The thread for space cadets!

[PlutonianEmpire]

A space question that I think is mathematical in nature, or something.

Posting it here, because moar visibility than the Math Q&A and Science Q&A threads combined.

How do I find the galactic anti-pode of a star other than a sun, as viewed from Earth? Meaning, Sol's galactic anti-pode has the same RA/Dec as Sgr A, but double the distance. How do I find that for a different star, but still viewing it from Earth, and thus said star's anti-podal RA/Dec and 2xDistance being different than that of Sgr A?

 

[Winner]

I actually think it is pretty realistic. The way they are doing it is they are basically dragging their launch-escape system up to orbit with them as it's built into the capsule instead of jettisoning it. Given that the system is designed to haul the capsule off of a supersonic exploding ball of fire, chances are it could handily slow down a capsule. I assume they will use a really blunt capsule to slow it down the old fashioned way and that will take care of the bulk of the velocity they need to shed.

I have no idea how they would make it work without a parachute though as a parachute, even a drogue, can kill so much more velocity. Maybe the retro's can handle it all on their own. I would guess that they'd need at least 300m/s delta V, (a little less than what it takes to go from Mach 1 --> 0m/s) but really that depends on so many other factors like how accurate constitutes a 'precision landing' and how much they can slow down due to aerodynamic forces.

Ah, I forgot about they way they do the escape system, my bad.

But even then, they still would need a parachute on the capsule, for safety reasons, right? (And if the escape system was used during abort, the capsule would need it to land anyway.) Seems a waste not to use at least a drogue to slow down, and the thrusters just for the last few seconds to slow down and land on a pad.

(Try asking questions like these on other forums, youTube, or wherever; SpaceX fanboiz will eat you alive "The rockets work because they're cool, get it?")

-----

Anyway, the British gov. has finally noticed, that something good is brewing at ReactionEngines, so they'll maybe throw in some cash for further development:

- UK pledges fresh support for revolutionary space engine

-> I wonder if SABRE can actually work as a rapidly reusable system. I think it will be quite a challenge, considering the experience with the Shuttle main engines. SABRE should have even higher thrust (around 3000 kN if I remember correctly), although split between four combustion chambers if I understand it right. Still, the materials will have to be pretty tough to ensure reusability with a reasonable degree of safety. After all, a SKYLON should fly for hundreds of times before it needs to be replaced, unlike an expendable booster which only needs to work fine once.

 

[hobbsyoyo]

Link to video.

A Russian rocket crash yesterday (July 1) was likely caused by an emergency shutdown of the booster's engines 17 seconds into the flight, according to news reports.

The unmanned Russian Proton-M rocket launched from the Baikonur Cosmodrome in Kazakhstanat 10:38 p.m. EDT (0238 GMT). The crash of the 17-story booster destroyed three onboard navigation satellites, which were worth almost $200 million. Video of the rocket crash from Russian state-run Rossiya-24 television shows the vehicle veering off course shortly after liftoff, and then breaking apart in mid-air and exploding in a fiery blaze once it hit the ground.

The rocket was carrying 600 tons of highly toxic heptyl, amyl and kerosene fuel, which were spilled when the booster was destroyed, Russian news service Ria Novosti reported. The burning fuel gives off a poisonous smoke, but officials said the cloud was being partially contained by rain at the launch site.

http://www.space.com/21811-russian-rocket-crash-details-revealed.html

 

[Thorgalaeg]

Out of control space rockets are scary things indeed.

 

[hobbsyoyo]

Here some more explosions:

Link to video.
The video follows the format where they show a failed launch followed by a successful launch of the same type of rocket. In order (to the best of my knowledge):
Jupiter (with some cool thrust vectoring going on)
Thor (there is a longer, less blunt nosecone on the second launch so it looks different)
Titan I
Polaris (watch when they pan back to the tower after the 2nd stage crashes back down - the first stage is still on the pad spouting flames out of the top and bottom)
Minuteman I (they only show a successful launch of the Minuteman)
Vanguard? (really grainy video)
Atlas I
Scout (successful launch)
Juno launching Explorer I successfully (the Juno/Jupiter/Redstone rockets were all in the same family)
Thor-Able or Delta B (can't see the top clearly and they look almost identical below that) (succesful)
Juno II (successful launch followed by a failure)
Atlas-Agena A (successful)
Freedom 7 launch on a Mercury-Redstone rocket with Alan Shephard

 

[Borachio]

Link to video.


Link to video.


Link to video.


Link to video.

 

[hobbsyoyo]

Now this is a hellish sight. Fast forward to the 2 minute mark to watch fire rain down from the sky of this failed Delta II launch.

Link to video.
Massive Chinese Rocket FAIL:

Link to video.
That launch led to a bunch of fines being leveled on US companies who helped the Chinese figure out what actually went wrong with the rocket (faulty welds were to blame instead of the 'gust of wind' they publicly pinned it on). Congress determined that this constituted an illegal technology transfer, though no one went to jail or even admitted guilt.

This is a cool launch. You can tell just how massive this rocket is by how slowly it lifts off. It's a Delta IV Heavy.

Link to video.

This was the final flight of the DC-XA (Delta Clipper Experimental Advanced) rocket, a single-stage-to-orbit rocket that would have provided relatively cheap and quick access to outer space if the program had not been cancelled.

Link to video.

Apparently this is what Polish people do for fun...pretty cool.

Link to video.

Look at this massive Saturn V replica model rocket:

Link to video.

 

[hobbsyoyo]

@Borachio - why did they cancel the Blue Streak program?

Oh and the Skylon project that Winner referenced a few posts back is from a British company and it's very cutting-edge stuff.

 

[Borachio]

edit: I really have no idea.

 

[hobbsyoyo]

Hmmm...wonder if it was meant to launch satellites or nuclear warheads?

I know quite a few British aerospace programs were cancelled when the US talked them into buying the Polaris and Trident missile systems. One of the missiles that blows up in the first video I posted is a Polaris btw.

Found the answer:

The origins of the Chevaline requirement grew from the conclusion of several British governments that in the event of a Soviet nuclear attack on the UK alone, as had been threatened in late 1950s by Soviet Premier Nikita Khrushchev and Prime Minister Nikolai Bulganin[1] it was unrealistic to expect that the US would retaliate against the Soviet Union and risk an attack on major American cities. That conclusion by successive British governments was the basis of their justification given to the British people for an independent nuclear retaliatory capability.

For some time this deterrent force had been based on the Royal Air Force's V bomber force. This looked increasingly vulnerable in the face of ever-increasing Soviet Air Defence Forces, and by the late 1950s the RAF was pursuing the Blue Steel II stand-off missile to allow its bombers to fire their weapons while still (hopefully) outside the range of the defensive fighters.

Another solution was the Blue Streak missile project, although this was running into continued delays. Blue Streak also had the serious problem of basing; the UK was small enough that it seemed possible for the USSR to spot the launch sites without much trouble and attack them directly.

A better solution came along in the form of the US's AGM-48 Skybolt missile. The US bomber force was facing the same sorts of problems as the British V bombers, and were attempting to solve it in a similar fashion, with a long-range standoff missile. In this case, however, the missile in question had a truly long range of just under 2,000 km. Considering the distance from London to Moscow is about 2,500 km, Skybolt would allow the V-bomber force to attack Russia from sites not far off the British coast, with complete immunity. Skybolt seemed like such a good solution that work on both Blue Steel II and Blue Streak were cancelled.

So the Blue Streak was to be an ICBM, it seems. It also seems the British weren't really given a choice about buying the Polaris system - they were forced to do it when the US cancelled the Skybolt system upon which the UK military had based all of their retaliatory strike capabilities on.

 

[Winner]

Proton fail

http://www.space.com/21811-russian-rocket-crash-details-revealed.html

And this is, kids, why I am SCARED ******* that the European ExoMars probes are set to fly on Protons. Seriously, that's like transporting Mona Lisa over the ocean in a 1930s vintage bi-plane...

ESA should get their heads out of their collective butt and book an Ariane 5 launch. It's a more powerful launch vehicle anyway with a near spotless launch record (55 successes in a row), so the mission would be allowed greater mass margins. Yes, it's more expensive than a Proton, but Proton is such a momentous piece of crap (always was and always will be, no matter what the Russians do with it) that flying your multi-billion FLAGSHIP exploration mission on it is verging on suicide.

(If they want to stick with that suicidal idea, I really hope they build the probes in triplicates... )

EDIT: Also, Proton uses hypergolic propellants as mentioned in the Euronews video, which means every **** up like this means a lot of cleaning, or a lot of waiting for rain... Sigh...

EDIT2: HD amateur footage of the failure:


Link to video.

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So the Blue Streak was to be an ICBM, it seems. It also seems the British weren't really given a choice about buying the Polaris system - they were forced to do it when the US cancelled the Skybolt system upon which the UK military had based all of their retaliatory strike capabilities on.

Also, Blue Streak was meant as the first stage of the Europa rocket, the precursor to Ariane. The rocket never succeeded, though the failures were due to the French and German upper stages. The Brits pulled out of the project, which gave the French the leading position in the European space launcher programmes. The result was the Ariane series.

If you ever have time to kill, read this Alternate History timeline (written by engineers/space historians): Eyes Turned Skywards. It's PoD is a decision by Nixon not to pursue space shuttle, but instead let NASA continue with Skylab and Apollo-derived hardware. The main focus there is obviously NASA spaceflight, but the European programmes are also mentioned; there, the Europa programme succeeds and the Brits are thus much more vested in ESA than they were in our timeline. It's a great stuff to read for any space nut

 

[hobbsyoyo]

Holy crap, that video is scary. I can't believe they were allowed to be that close...oh wait it's Russia lol. But seriously what if that rocket veered their way? That video also shows the scale better than the other one. I showed the other video to a friend and he wasn't impressed, 'Eh, it's not that big of a rocket'.--->he's not that smart.

I did some digging on the Proton yesterday and it had a full decade of failures before they got it to work...so yeah, piece of crap is a title well-earned.

 

[Winner]

Holy crap, that video is scary. I can't believe they were allowed to be that close...oh wait it's Russia lol. But seriously what if that rocket veered their way? That video also shows the scale better than the other one. I showed the other video to a friend and he wasn't impressed, 'Eh, it's not that big of a rocket'.--->he's not that smart.

I did some digging on the Proton yesterday and it had a full decade of failures before they got it to work...so yeah, piece of crap is a title well-earned.

I suck at judging distances, but to me it doesn't look much closer than the distance people used to watch shuttle launches from. (The speed of sound delay is about 10 seconds, so I would guess it was filmed from roughly 3.5 km distance). The main problem I see here is the toxic propellants; I wouldn't like to be caught downwind from this failure. But I don't know the conditions under which Russia leases the Baikonur cosmodrome from the Kazakhstan gov., or who should take care that people don't get too close.

BTW, did they self-destruct the vehicle, or did it start disintegrating as a result of the stresses as it went down? And what was the problem? On this video it shows the vehicle might have had some sort of steering failure, and then the engines gimballed and perhaps overcompensated?

Anyway, you see why this doesn't exactly boost my confidence concerning the ExoMars mission. Superstition is an additional factor, since the Russians have had terrible luck with Mars missions. Inviting them to ExoMars seemed to me like a kiss of death. ESA should remember the saying about saving a penny, losing a pound. Morons.

(BTW, have you noticed how many YouTube comments feature references to Kerbal Space Program? )

 

[Blue Emu]

On December 27th 2004, a high-energy blast of gamma rays and X-rays washed over the Earth. It was detected by the RHESSI High Energy Solar Spectroscopic Imager (which was pointed at the Sun at the time), by the INTEGRAL gamma-ray observatory... and most impressively, the newly-launched SWIFT gamma-ray burst observer not only detected the blast, but its measuring instruments were totally saturated by the intense gamma-ray flux, despite the fact that it was pointed at nearly 90 degrees to the oncoming radiation which therefore had to penetrate the casing of the satellite to reach the detectors.

The wave of high-energy photons was so intense that in addition to blinding several satellites, it ionized the Earth's upper atmosphere and caused the Earth's magnetic field to ring like a bell for days afterwards.

The intense gamma-ray burst was structured... after the initial extremely powerful blast, the "tail" of the burst consisted of a series of intense pulsations separated by 7.56 seconds.



Note that the intense initial gamma-ray spike (on the extreme left of the graph) is cut off in this plot. It would require a computer screen 300 meters tall to properly show it to scale.

Where did this huge burst of gamma-rays come from? From a stellar remnant called SGR 1806-20, over 50,000 light-years away.



... it came from the other side of the Galaxy.

There goes the neighborhood.

Current theory suggests that it was caused by a Richter magnitude 32 star-quake on a magnetar... a rotating neutron star with a magnetic field roughly one quadrillion times stronger than the Earth's field.

 

[Winner]

In other words, the cosmic filter at work?

 

[Thorgalaeg]

Anybody at an hypothetical base on mars or at a manned ship travelling through space beyond Earth´s magnetic shield protection would have been roasted i suppose.

ULTRA LATE EDIT: Re-reading my own post i just noticed how silly it is, having in mind gamma-rays might be unaffected by magnetic fields since they are photons and have not electric charge. In any case they would be mostly absorbed by high atmosphere. So i suppose the burst was not that hard since astronauts at ISS survived AFAIK.

 

[Winner]

Yeah, the problem is, if it happened 500, not 50,000 light-years from the Solar System, we might have had a serious problem.

There is a hypothesis out there, that the Universe is in reality pretty non-conducive for development of higher intelligence, since sooner or later one of these radiation spike events get you. And since they tend to lay waste to areas of space hundreds of light-years in diameter, for a civilization to survive, it has to be spread pretty wide.

 

[Thorgalaeg]

Thinking on it that way i find some quite interesting but depressing implications. I mean, i always though that the center of our galaxy is, with all probability, the best place to find life, even civilizations, due to very high star density. It is easy to imagine even interstelar communication among neighbour advanced civilizations given how close stars must be there.

However cosmic cataclysm like the 2004 one must be much probable there because the same reasons, making the center of the galaxy too deadly for civilization development.

It is sad to think on it as a bright but burnt and dead wasteland instead of a densely populated space opera style universe. Maybe isolated suburbs like ours are the best places to find life after all.

 

[hobbsyoyo]

I suck at judging distances, but to me it doesn't look much closer than the distance people used to watch shuttle launches from. (The speed of sound delay is about 10 seconds, so I would guess it was filmed from roughly 3.5 km distance). The main problem I see here is the toxic propellants; I wouldn't like to be caught downwind from this failure. But I don't know the conditions under which Russia leases the Baikonur cosmodrome from the Kazakhstan gov., or who should take care that people don't get too close.

BTW, did they self-destruct the vehicle, or did it start disintegrating as a result of the stresses as it went down? And what was the problem? On this video it shows the vehicle might have had some sort of steering failure, and then the engines gimballed and perhaps overcompensated?

Anyway, you see why this doesn't exactly boost my confidence concerning the ExoMars mission. Superstition is an additional factor, since the Russians have had terrible luck with Mars missions. Inviting them to ExoMars seemed to me like a kiss of death. ESA should remember the saying about saving a penny, losing a pound. Morons.

(BTW, have you noticed how many YouTube comments feature references to Kerbal Space Program? )

Clever observation - I hadn't thought to observe the time delay for the sound to work out the distance.

The problem was apparently one (or more) of the engines stopped working; which as you said can lead to overcompensation. I also don't think there is redundancy built into the Proton so if one engine fails, that's is probably it (compared to say the Saturn V which could survive if one engine failed in many cases - this happened on Apollo XIII during launch and they just burned the other four for longer). (*It's not uncommon to have non-redundancy in the launcher as far as the engines go)

I did a little reading and I read on Wikipedia somewhere that the Russians don't have self-destruct systems on their rockets for some reason. So it was definitely falling apart from the stress of off-vector thrust and aerodynamic forces as it fell. As for ExoMars - yup, I think the ESA is going to have to rethink their plans. Or at least they'd be wise to. Anything that depends on the Proton is suspect and IIRC even an unmanned Soyuz failed last year. Plus the Russians have problems not just in their launchers but in practically everything.

I think it was the electronics that failed for their Phobos-Grunt probe and a couple of years ago the reentry system on one of their Soyuz capsules misfired. The cosmonauts were put on a very rough ballistic reentry path that put them through some really high g forces and injured them. And when the hell is their new Angara rockets going to be ready????

I think they've moved too many resources over to their armed forces at the expense of their space program and they are relying too heavily on old, outdated systems and flawed construction/certification programs. It's just a freaking mess over there!

lol I did catch the KSP references in the comments.

 

[Glassfan]

Scientific Breakthrough Reveals Stars Consist Primarily Of Twinkies