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SpaceX Mars / Re: Elon The Boring Company
« Last post by speedevil on Today at 05:46 AM »
There sort of are underground stations.
If accelerating at 1g (quite a thrill ride!), you need around 125m of track next to the main traffic tunnel, for coming to 100mph in the main tunnel.
One G only works for people in cars.  For loose people in the glass fishbowl people mover who only have an overhead strap or a pole to hang onto gee, I think that would be too much acceleration.
In principle, no particular reason not to have multi-point harnesses or other retainer systems.
The only question I would have to clarify: would the Dragon 2 need more delta-v for the lunar mission, or would the 20+plus tons of LOX/RP1 be enough? In other threads, I have talked about a 'Propulsion Pallet' based in the Trunk that could be an 'Nonet' of 9x rearward firing Draco thrusters and a couple tons of propellants. But with that extra mass, the second Falcon 9 might have to be expendable as well :(
You need basically 3.5km/s to get to free-return.
With four tons of dry mass, 9 tons of dragon (I did not carefully compute this), you need about 36 tons initial, of which 23 tons needs to be propellant.
If the D2 stores/trunk are under 3 tons, then it may barely be done by an expendable.

In principle, and not saying they're going to do this, crappy-BFR-esque operations with refuelling in orbit, three RTLS launches for fuel, and recover the second stages might work well too cheaply.
SpaceX General Section / Re: Upcoming Talks - SpaceX Related
« Last post by lonestriker on Today at 05:26 AM »
I saw a couple of SpaceX interviews linked from Reddit threads over the last couple days:

Hans Koenigsmann at NEAF on April 22:


Hans' talk starts after the 4:00 hour mark in case anyone else wants to save time fast-forwarding in small chunks like I did.
I do think the idea of the government researching advanced technology is fundamentally sound.  Establishing institutions for very specific purposes can be a bad idea, though, as the institution is likely to outlive the usefulness of the concept on which it was founded.  Rocket propulsion may be sufficiently broad a topic that that's not too big a risk.  In the case of NIRPS, though, I see that it lists no publications since 2014, and its most recent annual report is for 2012.  Looks like it's not doing anything productive; I wonder whether it's still being funded.

The U.S. Government funding research is a great use of taxpayer money.

The U.S. Government helping industry with development, especially small companies, is a great use of taxpayer money.

The U.S. Government building things they think industry should use is a BAD use of taxpayer money.

I've been advocating that NASA should, to some degree, revert to being more NACA-like, in which case having the U.S. Government retain assets like MSFC would make sense if they are focused on helping the U.S. aerospace sector.

My $0.02
Indian Launchers / PSLV C4*/RISAT-2A 2018 Q4
« Last post by K210 on Today at 05:16 AM »
RISAT-2A is planned to be launched by a PSLV by year end

Risat-2A, which will be launched by the end of this year by a PSLV rocket, is an advanced remote sensing satellite that will boost the country’s surveillance capabilities.

The satellite, which will carry a sophisticated synthetic aperture radar that operates at 5.35 GHz in C band, will help in earth observation irrespective of the light and weather conditions of the area.

Risat-2A, which can be used for civilian purpose, will primarily be used for land mapping but will also be significant for analysis of the ocean surface. Risat-2A will be the third in the series of Risat satellites.

The secret X-37B/#OTV5 space plane passing over the Netherlands earlier this evening. It changed its orbit earlier in the week, and the amateur satellite tracking network has been hard at work determining its new, lower, orbit.

Quote from: @esa
The countdown rehearsal was completed successfully today. Liftoff set for 17:57 GMT (19:57 CEST) on Wednesday 25 April.
Why climb a mountain? “Because it’s there.”

Why go to space? The Right Stuff. Apollo 13. The Starship Enterprise.

Anyone can go climb a mountain. To go to space is a whole ‘nother thing.
More a flag Mo Brook's campaign  can wave before the November elections.
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