Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Dave W
#1519886
It seems unlikely, but NASA's Administrator opened up the possibility this week - using the imminent Space Launch System and Orion Multi-Purpose Crew Vehicle.

NASA is eyeing the moon again

Time wrote:On Wednesday, NASA's acting administrator Robert Lightfoot circulated a memo to employees hinting at the possibility of flying astronauts aboard the space agency's new heavy-lift rocket and crew vehicle as early as 2018. What's more, the mission would not just be to low-Earth orbit, but to lunar orbit — coming during the 50th anniversary year of the Apollo 8 mission, when astronauts first achieved that singular exploratory feat.


Then again, there's getting the money...

But let's keep incendiary politics out of this thread if we can.
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By Morten
#1519899
Egged on by similar stated ambitions by the Chinese... still if that's what it takes, that's fine.
Unfortunately, the cynic in me sees it as a bit of reverse ferret - the SLS is borderline funded and not that well supported and the overall case that it is needed is getting slimmer day by day. So, hey presto! Let's announce a moon programme which will make developing the SLS a lot more useful than it is today! Sort of doubling the ante.
Still, if that's what it takes... Go NASA!

Shame that the space elevator programme, or at least the potential Carbon Nanotube cable element of it, was given a bit of a blow last year w.r.t. strength requirements. The latest estimates now seem to say that we may get to a suitable material in 20 years time... but I've heard that before. But at least a Space elevator would truly revolutionise space. And once you had one around the Earth, you could (relatively!) easily put up a second one... and one on the moon, Mars, Venus...

But let's keep incendiary politics out of this thread if we can.

Wishful thinking :) Unfortunately, any publically funded programme of that scale will need to deal with the (incendiary) politics sooner or later!

Morten
#1519913
On a non incendiary, but still political point. One of Donald Trump's more rational policies has been to take away NASA's developed earth sciences activity, give that to NCAR and NOAA , and have NASA concentrate on the aerospace work that it was established to do.

Barack Obama, on the other hand, had been reducing space exploration budgets and spreading earth Sciences research across far more agencies than ever seemed particularly necessary.

On this one issue at least, Mr Trump does seem to have the better ideas.

G
By ChrisRowland
#1519938
Morten wrote:Shame that the space elevator programme, or at least the potential Carbon Nanotube cable element of it, was given a bit of a blow last year w.r.t. strength requirements. The latest estimates now seem to say that we may get to a suitable material in 20 years time... but I've heard that before. But at least a Space elevator would truly revolutionise space. And once you had one around the Earth, you could (relatively!) easily put up a second one... and one on the moon, Mars, Venus...

A space elevator on Mars would be easier because of the reduced gravity but you would need to arrange to miss Phobos and Deimos.

The Moon would be tricky because it's tidally locked to the Earth but it may be possible to set up a couple of elevators to the L1 and L2 points.

Venus would be really tricky because the slow rotation rate would make an elevator very long and the high surface temperature and pressure would preclude just about every material. Perhaps it could finish in the upper atmosphere.

There's an intermediate system using rotating tethers attached to massive objects in orbit. You get into the upper atmosphere and hook onto the tether, this transfers momentum from the massive object to you and gets you into orbit, maybe more than that. The same system run in reverse gets you out of orbit and recovers the momentum.
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By Morten
#1519968
Damn! Are you saying that the science fiction stories which use anchors on Mount Olympus and Kilimanjaro are wide of the mark? :shock:

It should be possible to have the bottom not anchored but skimming along at e.g. 10km, where you could hook up the climbers by the use of 'normal' aircraft. That would then make the system easier to deploy on e.g. the moon without needing to compromise between orbital velocity and spin. You would also free yourself from using the equatorial plane altogether and would be free to use any inclination you wanted, so you should be able to avoid any pesky low satellites if you need to. Some sort of blimp or other neutrally buoyant structure with limited mobility requirements could be used for the bottom station, as long as you accepted that the cable would not be 'straight up'. But again, this is mostly by sci-fi, not sure about the physics and orbital mechanics :oops: It would be fun to work out...

For sure, Venus may not be the best destination for a holiday but if Dubai can be made into a holiday resort, there must be hope for Venus as well :-)

Morten
By ChrisRowland
#1519976
Morten wrote:Damn! Are you saying that the science fiction stories which use anchors on Mount Olympus and Kilimanjaro are wide of the mark? :shock:

IIRC the point about Phobos and Deimos came from Kim Stanley Robinson's Red/Green/Blue Mars series. Bending the cable to miss passing satellites isn't impossible but the consequences of getting it wrong and breaking the cable aren't good.
The entire elevator cable is free and not attached at the base, just suspended. Keeping it stable could be a challenge.

Robert Forward came up with the spinning tether idea, searches on his name and space tether or momentum transfer should come up with something.
Dave W liked this
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By Morten
#1519978
Cool - thanks for the links, will google :-)

Back to the NASA moon shot - last month Boeing unveiled their new space suit design - they've gone from orange to blue!
The Starliner spacesuit is revealed publicly for the first time
I was interested to learn that our old friends David Clarke partnered with Boeing on this development, as they apparently did on the previous ones. I didn't realise that DC had space credentials - I should have known, really. Still, looks good... :thumleft:

Morten
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By Josh
#1520001
DC were in at the ground floor on space suit design. The blue is both the Boeing colour du jour and the colour of astronaut flight suits so no huge surprise.

On the man topic, I would love to see lunar flight outside a documentary or film. It will be really interesting to see what differences in engineering philosophy there are with the Apollo designs (redundancy for example) to see how NASA's approach to spaceflight has changed.
By zlhglp
#1520217
Thunderstorms and lightning... All a bit frightning for a space elevator. I think one might prove practical on the moon but I can't see an earthly one any time soon.

The good news is that Spacex and perhaps other reusable rockets will enable my son to become a Martian if that's still what he wants when he grows up.