CAP Talk

Operations => Tools of the trade => Topic started by: Live2Learn on December 15, 2017, 12:04:40 AM

Title: Space junk
Post by: Live2Learn on December 15, 2017, 12:04:40 AM
Space junk amount & hazard to Com/Nav satellites may be severely underestimated.  http://physicsworld.com/cws/article/news/2017/dec/11/space-debris-threat-to-geosynchronous-satellites-has-been-drastically-underestimated (http://physicsworld.com/cws/article/news/2017/dec/11/space-debris-threat-to-geosynchronous-satellites-has-been-drastically-underestimated)

Lotsa interesting implications for GPS, and dependent equipment.
Title: Re: Space junk
Post by: PHall on December 15, 2017, 01:12:25 AM
The GPS birds are in a lower orbit where's a LOT of space junk around. One of the reasons they have on-orbit spare satellites.
Title: Re: Space junk
Post by: ColonelJack on December 15, 2017, 11:51:35 AM
Well, if you listen to the "Flat Earth" group, there's nothing up there at all.  (How they can refute in-your-face science is beyond me.)

Jack
Title: Re: Space junk
Post by: vorteks on December 15, 2017, 02:29:26 PM
Quote
...all in the industry need to ensure that effective mitigation measures are implemented to avoid placing the entire market for GEO-based satellite services at risk

Mitigation measures such as......what? Article doesn't get into it.
Title: Re: Space junk
Post by: Live2Learn on December 15, 2017, 04:30:00 PM
Quote
...all in the industry need to ensure that effective mitigation measures are implemented to avoid placing the entire market for GEO-based satellite services at risk

Mitigation measures such as......what? Article doesn't get into it.

I'd guess "mitigation measures" are firmly planted in the "TBD" category.  However these unknown and likely highly speculative measures might be funded, operated, and be coordinated with all of the internationally competing interests is a tough question.  IOW, "lotsa luck" on a quick fix to the bourgeoning problem.  :)   That, and keep pilotage & VOR skills current.   
Title: Re: Space junk
Post by: Spam on December 15, 2017, 06:59:26 PM
This has been a recognized threat for decades.

Go read the Ben Bova "Kinsman" SF books (70s/80s). He had clean up of the low to mid orbitals as a strategic space access mission of the US Space Force. Locate>track>monitor>assess threat>mitigate by planning>mitigate by on-orbit adjustment burns and deorbiting of large items.

(MAN we shoulda had a permanent off-planet presence by now)!

V/r
Spam


Title: Re: Space junk
Post by: Spam on December 15, 2017, 07:14:56 PM
As to specific measures, consider:

1. Mitigate risk by Planning. Don't put payloads into threatened orbits with high impact potential. Select and insert into selections which optimize likelihood of impacts vs. coverage over time.

2. Mitigate risk by Design. Assess vulnerability against the threat at your selected orbitals, and design for survivability (single hit, multi hit, prox, rad, etc.). Got a copy of the R.E. Ball book "Combat survivability analysis and design" on the table here in my office... same basic principles of shot line analysis and designing for graceful degradation, etc. Consider that some payloads have been considering this for decades already (hardening).

3. Mitigate risk by Control. This can include sending either manned (like in "Kinsman") or unmanned (preferably) craft to deorbit chunks of debris or nudge them into safer orbits. It need not be space based, though. Consider the potential for the use of directed energy to heat/ablate a surface of an object to perform the same task: sustained outgassing, over a long baseline, can produce a significant vector product.


The worst thing you could do, probably, is yet another demo of being able to "shoot down" an object, which (as the Chinese and US forces have each demonstrated) just magnifies the problem. There are many people working these issues in the systems effectiveness and survivability/vulnerability communities, as they are with many things brought up here (e.g. the UAVs on the White House thread from a couple of years ago).


I'm surprised no one has made a WALL-E space junk reference yet.


R/s
Spam

Title: Re: Space junk
Post by: vorteks on December 15, 2017, 07:59:15 PM
Was thinking more along the lines of installing sloped armor on the sats.  8)
Title: Re: Space junk
Post by: stillamarine on December 15, 2017, 07:59:35 PM
This has been a recognized threat for decades.

Go read the Ben Bova "Kinsman" SF books (70s/80s). He had clean up of the low to mid orbitals as a strategic space access mission of the US Space Force. Locate>track>monitor>assess threat>mitigate by planning>mitigate by on-orbit adjustment burns and deorbiting of large items.

(MAN we shoulda had a permanent off-planet presence by now)!

V/r
Spam

It always saddens me when I watch an old movie from my younger days that is supposed to be in the high tech fancy future......but we are already past the date in the movie........
Title: Re: Space junk
Post by: Dwight Dutton on December 15, 2017, 08:48:40 PM
Was thinking more along the lines of installing sloped armor on the sats.  8)
If the junk is coming the other way thats a 36,000 MPH collision.  It would take a Saturn V to launch a satellite with enough armor to help - and then the collision would probably send it down in flames or off into space to join Voyager.
Title: Re: Space junk
Post by: PHall on December 16, 2017, 12:33:44 AM
Was thinking more along the lines of installing sloped armor on the sats.  8)
If the junk is coming the other way thats a 36,000 MPH collision.  It would take a Saturn V to launch a satellite with enough armor to help - and then the collision would probably send it down in flames or off into space to join Voyager.

At 36,000mph even a paint flake will cause serious damage. The Laws of Physics are pretty much the same even in Microgravity.
Title: Re: Space junk
Post by: SarDragon on December 16, 2017, 03:54:40 AM
Kinetic energy is equal to 1/2 the product of the mass and the square of the speed. In formula form: Ek=1/2m*v^2

Even small things traveling really fast have a lot of energy. According to my calculations, a 1 gram particle, traveling at 36,000 mph has the same energy as a 3000 pound car traveling at 975 mph.
Title: Re: Space junk
Post by: PHall on December 16, 2017, 04:06:29 AM
Kinetic energy is equal to 1/2 the product of the mass and the square of the speed. In formula form: Ek=1/2m*v^2

Even small things traveling really fast have a lot of energy. According to my calculations, a 1 gram particle, traveling at 36,000 mph has the same energy as a 3000 pound car traveling at 975 mph.

The shuttles had chips out of their windshields that NASA said were caused by paint flakes impacting at 36,000 mph.
Title: Re: Space junk
Post by: Live2Learn on December 16, 2017, 04:08:29 AM
Kinetic energy is equal to 1/2 the product of the mass and the square of the speed. In formula form: Ek=1/2m*v^2

Even small things traveling really fast have a lot of energy. According to my calculations, a 1 gram particle, traveling at 36,000 mph has the same energy as a 3000 pound car traveling at 975 mph.

Physics is stark.   We better not retire the VOR network.  No, not 'til there's a solid work around to physics.
Title: Re: Space junk
Post by: SarDragon on December 16, 2017, 04:09:26 AM
Kinetic energy is equal to 1/2 the product of the mass and the square of the speed. In formula form: Ek=1/2m*v^2

Even small things traveling really fast have a lot of energy. According to my calculations, a 1 gram particle, traveling at 36,000 mph has the same energy as a 3000 pound car traveling at 975 mph.

The shuttles had chips out of their windshields that NASA said were caused by paint flakes impacting at 36,000 mph.

No argument there.
Title: Re: Space junk
Post by: Spam on December 16, 2017, 04:35:55 AM
Kinetic energy is equal to 1/2 the product of the mass and the square of the speed. In formula form: Ek=1/2m*v^2

Even small things traveling really fast have a lot of energy. According to my calculations, a 1 gram particle, traveling at 36,000 mph has the same energy as a 3000 pound car traveling at 975 mph.

The shuttles had chips out of their windshields that NASA said were caused by paint flakes impacting at 36,000 mph.

No argument there.


Seriously!  Back when I was 19 - 20 I was working as a tech for McDonnell to pay for my BS degree (on the PGOC contract, payload ground ops) and was up on the white floor in OPF2 (I think it was) and they took me over and showed me a dime sized star crack apparently caused by a micrometeor. They said that the thing (looked like what you get on your windshield from a rock on the freeway) probably was a paint fleck sized bit of dust. Can't remember what orbiter it was, though. Probably the "Orbiter from Hell" (Columbia)... everything bad happened to it.

IIRC there was a payload which was orbited for a couple of years in the 80s just to test micrometeor and vacuum and rad damage. Long Duration Exposure Satellite or Facility or something. It was a horizontally integrated payload in the OPF before I started at KSC, though.

V/r
Spam

PS Live2Learn: thanks much! This is an interesting post and discussion.

Title: Re: Space junk
Post by: Live2Learn on December 16, 2017, 02:42:13 PM
 :'(Maybe, rather than fighting cell towers and band issues, we might embrace them as a nearly complete coverage, geo-referenced ground network for 'alternate nav' purposes.  That would perhaps be less expensive than installing 'every woman's intertial guidance units (IGU)' in the 250 K aircraft in the US.  If ADS/B take 2 included an IGU lat/long data burst we'd perhaps receive the same real tiem, in-cockpit position data as from our current ADS/B 'in' boxes and space junk would be irrelevant (for that application).  We might even get wx, Sunday morning cartoons, and music!  With AI and onboard celestial nav tools the very fragile nav constellation would, perhaps, become irrelevant as ( last I heard) celestial navigation, like paper charts, is unhacable.  NASA published a very interesting, unclassified verson of a much more detailed threat analysis of GPS several years ago.  FWIW, after reading it I wondered about the bureaucratic inertia that kept satellite based reference technology firmly in place as the 'nav system for the future.  It looks to me like the FAA decision makers for ADS/B and their supporting staff ignored, dismissed, or were unaware of the inherent fragility of their fundamental technology.  Just my casual and very humble opinion, of course.  :(