SpaceX Tuesday...

[saaby93]

annodomini2 said:

CraigyMc said:

Beati Dogu said:

fiatpower said:

Eric Mc said:

Does NASA only employ US citizens? In days gone by it was very multi-national.

Yeah unfortunately apart from in very rare circumstances. Presumably where you are the world leading expert in something they need.

They used to employ a lot of Germans.

They made them US citizens. Job Jobbed.

SpaceX work on military stuff, those working on it need security clearance. Which in the US requires Citizenship.

Refer to job jobbed

What ws it that led to Germany being so far ahead technology wise by the 2nd world war

[Rod200SX]

annodomini2 said:

CraigyMc said:

Beati Dogu said:

fiatpower said:

Eric Mc said:

Does NASA only employ US citizens? In days gone by it was very multi-national.

Yeah unfortunately apart from in very rare circumstances. Presumably where you are the world leading expert in something they need.

They used to employ a lot of Germans.

They made them US citizens. Job Jobbed.

SpaceX work on military stuff, those working on it need security clearance. Which in the US requires Citizenship.

Yeah, I'm sure Elon answered this publicly at some point in a fairly decent way. Was basically "We really would love to but restrictions with us working on government/security stuff restricts us to US citizens".

[menguin]

saaby93 said:

Refer to job jobbed

What ws it that led to Germany being so far ahead technology wise by the 2nd world war

So far ahead in one specific area - rockets. Because V-1 and V-2. Others were focusing on other areas! Just turned out that rockets ended up being the next big thingTM

[CrutyRammers]

Saw a close up vid this morning, several of the little stumpy landing legs didn't lock down and were flapping around, which explains the lean, and probably explosion.

[Eric Mc]

Beati Dogu said:

They used to employ a lot of Germans.

They were already US citizens by the time NASA took them on. They'd been in the USA since 1945 working for the US Army. Most of them became US citizens in the mid 1950s and transferred to NASA at the end of the 1950s when the Army decided they didn't want them any more.

I was thinking more of the massive number of "foreigners" recruited by NASA in the mid 1960s as the Apollo programme ramped up.

The head of their geology team was Egyptian.

A whole bunch of Canadians and Brits had very important roles at Mission Control and in mission planning. One of their main Flight Directors was an English chap called John Hodge. David Baker, who nowadays edits and writes for Spaceflight magazine (and has authored quite a few Haynes space related books) was employed at Mission Control during the final Apollo missions and Skylab.

[Eric Mc]

menguin said:

saaby93 said:

Refer to job jobbed

What ws it that led to Germany being so far ahead technology wise by the 2nd world war

So far ahead in one specific area - rockets. Because V-1 and V-2. Others were focusing on other areas! Just turned out that rockets ended up being the next big thingTM

The Germans had developed rockets to a higher extent in the mid 1930s because up to then, other aspects of aviation related engineering had been closed off to them. The other area which was available to them was gliders and sailplanes - which is why, to this day, some of the best sailplanes around are German designs.

[RizzoTheRat]

Eric Mc said:

A whole bunch of Canadians and Brits had very important roles at Mission Control and in mission planning. One of their main Flight Directors was an English chap called John Hodge. David Baker, who nowadays edits and writes for Spaceflight magazine (and has authored quite a few Haynes space related books) was employed at Mission Control during the final Apollo missions and Skylab.

Quite a few Canadians joined together from Avro after they cancelled the Arrow, presumably a happy coincidence of skilled engineers looking for work just as NASA was looking for skilled engineers, and at the time it was a pretty new field while the US aviation industry was going strong so I guess they might have struggled to recruit Americans away from safe jobs that were already cutting edge.

[Eric Mc]

I'm sure those are the exact reasons why they were recruited. But it does show that NASA has been quite willing to recruit non-US nationals as and when they needed to.

[Talksteer]

Eric Mc said:

Does NASA only employ US citizens? In days gone by it was very multi-national.

You need to be a lawful permanent resident e.g. green card.

There are plenty of foreign people working with NASA on NASA sites via universities and other space agencies.

[Beati Dogu]

Service guarantees citizenship! - Join Elon's Starship Troopers:

[anonymoususer]

That landing wasnt too far away from You Only Live Twice
Fantastic stuff

[Talksteer]

hidetheelephants said:

annodomini2 said:

hidetheelephants said:

Would need to be a very big one and even then it'll be veeery slooow; an MSR would be a better bet, orders of magnitude higher power density. Just the small matter of funding someone to perfect a working example, NASA's SLS budget would comfortably pay for the development several times.

MSR would probably be too heavy for space use.

GFR would probably be more practical.

More advanced designs would be more suited, but obviously further from reality.

Gas-cooled reactors are orders of magnitude poorer in power density and require massive pressure vessels to contain high pressure; MSRs can operate at around 1 atmosphere, so even on Mars the reactor vessel can be quite lightweight.

No-one has even built an experimental GFR, at least there have been actual MSRs built and operated.

Really?

The last generation of nuclear powered gas turbine (XNJ140E) had a power output of 136MWt in a core 0.99m long by 1.14m diameter. That core also had a gas turbine shaft going down the middle. That was in 1961, fuel was run successfully in HRTE-3.

Fuel was HEU in beryllium oxide and it operated at around 1300K, you can always trade delta T for mass flow if you have the balls.

The issue with Mars in the unsubstantial atmosphere which basically leaves you with radiating the heat away to drive your heat engine. This the drives you to liquid metal coolants to allow you to reject heat at a higher temp.

The fascinating thing is with additional compressor the XNJ140E would actually work on the surface of Mars a bit at lower power levels.

[Beati Dogu]

Now we know how SN10 managed to land. It had Matthew McConaughey flying it:

https://www.facebook.com/AstroBrew0/videos/2773681...

[hidetheelephants]

Talksteer said:

Really?

The last generation of nuclear powered gas turbine (XNJ140E) had a power output of 136MWt in a core 0.99m long by 1.14m diameter. That core also had a gas turbine shaft going down the middle. That was in 1961, fuel was run successfully in HRTE-3.

Fuel was HEU in beryllium oxide and it operated at around 1300K, you can always trade delta T for mass flow if you have the balls.

The issue with Mars in the unsubstantial atmosphere which basically leaves you with radiating the heat away to drive your heat engine. This the drives you to liquid metal coolants to allow you to reject heat at a higher temp.

The fascinating thing is with additional compressor the XNJ140E would actually work on the surface of Mars a bit at lower power levels.

It's got beryllium in it so I can't see how it's a GFR; are we all talking about the same thing, I googled it and got gas-cooled fast reactor? ANP derivatives have potential(the brayton cycle today seems to be where steam turbines were at the beginning of the 20th century) but materials tech would need a lot of proving as the ANP experiments lasted for a few days at most. The MSRE ran for thousands of hours over 4 years. Anyhoo, regardless of the specifics NASA/whoever would need to direct a few $bn at it to get it to a useable device.

[anonymous-user]

Beati Dogu said:

Now we know how SN10 managed to land. It had Matthew McConaughey flying it:

https://www.facebook.com/AstroBrew0/videos/2773681...

Actually very funny

[annodomini2]

Only 3 legs deployed, as they are crush structures it experienced a hard landing, this looks to have weakened the LOX tank, which ruptured, causing the explosion.

[Slackline]

thatsprettyshady said:

you can rewind any of these:

https://multistream.co/p/j82iAYqlPTD/r_SpaceX_Star...

[mybrainhurts]

Sky News covered this on youtube.

One comment, with 2000 likes, said "That rocket was more successful than your journalists".

Which was nice...

[Flooble]

I make a point of reading the (sensible) science stories on the BBC website as many times as possible, in an effort to game their "most read" algorithm.

I pondered writing a bot to do it from multiple IPs but that's probably going too far!

[Quisling]

F20CN16 said:

Beati Dogu said:

Now we know how SN10 managed to land. It had Matthew McConaughey flying it:

https://www.facebook.com/AstroBrew0/videos/2773681...

Actually very funny

I prefer this one

https://www.youtube.com/watch?v=aQ0PP0BoOpo