A New Generation Of Spacecraft Head To The ISS

While many in the industry were at first skeptical of NASA’s goal to put resupply flights to the International Space Station in the hands of commercial operators, the results speak for themselves. Since 2012, the SpaceX Dragon family of spacecraft has been transporting crew and cargo from American soil to the orbiting laboratory, a capability that the space agency had lost with the retirement of the Space Shuttle. Putting these relatively routine missions in the hands of a commercial provider like SpaceX takes some of the logistical and financial burden off of NASA, allowing them to focus on more forward-looking projects.

SpaceX Dragon arriving at the ISS for the first time in 2012.

But as the saying goes, you should never put all of your eggs in one basket. As successful as SpaceX has been, there’s always a chance that some issue could temporarily ground either the Falcon 9 or the Dragon.

While Russia’s Progress and Soyuz vehicles would still be available in an emergency situation, it’s in everyone’s best interest that there be multiple backup vehicles that can bring critical supplies to the Station.

Which is precisely why several new or upgraded spacecraft, designed specifically for performing resupply missions to the ISS and any potential commercial successor, are coming online over the next few years.

In fact, one of them is already flying its first mission, and will likely have arrived at the International Space Station by the time you read this article.

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Dragon Is The Latest, And Final, Craft To Reboost ISS

The International Space Station has been in orbit around the Earth, at least in some form, since November of 1998 — but not without help. In the vacuum of space, an object in orbit can generally be counted on to remain zipping around more or less forever, but the Station is low enough to experience a bit of atmospheric drag. It isn’t much, but it saps enough velocity from the Station that without regular “reboosts” to speed it back up , the orbiting complex would eventually come crashing down.

Naturally, the United States and Russia were aware of this when they set out to assemble the Station. That’s why early core modules such as Zarya and Zvezda came equipped with thrusters that could be used to not only rotate the complex about all axes, but accelerate it to counteract the impact of drag. Eventually the thrusters on Zarya were disabled, and its propellant tanks were plumbed into Zvezda’s fuel system to provide additional capacity.

An early image of ISS, Zarya module in center and Zvezda at far right.

Visiting spacecraft attached to the Russian side of the ISS can transfer propellant into these combined tanks, and they’ve been topped off regularly over the years. In fact, the NASA paper A Review of In-Space Propellant Transfer Capabilities and Challenges for Missions Involving Propellant Resupply, notes this as one of the most significant examples of practical propellant transfer between orbital vehicles, with more than 40,000 kgs of propellants pumped into the ISS as of 2019.

But while the thrusters on Zvezda are still available for use, it turns out there’s an easier way to accelerate the Station; visiting spacecraft can literally push the orbital complex with their own maneuvering thrusters. Of course this is somewhat easier said than done, and not all vehicles have been able to accomplish the feat, but over the decades several craft have taken on the burden of lifting the ISS into a higher orbit.

Earlier this month, a specially modified SpaceX Cargo Dragon became the newest addition to the list of spacecraft that can perform a reboost. The craft will boost the Station several times over the rest of the year, which will provide valuable data for when it comes time to reverse the process and de-orbit the ISS in the future.

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The Sense And Nonsense Of Virtual Power Plants

Over the past decades power grids have undergone a transformation towards smaller and more intermittent generators – primarily in the form of wind and solar generators – as well as smaller grid-connected batteries. This poses a significant problem when it comes to grid management, as this relies on careful management of supply and demand. Quite recently the term Virtual Power Plant (VPP) was coined to describe these aggregations of disparate resources into something that at least superficially can be treated more or less as a regular dispatchable power plant, capable of increasing and reducing output as required.

Although not actual singular power plants, by purportedly making a VPP act like one, the claim is that this provides the benefits of large plants such as gas-fired turbines at a fraction of a cost, and with significant more redundancy as the failure of a singular generator or battery is easily compensated for within the system.

The question is thus whether this premise truly holds up, or whether there are hidden costs that the marketing glosses over.

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The Browser Wasn’t Enough, Google Wants To Control All Your Software

A few days ago we brought you word that Google was looking to crack down on “sideloaded” Android applications. That is, software packages installed from outside of the mobile operating system’s official repository. Unsurprisingly, a number of readers were outraged at the proposed changes. Android’s open nature, at least in comparison to other mobile operating systems, is what attracted many users to it in the first place. Seeing the platform slowly move towards its own walled garden approach is concerning, especially as it leaves the fate of popular services such as the F-Droid free and open source software (FOSS) repository in question.

But for those who’ve been keeping and eye out for such things, this latest move by Google to throw their weight around isn’t exactly unexpected. They had the goodwill of the community when they decided to develop an open source browser engine to keep the likes of Microsoft from taking over the Internet and dictating the rules, but now Google has arguably become exactly what they once set out to destroy.

Today they essentially control the Internet, at least as the average person sees it, they control 72% of the mobile phone OS market, and now they want to firm up their already outsized control which apps get installed on your phone. The only question is whether or not we let them get away with it.

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Ask Hackaday: Where Are All The Fuel Cells?

Given all the incredible technology developed or improved during the Apollo program, it’s impossible to pick out just one piece of hardware that made humanity’s first crewed landing on another celestial body possible. But if you had to make a list of the top ten most important pieces of gear stacked on top of the Saturn V back in 1969, the fuel cell would have to place pretty high up there.

Apollo fuel cell. Credit: James Humphreys

Smaller and lighter than batteries of the era, each of the three alkaline fuel cells (AFCs) used in the Apollo Service Module could produce up to 2,300 watts of power when fed liquid hydrogen and liquid oxygen, the latter of which the spacecraft needed to bring along anyway for its life support system. The best part was, as a byproduct of the reaction, the fuel cells produced drinkable water.

The AFC was about as perfectly suited to human spaceflight as you could get, so when NASA was designing the Space Shuttle a few years later, it’s no surprise that they decided to make them the vehicle’s primary electrical power source. While each Orbiter did have backup batteries for emergency purposes, the fuel cells were responsible for powering the vehicle from a few minutes before launch all the way to landing. There was no Plan B. If an issue came up with the fuel cells, the mission would be cut short and the crew would head back home — an event that actually did happen a few times during the Shuttle’s 30 year career.

This might seem like an incredible amount of faith for NASA to put into such a new technology, but in reality, fuel cells weren’t really all that new even then. The space agency first tested their suitability for crewed spacecraft during the later Gemini missions in 1965, and Francis Thomas Bacon developed the core technology all the way back in 1932.

So one has to ask…if fuel cell technology is nearly 100 years old, and was reliable and capable enough to send astronauts to the Moon back in 1960s, why don’t we see them used more today?

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Death Of The Cheque: Australia Moves On

Check (or cheques) have long been a standard way for moving money from one bank account to another. They’re essentially little more than a codified document that puts the necessary information in a standard format to ease processing by all parties involved in a given transaction.

The check was once a routine, if tedious, way for the average person to pay for things like bills, rent, or even groceries. As their relevance continues to wane in the face of newer technology, though, the Australian government is making a plan to phase them out for good.

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How To Sink A Ship: Preparing The SS United States For Its Final Journey

When we last brought you word of the SS United States, the future of the storied vessel was unclear. Since 1996, the 990 foot (302 meter) ship — the largest ocean liner ever to be constructed in the United States — had been wasting away at Pier 82 in Philadelphia. While the SS United States Conservancy was formed in 2009 to support the ship financially and attempt to redevelop it into a tourist attraction, their limited funding meant little could be done to restore or even maintain it. In January of 2024, frustrated by the lack of progress, the owners of the pier took the Conservancy to court and began the process of evicting the once-great liner.

SS United States docked at Pier 82 in Philadelphia

It was hoped that a last-minute investor might appear, allowing the Conservancy to move the ship to a new home. But unfortunately, the only offer that came in wasn’t quite what fans of the vessel had in mind: Florida’s Okaloosa County offered $1 million to purchase the ship so they could sink it and turn it into the world’s largest artificial reef.

The Conservancy originally considered it a contingency offer, stating that they would only accept it if no other options to save the ship presented themselves. But by October of 2024, with time running out, they accepted Okaloosa’s offer as a more preferable fate for the United States than being scrapped.

It at least means the ship will remain intact — acting not only as an important refuge for aquatic life, but as a destination for recreational divers for decades to come. The Conservancy has also announced plans to open a museum in Okaloosa, where artifacts from the ship will be on display.

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