Chinese Space Program (CNSA) & Ch. commercial launch and discussion

[YNM]

8 hours ago, kerbiloid said:

I almost believe that all talks about lunar programs will stay talks, and any lunar base will start being built only when it becomes economically reasonable, i.e. when it will be possible to mine rare metals (if any) in industrial amounts, i.e. when the lunar He-3 from regolith  and the lunar D from ice can feed a fusion reactor, i.e. not earlier than 2050 or so, i.e. a couple of new orbital stations later.

They're projecting power there, really. Have you not seen them retrieve samples again from the Moon ? Yes it's very far from a manned mission but that shows they're willing to do it if it means they're projecting power.

Spoiler

2 hours ago, RCgothic said:

How not to win international friends:

Who needs friends if they have money ?

 

[steve9728]

Docking a Shenzhou at the end of the Tianhe*

Russian astronaut: I know that!

[JcoolTheShipbuilder]

Uh oh big rocket reentering and having other countries try to predict where it’ll land? Hmm yea that’s not really a way to make international friends..

Edited April 30, 2021 by JcoolTheShipbuilder

[tater]

https://spacenews.com/huge-rocket-looks-set-for-uncontrolled-reentry-following-chinese-space-station-launch/

[SunlitZelkova]

Apart from "more (maybe bigger) bits" what makes this more dangerous than say, the Falcon 9 second stage reentering over Oregon and Washington?

Edited April 30, 2021 by SunlitZelkova

[YNM]

28 minutes ago, SunlitZelkova said:

Apart from "more (maybe bigger) bits" what makes this more dangerous than say, the Falcon 9 second stage reentering over Oregon and Washington?

It's like a pickup truck crashing into your house (F9 2nd stage empty mass ~3.9 tonnes) vs. an 18-wheeler crashing into your house (LM-5B first stage empty mass ~21 tonnes).

LM-5B only features side boosters and 1st stage. LM-5 is the one that have a 2nd stage, so the 1st stage doesn't reach orbit, but the problem is that this time the first stage reaches orbit.

Edited April 30, 2021 by YNM

[kerbiloid]

The rocket took evasive action.

[sevenperforce]

The good news is that based on launch inclination we know it will land somewhere above New Zealand but below New York.

The bad news is that's most of the people.

[SuperFastJellyfish]

https://heavens-above.com/orbit.aspx?satid=48275&lat=0&lng=0&loc=Unspecified&alt=0&tz=UCT

 

If it becomes known that it is coming down on a huge metro area, what is the best way to minimize damage?

Edited May 1, 2021 by SuperFastJellyfish

[sevenperforce]

47 minutes ago, SuperFastJellyfish said:

https://heavens-above.com/orbit.aspx?satid=48275&lat=0&lng=0&loc=Unspecified&alt=0&tz=UCT

 

If it becomes known that it is coming down on a huge metro area, what is the best way to minimize damage?

Stay indoors. Preferably as low as possible. Park cars in garages.

[SOXBLOX]

2 hours ago, SuperFastJellyfish said:

If it becomes known that it is coming down on a huge metro area, what is the best way to minimize damage?

Get an Aegis-equipped destroyer to hit it with a couple SM-3's. 

Just joking...

[SuperFastJellyfish]

42 minutes ago, SOXBLOX said:

Get an Aegis-equipped destroyer to hit it with a couple SM-3's. 

Just joking...

That's closer to  what I was thinking.  Though the SM-3 is a kinetic kill vehicle.  Would it break it up enough?  I was thinking more along the lines of Sprint.  Although, I don't know if a non-kinetic kill vehicle exists on alert, at the moment.

Edited May 2, 2021 by SuperFastJellyfish

[kerbiloid]

30 minutes ago, SuperFastJellyfish said:

Although, I don't know if a non-kinetic kill vehicle exists on alert, at the moment.

Spoiler

 

3 hours ago, sevenperforce said:

Stay indoors. Preferably as low as possible.

== just close the curtains, lie under a window or in a closet, and sleep/watch TV.
So you'll be indoors, far from glasses, low, and horizontal.
More chances to get the debris from aside than the whole rocket from top, and in the latter case one can do anything he wants anyway.

1 hour ago, SOXBLOX said:

Get an Aegis-equipped destroyer to hit it with a couple SM-3's.

To hurt it in revenge.

6 hours ago, sevenperforce said:

The good news is that based on launch inclination we know it will land somewhere above New Zealand but below New York.

The bad news is that's most of the people.

It's nice that they rejected the inclination change.

Now do you get, who won?

[SOXBLOX]

2 hours ago, SuperFastJellyfish said:

Although, I don't know if a non-kinetic kill vehicle exists on alert, at the moment.

Well, the deployed/operational missiles known to be capable of mid-course kills are the Ground-based Mid-course Defence (USA), the SM-3 BlkII (USA), Arrow 3 (Isr. and USA), and...I think that's it...?

Of course, there are others which can hit it as it reenters. Patriot, THAAD, and the rest of Aegis (USA & co.), A-135 and some SAM systems (Ru.), and Aster (UK and France). Also, Israel's SAM's.

Of these, only most terminal interceptors have non-kinetic warheads. Patriot, the rest of the SM family, maybe David's Sling, and Aster Blk 30 could probably two-shot it. With KKV's, it could take a while.

The A-135 is overkill.  Who needs aiming when you have nukes?

[YNM]

8 hours ago, SuperFastJellyfish said:

If it becomes known that it is coming down on a huge metro area, what is the best way to minimize damage?

Have a good insurance ?

[SunlitZelkova]

On 4/30/2021 at 3:14 PM, YNM said:

It's like a pickup truck crashing into your house (F9 2nd stage empty mass ~3.9 tonnes) vs. an 18-wheeler crashing into your house (LM-5B first stage empty mass ~21 tonnes).

LM-5B only features side boosters and 1st stage. LM-5 is the one that have a 2nd stage, so the 1st stage doesn't reach orbit, but the problem is that this time the first stage reaches orbit.

Ok reading the further discussion I am a bit confused. Will the LM-5 break up or not? The Falcon 9 second stage was reduced to pretty small bits by the time it hit. Not that it would lessen the damage should the bits hit something though.

I only ask as people outside of this forum seem to discuss this as though it will hit in very large pieces (little break up) or even in one piece. I apologize if this is a stupid question.

On another note, CCTV-13 (domestic Chinese broadcaster) has supposed "experts" being interviewed, claiming the stage is conducting "active de-orbiting".

2 hours ago, SOXBLOX said:

Well, the deployed/operational missiles known to be capable of mid-course kills are the Ground-based Mid-course Defence (USA), the SM-3 BlkII (USA), Arrow 3 (Isr. and USA), and...I think that's it...?

Of course, there are others which can hit it as it reenters. Patriot, THAAD, and the rest of Aegis (USA & co.), A-135 and some SAM systems (Ru.), and Aster (UK and France). Also, Israel's SAM's.

Of these, only most terminal interceptors have non-kinetic warheads. Patriot, the rest of the SM family, maybe David's Sling, and Aster Blk 30 could probably two-shot it. With KKV's, it could take a while.

The A-135 is overkill.  Who needs aiming when you have nukes?

THAAD can likely hit it but for Patriot it depends on the terminal velocity (I don't whether junk reentering has the same velocity as a reentry vehicle or warhead). The Patriot and (maybe THAAD too) would need to be in position to where the target hits as the Patriot is a point defence interceptor, while the THAAD is a rather tactical weapon (tactical insofar as it can hit missiles targeting a broad region of say, South Korea, but that same battery would not be able to intercept missiles targeting Japan, whereas an SM-3 armed destroyer in the western Sea of Japan could probably hit both).

In addition presumably the target will be rapidly disintegrating as the missile flies towards it. I wonder how that would affect accuracy. All of these interceptor systems are designed to hit reentry vehicles/warheads, that remain in one shape until hitting their target.

[YNM]

9 hours ago, SunlitZelkova said:

Ok reading the further discussion I am a bit confused. Will the LM-5 break up or not? The Falcon 9 second stage was reduced to pretty small bits by the time it hit. Not that it would lessen the damage should the bits hit something though.

I only ask as people outside of this forum seem to discuss this as though it will hit in very large pieces (little break up) or even in one piece. I apologize if this is a stupid question.

Well... that's the question, isn't it ? We just don't have any idea.

Stages are generally a lot more sturdy than satellites and stations. Skylab utilized a modified Saturn V upper stage (S-IVB) which massed 35 tonnes (out of 76.5 tonnes for the whole station). Empty mass of the stage itself as used in Saturn V was 13.5 tonnes. Skylab re-entry made for quite the spectacle. The largest fragment was tanks that were located inside the main station itself as they're relatively protected. That does mean the stage-based station itself was destroyed, but there were other stuff inside it that survived pretty much intact.

So, will this one lands in big pieces ? We don't know. The stage of LM-5B is longer in aspect; but it is more massive than the S-IVB upper stage (21 tonnes vs. 13.5 tonnes).

Edited May 2, 2021 by YNM

[kerbiloid]

15 minutes ago, YNM said:

The largest fragment was tanks that were located inside the main station itself as they're relatively protected.

And one of them was a waste collector.

Somebody found...

[RCgothic]

Being a bigger stage, even though it will almost certainly break up the chances are the bits will be bigger. Bigger first stage engines. Bigger internal tanks. Larger thrust structures.

And because it's uncontrolled we're probably not going to get enough time for an actionable warning.

A single orbit is around a thousand miles ground track, and twelve minutes is the difference between coming down on NY or London. 

[YNM]

3 hours ago, RCgothic said:

Being a bigger stage, even though it will almost certainly break up the chances are the bits will be bigger.

I wonder if the more slender aspect would help it break up or make it harder to break up...

[kerbiloid]

Spoiler

Let's divide the equatorial circle into 38 sectors.

Black and red.

 

[SOXBLOX]

19 hours ago, SunlitZelkova said:

THAAD can likely hit it but for Patriot it depends on the terminal velocity (I don't whether junk reentering has the same velocity as a reentry vehicle or warhead). The Patriot and (maybe THAAD too) would need to.........

Yeah, everything but the first three I listed (GMD, SM-3, Arrow) are terminal-phase intercept, or slightly better. Pretty sure only those first three can do exoatmospheric kills. Maybe Aster Block 30 can? The Wiki article isn't clear. This junk will be going slower than an RV, I think. It has a lot more surface for its density. Patriot would probably do more damage than THAAD, because of its warhead. THAAD is just a KKV.

[tater]

 

[sevenperforce]

Most of the rocket body will be shredded by the heat of re-entry and what reaches the ground will be small pieces of debris falling at fairly low speeds.

But the helium COPV(s) for the LOX tank will reach the ground. Not sure how big the Long March 5 COPVs are.

And the two engines will reach the ground. Each one is 2,700 kg or just under 6,000 pounds.

[sevenperforce]

59 minutes ago, sevenperforce said:

And the two engines will reach the ground. Each one is 2,700 kg or just under 6,000 pounds.

By my math, these engines are going to hit the ground at just over Mach 1 with the equivalent kinetic energy of a warhead with about 40 kg of TNT.

A little bit less than the yield of the AGM-88 HARM tactical air-to-surface missile.

This is the size of the crater left in loose soil by the Qassam 3 rocket, which has about half that much yield: