For Questions That Don't Merit Their Own Thread

[kerbiloid]

1 hour ago, SunlitZelkova said:

1. In nuclear weapons development, does one need to go "atomic bomb first, then hydrogen bomb" or can you jump straight to hydrogen bomb?

I believe, it's more releveant to say "hydrogen bomb" or "simplified hydrogen bomb", as in any case it would include a fusion gaseous booster.

And why bother with the simplified design when even advanced ones are known for a long while.

1 hour ago, SunlitZelkova said:

Specifically within the context of Japan's nuclear industry.

I believe, they already have special Lego kits for that for decades.

With catgirls and pokemons included.

Just proper Legos should be combined in right order.

1 hour ago, SunlitZelkova said:

2. How long would it take to convert an orbital launch vehicle into an ICBM (namely the M-V rocket), assuming national survival level urgency (ZiS-30 tank destroyer urgency)? Specifically, time to first test flight.

When it's relevant. they are derived from the ICBM.

Some of them on tanks.

1 hour ago, SunlitZelkova said:

3. If mission control can't "keep the lights on" (that is, NASA is bankrupt and the Texas electrical grid has completely ceased to operate) could astronauts "fly back" on their own (with little to no aid from mission control)? Namely from a Mars or Moon base.

Of course they can. Otherwise how could a Mars-based interplanetary bomber return for reload?

[magnemoe]

2 hours ago, SunlitZelkova said:

A couple of questions in regards to a story I am writing to use as background for things in two games (KSP and a post-WWII milsim)-

1. In nuclear weapons development, does one need to go "atomic bomb first, then hydrogen bomb" or can you jump straight to hydrogen bomb? Specifically within the context of Japan's nuclear industry.

2. How long would it take to convert an orbital launch vehicle into an ICBM (namely the M-V rocket), assuming national survival level urgency (ZiS-30 tank destroyer urgency)? Specifically, time to first test flight.

3. If mission control can't "keep the lights on" (that is, NASA is bankrupt and the Texas electrical grid has completely ceased to operate) could astronauts "fly back" on their own (with little to no aid from mission control)? Namely from a Mars or Moon base.

1 You need an atom bomb as in fission to set off the fusion reaction. If you could set off the fusion reaction directly you had fusion power. 

2 That would be pretty easy, you just has to program an trajectory who is ballistic, the L-V rocket has the downside that its all solid so it will be problems getting it to hit something accurately. Modern ICBM tend to have an upper stage with the warheads who do the aiming part. 

3) good question, more of an issue would be getting their position accurately enough. But if you have an moon base you probably have that capability. 

[SOXBLOX]

You can absolutely go straight to hydrogen bombs. With a technical base and work ethic like Japan's, it shouldn't be difficult. (I think the hard part would be convincing your citizens/engineers they need an atomic bomb.) 

Converting the M-V is probably easy-ish. You'll need a reentry vehicle. I figure the M-V has pretty good throw weight, so you can either do a very well-engineered RV for MIRV capability, or use one very rudimentary, large RV for a single warhead. Option 2 could probably be cranked out fast.

I just checked Wikipedia:

Quote

At a technical level the M-V design could be weaponised quickly (as an Intercontinental ballistic missile, since only payload and guidance have to be changed) although this would be politically unlikely.[9] The M-V is comparable in performance to the LGM-118 Peacekeeper ICBM.

I don't know about in-space navigation, but I think that if the mission controllers thought the astronauts needed help, they'd improvise. Even if they weren't operating under the guise of NASA, I can see them borrowing a HAM radio operator's setup and contacting the spacecraft with a deorbit maneuver plot.

We have lots of HAM radios, operators, and generators in Texas, so this wouldn't be a problem.

[kerbiloid]

Space LV tend to be cryogenic, so poor as ICBM.

But LV derived from ICBM are hypergolic, and good for both purposes.

[SOXBLOX]

1 minute ago, kerbiloid said:

Space LV tend to be cryogenic, so poor as ICBM.

But LV derived from ICBM are hypergolic, and good for both purposes.

The M-V is American-style solid-fuel for all three stages.

[JoeSchmuckatelli]

Could a 3-point array telescope, with satellites at L4 and L5 and this wet rock work? 

Are we already getting the benefits of that by taking separate images 6 months apart and then combining them? 

 

(edit - I know it would work, but would it be optimal to build one or are there more efficient methods?) 

Edited September 14, 2021 by JoeSchmuckatelli

[SOXBLOX]

DARPA wants a cross-platform laser communications system for its satellites. The acronym is BACN, pronounced "bacon". Since this BACN will be in space, does this mean pigs will fly? 

https://www.thedrive.com/the-war-zone/42357/darpa-wants-cheap-laser-communications-terminals-to-allow-any-satellite-to-talk-to-another

[kerbiloid]

23 minutes ago, JoeSchmuckatelli said:

or are there more efficient methods?

Are.
But far.
542 AU far.

https://en.wikipedia.org/wiki/Solar_gravitational_lens

Though, it's used in KSPI-E mod for ages.

[SunlitZelkova]

Doh in regards to needing fission weapon technology to build a hydrogen bomb in the first place. Thanks for the answers guys!

----------------------------

9 hours ago, SOXBLOX said:

Converting the M-V is probably easy-ish. You'll need a reentry vehicle. I figure the M-V has pretty good throw weight, so you can either do a very well-engineered RV for MIRV capability, or use one very rudimentary, large RV for a single warhead. Option 2 could probably be cranked out fast.

Supposedly part of the reason Hayabusa got funding was to demonstrate that Japan could build an RV if it wanted to.

[JoeSchmuckatelli]

1 hour ago, SunlitZelkova said:

Supposedly part of the reason Hayabusa got funding was to demonstrate that Japan could build an RV if it wanted to.

A large part of the achievement in space is to remind people that if you can hit a target far away, you can certainly hit one closer to home.  Peaceful flexing with a touch of 'who me?  I'm just doing science' thrown in 

[magnemoe]

13 hours ago, SOXBLOX said:

DARPA wants a cross-platform laser communications system for its satellites. The acronym is BACN, pronounced "bacon". Since this BACN will be in space, does this mean pigs will fly? 

https://www.thedrive.com/the-war-zone/42357/darpa-wants-cheap-laser-communications-terminals-to-allow-any-satellite-to-talk-to-another

Newer starlink satellites does this but the darpa plan is to make an standard for this. Might be an idea to use starlink's system if spaceX will share and if it meet darpa's requirement

[DDE]

16 minutes ago, magnemoe said:

Newer starlink satellites does this but the darpa plan is to make an standard for this. Might be an idea to use starlink's system if spaceX will share and if it meet darpa's requirement

Given the success of other standardized systems like Link 16, there's a pretty strong imperative to develop something like that, fast.

[AHHans]

13 hours ago, JoeSchmuckatelli said:

Could a 3-point array telescope, with satellites at L4 and L5 and this wet rock work? 

Yes, kind of. But with only three stations your image fidelity will suck. With the three of them in more or less on one line and the middle one being at the halfway point even more so. Without intermediate baselines (distances between stations) you don't get images but more like data-points that can tell you if a given source fits or doesn't fit with the model you made for said source.

So as you said, the problem is not: "can this be done?" Yes, it can. But: "what would we want to do with it?" You only actually see very bright and compact objects with such an array, and there aren't that many of these objects around. (Any such object is already visible with smaller arrays as an unresolved source.) And what you would be able to learn about these sources would be rather limited.

Much more interesting would be a fleet of satellites in (highly elliptical) orbits around Earth that can connect to the baselines we already have with ground-based antennas.

14 hours ago, JoeSchmuckatelli said:

Are we already getting the benefits of that by taking separate images 6 months apart and then combining them?

Not in the sense of increasing the resolution of observations. But look up the definition of parsec.

[JoeSchmuckatelli]

On 9/15/2021 at 6:11 AM, AHHans said:

With the three of them in more or less on one line and the middle one being at the halfway point even more so

I was thinking it would be more like a big (really big) triangle, and an array like that could provide relevant info.  Clearly if they're aimed at something along the orbital plane (like any of the planets) it would be, effectively, linear.

Short of doing what Kerbiloid suggests with gravitational lensing... I was thinking about what the EHT did, effectively making an 'earth-sized' telescope, and wondering if there was an effective way for us to increase the surface area and hopefully get good info at both a reasonable cost and within our current technological abilities.

Edit - I haven't had enough coffee: using the same words and phrases too much this morning!

 

[SunlitZelkova]

To what extent were the failures of early space probes caused by the inherent immaturity of the technology, and to what extent was it poor management/engineering practices?

A lot of them seem to have been lost in launch vehicle failures, which would imply no relation to the spacecraft itself, but there are also things that point to problems with the spacecraft themselves- Korolev refused to do bench testing for uncrewed spacecraft and there seem to have been management problems with the Ranger program as well.

With better decision making could these errors have been avoided? Or were these pretty reasonable failures and to over criticize them is to delve too deep into hindsight?

Edited September 17, 2021 by SunlitZelkova

[JoeSchmuckatelli]

13 hours ago, SunlitZelkova said:

To what extent were the failures of early space probes caused by the inherent immaturity of the technology, and to what extent was it poor management/engineering practices?

A lot of them seem to have been lost in launch vehicle failures, which would imply no relation to the spacecraft itself, but there are also things that point to problems with the spacecraft themselves- Korolev refused to do bench testing for uncrewed spacecraft and there seem to have been management problems with the Ranger program as well.

With better decision making could these errors have been avoided? Or were these pretty reasonable failures and to over criticize them is to delve too deep into hindsight?

A very interesting question - and given the mammoth egos and national-pride aspects of many of these 'firsts' I'm not sure there's going to be a definitive answer.  Remember - folks with very limited computational power at their disposal built the Voyagers, landed on Venus and Mars and had dozens of other successes.  Fabulous examples of hard math and determination.  I'm interested to hear from those who've delved into this history more!

Edited September 17, 2021 by JoeSchmuckatelli

[magnemoe]

2 hours ago, JoeSchmuckatelli said:

A very interesting question - and given the mammoth egos and national-pride aspects of many of these 'firsts' I'm not sure there's going to be a definitive answer.  Remember - folks with very limited computational power at their disposal built the Voyagers, landed on Venus and Mars and had dozens of other successes.  Fabulous examples of hard math and determination.  I'm interested to hear from those who've delved into this history more!

Add luck and probably an bit smartness, Like R7 who become the legendary Soyuz  was probably sold in as an heavy ICBM with an secondary function of deploying satellites. 
That rocket has loads of obsolete features like using an separate gas generator to run the turbo pump who was copied from the V2 missile. 
Benefit is that the turpo pump is now an steam turbine rater than an gas turbine burning LOX who does not really work well unless you go fuel or oxidizer rich or full flow.  In short it might not be an bad solution after all for a very long time. 

Luck also plays in later on SpaceX going for 9 engines on falcon 9 made them manage to land had they developed an twice as strong engine and used four  

 

[DDE]

1 hour ago, magnemoe said:

Like R7 who become the legendary Soyuz  was probably sold in as an heavy ICBM with an secondary function of deploying satellites. 

Why bother guessing when you can be definitive.

1 hour ago, magnemoe said:

Luck also plays in later on SpaceX going for 9 engines on falcon 9 made them manage to land had they developed an twice as strong engine and used four  

*gives side-eye to RD-171MV*

17 hours ago, SunlitZelkova said:

To what extent were the failures of early space probes caused by the inherent immaturity of the technology, and to what extent was it poor management/engineering practices?

It's rather difficult to tell. There's a reason why management/engineering practices get lumped into "production technology" in Russian vernacular.

On the other hand, there's a consensus view that Lavochkin et al were never able to maintain the same vaunted standards as JPL. On the other, we know extremely well that the Soviet/Russian electronics base remains pretty rubbish and unreliable.

[wumpus]

1 hour ago, magnemoe said:

Add luck and probably an bit smartness, Like R7 who become the legendary Soyuz  was probably sold in as an heavy ICBM with an secondary function of deploying satellites. 
That rocket has loads of obsolete features like using an separate gas generator to run the turbo pump who was copied from the V2 missile. 
Benefit is that the turpo pump is now an steam turbine rater than an gas turbine burning LOX who does not really work well unless you go fuel or oxidizer rich or full flow.  In short it might not be an bad solution after all for a very long time. 

Luck also plays in later on SpaceX going for 9 engines on falcon 9 made them manage to land had they developed an twice as strong engine and used four  

 

I'm  all but certain that the R7 was sold entirely as an ICBM.  Deploying satellites was likely something Korolev didn't even try suggesting until the Americans suggested launching a satellite and he could point out the benefits of beating them to orbit.  Few countries have science budgets that approach the war budget, and none of them are space-faring.

If the Soyuz engine is so superior, why haven't later engines used such a design?  It seems to be in the "too good to ECO, not good  enough to use elsewhere" region.  In many ways, that isn't all that lucky.  Also SpaceX's luck seems to center on how deep the Merlin can throttle, if it was half as strong it would require nearly 18 engines to lift off (ok, maybe 15-16 since the first Falcon9 went to orbit on 8 engines).

4 minutes ago, DDE said:

It's rather difficult to tell. There's a reason why management/engineering practices get lumped into "production technology" in Russian vernacular.

On the other hand, there's a consensus view that Lavochkin et al were never able to maintain the same vaunted standards as JPL. On the other, we know extremely well that the Soviet/Russian electronics base remains pretty rubbish and unreliable.

Musk seems to think that the difficult/critical tech is in mass producing something, not what you can build a one-off in the lab.  Probably learned that the hard way with the Telsa model 3.  See the Everyday Astronaut interview (probably end of part 2 or in part 3).

[JoeSchmuckatelli]

In case you missed this: Jupiter wins again!

Amateurs Spot New Impact Flash at Jupiter - Sky & Telescope - Sky & Telescope (skyandtelescope.org)

 

[DDE]

3 hours ago, wumpus said:

Deploying satellites was likely something Korolev didn't even try suggesting until the Americans suggested launching a satellite and he could point out the benefits of beating them to orbit.

December 1953 in a letter to Ustinov based on research papers from Tikhonravov dating back to 1950. So, no.

3 hours ago, wumpus said:

If the Soyuz engine is so superior, why haven't later engines used such a design?

The Merlin is far simpler than an RD-107. It is also mich simpler and less efficient ISP-wise than a staged combustion engine. There are trade-offs to be had... but having to lug around hydrogen peroxide is probably a negative all around.

3 hours ago, wumpus said:

Also SpaceX's luck seems to center on how deep the Merlin can throttle

That's not luck. They employ ex-Northrop Grumman engineers (including Mueller) using the company's signature pintle inhectors. The ones that put the LEM on the Moon.

Edited September 17, 2021 by DDE

[Admiral Fluffy]

Using the shuttle, could you return the HST to earth?

[kerbiloid]

9 minutes ago, Admiral Fluffy said:

Using the shuttle, could you return the HST to earth?

HST is KH-11 upside down. Shuttle is natural kangaroo mom for it.

[Admiral Fluffy]

9 minutes ago, kerbiloid said:

HST is KH-11 upside down. Shuttle is natural kangaroo mom for it.

What?
I’m confused.

[kerbiloid]

2 minutes ago, Admiral Fluffy said:

What?
I’m confused.

Hubble is based on the spysat, the shuttle was developed for.