The Myth Of Propellantless Space Propulsion Refuses To Die

In a Universe ruled by the harsh and unyielding laws of Physics, it’s often tempting to dream of mechanisms which defy these rigid restrictions. Although over the past hundred years we have made astounding progress in uncovering ways to work within these restrictions — including splitting and fusing atoms to liberate immense amounts of energy — there are those who dream of making reality a bit more magical. The concept of asymmetrical electrostatic propulsion is a major player here, with the EmDrive the infamous example. More recently [Dr. Charles Buhler] proposed trying it again, as part of his company Exodus Propulsion Technologies.

This slide from Dr. Buhler’s APEC presentation shows the custom-made vacuum chamber built to test their propellantless Propulsion drive in a simulated space environment. Image Credit: Exodus Propulsion Technologies, Buhler, et al.
This slide from Dr. Buhler’s APEC presentation shows the custom-made vacuum chamber built to test their propellantless Propulsion drive in a simulated space environment. Image Credit: Exodus Propulsion Technologies, Buhler, et al.

The problem with such propellantless space propulsion proposals is that they violate the core what we know about the physical rules, such as the conclusion by Newton that for any action there has to be an opposite reaction. If you induce an electrostatic field or whatever in some kind of device, you’d expect any kind of force (‘thrust’) this creates to act in all directions equally, ergo for thrust to exist, it has to push on something in the other direction. Rocket and ion engines (thrusters) solve this by using propellant that create the reaction mass.

The EmDrive was firmly disproven 2021 by [M. Tajmar] and colleagues in their paper titled High-accuracy thrust measurements of the EMDrive and elimination of false-positive effects as published in CEAS Space Journal, which had the researchers isolate the EmDrive from all possible outside influences. Since the reported thrust was on the level of a merest fraction of a Newton, even the impact from lighting in a room and body heat from the researchers can throw off the results, not to mention the heat developed from a microwave emitter as used in the EmDrive.

Meanwhile True Believers flock to the ‘Alt Propulsion Engineering Conference’ (APEC), as no self-respecting conference or scientific paper will accept such wishful claims. In the case of [Buhler], he claims that their new-and-improved EmDrive shows a force of 10 mN in a ‘stacked system’, yet no credible paper on the experiments can be found other than APEC presentations. Until their prototype is tested the way the EmDrive was tested by [M. Tajmar] et al., it seems fair to assume that the rules of physics as we know them today remain firmly intact.

NASA’s Voyager 1 Resumes Sending Engineering Updates To Earth

After many tense months, it seems that thanks to a gaggle of brilliant engineering talent and a lucky break the Voyager 1 spacecraft is once more back in action. Confirmation came on April 20th, when Voyager 1 transmitted its first data since it fell silent on November 14 2023. As previously suspected, the issue was a defective memory chip in the flight data system (FDS), which among other things is responsible for preparing the data it receives from other systems before it is transmitted back to Earth. As at this point in time Voyager 1 is at an approximate 24 billion kilometers distance, this made for a few tense days for those involved.

The firmware patch that got sent over on April 18th contained an initial test to validate the theory, moving the code responsible for the engineering data packaging to a new spot in the FDS memory. If the theory was correct, this should mean that this time the correct data should be sent back from Voyager. Twice a 22.5 hour trip and change through Deep Space and back later on April 20th the team was ecstatic to see what they had hoped for.

With this initial test successful, the team can now move on to moving the remaining code away from the faulty memory after which regular science operations should resume, and giving the plucky spacecraft a new lease on life at the still tender age of 46.

NASA’s Ingenuity Mars Helicopter Transitions Into Stationary Testbed

On April 16th NASA announced the formal end to Ingenuity’s days as the first ever Martian helicopter, following its 72nd and final flight mission in January. This flight ended with a rough landing during which the helicopter’s blades got damaged and separated, leaving the plucky flying machine with its wings clipped. During the final meet-up of the Mars Helicopter Team there was cake, but none for Ingenuity as its latest data set was reviewed by the team from 304 million kilometers away. This data confirms the latest software patch allows it to work stand-alone as a data collection platform.

With these latest software changes, Ingenuity will wake up daily, activate its computers and perform a self-check of all its components before collecting sensor data and images. The main goal of this is to collect long-term performance data on the helicopter’s systems, with enough onboard memory to allow for measurements to be stored for around 20 years. This means that although the Perseverance rover will have to trundle on without its flying mission buddy, one day in the future another rover, helicopter or primate will presumably drop by to either communicate with Ingenuity if it’s still alive, or harvest its memory unit for data retrieval.

Thanks to [Mark Stevens] for the tip.

Chandra X-ray Observatory Threatened By Budget Cuts

Launched aboard the Space Shuttle Columbia in July of 1999, the Chandra X-ray Observatory is the most capable space telescope of its kind. As of this writing, the spacecraft is in good health and is returning valuable scientific data. It’s currently in an orbit that extends at its highest point to nearly one-third the distance to the Moon, which gives it an ideal vantage point from which to make its observations, and won’t reenter the Earth’s atmosphere for hundreds if not thousands of years.

Yet despite this rosy report card, Chandra’s future is anything but certain. Faced with the impossible task of funding all of its scientific missions with the relative pittance they’re allocated from the federal government, NASA has signaled its intent to wind down the space telescope’s operations over the next several years. According to their latest budget request, the agency wants to slash the program’s $41 million budget nearly in half for 2026. Funding would remain stable at that point for the next two years, but in 2029, the money set aside for Chandra would be dropped to just $5.2 million.

Drastically reducing Chandra’s budget by the end of the decade wouldn’t be so unexpected if its successor was due to come online in a similar time frame. Indeed, it would almost be expected. But despite being considered a high scientific priority, the x-ray observatory intended to replace Chandra isn’t even off the drawing board yet. The 2019 concept study report for what NASA is currently calling the Lynx X-ray Observatory estimates a launch date in the mid-2030s at the absolute earliest, pointing out that several of the key components of the proposed telescope still need several years of development before they’ll reach the necessary Technology Readiness Level (TRL) for such a high profile mission.

With its replacement for this uniquely capable space telescope decades away even by the most optimistic of estimates, the  potential early retirement of the Chandra X-ray Observatory has many researchers concerned about the gap it will leave in our ability to study the cosmos.

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Voyager 1 Issue Tracked Down To Defective Memory Chip

After more than forty-six years all of us are likely to feel the wear of time, and Voyager 1 is no different. Following months of harrowing troubleshooting as the far-flung spacecraft stopped returning sensible data, NASA engineers now feel confident that they have tracked down the cause for the problem: a single defective memory chip. Why this particular chip failed is unknown, but possibilities range from wear and tear to an energetic particle hitting it and disrupting its operation.

We’ve covered the Voyager 1 troubleshooting saga so far, with the initial garbled responses attributed to a range of systems, but narrowed down to the Flight Data Subsystem (FDS), which prepares data for transmission by the telemetry modulation unit (TMU). Based on a recent ‘poke’ command that returned a memory dump engineers concluded that the approximately 3% of corrupted data fit with this one memory chip, opening the possibility of a workaround.

Recently NASA engineers have also been working on patching up the firmware in both Voyager spacecraft, against the background of the dwindling energy produced by the radioisotope generators that have kept both spacecraft powered and warm, even in the cold, dark depths of Deep Space far beyond the light of our Sun.

An image of the surface of Europa. The top half of the sphere is illuminated with the bottom half dark. The surface is traced with lineae, long lines across its surface of various hues of grey, white, and brown. The surface is a brown-grey, somewhat like Earth's Moon with the highest brightness areas appearing white.

Europa Clipper Asks Big Questions Of The Jovian Moon

Are we alone? While we certainly have lots of strange lifeforms to choose from as companions here on our blue marble, we have yet to know if there’s anything else alive out there in the vastness of space. One of the most promising places to look in our own solar neighborhood is Europa.

People in bunny suits swarm underneath the main section of the Europa Clipper. It is predominantly white, with various tubes and structures of silver metal protruding and many pieces of yellow kapton tape are visible. A large orange module is strapped to the side around the middle of the semi-cylindrical craft. Several other dark orange metallic plates that are much smaller adorn various pieces of the craft. It looks both chonky and delicate at the same time. Underneath its icy surface, Europa appears to have a sea that contains twice as much water as we have here on Earth. Launching later this year and arriving in 2030, NASA’s Europa Clipper will provide us with our most up-close-and-personal look at the Jovian Moon yet. In conjunction with observations from the ESA’s Jupiter Icy Moons Explorer (JUICE), scientists hope to gain enough new data to see if the conditions are right for life.

Given the massive amounts of radiation in the Jovian system, Europa Clipper will do 50 flybys of the moon over the course of four years to reduce damage to instruments as well as give it windows to transmit data back to Earth with less interference. With enough planning and luck, the mission could find promising sites for a future lander that might be able to better answer the question of if there actually is life on other worlds.

Some of the other moons around Jupiter could host life, like Io. Looking for life a little closer? How about on our nearest neighbor, Venus, or the ever popular Mars?

Space Mirrors: Dreams Of Turning The Night Into Day Around The Clock

Recently, a company by former SpaceX employee Ben Nowack – called Reflect Orbital – announced that it is now ready to put gigantic mirrors in space to reflect sunshine at ground-based solar farms. This is an idea that’s been around for a hundred years already, both for purposes of defeating the night through reflecting sunshine onto the surface, as well as to reject the same sunshine and reduce the surface temperature. The central question here is perhaps what the effect would be of adding or subtracting (or both) of solar irradiation on such a large scale as suggested?

We know the effect of light pollution from e.g. cities and street lighting already, which suggests that light pollution is a strongly negative factor for the survival of many species. Meanwhile a reduction in sunshine is already a part of the seasons of Autumn and Winter. Undeniable is that the Sun’s rays are essential to life on Earth, while the day-night cycle (as well as the seasons) created by the Earth’s rotation form an integral part of everything from sleep- and hibernation cycles, to the reproduction of countless species of plants, insects, mammals and everyone’s favorite feathered theropods.

With these effects and the gigantic financial investments required in mind, is there any point to space-based mirrors?

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