Search found 2245 matches

by DeltaV
Wed May 18, 2016 4:03 pm
Forum: General
Topic: Second Worst President in US History.
Replies: 530
Views: 199551

Re: Second Worst President in US History.

Yeah, it appears that it can only deal with a launched missile, not an orbiting one. Probably not enough time to intercept it if it is fired from space. Yeah, it is a quick jump from orbit for a propelled weapon, especially if they fake a failure to attain a stable altitude. http://history.nasa.gov...
by DeltaV
Wed May 18, 2016 3:41 pm
Forum: General
Topic: Skynet is coming.
Replies: 802
Views: 386712

Re: Skynet is coming.

You Can Now Buy Shotgun Shells Designed Specifically For Shooting Down Drones http://www.popphoto.com/sites/popphoto.com/files/styles/medium_1x_/public/drone-munitions-600x338.jpg?itok=9D0PTEjl The packaging says, “Prepare for the drone apocalypse!” which is either a joke or a really alarmist thing...
by DeltaV
Thu May 12, 2016 7:16 pm
Forum: News
Topic: New Polywell Article On HotGas
Replies: 69
Views: 50653

Re: New Polywell Article On HotGas

It used to be that, to get a PhD, you could submit a thesis to certain schools and successfully defend it, not having taken any classes. I wonder if any schools still allow that route.
by DeltaV
Thu May 12, 2016 7:06 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

Attitude control fails, even briefly, and the stage is back to tail first. The best feature of the Soyuz capsule is fault tolerance, bringing passengers back alive, if not comfortable, in the event systems like attitude control malfunctions. Modern airliner doctrine is undersized control surfaces t...
by DeltaV
Thu May 12, 2016 6:03 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

Regarding hot spots, I was thinking more of the plumbing, wiring and structure surrounding the engines. Looking at a photo of a landed F9, however, they seem to be sealed up better than I had thought. http://i.stack.imgur.com/GZUts.jpg But those seals are not good enough for tail-first reentry from ...
by DeltaV
Wed May 11, 2016 1:34 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

Why would it have to be the same shape as a F9 first stage? I don't think an F9 based SSTO makes much sense. The payload mass ratio would be too low. What I could see is an SSTO based on the upcoming Raptor engines. If the Merlins are any indication, we might see an engine that combines an extremel...
by DeltaV
Wed May 11, 2016 1:19 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

Weight of the engines makes it difficult getting anything similar to the Falcon9 first stage to reenter at any attitude other than tail first. One option for keeping the engines cool is running an expander cycle transpiration system: fluid through nozzle coolant passages, hot fluid powering a turbo...
by DeltaV
Wed May 11, 2016 1:12 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

Something that might work along these lines is to have a translating interstage section that slides back to reveal a PICA-covered nose. The engine end is hopeless in this regard. How would you manage the pitch over maneuver once in lower atmosphere in preparation for landing? Seems like a lot of po...
by DeltaV
Tue May 10, 2016 1:00 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

People generally overestimate the weight of the TPS for a VTOL SSTO. The shuttle could have gotten away with much less heavy TPS if it had not needed the height cross range. PICA-X is extremely lightweight at less than 0.25 grams per cm3. For a PICA shield, there is the issue of the unfavorable geo...
by DeltaV
Sun May 08, 2016 9:22 pm
Forum: News
Topic: Rick Nebel Discussed DC Transformer Project in Los Alamos
Replies: 34
Views: 34092

Re: Rick Nebel Discussed DC Transformer Project in Los Alamos

Update from Nov 2015: ARPA-E Awards Tibbar Plasma Technologies Of Los Alamos $3.5M For Transformational Energy Technology http://www.ladailypost.com/content/arpa-e-awards-tibbar-plasma-technologies-los-alamos-35m-transformational-energy-technology http://tibbartech.com/ They are hiring. Tibbar Plasm...
by DeltaV
Sat May 07, 2016 12:14 pm
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

If you assume a capability for stage 1 to reach a minimal orbit, it still needs to dump all of that energy upon return. There is no chance of it surviving reentry without a Thermal Protection System (TPS), for which there is no margin. Unless... 1) Enough fuel remains to use engine exhaust plume(s) ...
by DeltaV
Fri May 06, 2016 1:32 am
Forum: News
Topic: SpaceX News
Replies: 2324
Views: 1154336

Re: SpaceX News

Tesla Model X has a Bioweapon Defense mode. Does it work for Republicans, or will only Democrats make it to Mars? :)
https://pbs.twimg.com/media/Chdy3FOW4AcOZvL.jpg
by DeltaV
Tue May 03, 2016 4:31 pm
Forum: News
Topic: EM Drive
Replies: 785
Views: 601950

Re: EM Drive

Possibly of interest for some of the EMdrive hypotheses being discussed at NSF. I'd post these there if I had an account, maybe someone both here and on NSF can link. (May have found one or more of these on NSF, don't recall... apologies if any repeats.) On Divergence in Radiation Fields http://arxi...
by DeltaV
Tue May 03, 2016 2:37 pm
Forum: News
Topic: Joe Eck hits Tc = 187 C, 368 F
Replies: 70
Views: 65992

Re: Joe Eck hits Tc = 187 C, 368 F

Chemistry... definitely not my gig. Spent too much time chuckling at a professor who would scratch his bald head with a whiteboard marker in his hand and leave tracks, so I never learned how to get chemical equations to balance.
by DeltaV
Mon May 02, 2016 6:28 pm
Forum: News
Topic: Joe Eck hits Tc = 187 C, 368 F
Replies: 70
Views: 65992

Re: Joe Eck hits Tc = 187 C, 368 F

187 Celsius (460K/368F) from Sn10SbTe9Ba2MnCu21O42+. http://www.superconductors.org/187C.htm Enough already with the Tc. Increase the volume fraction, volume fraction, volume fraction, volume fraction, volume fraction, ... (cyberecho for emphasis), or mainstream science will simply continue to dismi...