Starlink’s Inter-Satellite Laser Links Are Setting New Record With 42 Million GB Per Day

February 5, 2024 by Maya Posch 44 Comments

Slide from the SpaceX Starlink presentation on mesh routing via the laser links. (Credit: PCMag/Michael Kan)

Although laser communication in space is far from novel, its wide-scale deployment as seen with SpaceX’s Starlink satellite internet constellation has brought the technology to the forefront like never before. This was quite apparent during the SPIE Photonics West event on January 30th when [Michael Kan] and other journalists attended a presentation by SpaceX’s [Travis Brashears] on the inter-satellite laser communication performance that was first enabled with the Starlink v1.5 satellites.

Among currently active inter-satellite communication systems, Starlink is by far the most numerous and with the highest bandwidth, reaching over 42 PB per day across its over 9000 space lasers (yes, that is over 9000) for a 5.6 Tbps throughput. Since these satellites form a mesh network with their 100 Gbps laser transceivers, a big part of using it efficiently is to route any data with the least amount of latency while taking into account link distance (maximum of 5,400 km), link duration (up to multiple weeks) and presence of other Starlink satellites before they become within reach. With this complex mesh in LEO, this also means that a very high uptime can be accomplished, with a claimed 99.99% due to rapid route changing.

For the future, SpaceX has plans to not only keep upgrading its own Starlink satellites with better laser transceivers, but to also make them available to third-party satellites, as well as beam the lasers directly down to Earth for ground-based transceivers. The latter is still cutting edge, despite it being tested to beam cat videos to Earth from Deep Space.

Decoding JS1YMG: First Ham Radio Station On The Moon After SLIM Mission

February 4, 2024 by Maya Posch 14 Comments

When Japan’s SLIM lunar lander made a rather unconventional touch-down on the lunar surface, it had already disgorged two small lunar excursion vehicles from its innards: LEV-1 and LEV-2. Of these, the LEV-1 is not only capable of direct to Earth transmission, but it also has been assigned its own amateur radio license: JS1YMG, which makes it the first Ham radio station on the Moon. LEV-1 receives data from LEV-2, which is transmitted to Earth using its 1 Watt UHF circular polarization antenna as Morse code at 437.410 MHz. Although the data format hasn’t been published, [Daniel Estévez] (EA4GPZ) has been sleuthing around to figure it out.

Using captures from the 25 meter radiotelescope at Dwingeloo in the Netherlands, [Daniel] set to work deciphering what he knew to be telemetry data following a CCSDS standard. After some mix-and-matching he found that the encoding matched PCM/PSK/PM with a symbol rate of 64 baud and 2048 kHz subcarrier. The residual carrier is modulated in amplitude with Morse code, but initially this Morse code made no sense.

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The Past, Present, And Future Of Inflatable Space Habitats

January 30, 2024 by Tom Nardi 24 Comments

Recently, a prototype inflatable space station module built by Sierra Space exploded violently on a test stand at NASA’s Marshall Space Flight Center in Alabama. Under normal circumstances, this would be a bad thing. But in this case, Sierra was looking forward to blowing up their handiwork. In fact, there was some disappointment when it failed to explode during a previous test run.

That’s because the team at Sierra was looking to find the ultimate bust pressure of their 8.2 meter (26.9 foot) diameter Large Integrated Flexible Environment (LIFE) module — a real-world demonstration of just how much air could be pumped into the expanding structure before it buckled. NASA recommended they shoot for just under 61 PSI, which would be four times the expected operational pressure for a crewed habitat module.

By the time the full-scale LIFE prototype ripped itself apart, it had an internal pressure of 77 PSI. The results so far seem extremely promising, but Sierra will need to repeat the test at least two more times to be sure their materials and construction techniques can withstand the rigors of spaceflight.

Sierra is a targeting no earlier than 2026 for an in-space test, but even if they nail the date (always a dubious prospect for cutting edge aerospace projects), they’ll still be about 20 years late to the party. Despite how futuristic the idea of inflatable space stations may seem, NASA first started experimenting with the concept of expandable habitat modules back in the 1990s, and there were practical examples being launched into orbit by the early 2000s.

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Ingenuity May Be Grounded, But Its Legacy Will Be Grand

January 30, 2024 by Donald Papp 11 Comments

[Eric Berger] has a thoughtful and detailed article explaining why Ingenuity, NASA’s small helicopter on Mars, was probably far more revolutionary than many realize, and has a legacy to grant the future of off-world exploration that is already being felt.

Ingenuity was recently grounded due to rotor damage, having already performed far beyond the scope of its original mission. The damage, visible by way of a shadow from one of the rotors, might not look like much at first glance, but flying in the vanishingly-thin atmosphere of Mars requires the 1.18 meter (3.9 foot) carbon fiber blades to spin at very high speeds — meaning even minor rotor damage could be devastating.

Perseverance and Ingenuity pose for a selfie on Mars.

[Eric] points out a lot that is deeply interesting and influential about Ingenuity. Not only is successful powered flight on another planet a real Wright brothers moment, but how Ingenuity came to be validates a profoundly different engineering approach for NASA.

To work in the space industry is to be constrained by mass. But even so, Ingenuity‘s creators had a mere four pounds to work with. That’s for rotors, hardware, electronics, batteries, solar panel — all of it. NASA’s lightest computer module alone weighed a pound, so engineers had no choice but to depart from the usual NASA way of doing things to get it done at all. Not everyone at NASA was on board. But Ingenuity worked, and it worked wonderfully.

Powered flight opens new doors, and not just for support roles like navigation planning. There’s real science that can be done if powered flight is on the table. For example, [Eric] points out that inaccessible terrain such as the Valles Marineris canyon on Mars is doubtlessly scientifically fascinating, but at 4,000 km long and up to 7 km deep, rover-based exploration is not an option.

So Long And Thanks For All The Flights: Ingenuity Permanently Grounded After 72 Flights

January 25, 2024 by Dan Maloney 43 Comments

Just a few hours ago, NASA dropped some devastating news: Ingenuity will fly no more. Three years after dropping from the belly of the Perseverance rover and after 72 flights through the thin Martian atmosphere, the little helicopter that could now can’t, after having sustained damage to one or more of its rotors during its final landing.

Shadow of *Ingenuity*‘s rotor blade, showing damage suffered during a rough landing.

NASA’s terminal diagnosis of Ingenuity comes from a photo from one of the helicopter’s cameras, which shows a chunk missing from the tip of one of its rotors, likely caused by a rough landing after transiting a flat, sandy area that may have confused the aircraft’s navigational cameras.

While this is anything but good news, it’s not at all unexpected and in a way long overdue. Ingenuity was designed for a primary mission of just five flights, which it accomplished all the way back in May of 2021. There was heavy speculation at the time that Ingenuity might not even do that; we can recall one of the team members suggesting the odds were that Ingenuity’s tenure as the first controlled powered flying machine on another world would end as twisted wreckage in the newest, smallest crater on Mars.

But happily, Ingenuity proved the oddsmakers — and possibly those wishing to temper expectations — spectacularly wrong. In fact, by the fourth flight, it was clear that Ingenuity was in it for the long haul, enough so that NASA redefined its mission to “operational demonstration” and gave it another 30 sols of flight time. This gave the team the flight time needed to prove the helicopter’s worth as a scout for Perseverance and not just a distracting sideshow from the primary mission of searching for signs of ancient life on Mars.

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Crippled Peregrine Lander To Make Fiery Return Home

January 18, 2024 by Tom Nardi 9 Comments

Within a few hours of this post going live, Astrobotic’s Peregrine spacecraft is expected to burn up in the Earth’s atmosphere — a disappointing end to a mission that was supposed to put the first US lander on the Moon since the Apollo program ended in 1972.

In their twentieth mission update since Peregrine was carried into space on the inaugural flight of the United Launch Alliance Vulcan Centaur rocket, Astrobotic explains that the craft has been put on a trajectory designed to ensure it breaks up over a remote area of the South Pacific.

Predicted re-renty point for the *Peregrine* lander.

It was previously hoped the lander, which suffered a severe system malfunction just hours after liftoff, could have at least made a close pass of the Moon in lieu of touching down. But mission controllers felt the more responsible approach was to have Peregrine make a controlled re-entry while they still had the ability to maneuver it. The alternative, allowing the craft to remain in an uncontrolled orbit between the Earth and Moon, could potentially have caused problems for future Artemis missions.

Over the last ten days, ground controllers at Astrobotic have been working to piece together what happened to the doomed lander, while at the same time demonstrating a remarkable level of transparency by keeping the public informed along the way. It’s now believed that the stream of gas being expelled from a rupture in one of the craft’s propellant tanks was acting as a sort of impromptu thruster. This not only made the craft difficult to keep oriented, but also wasted the propellants that were necessary to perform a soft landing on the lunar surface.

Although the craft was eventually brought under control, the damage to the mission had already been done. While this obviously isn’t the ending that Astrobotic was hoping for, we have no doubt that the company collected valuable data during the craft’s flight through space, which took it approximately 390,000 kilometers (242,000 miles) from Earth.

As for us space nerds, we won’t have to wait long before another lunar lander makes its attempt. Japan’s Smart Lander for Investigating Moon (SLIM) should be touching down at around 10 AM Eastern on Friday (YouTube Live Stream), and the Nova-C lander from Intuitive Machines is scheduled to be launched aboard a Falcon 9 rocket sometime next month.

NASA Adjusts Course On Journey To The Moon

January 11, 2024 by Tom Nardi 61 Comments

It’s already been more than fifty years since a human last stepped foot on another celestial body, and now that NASA has officially pushed back key elements of their Artemis program, we’re going to be waiting a bit longer before it happens again. What’s a few years compared to half a century?

The January 9th press conference was billed as a way for NASA Administrator Bill Nelson and other high-ranking officials within the space agency to give the public an update on Artemis. But those who’ve been following the program had already guessed it would end up being the official concession that NASA simply wasn’t ready to send astronauts out for a lunar flyby this year as initially planned. Pushing back this second phase of the Artemis program naturally means delaying the subsequent missions as well, though during the conference it was noted that the Artemis III mission was already dealing with its own technical challenges.

More than just an acknowledgement of the Artemis delays, the press conference did include details on the specific issues that were holding up the program. In addition several team members were able to share information about the systems and components they’re responsible for, including insight into the hardware that’s already complete and what still needs more development time. Finally, the public was given an update on what NASA’s plans look like after landing on the Moon during the Artemis III mission, including their plans for constructing and utilizing the Lunar Gateway station.

With the understanding that even these latest plans are subject to potential changes or delays over the coming years, let’s take a look at the revised Artemis timeline.

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