The skyhook solution | Hacker News Reader

The skyhook solution

aeon.co

26 pointsHooke29 comments

There's a team of three young guys who have started a company to harvest space junk. NASA likes their technology and has given them a contract to harvest some Apollo era rocket boosters floating in a bad spot. So what is the problem? They're in Michigan's upper peninsula and what they're doing is too risky for Midwest VC's. I've heard their presentation and was impressed with them.

So why are they in Michigan's upper peninsula? It's not as strange as it sounds. All three met while students at Northern Michigan University. Ninety miles away is the campus of Michigan Tech University which is the mining industry's MIT. Few people know it but NASA actually launched satellites nearby in the sixties and early seventies. A lot of people that had the skills to help weren't excited in living that far North. So Michigan Tech with NASA's assistance created a space technology curriculum.

Course that provides a steady stream of recent graduates that can stay in the upper peninsula after school. I am surprised the state of Michigan hasn't found a way to help these guys.

https://www.secondwavemedia.com/upword/features/kmicompany.a...

>They're in Michigan's upper peninsula and what they're doing is too risky for Midwest VC's.

Can't they connect with VCs anywhere in the world over the internet?

I don't know, perhaps they have by now. But it is typical for local founders to start pitching in the Midwest. Midwest VC's are generally more conservative and I've never seen them invest in space related ventures.

> Michigan Tech University, which is the mining industry's MIT

ehhh...Colorado School of Mines is a much more significant powerhouse in the mining industry. I say this as an MTU alum.

> I am surprised the state of Michigan hasn't found a way to help these guys.

Not really surprised, Upper Peninsula doesn't afford many political connections. Families who go to that school aren't well-connected and typically earn quite a bit less than families at University of Michigan. Distance matters too -- it's a very, very long drive so there's not a lot of cross-pollination between the political centers and population centers and the Keweenaw Peninsula.

It's isolated enough from the rest of Michigan that the McDonald's by Michigan Tech is an official supporter of the Green Bay Packers, not Detroit Lions. Wisconsin and Minnesota students pay in-state tuition there. It's really not "Michigan", culturally. It's also very sparsely populated -- the nearest Wendy's is a two-hour drive away.

I'm sorry, "harvest space junk"? How on earth could that possibly be profitable? There is zero mystery why any VC, Midwest or otherwise, would not be interested in that business model.

Isn’t it a simple case of NASA is paying for a contract so if we do it with a good enough margin we make a profit?

Its really a play on real estate. There are a finite number of spots available in geo-synchronous orbit. Plenty of long dead satellites that could provide new spots if only they were placed in a lower orbit where they would eventually crash into the Pacific ocean.

The only reason that there isn't an active market is because there is no way to free up space. Once there is such a method I predict there will be auctions for prime spots.

This makes no sense to me. Most talk about "recycling" space junk forgets that it's a lot like recycling bullets on a battlefield. The mass is there, but good luck catching it.

I imagine there is quite an investment simply bringing all the stuff together into identical orbits. Like "waste heat", part of the problem is the disorder.

If all you need is mass, it might be more profitable to send a robot to a small asteroid and nudge it on its way towards us.

> simply bringing all the stuff together into identical orbits

This only works for orbits of similar inclination, unfortunately. Shifting orbital planes is prohibitively expensive in terms of energy due to the conservation of angular momentum [1] and the rocket equation.

It might work for similar-enough orbits, though.

[1] https://orbital-mechanics.space/orbital-maneuvers/plane-chan...

We don't have to solve all of it, only a significant amount.

Also, perhaps the most important thing to solve is a proof of concept - that we can remove any space junk. From there we can start to compare and refine ideas to figure out what the possible solutions are.

In addition you're attempting to recycle space junk ("bullets") when you're quite literally standing on planet packed to rafters with junk. The energy required to harvest the material in orbit makes it extremely hard to make a case that it is economical.

You didn't read the article. The point is that you want to use the space junk as a mass filler for your skyhook. The skyhook needs a lot of mass, a thousand times more mass than the payload. To boost a 100 ton payload, you need a 10000 ton skyhook. Junk on earth is worthless as that has to be launched into LEO.

My biggest concern however is how they are going to keep the skyhook rotating. If it needs energy from earth the entire concept is kind of meaningless.

The book Seveneves has a lot of vivid descriptions of futuristic orbital mechanics solutions.

It's a bit of a heavy read emotionally but it's very rare to find hard sci-fi of that quality.

I actually don't think the later orbital development makes any sense at all. Assuming you could even build it, and I think that's doubtful, it's almost certain to get trashed along large enough time spans, and the problems it would cause clearly outweigh any benefits. See Chasm City by Alastair Reynolds for a modification of physics that allows such structures but shows why it's a bad idea anyway. Does the same thing for mind uploading, in case you are interested.

Currently reading this and thought the same. Lots of scenarios I hadn't considered, and fun to see IRL work in the same vein.

Makes me think of the anime/manga Planetes, which follows the lives of future, er, space waste sanitation engineers.

Or the short story Tank Farm Dynamo, by David Brin.

This is not about the one you think - that was used by Batman.

The Fulton surface-to-air recovery system (STARS)[1], also known as Skyhook, is a system used by the Central Intelligence Agency (CIA), United States Air Force, and United States Navy for retrieving individuals on the ground using aircraft such as the MC-130E Combat Talon I and B-17 Flying Fortress. It involves using an overall-type harness and a self-inflating balloon with an attached lift line. An MC-130E engages the line with its V-shaped yoke and the person is reeled on board. Red flags on the lift line guide the pilot during daylight recoveries; lights on the lift line are used for night recoveries. Recovery kits were designed for one- and two-man retrievals.

https://en.wikipedia.org/wiki/Fulton_surface-to-air_recovery...

Picking up people from the ground with a plane sounds... batshit insane. Almost on the level of individual reentry decelerators like MOOSE.

My favorite part: "After experiments with instrumented dummies, Fulton continued to experiment with live pigs, as pigs have a nervous system close to humans. Lifted off the ground, the pig began to spin as it flew through the air at 125 miles per hour (200 km/h). It arrived on board uninjured, but in a disoriented state. When it recovered, it attacked the crew.[3]"

I didn't know this was actually real. I couldn't tell if it was real or fake when I saw it used during the final moments of a Bond movie.

TBH I think catching spy satellite film cannister re-entry vehicles, during their descent stage in the air, with aircraft was slightly more impressive.

I think a bond movie used that as a plot point at one point too, again based on reality.

(Although the 'film canister' vehicles were larger than most people would imagine, I guess)

https://www.wearethemighty.com/mighty-history/air-force-caug...

What if, for every ton of material lifted into orbit, the company doing the lifting was required to remove a ton of debris from orbit?

Yes I know government regulations make it all so much more difficult - paraphrasing Sam Bankman-Fried.

Hey I have a pitch for you... unfortunately, it will require you to work your sorry asses off for about three decades to make it work out, are you down for that, you bloated VC ticks?

I don't understand how this proposed system would work. Doesn't accelerating some payload into its orbit drain inertia from the skyhook? If we need to continue supplying the skyhook with new inertia, how is that better than just boosting payloads?

there is an assumption that you will be deorbiting a similar mass on the return, which would mostly address the balance (with the exception of energy lost to atmospheric drag)

If you mean the system shown in the illustration in the article, the tether's orbit does change: the illustration shows the tether's orbit changing after it catches the payload and again after it releases the payload.

What is weird to me is that the tether's trajectory is shown as curving upward instead of downward. That doesn't make sense to me.

I was really hoping this would be about https://en.wikipedia.org/wiki/Darwin%27s_Dangerous_Idea#Skyh...

I was hoping yours was going to be this one: https://en.wikipedia.org/wiki/Fulton_surface-to-air_recovery...

After experiments with instrumented dummies, Fulton continued to experiment with live pigs, as pigs have a nervous system close to humans. Lifted off the ground, the pig began to spin as it flew through the air at 125 miles per hour (200 km/h). It arrived on board uninjured, but in a disoriented state. When it recovered, it attacked the crew.[3]

TLDR: 'Space junk' needn't just be tracked & dodged, or de-orbited; some of its materials & mass could be repurposed to remain of use in orbit. In particular, some large existing masses that would otherwise need to be safely de-orbited, like the ISS, could become anchors for the 'skyhook' method of moving other payloads from high-altitude into orbit, via long tethers extending downward from the anchors.

Reply on news.ycombinator.com