20-year-old Military Weather Satellite Apparently Exploded in Orbit

a reply to: TDawg61

The only ones I've heard of, just going by memory were deliberately blown up after reaching the end of their lifespan, or because they were coming down anyway and were something of a risk to the ground.

originally posted by: Zaphod58
a reply to: TDawg61

The only ones I've heard of, just going by memory were deliberately blown up after reaching the end of their lifespan, or because they were coming down anyway and were something of a risk to the ground.

Thank you for your reply Zaphod.I didn't think our satellites were regularly exploding unexpectedly.

a reply to: M5xaz

I think you are wrong in your assumption concerning a Hydrazine leak. It is one thing for a fairly recent spacecraft to still have hydrazine aboard. A 20 year old ship is not keeping itself aloft with some never ending supply of hydrazine and in this case it is clear since it was designed for a 48 month mission cycle there is no way they planned to have enough hydrazine aboard to cause the craft to explode nearly 18 years from the end of its service life.

I posted this link: nsidc.org...

Within it there is a statement about the ships attitude control and it operated on 4 Axis using momentum exchange.

Three-axis attitude control is maintained in the orbital configuration by automatic momentum exchange between three momentum wheels. On board magnetic coils provide controlled interaction with the Earth's magnetic field to prevent the accumulation of wheel secular momentum. Operations of these coils is under control of the closed loop spacecraft attitude control system. Both the momentum wheels and gyroscopes are backed up by a fourth skewed unit for redundancy.

This ship was out at 840 kilometers and remained on station using momentum exchange not hydrazine based reaction thrust. Likely it used up any hydrazine on board getting up to that altitude.

a reply to: machineintelligence

No.
The DMSPs are equipped with BOTH.

They mostly rely on the momentum wheels for attitude control, the thrusters are almost never used which is why there would still be hydrazine aboard.

The thrusters would only be fired if there was a need for a slight orbit change

a reply to: Zaphod58

"It's a stretch that this satellite worked perfectly for 20 years and suddenly after its not in use anymore a hydrazine tank fails."

No, it's not a stretch, the DMSP was designed for a 48 month lifespan , not 20 years.

20 years in space means a lot of extreme heating cooling cycles as the DMSPs go in and out of the shadow of the Earth.

In turn, the heating/cooling cycles mean a lot of expansion/contraction cycles on metal components of the spacecraft.


After 20 years, you get metal fatigue failure, guaranteed.

a reply to: Bedlam

Yes, lasers could have done it. Sometimes a conspiracy is called for.

However, you must first rule out more mundane explanations before going to conspiracies.

Something similar happened to an AT&T satellite in the early 90s not long after launch - hydrazine was the cause.

originally posted by: M5xaz...hydrazine was the cause.

Like I said, I can see it, but I would not expect a two stage failure wherein you break up into five or six chunks, then sometime later, more than one of the chunks goes off as well, leaving it pulverized.

THAT is a bit stretchy.

originally posted by: Zaphod58
a reply to: TDawg61

The only ones I've heard of, just going by memory were deliberately blown up after reaching the end of their lifespan, or because they were coming down anyway and were something of a risk to the ground.

So, how do they blow them up? DO they keep a spare hydrazine tank onboard or some other fancy explosive with an ignitor attached to a radio link, if so, maybe the new guy in the command center was playing with the big red button labeled "do not touch" - at least they could say it was a hydrazine explosion after all

a reply to: Bedlam
Satellites are made to be relatively sturdy, as once in orbit, they must operate with no maintenance for years.

When Columbia was destroyed, it gradually broke up - multiple step failure

Big explosions, when they happen, happen almost exclusively at the launch of a fully fuelled rocket.

Apollo 13 is another example of multiple stage failure where the whole spacecraft was not destroyed in one shot.


An Apollo 13 like failure for the DMSP is more common, more probable than a shot from a laser.

a reply to: evc1shop

ASAT tests.

originally posted by: M5xaz
a reply to: Bedlam
Satellites are made to be relatively sturdy, as once in orbit, they must operate with no maintenance for years.

When Columbia was destroyed, it gradually broke up - multiple step failure

Yeah, but that was a catastrophic re-entry, not just an explosion in orbit. And with 13, what you got was a lot of gas venting but not a lot of continued fragmenting. Once the initial bang was done, it didn't keep falling apart into smaller and smaller bits.

originally posted by: Zaphod58
a reply to: evc1shop

ASAT tests.

Ah, I thought perhaps they had better self destruct capabilities back then than our current drones.

I didn't think we would actually shoot it down, figured there was another option.
Thanks!

a reply to: Bedlam

You might want to Google the Apollo 13 accident. It was not a mere venting of gas. It was a cascade failure of multiple components, two oxygen tanks in particular. It's a miracle the hydrogen tanks did not also rupture.

Hydrazine failure of the DMSP remains more probable than anything else. I could be wrong, but I suspect that this will be the conclusion of the Air Force.

We'll see.

Cheers.

a reply to: PeterMcFly

I was drawing on old and probably now well outdated knowledge but I have heard of Microwave technology and low frequency being used to interfere with the nervous system even induce seizure's, the cardio vascular system is very complicated and of course as it is a natural nerve centre anything that can interfere there can do as you say but the specific early type of EM microwave emitter I am talking about pushed the temperature up radically much like a directed microwave oven without and so had to be aimed precisely which today would not a such a problem problem with today's computer targeting systems of course.

There are other method's of causing nerve interference or muscular spasm's as well and as you know sound based ultra low frequency can have a drastic effect though exposure over a fairly long period is required, remember how the Soviets were bombarding the US embassy in Moscow to test there own technology.

I can not attest to the voracity of this article but here is some interesting reading.
www.tldm.org...

And here is a better researched article
www.whale.to...

At any rate the type you are talking about are a generation ahead of the concept I am talking about but in line with many of the application's described in this second article, much of the information I drew on is 70's and 80's through to the very early 90's so is maybe not one but several generation's behind what you are talking about but yes what you talk about would be even harder to detect and more suitable for such a covert use, I wonder if it could also be made much smaller as frequency rather than brute force would be more key to overriding the nervous system in that manner.

As for Variable voltage over variable temperature the effect would be dependant entirely upon both the amplitude at the target and how dynamic the range implied by Delta of the output was and if it caused a virtual white noise of micro muscular voltage induced contraction's to the localized nervous system or area of the muscular nervous system at the target location but I can see that being very hand as a covert assassination device or area suppression device, as this kind of anti personnel device evolves earlier systems such as the dreaded Neutron bomb look more and more clumsy as the area suppression of this kind of device must make certain strategic planners water at the mouth, it is all too easy to forget these thing's kill human being's but still, clean, no residual radiation or structural damage, of course if the enemy is hidden in a multi layered faraday enclosure with dielectric like layers and ferrous wave guide's to prevent magnetic attack then it is just as redundant as a snow ball in the Sahara but in it's place would remain invaluable as only highly prized assets would thus be protected and general population or military asset's would only have minimal protection such as tank's hull's etc.

Colour me intrigued I may have to look up this new application.

a reply to: M5xaz

Yes it was an explosion, but it didn't explode once the explode again days later.

possibilities I've seen on thread;
1) unit broke down from normal wear/tear; 'explosion' caused by equipment failure.
2) micrometeor strike caused failure.
3) US testing experimental anti-sat weapon (laser?) on old gear.
4) hostile nation (Norks, Iran, Putin) shows us what they are capable of.

any more?

would like to here Mr. Obert, or Phage, on this.

a reply to: LABTECH767

As for Variable voltage over variable temperature...

I don't want to drift the thread further, then I'll pretend it is for an ASAT microwave beam weapon. When I was talking about dV/dt, it was deltaV on deltatime, that's the rate of change of an electric field. Once this rate is past a specific threshold, ionic conduction channel in nervous cell is activated. Of course we need a sat with a nervous system...

Back on topic, more than one explosion make me think loss of thermal control (or agravation) after first explosion made other components go bang. It is still not clear if this sat had hydrazine or reaction whell for attitude control, but one thing for sure is it had to have batteries.

An internal short inside a battery is probably the cause.

originally posted by: Zaphod58
a reply to: AreUKiddingMe

Yeah and this particular satellite was for weather. Which is why it was in that orbit.

If somebody wanted to send a message that they could zap other, expensive satellites in that orbit, this one seems like a good candidate.

a reply to: mbkennel

Exactly. And with it being in a backup role the outrage over it won't be as high.

originally posted by: M5xaz
a reply to: Bedlam

You might want to Google the Apollo 13 accident. It was not a mere venting of gas.

Nor did I say it was. But the major long-term "ongoing" event was gas venting. Here, let's look at what I said, word for word:

"And with 13, what you got was a lot of gas venting but not a lot of continued fragmenting. Once the initial bang was done, it didn't keep falling apart into smaller and smaller bits."

There's this neat phrase there: "Once the initial bang was done". This implies it wasn't "a mere venting of gas". But what you DID get, over time, was a lot of gas venting from all the ruptured plumbing. You also got some problems because some of the intentional vents that were supposed to be non-thrust-inducing were, and they hadn't counted on the sublimator on the LEM causing thrust in orbit.

But again, once the initial bang was done, it didn't keep falling apart into smaller and smaller bits. You had a blow out disc on the helium tank, and one of the LEM batteries blew, but neither caused any issues except some unwanted net thrust caused by the gas release.

BTW, we have done design of in-flight systems for the STS and Mir under contract to Marshall, and some satellite systems design for someone else. So it's not like I'm some random poster.

A single event with a satellite is surprising, but not that odd. The ONGOING part here is what's interesting. You don't generally get event after event in the individual chunks.

It was a cascade failure of multiple components, two oxygen tanks in particular. It's a miracle the hydrogen tanks did not also rupture.

It was a failure of one o2 tank, due to running the tank heater at too high a voltage on the ground, fusing the thermostat shut. There was also a problem with the internal thermocouples having limits on their output so that no one knew the thermostat was fused and that the internal tank temperatures went high enough to cause major damage to the wiring. And in orbit a spark occurred, and the remains of the teflon insulation burned off catastrophically, causing an overpressure explosion of that tank. And before all that, they used the heater on the ground to boil the tank dry because a siphon inside the tank came loose, which traces back to a dropped frame that the tank was mounted on, but I digress.

But that aside, once the tank detonated and blew some of the side panels off the service module, the major "break up" of the craft was over. It didn't keep on breaking up into smaller bits later.

And that, of course, is where we keep coming back to. One bang, no biggy. A bang, then a set of separate smaller bangs that ends up fragmenting the chunks, not so likely.

eta: it would have been even more spectacular if the propellant tanks for the service module propulsion system had ruptured...they're hypergolic.