Recent Posts

Pages: [1] 2 3 ... 10 Next
1
Quote
"Made in Denmark by humans. We come in peace."
Jørgen Skyt and Anna Hovalt gave Nexø II the final layer of beautification.
If we have miscalculated a bit, the Pioneer reference may even come into play 👽

https://twitter.com/copsub/status/1000418556939591682
2
Very sad news. RIP.

May 26, 2018
RELEASE 18-044
Family Release Regarding the Passing of Apollo, Skylab Astronaut Alan Bean

The following is an obituary article released on the behalf of Alan Bean’s family:

Alan Bean, Apollo Moonwalker and Artist, Dies at 86

HOUSTON, Texas — Apollo and Skylab astronaut Alan Bean, the fourth human to walk on the moon and an accomplished artist, has died.

Bean, 86, died on Saturday, May 26, at Houston Methodist Hospital in Houston, Texas. His death followed his suddenly falling ill while on travel in Fort Wayne, Indiana two weeks before.

“Alan was the strongest and kindest man I ever knew. He was the love of my life and I miss him dearly,” said Leslie Bean, Alan Bean’s wife of 40 years. “A native Texan, Alan died peacefully in Houston surrounded by those who loved him.”

A test pilot in the U.S. Navy, Bean was one of 14 trainees selected by NASA for its third group of astronauts in October 1963. He flew twice into space, first as the lunar module pilot on Apollo 12, the second moon landing mission, in November 1969, and then as commander of the second crewed flight to the United States’ first space station, Skylab, in July 1973.

“Alan and I have been best friends for 55 years — ever since the day we became astronauts,” said Walt Cunningham, who flew on Apollo 7. “When I became head of the Skylab Branch of the Astronaut Office, we worked together and Alan eventually commanded the second Skylab mission.”

“We have never lived more than a couple of miles apart, even after we left NASA. And for years, Alan and I never missed a month where we did not have a cheeseburger together at Miller’s Café in Houston. We are accustomed to losing friends in our business but this is a tough one,” said Cunningham.

On Nov. 19, 1969, Bean, together with Apollo 12 commander Charles “Pete” Conrad, landed on the Ocean of Storms and became the fourth human to walk on the moon. During two moonwalks Bean helped deploy several surface experiments and installed the first nuclear-powered generator station on the moon to provide the power source. He and Conrad inspected a robotic Surveyor spacecraft and collected 75 pounds (34 kilograms) of rocks and lunar soil for study back on Earth.

“Alan and Pete were extremely engaged in the planning for their exploration of the Surveyor III landing site in the Ocean of Storms and, particularly, in the enhanced field training activity that came with the success of Apollo 11. This commitment paid off with Alan's and Pete's collection of a fantastic suite of lunar samples, a scientific gift that keeps on giving today and in the future,” said Harrison Schmitt, Apollo 17 lunar module pilot and the only geologist to walk on the moon. “Their description of bright green concentrations of olivine (peridot) as ‘ginger ale bottle glass,’ however, gave geologists in Mission Control all a big laugh, as we knew exactly what they had discovered.”

“When Alan's third career as the artist of Apollo moved forward, he would call me to ask about some detail about lunar soil, color or equipment he wanted to have represented exactly in a painting. Other times, he wanted to discuss items in the description he was writing to go with a painting. His enthusiasm about space and art never waned. Alan Bean is one of the great renaissance men of his generation — engineer, fighter pilot, astronaut and artist,” said Schmitt.

Four years after Apollo 12, Bean commanded the second crew to live and work on board the Skylab orbital workshop. During the then-record-setting 59-day, 24.4 million-mile flight, Bean and his two crewmates generated 18 miles of computer tape during surveys of Earth’s resources and 76,000 photographs of the Sun to help scientists better understand its effects on the solar system.

In total, Bean logged 69 days, 15 hours and 45 minutes in space, including 31 hours and 31 minutes on the moon’s surface.

Bean retired from the Navy in 1975 and NASA in 1981. In the four decades since, he devoted his time to creating an artistic record of humanity’s first exploration of another world. His Apollo-themed paintings featured canvases textured with lunar boot prints and were made using acrylics embedded with small pieces of his moon dust-stained mission patches.

“Alan Bean was the most extraordinary person I ever met,” said astronaut Mike Massimino, who flew on two space shuttle missions to service the Hubble Space Telescope. “He was a one of a kind combination of technical achievement as an astronaut and artistic achievement as a painter.”

“But what was truly extraordinary was his deep caring for others and his willingness to inspire and teach by sharing his personal journey so openly.  Anyone who had the opportunity to know Alan was a better person for it, and we were better astronauts by following his example.  I am so grateful he was my mentor and friend, and I will miss him terribly.  He was a great man and this is a great loss,” Massimino said.

Born March 15, 1932, in Wheeler, Texas, Bean received a Bachelor of Science degree in aeronautical engineering from the University of Texas in 1955. He attended the Navy Test Pilot School and accumulated more than 5,500 hours of flying time in 27 different types of aircraft.

He is survived by his wife Leslie, a sister Paula Stott, and two children from a prior marriage, a daughter Amy Sue and son Clay.

-end-
3
If the US side needs to take over boosting is there any reason to not turn the station permanently? As long as the Russians can do reboost there is no reason the US would have to do it at all. The ability is enough.

It could mess with some of the external experiments that are predicated on specific orientation.  They'd have to spin it around horizontally, keeping nadir/zenith the same, because otherwise all the Earth-facing instruments would be pointed in the wrong direction.  But, then things like materials science projects that want to be facing ram or wake would be facing the wrong direction.

I see, yes. But there would be ways around it. All such experiments are time limited, I think. They could reorient some as well. All a matter of timing experiments and preparing for the switch.
4

If the bomber was the B52 and the passenger aircraft was the 707 the resemblance would be rather more than superficial.


Nope. They don't even have the same number of engines (4 vs 8 ) or wing type... (anhedral vs. dihedral)


If your shot by a bow and arrow or the self forging fragment from a submunition, dead is dead.  :(

Personally I'd be most suspicious of any country seeking to acquire solid rocket technology for space launch. The performance hit, relative to any liquid fueled system, is huge. Big solids can't be shut down. They don't really have "benign" failure modes. They make excellent ICBM's for deterrence.

But the reality is the acquisition of any VTO TSTO by any nation make other countries nervous. There are no international inspection treaties for them, in the way there are for nuclear weapons, and every reason to doubt there never will be.

This whole train of thought is nonsense concern trolling
5
The following would have to happen for AR-1 to be selected. BE-4 having a major technical setback delaying it by a couple of years. Such that AR-1 would be into production before BE-4. ULA's main interest for Vulcan is schedule. The sooner the better in getting it flying. At the moment there is nearly a 2 year gap between BE-4 schedules for production units and AR-1 for production units. Late 2019 for BE-4 and sometime in 2021 for AR-1 although AJR keeps insisting that they can deliver in 2020. They still have not done any full engine tests of any kind. Expect that these tests of a development engine to be over a period of ~ 1 year. Followed by a very limited number of production engines for use in qualification testing. The latest is that AR-1 is unlikely to start full engine testing until late 2019 putting the first production engines late 2020 and then the first flight units H1 2021.
6


So, does the New Glenn or Vulcan "Heavy" offer better performance?  Well using the initial version of Vulcan (with the Centaur V), the Vulcan Heavy is supposed to have 16 ton performance to GTO:
 https://twitter.com/torybruno/status/987473611672858624
The New Glenn is supposed to have 13 tons to GTO:
https://www.blueorigin.com/new-glenn



They changed the New Glenn upper stage from a Methalox BE-4U stage to a Hydrolox 2xBE-3U stage. This has massively increased performance to the higher orbits. Payload to GTO is probably on the order of 18 tonnes now, with stage recovery. It was a real signal that Blue Origin is going to attack ULA and Ariane's home turf.

New Glenn really is a monster. Falcon heavy needs to expend the center core to match it. It has a big, fat 7m PLF to take advantage of this performance as well. It can probably do 0 deg supersynch for dual-manifested Ariane-sized payloads, while recovering the first stage now.
7
.......

A -55dB rtn loss from the S11 VNA scan represents a VSWR of 1.004:1 which is an impossible real world result.

Yet it is there.

One explication is it was caused by coupler self resonance, which ignores cavity eddy current losses.

BTW a -25dB S11 rtn loss is an excellent real world result, VSWR 1.2:1, when dealing with a high Q EmDrive.

Maybe ask Jamie what S11 rtn loss his cavity generates?

The VNA measured a S11 = -55dB so you can't say it is not a real world result.   If instead there was a high quality dummy load S11 would be just as low, but over a wide range of frequencies.   That would be another real world result.  The cavity just happens to be resonant at 1866 MHz and just about all the RF power is dissipated inside the cavity with very little being reflected.   I see nothing unusual about that.  We are barking up the wrong tree.

There are inconsistencies with the geomagnetic field interaction and other magnetic theories that explain the thrust.    Twisted power cables should cancel out any magnetic effects.  Even parallel conductors will do that quite well.   No attempt has been made yet to determine an optimum orientation of the experiment for the magnetic interaction.   If the whole apparatus was rotated there should be nulls and peaks.  This may be difficult to do but the fact remains there is not enough variability in the thrust to support a magnetic cause.   Mumetal is a wonderful material but is over-rated as a magnetic shield.  It's OK if you want to shield a Gaussmeter probe during calibration but for the purposes of isolating an EM-drive from the geomagnetic field it just won't work.

I still believe the "thrust" is a thermal effect.   Reading the paper by Martin Tajmar et al I see a very faithful replication of the work done by White et al at Eagle Works Lab at JSC.   The German team used a capacitor device for calibrating the force.   The thrust waveform when it is energized has a fast risetime and the appearance of an under-damped step response (ringing, etc) for a first order driving force.   That is what is expected.   However when the power is applied the trust wave form has a rounded and slower rise-time.   Immediately after the power is switched off the thrust drops with the shape of a decaying exponential waveform.   Those are the characteristic shapes of a second order step response.   I saw the same characteristics in the thrust waveforms that the Eagle Works tests produced.   Both are due to thermal effects.   Any EM-drive thrust due to RF being bottled up in a particular shaped cavity should have the characteristics of a first order step response, like the capacitive device.

Below is a section of one of the JSC EM-drive thrust waveform (Green) fitted to the temperature graph of an incandescent light bulb (Blue) after power on.   The time scales and vertical scales are different.  Both are exponential waveforms.  The latest experiments from Germany are similar.   I believe the EM-drive thrust is a thermal artifact.
8
Indian Launchers / Re: GSAT-29 - GSLV MK-III D2 July 2018
« Last post by TheVarun on Today at 05:17 PM »
 Is the 4 tonne satellite weight/mass for the GSLV Mark 3 D-2, confirmed?  If so, excellent!  It would show that ISRO is quite confident of the vehicle, and satisfied with the result of the D-1 mission, that they could raise the satellite weight by 900kgs or more.
9
Indian Launchers / Re: Indian launch schedule
« Last post by input~2 on Today at 05:06 PM »
Please keep this thread to launch schedule related posts only
10
I just want to add a comment to this gem:

For space launch, airline type operations and airline type risks are mutually exclusive.  The margin of safety whether it is 1.25 or 1.4 is too low.   That is why It has nothing to do with reusability.

But I thought aircraft only has a factor of safety 1.5? Wayne Hale even had a blog about it: https://blogs.nasa.gov/waynehalesblog/2008/12/16/post_1229459081779/

I'm not a mechanical engineer, but it looks to me the difference between FS 1.4 and 1.5 is not that large. How much performance would it cost to increase FS to 1.5 for launch vehicles?

On a related note, in 2016 AMA, Elon Musk mentioned this:
IIRC Wasn't one of F9's big selling points that it's been crew rated from day 1? I'm pretty sure he's said it's been designed to an SF of 1.4 and still turned out to be a very light vehicle.  However this may be because it uses "semi-pressure stabilized" tanking, more like the British Blue Streak IRBM and Atlas 1-3  than statically stable designs like Delta
Pages: [1] 2 3 ... 10 Next