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Look up 'Project Orion'.

I can design a trebuchet to get me from my back yard to the nearest grocery store. It will work. It will be reusable. I'm not going to do it. It's not a holdback on new technology. It's not new technology at all.


Project Orion is hard to even call new technology. Riding a shock wave happens often, its just the riders are usually victims.

It had numerous issues working against it. I doubt anyone denies that theoretically blowing things up behind a giant shock absorber will work. It's not cheap for starters.  An Orion ship would have required multiple detonation devices, and military devices would have been overkill. There is not an inexhaustible amount of fissile material. The vehicles would have to have been constructed in orbit (realistically launching these from Earth was never a real option. We can discuss that on some other thread, but i think it's been done before) very stoutly. Again, not cheap, and the engineering was not certain. Throw in possible treaty violations, radiation concerns, etc, Orion is just an idea that must probably sit forever on the shelf of history unless for some reason someone is desperate enough to need it and has no other option. The problem is there are always other options.

I'm as tired of the frauds as anyone, but I don't see the EMdrive experimenters and theorists putting incredible efforts into this in any such light. Even if it has no more thrust than is useful for station-keeping, that will be extremely useful. That's why I keep watching this.
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Space Science Coverage / Re: Possible Mars-mass Body @ 60 AU
« Last post by sanman on Today at 05:24 PM »
Why do we have to rely on optical methods or even gravitational calculations to locate such bodies? Why can't this be done radar-style?
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hmmmm. maybe this is the hull plating for mah star cruiser?

https://phys.org/news/2017-06-carbon-harder-diamond-flexible-rubber.html

bendy and stretchy as rubber but harder than diamond?

Hardness is good against abrasion, but not as useful as structural strength.
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Indian Launchers / Re: GSLV-Mk III - General Discussion
« Last post by sanman on Today at 05:15 PM »
Yes, it is a constraint, but an not as important as it might seem. An upper stage with 5km/s delta-v is not that unusual and does not require hydrogen. For example, the F9 upper stage (again KeroLox) provides 7.5-8 km/s of delta-V.

It does bug me when the Sriharikota location is used an excuse like that. Most countries would LOVE to have that location. It may be the 2nd best located launch complex on earth after French Guyana, and many two-stage launch vehicles could operate out of there without making any changes.

Well, I'd prefer a precedent from a pre-Falcon rocket, because GSLV was conceived long before it. Besides, ISRO was looking to scale past what individual expendable Falcon9 can do.

But I'd agree that Sriharikota is a pretty decent launch site, overall - other than the fact that nearby Sri Lanka forces ISRO rockets to do a dog-leg maneuver for some launches. Once ISRO develops a reusable booster, I'd imagine that it could have more latitude in turning around rather than traveling ballistically.
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Space Science Coverage / Re: Possible Mars-mass Body @ 60 AU
« Last post by llanitedave on Today at 05:15 PM »
It seems like our basic picture of our Solar System is still evolving - I'm wondering how it might affect our longer-term outlook for space travel in the far future. Suppose we end up finding other major bodies even farther out from our Sun, and maybe even rogue planets farther still, along with brown dwarves, etc. Maybe we could end up planet-hopping our way out from our Solar System, like island-hopping across the Pacific Ocean, until we get to another star.


That could be almost a guarantee, except you don't need "major" bodies to do it.  Any extended population of icy bodies will allow all the hopping resources you need.
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Historical Spaceflight / Re: The Different Variants of Titan Boosters
« Last post by WallE on Today at 05:15 PM »
Here's another bit of information, from January 1981 by Martin Marietta.  It says that there had been 62 Titan IIIB launches by then with 61 successes.  There had in fact been 62 Titan IIIB launches by then, and four failures, but at least two, and maybe three, involved Agena rather than Martin's Titan stages.  The April 26, 1967 failure is typically listed as due to the second stage not developing sufficient thrust.  Two 1972 failures involved Agena.  That leaves June 26, 1973, which, if the 1967 failure did involve Stage 2, Martin Marietta did not report to be a failure involving the Titan stages.

That sounds about right. They only list failures involving the core Titan stages, and just one is indicated for the Titan 3B, which of course be the 4/27/67 launch. Also FWIW they list two Titan 3C failures in 29 launches, which would be the 8/26/66 launch (although I don't know why that counts since it was a payload shroud failure) and the 3/25/78 launch, while excluding the four Transstage failures.

That leaves very puzzling questions.  Where did Robert Perry get the story about the Titan tank leaking at T+12 sec?  And why did he record that as a historical fact?  (Could Titan have had a small leak and Agena failed to start?)

Apparently he got it from the same place as the story about Atlas-Able 3 experiencing a premature Able ignition and Atlas-Centaur 1 exploding when the LH2 contacted the engines, both of which we now know to not be true.

If there was a Titan propellant leak, it must have been at best incidental and not the main contributing factor to the failure.
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James Dean reported earlier this morning that the NET date could be as soon as July 2nd. This is or course highly dependent upon pad flow, as Chris mentioned.
https://mobile.twitter.com/flatoday_jdean/status/879734053104218113
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New Physics for Space Technology / Re: Blacklight Power
« Last post by bad_astra on Today at 05:12 PM »
What puzzles me even more than hydrino, is why, after 8 years, the moderators haven't deleted this thread.

If there is anything to this power source, then it certainly has space based applications. Compact heat and electrical power sources are critical to cheaper deep space utilization. I don't know if there's anything to this or not. So many times with too many miracle power sources it has been bait and switch. I remain open to seeing what will happen.

More realistic sources like Helion or LPP don't make claims as fantastic as BLP or Rossi, and there really is not much to say about them. Other fusion attempts like Wendelstein, ITER, or General are just too large to have much applicable use near-term, even if they were suddenly working tomorrow.
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Space Science Coverage / Re: Proposed Europa Missions
« Last post by sevenperforce on Today at 05:11 PM »
Does anyone know what propellant will be used for Europa Clipper's thrusters? Is it ion, mono, or biprop?
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