For humans and satellites alike, making a living in space is hard. First, there’s the problem of surviving the brief but energetic and failure-prone ride there, after which you get to alternately roast and freeze as you zip around the planet at 20 times the speed of sound. The latter fact is made all the more dangerous by the swarm of space debris, both natural and man-made, that whizzes away up there along with you, waiting to cause an accident.
One such accident has apparently led to the early demise of a Russian weather satellite. Just a few months after launch, Meteor-M 2-2 suffered a sudden orbital anomaly (link to Russian story; English translation). Analysis of the data makes it pretty clear what happened: the satellite was struck by something, and despite some ground-controller heroics which appear to have stabilized the spacecraft, the odds are that Meteor-M 2-2 will eventually succumb to its wounds.
In the early days of spaceflight, when only the governments of the United States and the Soviet Union had the ability to put an object into orbit, even the most fanciful of futurists would have had a hard time believing that commercial entities would one day be launching sixty satellites at a time. What once seemed like an infinite expanse above our heads is now starting to look quite a bit smaller, and it’s only going to get more crowded as time goes on. SpaceX is gearing up to launch nearly 12,000 individual satellites for their Starlink network by the mid-2020s, and that’s just one of the “mega constellations” currently in the works.
It might seem like overcrowding of Earth orbit is a concern for the distant future, but one needs only look at recent events to see the first hints of trouble. On September 2nd, the European Space Agency announced that one of its research spacecraft had to perform an evasive maneuver due to a higher than acceptable risk of colliding with one of the first-generation Starlink satellites. Just two weeks later, Bigelow Aerospace were informed by the United States Air Force that there was a 1 in 20 chance that a defunct Russian Cosmos 1300 satellite would strike their Genesis II space station prototype.
A collision between two satellites in orbit is almost certain to be catastrophic, ending with both spacecraft either completely destroyed or severely damaged. But in the worst case, the relative velocity between the vehicles can be so great that the impact generates thousands of individual fragments. The resulting cloud of shrapnel can circle the Earth for years or even decades, threatening to tear apart any spacecraft unlucky enough to pass by.
Fortunately avoiding these collisions shouldn’t be difficult, assuming everyone can get on the same page before it’s too late. The recently formed Space Safety Coalition (SSC) is made up of more than twenty aerospace companies that realize the importance of taking proactive steps to ensure humanity retains the unfettered access to outer space by establishing some common “Rules of the Road” for future spacecraft.
Who has dibs on space debris? If getting to it were a solved problem, it sure would be fun to use dead orbital hardware as something of a hacker’s junk bin. Turns out there is some precedent for this, and regulations already in place in the international community.
To get you into the right frame of mind: it’s once again 2100 AD and hackers are living in mile-long space habitats in the Earth-Moon system. But from where do those hackers get their raw material, their hardware? The system abounds with space debris, defunct satellites from a century of technological progress. According to Earth maritime law, if space is to be treated like international waters then the right of salvage would permit them to take parts from any derelict. But is space like international waters? Or would hacking space debris result in doing hard time in the ice mines of Ceres?
Space is a mess, and the sad truth is, we made it that way. Most satellites that have been lofted into Earth orbit didn’t have a plan for retiring them, and those dead hulks, along with the various bits of jetsam in the form of shrouds, fairings, and at least one astronaut’s glove, are becoming a problem.
A mission intended to clean up space junk would be fantastically expensive, but money isn’t the only problem. It turns out that it’s really hard to grab objects in space unless they were specifically designed to be grabbed. Suction cups won’t work in the vacuum of space, not everything up there is ferromagnetic, and mechanical grippers would have to deal with a huge variety of shapes, sizes, and textures.
But now news comes from Stanford University of a dry adhesive based on the same principle a gecko uses to walk up a wall. Gecko feet have microscopic flaps that stick to surfaces because of Van der Waals forces. [Mark Cutkosky] and his team’s adhesive works similarly, adhering to surfaces only when applied in a certain direction. This is an advantage over traditional pressure-sensitive adhesives; the force needed to apply them would cause the object to float away in space. The Stanford grippers have been tested on the “vomit comet” and aboard the ISS.
We can think of tons of terrestrial applications for this adhesive, including the obvious wall-walking robots. The Stanford team also lists landing pads for drones that would let then perch in odd locations, which we find intriguing.