), so its dirt is partly Martian.

The second argument for bringing material home is that Earth owns instruments that cannot fly. ESA’s MMX project scientist Elliot Sefton-Nash calls the returned data and samples “a window to study the evolution of Mars and the Solar System” and notes that once they are here, “our most precise instruments are too large, complex or sensitive to send to space” (ESA, October 2026). Ten grams sounds like nothing, but a few documented grains in a mass spectrometer settle questions orbiters have argued about for decades. There is also a deadline of sorts. Phobos is losing orbit to Mars at about two centimetres a year and will be pulled apart in 30 to 50 million years (NASA, 2023), so its surface is not a permanent archive.

MMX was announced in 2015, cleared for development in 2020, and reached Tanegashima in March 2026 (Wikipedia). It is the largest mission JAXA has flown beyond Earth, and a consortium effort: ESA supplied the transponder and power amplifier and will run ground support from its Estrack stations, while CNES and DLR built the small rover riding between the lander’s legs. The H3-24L stands 63 metres tall and weighs 574 tonnes without payload. The spacecraft is 4,480 kg, split into a propulsion module holding 1,840 kg of propellant, a return module holding 1,190 kg, and the exploration module that lands (Wikipedia). Flight 10 was the H3’s first interplanetary launch, and separation came an hour and eleven minutes after liftoff (NASASpaceflight, October 2026).

Arrival is expected in August 2027, and a month later the spacecraft drops into a quasi-satellite orbit around Phobos, a path that keeps it close to the moon while circling Mars, because the moon is too small to hold a conventional orbit. For the first eighteen months MMX only watches, mapping Phobos, cataloguing candidate landing sites and studying Deimos with a payload ESA counts as eleven science instruments, seven on the main spacecraft and four on the rover (ESA, October 2026). The near-infrared spectrometer from the Paris Observatory targets exactly that question.

Then, around the turn of 2028 and 2029, the mothership drops the rover Idefix (DLR, 19 October 2026). The name comes from Asterix’s dog and was announced at the 2023 Paris Air Show. It weighs 23.47 kg. It falls 40 to 100 metres with no braking, bounces, and must right itself on its four wheels before folding out its solar panels; fail that and the mission is over, since the panels keep its electronics warm. The teams in Toulouse and Cologne never talk to it directly: every command and byte of telemetry goes through MMX and JAXA’s Sagamihara station, twice a day (Wikipedia).

In 2030 MMX lands on Phobos itself, aiming at a box about 20 by 20 metres inside a 300 by 300 metre zone the rover will already have surveyed. The lander carries two samplers, a corer that takes cores a couple of centimetres deep and a pneumatic sampler that lifts loose grains with pressurised gas, and it works both the face looking back toward Mars and the one looking away, because the two are not alike (ESA, October 2026). On the way home it swings past Deimos, releases the sample capsule, and lets it fall to Earth, arriving in Australia in 2031 (Wikipedia). The capsule is roughly 60 centimetres across with a heat shield, because it comes in at interplanetary speed: Hayabusa2 dropped a look-alike canister over Woomera in December 2020 at about 12 km/s, and MMX targets the same range.

Those numbers explain why DLR project manager Markus Grebenstein calls landing and driving on Phobos “uncharted territory for robotics” (DLR, October 2026). Phobos has a mass of 1.06 x 10^16 kg and a surface gravity of 0.0057 m/s², and escape velocity at its surface is only about 11.4 m/s. Leaving Mars altogether is a different order of problem: computed as v_esc(r) = sqrt(2GM_mars/r) at Phobos’s 9,375 km, it takes roughly 3 km/s. There is no atmosphere to brake against, so every metre per second must be cancelled by thrusters, and the ground is barely known: a rubble pile with an estimated 30 percent porosity, a regolith layer at least 100 metres deep, and boulders scattered across it. Gravity varies across Phobos because its mass is lumped unevenly, so a probe cannot simply hover over it. Surface temperatures run from about minus 4 degrees Celsius in sunlight to minus 112 in shadow (Wikipedia), a swing DLR puts above 200 degrees.

The rover is built around that same arithmetic. Each of its four wheels is driven separately, carries nine grousers for grip, and weighs 190 grams after a topology optimisation left it a mesh rather than a solid disc (Wikipedia). Four panels totalling 0.36 square metres should yield at least 60 watt-hours per Phobos day, about 8.6 watts averaged across seven hours of sunlight, so the machine’s working life follows the sun’s schedule. The wheels also roll the rover upright after the drop, and two downward-facing cameras watch the soil move, the only way to learn how regolith behaves under a vehicle. Testing proved awkward: reproducing Phobos’s gravity in a test article would need a rover two thousand times lighter than the real one, so the team simulated the landing and righting sequence instead (Wikipedia). The science payload mixes scales too: MEGANE reads composition with gamma rays and neutrons, LIDAR and OROCHI map the surface, and the rover’s RAX Raman spectrometer fires a green Nd:YAG laser at a 50-micrometre spot, naming minerals from the scattered light it sorts between 535 and 680 nanometres.

The spacecraft reaches Mars in August 2027, the rover reaches Phobos around the end of 2028, the lander follows in 2030, and the sample lands in Australia in 2031. The same months deliver another small-body milestone: ESA’s Hera is on track to reach the Didymos system in November 2026, a month ahead of plan, to survey the scar left by NASA’s DART impact (ESA, 2025). One mission arrives to look, and one is on its way to bring something back. When the ten grams are finally in a laboratory, the argument about whether Phobos is a captured asteroid or a piece of Mars will stop being a debate about models and become a question about atoms.

NASA’s Artemis III does not land anyone on the Moon. It flies to low Earth orbit, carries no lander that touches a surface, and is built around a docking test between two commercial spacecraft and a NASA capsule. Two engineers who work on NASA’s Human Landing System program explained what the test involves on the most recent episode of the Johnson Space Center’s Houston We Have a Podcast.

The guests are Kent Criswell, lead systems engineer for HLS at Blue Origin, and Reid Ruggles, lead systems engineer for HLS at SpaceX. They describe a mission built around a problem that looks easy on paper. Docking in low Earth orbit is solved, has been since Gemini and perfected by the Shuttle and the ISS. What has never been attempted is doing it with hardware that two different companies built separately, on a schedule that depends on a third rocket landing on time.

NASA’s own program page lays out the sequence step by step, and NASA’s Artemis III mission page repeats it in detail. Artemis III is a 14-day flight sending Randy Bresnik, Frank Rubio, Andre Douglas, and ESA astronaut Luca Parmitano up on SLS from Kennedy, with the crew launching only after a Blue Origin lander test article is already in orbit and has passed its checkout. That article goes into a circular orbit roughly 273 miles above the surface and can loiter there for up to 30 days, which is the schedule cushion the rest of the sequence depends on. Starship flies later, since it has a much shorter on-orbit lifetime, and settles into a lower orbit at 206 nautical miles chosen for its communications coverage. Orion itself flies a circular orbit throughout, and all three vehicles have more launch opportunities available than a lunar trip would allow, which is what makes the tight sequence workable.

Each lander gets different hardware and a different set of test objectives. The Blue Moon article carries the real crew cabin, the environmental control and life support system, and enough avionics and flight software that NASA’s page describes it as an early look at how a commercial lander behaves as an integrated vehicle in space. Up to two crew members in orange survival suits open the hatch and go inside to assess the cabin environment and the controls firsthand, spending roughly two days aboard. An instrumented spacesuit mass simulator stands in for a person and reports on conditions inside the cabin in real time, the same trick the agency used with the suited Moonikin on Artemis I. SpaceX’s version is thinner, and the details are harder to come by. The Starship Version 3 article flies without a crew cabin and nobody goes inside it, and the demonstration runs up to two hours. For that leg, what matters is where the docking hardware sits and who flies the stack. Orion connects to Blue Moon along the side of the vehicle, next to the crew cabin, and Orion’s software controls the joined stack once the two are mated. Later, Orion aligns nose to nose with the Starship article, and the SpaceX test article takes over control of the stack. The mission covers two docking geometries, and two different companies hold the controls.

Ruggles describes what low Earth orbit does to Orion that deep space does not. In orbit, a spacecraft moving from full sun into Earth’s shadow can swing from hundreds of degrees Fahrenheit to something near freezing inside forty-five minutes, and metal in a docking mechanism expands and contracts with that cycle, changing the hardware that has to mate. Orion’s thermal control system was built for deep space, and low Earth orbit is not that. Light bouncing off Earth is a steady heat input that a lunar polar orbit does not deliver in the same way, since the Moon’s surface is far less reflective. Getting Orion into the shadow of a lander also breaks the tail-to-sun attitude that keeps the capsule thermally stable, a constraint that did not exist in the mission designs the capsule was originally drawn for.

There is also an optical problem. Ruggles notes that Orion has to acquire its target visually, and that the target’s surface finish changes how it looks. Bare stainless steel reflects differently from a vehicle painted in AZ-93 white, the standard space paint used across the industry, and the acquisition software has to cope with both. He also raises the case of Orion’s own thrusters firing close to a station-keeping lander, a plume impingement problem that cannot be replicated on the ground, because ground tests do not run one spacecraft’s thrusters against another parked vehicle.

The rehearsal stops short of the landing. Both engineers are clear that the real risk sits in the landing itself, where the exhaust plume interacts with the regolith and the vehicle has to find a safe spot among craters, hills, and boulders tens of feet tall. Ruggles calls the uncrewed demonstration mission the linchpin, because it is the first time either company will show that its lander can reach the Moon, land, stay, and lift off again. Criswell, describing Blue Origin’s Mark 1 robotic south pole landing, notes that the uncrewed demonstration comes after Artemis III and that Blue Origin chose to exceed the contract by flying the uncrewed mission for the same duration as the crewed one and ascending back off the surface. NASA built the HLS contracts in the order that worked for the ISS, where an uncrewed demonstration comes before the crewed one, and both companies say they have already qualified their docking hardware on the ground, with SpaceX doing so in 2023 and Blue Origin running pressurized docking tests earlier this year. What remains untested in Earth orbit is the thermal environment a real lunar descent brings, where the sun angle is low, the surface is cold and dark, and the landing plume has to be contained by an engine that has not yet flown.

Both engineers make the same point. Ruggles argues that Apollo succeeded because the program climbed from Mercury to Gemini to Apollo, letting hardware and crews build up in steps, and notes that the agency has not attempted deep space missions in a long time. Criswell puts it more bluntly, pointing out that one company doing something does not mean everyone can. NASA supports the providers with collaboration work worth roughly 80 person-years each, shared through thermal analysis of cryogenic boil-off, landing site selection standards, and propulsion rules written over six decades of agency experience. Artemis III puts two commercial landers, one NASA capsule, and three separate launch campaigns on one timeline, and works through the docking in low Earth orbit before anyone rides a lander down to the south pole.

Artist’s concept of Blue Origin’s Blue Moon Mark 2 test article docked with Orion in Earth orbit. Credit: NASA, from NASA’s Human Landing System program page.

On 27 October 2026 the Minor Planet Center issued a circular announcing a new arrival in the outer Solar System: the object 2026 ED138, currently about 47 au from the Sun and brighter than almost anything else catalogued that far out. The unusual part is the method. Nobody was at a telescope. The detection came out of software comparing survey images, and the circular announcing it carried 74 observations strung across a decade with residuals of a tenth of an arcsecond. The object had been on camera since 2016, sitting in a crowded stretch of the Milky Way’s plane, and nobody had noticed.

Beyond Neptune lies a population that would not be there if the Solar System had been built and then left alone. The Kuiper belt holds tens of thousands of icy bodies, most on near-circular orbits close to the plane of the ecliptic. Those are called cold classical objects, and they sit roughly where the protoplanetary disk left them. A minority tilt and stretch their orbits instead. Those are called hot, and they are the ones Neptune scattered when the giant planets migrated outward, which makes their inclinations a fossil record of that migration. The Minor Planet Center’s orbit for ED138 gives a semi-major axis of 42.95 au, an eccentricity of 0.142, an inclination of 24.47 degrees and a Tisserand parameter of 5.3. That inclination puts it squarely in the hot population, and it is currently near aphelion at 49 au. Neptune has been near this object.

To count as a dwarf planet rather than a large asteroid, a body has to be round, which means its own gravity has to beat down the rigidity of its material. The International Astronomical Union recognizes five: Pluto, Ceres, Eris, Haumea and Makemake. Rubin’s Solar System team puts ED138’s diameter between 600 and 1,500 kilometres, which would place it among the largest candidates ever found beyond Neptune (NOIRLab, October 2026). That diameter is inferred from brightness rather than measured, and the difference decides whether this is a planet.

How it turned up matters more than the announcement. On the evening of 13 October, Matthew Holman, a Rubin Operations team member at the Center for Astrophysics | Harvard & Smithsonian, ran 2026 survey data through a search code written with CfA colleague Kevin Napier. The code takes billions of individual moving-object detections, compares them, and picks out the sets that belong to the same object. ED138 came out of that run. Holman’s first reaction, as he described it, was “excited disbelief” (NOIRLab, October 2026). Objects that large are rare, so he went straight to work checking whether he or the code had erred.

Mario Jurić, Rubin’s Solar System lead scientist at the University of Washington, went looking for more. Sifting through the observatory’s catalogues and images, he turned up 20 further detections reaching back to 4 March 2026. All told the Simonyi Survey Telescope saw ED138 30 times on 20 nights between 4 March and 11 July. The next step was precovery, pulling the object out of old archives where nobody had thought to look: frames from the Dark Energy Camera on the Victor Blanco 4-m telescope at Cerro Tololo, run through the Asteroid Institute’s ADAM precovery service, extended the trail back to 2016. The Minor Planet Center’s current orbit solution reaches further still, to March 2010, using 89 observations across an arc of 5,959 days and eight oppositions, with an RMS residual of 0.07 arcseconds. Jurić and Holman presented the result at the 58th Annual Division for Planetary Sciences meeting in Spokane, and MPEC 2026-U85 went out the same day.

The decade of silence has little to do with faintness. ED138 sits close to the galactic plane, where the sky is thick with stars, and to most telescopes it was simply lost among the background sources (NOIRLab, October 2026). What changed is how Rubin looks. The LSST Camera is a 3.2-gigapixel focal plane built from 189 science CCDs in 21 rafts of nine sensors each, and it reads out in two seconds, about two orders of magnitude faster than a conventional astronomical camera (Brookhaven National Laboratory). Data comes off it at roughly 11 trillion bits per hour, so a ten-hour night of raw camera output runs to about 14 terabytes. The Simonyi Survey Telescope behind it has an 8.4-metre primary and a 3.42-metre convex secondary, feeding a 3.5-degree field that covers about 10 square degrees in one exposure (NOIRLab). The survey takes an image every 40 seconds and will do so for ten years. Software differences each exposure against a static model of the stars and hunts for what is left over and has moved. Repeating the same field thousands of times turns the sky into a film, and moving objects are what change between the frames.

The second half of the problem is turning brightness into size. The standard relation for a small body is D = 1329 / sqrt(p) * 10^(-H/5) km, where D is the diameter, p the geometric albedo and H the absolute magnitude. The Minor Planet Center lists ED138’s H as 2.93 and its phase slope G as 0.15, and the object sits near magnitude 20 at opposition. Substituting gives D = 344 / sqrt(p) km, so a 600-kilometre diameter requires an albedo near 0.33 while a 1,500-kilometre diameter requires one near 0.05. Both are plausible for icy bodies, and that ambiguity is the difficulty: a single measurement of reflected light cannot separate a large dark object from a smaller bright one. Infrared settles it. At 47 au the equilibrium temperature works out to T = 278 / sqrt(p * D) * sqrt(40/r) K, which for a 900-kilometre body of albedo 0.15 comes to about 22 K. At that temperature nitrogen ice has largely sublimated away while methane and carbon monoxide hold on, so the ratio of thermal emission to reflected light fixes the albedo and the spectrum fixes the composition. No infrared follow-up has been scheduled yet, and the Centre lists the object as receding from Earth at 13.8 km per second, so whoever takes that measurement will be chasing it.

One detail in the orbit deserves a pause. ED138’s perihelion fell on 4 February 1926. It has not been this close to the Sun in a hundred years and will not be again until 2207. Everything known about it comes from light that left it far beyond Neptune, spread thin enough that a single telescope sees a moving dot. Rubin’s answer is not a bigger telescope but ten years of smaller ones, and the survey has barely started. In April 2026, before the formal ten-year run began, Rubin’s Solar System team submitted more than 11,000 new asteroids to the Minor Planet Center, about 380 of them trans-Neptunian objects, and called the batch “the tip of the iceberg” (NOIRLab, October 2026). ED138 was already in the data collected before the survey started. The sky has been recording itself for billions of years. The new part is that someone finally built a camera fast enough to read the frames back.