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SpaceX "DARKSAT" results: can Starlink and astronomy happily coexist?
Astronomers have begun to gather and analyze detailed observations of a SpaceX Starlink satellite prototype officially labeled DARKSAT and the initial results hint that the satellite constellation should be able to happily coexist with ground-based astronomy in the future.
Since SpaceX began launching batches of 60 Starlink satellites in May 2019, the company has raised the ire of parts of the astronomy community and simultaneously awed and inspired many less technical observers with clusters of shooting star-like satellites that are easily visible after launches. While the mid-sized spacecraft do become much dimmer as they raise their orbits from ~300 km (185 mi) to 550 km (340 mi), they are far from invisible even at that operational altitude. It’s safe to say that the current impact on ground-based astronomy is still just shy of negligible even with 360 satellites in orbit, but that impact is assuredly greater than zero and the relatively bright spacecraft have already interrupted telescope observations at many sites around the world.
Given that the 360 satellites already in orbit are just a tiny fraction of the ~4400, ~12,000, or even ~40,000 that SpaceX could one day launch, it would be irresponsible to argue that the constellation’s impact – and the impact of others like it – will continue to be minor as the number of satellites grows. Thankfully, while it doesn’t appear that prospective low Earth orbit (LEO) constellation architects anticipated the potential astronomy impact, SpaceX’s Starlink team has rapidly responded and already launched a satellite featuring tweaks designed to dim its appearance from the ground. For several reasons, the initial results from “DARKSAT” are extremely promising – now visible below in some of the first photos offering a useful comparison.
Launched on January 7th, 2020, a set of 20 spacecraft including DARKSAT – representing a single “plane” of the broader Starlink constellation – all arrived at their operational ~550 km (340 mi) orbits by February 23rd. As previously discussed on Teslarati, initial results first published on March 18th revealed that the Starlink DARKSAT prototype – essentially an early alpha test for darkening techniques – was already 55% darker than unmodified spacecraft. While making satellites less reflective makes thermal management a much greater challenge, DARKSAT has managed to raise its orbit and begin operations without issue, although it’s unknown whether the satellite’s antennas and avionics are also functioning nominally.
For darker spacecraft, perhaps the most important test will be long-term reliability, as constantly absorbing more heat than a reflective satellite is likely to put their structure, avionics, and radiators through significantly more thermal stress. As such, SpaceX may launch a limited number of additional darkened prototypes over the coming months but is much less likely to darken all satellites on any given launch until DARKSATs have successfully operated in orbit for months or even years.
On the ground, SpaceX may try to perform sped-up stress testing, but proving that darker satellites are a viable solution will almost invariably take time. Earlier this month, CEO Elon Musk revealed that SpaceX may attempt to design deployable solar shades for Starlink satellites if darkening their bodies is not enough to fully mitigate major impacts to astronomy. Knowing SpaceX, the first in-orbit solar shade test(s) could happen during any of several upcoming Starlink launches.
Adding reliable, deployable solar shades without appreciably raising Starlink’s production costs could be a major challenge, given the fundamental complexity of large, deployable mechanisms in space, but SpaceX – if anyone – is likely up to the challenge. More importantly, the fact that SpaceX’s very first attempt at reducing Starlink albedo (reflectivity) has produced a satellite 55% darker than its peers suggests that much more can probably be done along those lines, given additional time for extra experiments and deeper optimization.
As a result, it may be the case that SpaceX ends up launching 750-1000+ reflective Starlink satellites before an affordable, mass-producible DARKSAT variant is ready to take over. In that event, Starlink could plausibly have a small to moderate negative impact on ground-based astronomy for several years. However, comments made by SpaceX executives over the years suggest that no single Starlink satellite is likely to operate for more than five or so years before being replaced, meaning that the entire constellation would be continuously refreshed (as long as it’s generating revenue). Even if a thousand bright(er) Starlink satellites make life a bit harder for some astronomers, the fact remains that the consequences of any single Starlink satellite variant – assuming SpaceX remains serious about fully mitigating the constellation’s impact – are inherently temporary.
If SpaceX continues to make progress darkening satellites and developing cheap solar shades, it seems all but guaranteed that even a constellation of tens of thousands of Starlink satellites will be able happily coexist with the astronomy community, all the while delivering cheap, fast internet to millions of people – especially those lacking access – around the world.
Tesla has reached a notable benchmark in its autonomous driving program after its Robotaxi fleet surpassed one million miles of unsupervised operation. The company made the announcement during its Cybercab event in Austin on September 3.
Tesla Vice President of AI Ashok Elluswamy told attendees he was happy to report the fleet had achieved one million miles of unsupervised Robotaxi operation as a testament to safety.
The new total marked a sharp increase from the 380,000 unsupervised miles Tesla disclosed during its second-quarter 2026 earnings update in late July.
In roughly six weeks, the company added about 620,000 miles. That acceleration followed Tesla’s decision to remove in-vehicle safety monitors from most of its operations outside the San Francisco Bay Area.
Credit: Tesla
Tesla first launched Robotaxi service in Austin in June 2025 with safety drivers present. It later began fully unsupervised rides and expanded into Dallas, Houston, Miami, Orlando, and Tampa. The San Francisco Bay Area remains the exception, where a safety monitor still rides in the vehicle under California permitting rules.
The company has not released a city-by-city breakdown of the one million unsupervised miles.
The milestone arrived as Tesla began offering public Cybercab rides in Austin. The purpose-built vehicle has no steering wheel or pedals and is designed only for autonomous ride-hailing. Production versions joined the existing fleet of modified Tesla vehicles already operating in the service.
Tesla’s unsupervised mileage is growing at a double-digit weekly rate according to earlier company comments, yet its fleet size remains modest compared with established competitors. Waymo has accumulated more than 200 million fully autonomous rider-only miles. Tesla has described its own unsupervised operations as having recorded zero notable incidents in the period leading up to the July update.
The one-million-mile figure reflects Tesla’s shift from supervised testing to broader driverless service in multiple states. It also highlights the company’s strategy of using both existing Model Y vehicles and the new Cybercab to scale its network.
Credit: Tesla
Whether the rapid recent growth continues will depend on further city expansions, regulatory approvals, and the performance of the purpose-built Cybercab in everyday paid rides. Tesla has not specified how many of the latest miles involved the new vehicle versus the rest of the fleet.
The announcement underscores Tesla’s progress toward a larger robotaxi network while illustrating the remaining gap in total autonomous experience relative to longer-operating rivals.
Tesla AI lead Ashok Elluswamy said this week that 24-hour Robotaxi service is close. Replying on X to a rider who wanted Cybercab trips all night, he wrote that the capability would arrive “next month or so” once “the next tech to merge on the v15 plan” is ready.
The comment landed on September 4, one day after Tesla opened public Cybercab rides in Austin. It is the clearest near-term timeline yet for overnight unsupervised operation. Tesla’s paid Robotaxi network currently runs from 6 a.m. to 10 p.m. seven days a week across Austin, Dallas, Houston, Miami, Orlando, and Tampa.
next month or so. the next tech to merge on the v15 plan will enable it.
— Ashok Elluswamy (@aelluswamy) September 4, 2026
That 16-hour window is shorter than the 6 a.m. to 2 a.m. schedule the company used for much of the prior year.
Elluswamy did not name the specific feature or say whether the change would apply first to purpose-built Cybercabs, the existing Model Y fleet, or both. He also offered no city-by-city rollout list. The link to Full Self-Driving v15 is nevertheless significant.
Tesla has described v15 as a step-change architecture with seven parallel improvement tracks and roughly ten times more parameters than earlier builds. Early versions of that software already operate on the Robotaxi fleet and contain about 40 percent of the planned gains.
By July 2026, the unsupervised fleet had logged more than 380,000 miles across six cities in two states with what the company called an impeccable safety record and no notable incidents caused by the vehicles themselves. Tesla has repeatedly argued that camera-based end-to-end neural networks, rather than extra sensors, are the core of the solution.
Overnight service would test that claim in lower-light conditions and would also raise vehicle utilization, a key variable for Robotaxi unit economics. The company has already begun using public Superchargers at night and is building dedicated Robotaxi charging sites.
Riders have asked why software must change if the cars already drive in the dark. The practical answer appears to be reliability and scale: Tesla has held back mass expansion until more of the v15 stack is merged, citing the need for higher confidence before putting thousands of unoccupied vehicles on streets around the clock.
If the next module arrives on the timetable Elluswamy sketched, 24-hour service could begin in October 2026 in at least some markets.
That would mark a shift from a daytime-bounded pilot to a service that can run whenever demand exists, including the late-night hours that have so far remained out of reach.
Tesla is beginning to roll out Full Self-Driving Supervised v14.3.9 with a new active safety layer that can take control even when the driver is operating the car manually.
Tesla AI said the software can activate FSD on the driver’s behalf when an imminent collision is detected and Automatic Emergency Braking may not be enough. It may also engage if the system detects heavy distraction or an accidental FSD disengagement.
FSD Supervised v14.3.9 starting to roll out shortly
This release includes a new active safety feature set: FSD Supervised can now activate on your behalf when an imminent collision is detected and Automatic Emergency Braking (AEB) may not be enough.
It may also engage if we…
— Tesla AI (@Tesla_AI) September 4, 2026
The capability is essentially Automatic Collision Evasion. However, unlike conventional AEB, which mainly applies the brakes in a straight line, this feature can use steering, braking, and acceleration together if the car calculates that stopping alone will not prevent impact and a safer path exists. The system may change lanes or move toward a shoulder when conditions allow, then continue driving after the immediate threat is handled rather than simply coming to a stop.
The intervention is meant as a last-resort safety net, not a replacement for attentive driving.
Tesla Full Self-Driving v14.3.7 early review: FSD saved me from an accident
Tesla’s own description still frames FSD as supervised assistance. Secondary reports on internal release notes say the feature can fire while the car is being driven manually if cabin-camera monitoring suggests the driver is not sufficiently attentive, such as reaching toward the back seat, or if FSD appears to have been turned off unintentionally.
After the emergency maneuver, the car is expected to alert the driver and request a return to manual control.
The safety case is straightforward. Many collisions happen in the last second because a driver is looking away, fumbles a control, or faces an obstacle that braking cannot fully solve. A system that can both recognize that AEB is insufficient and execute a coordinated evasive path can reduce those remaining high-severity events.
Re-engaging after accidental disengagement also addresses a practical failure mode: a small steering nudge that drops FSD at the worst moment. The advantage is a background safety net that uses the same vision stack already running in v14, instead of leaving the car solely to emergency braking once the driver is no longer in command.
The feature still depends on FSD being enabled and, according to reports, an active FSD purchase or subscription. It does not make the vehicle unsupervised. Drivers remain responsible, and Tesla has not published how often the system is expected to intervene or how it will handle false positives.
If the rollout is conservative and the false-alarm rate stays low, the update is a meaningful step: FSD is no longer only a feature the driver turns on. In the rare moments when disaster is already forming, it can step in.
Tesla crosses major Unsupervised Self-Driving milestone
Tesla Robotaxi will be a 24/7 service: here’s when
