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93 points cratermoon | 2 comments | | HN request time: 0s | source
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mapt ◴[] No.42198516[source]
The current trajectory is that SpaceX proved the commercial and military viability of an LEO megaconstellation, repeatedly lowering their target altitudes and raising their satellite count because of debris and cell size concerns...

And now the rest of the world is trying to catch up in a sort of arms race, and not taking any care about debris concerns. The most tempting orbits are the ones in upper LEO that permit them to launch fewer satellites.

SpaceX are going to end up well under 500km (orbital lifespan: a decade) before things are finished, and they switched to very low orbit staging with SEP spiral out to reach final orbit a ways back.

China's newest constellation Thousand Sails is at an altitude of 800km (orbital lifespan: thousands of years), with a thousand satellites in the works over the next year or so and 14,000 planned, and they're launching them using chemical upper stages designed to explode into a thousand pieces at the target altitude. This is sufficient for Kessler Syndrome all on its own, without counting interactions with anything else up there. A catastropic debris cascade at 800km percolates down to lower altitudes over time and impacts.

We need viable treaties limiting development beyond 400 or 500km and we need them ten years ago.

I don't know how to sell the urgency of this predicament. You can have as many satellites as you want, a million uncoordinated bodies, at 400km because direct collision potential scales with (satellite count / orbital lifespan) ^2 . At 1000km, satellites decay so slowly we are already too crowded; we have already overused the space. We are speed-running the end of the space age and we are doing it to save a small number of dollars and to avoid a small amount of diplomacy.

This is not something we get a do-over on. There is no practical way to collect ton-scale debris at present, no way to track kilogram-scale debris, no practical way to shield pressure vessels against gram-scale debris, and even milligram-scale debris can hit with the force of a bullet. After collisions start occurring at a rapid clip, the mass of potential impactors quickly forms a long tailed lognormal distribution that denies us space for centuries.

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bamboozled ◴[] No.42198775[source]
One way is for the the US to be more politically stable again (some how). Every country with an army will want its own star link now for trust reasons.
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nradov ◴[] No.42200796[source]
The US is politically stable already (by historical and international standards), and has been since 1865. If you ignore the rhetoric and focus on actions there has been very little substantiative difference in foreign policy across the last 7 presidential administrations.
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dangerwill ◴[] No.42201189{3}[source]
The US civil war is not the only time the US has been politically unstable. The civil rights movement, the labor disputes of the 1970s, the economic shocks every decade or so from market crashes all have been moments of instability.

What is January 6th if not a concrete example of recent political instability?

As for foreign policy consistency, 7 administrations takes us back to Reagan... The entire movement to sell out our industrial capacity to China and now the movement to try to reverse that have occurred in this time frame. This is just as important as our endless wars in the middle east, imo.

I don't disagree totally but I felt the need to put some nuance here.

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1. nradov ◴[] No.42201528{4}[source]
Stability doesn't mean statis. The USA has been remarkably resilient to those minor shocks you listed. It continues to be the most politically stable of all the countries that actually count for anything in international affairs.
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2. lucianbr ◴[] No.42202574[source]
If some catastrophic event is required to define instability, then by definition any country will be stable right until one second before catastrophe. This may work fine for certain analyses, but for predicting if or when that event may happen it is useless.

You're saying "nothing bad will happen because nothing bad has happened so far". There's a first time for everything.