Space Thread

[ajax34i]

I think terraforming Venus is too difficult.  Its atmosphere has 96% CO₂, and (4% combined) H₂SO₄, water, and N₂.   This means there are many issues:

- Venus does not have the huge quantities of nitrogen required for an atmosphere that's breathable by us.
- Not enough water either.
- Too much CO₂, which is poisonous and is heavier than N₂, so dumping nitrogen into the atmosphere won't work until the CO₂ is gone.

So, IMO, comet bombardment can't really be used to add the water; photosynthesis must be used to break down the carbon dioxide, to get rid of it.  Nitrogen has to be collected from Jupiter's outer clouds or from Titan's atmosphere, so if we're shipping stuff from Jupiter, might as well collect Nitrogen AND Hydrogen, and burn the Hydrogen to make water on Venus, then dump in the Nitrogen to create the 78/21 atmosphere that we're used to.

Mars is easy by comparison:  it has gravity and a rocky surface, all you need is to build some domes and bring in the (relatively small) quantities of atmosphere and water that you need.  It's a few hundred round trips between Earth and Mars, rather than a billion round trips between Jupiter and Venus.

[Bungee]

Some time ago I read about having floating cities in the upper atmosphere of Venus as that might be a nice place to be. Related Wikipedia article

Edit:
Oh and there is of course HAVOC.

[calapine]

ExoMars update:

Schiaperlli has successfully detached from the Trace Gas Orbiter. Tense moments included:

The High-Gain antenna had to be re-positioned better deal with the shock forces of the separation. When it came back there was a strong carrier signal but no telemetry. Cue everyone standing in a circle looking concerned followed by a cut of webcast as meetings were called.

Now data is back as well, everything fine. They didn't yet announce a cause or what they did to fix the issue.

Landing is on the 19th.

[Khaldun]

If you're terraforming Venus, you're a civilization that has technology that's probably better spent on building megastructures of various kinds, etc.--by the time you plausibly can terraform Venus, you'd just be doing it for shits and giggles.

[calapine]

Rather tired, so short text-light update for tomorrow's Schiaparelli landing

Video 3m14s explaining the descent


Infographic - click for full size:



In short:

1) Aerobraking
2) Parachute breaking
3) Breaking with thrusters
4) 2 meter freefall
5) Breaking through crushable honey-comb structure.


The first activation of EDM showed that a radio-telescope in Pune, India can pick up it's faint UHF signal, thus we will know the outcome in almost real-time. If the signal doesn't suddenly stop it will have been a success.

NASA is helping out with downloading the landing and science data. Mars Reconnaissance Orbiter, Maven and Odyssey will all (together with the Trace Gas Orbiter) communicate with EDM during their passes.

Something that people complain about is that, while Schiaperelli will take 15 pictures during the descent phase, there aren't any surface cameras, so no after-landing images.

Edit: Atlought there is a very low chance that Opportunity might get a glimpse of landing Schiaparelli.




Questions?  

[MahrinSkel]

It appears that this is essentially a big technology demonstration, there isn't much of a science package and the batteries will only last a few days. Is that a fair assessment?

--Dave

[calapine]

It appears that this is essentially a big technology demonstration, there isn't much of a science package and the batteries will only last a few days. Is that a fair assessment?

--Dave

Yes. EDM mission's is to demonstrate that esa has the capability to build a probe that survives the Entry, Descent and Landing phase.

For 2016 the science part will be the Trace Gas Orbiter.


The ground-side half of the research begins in 2020 with the Rover (special feature: 2 meter drill) and the surface platform it lands on (equipped with solar panels and more comprehensive instruments than Schiaparelli).

Edit: And a picture:

All 28 45-m antennas of the earlier mentioned 'Giant Metrewave Radio Telescope' in Pune, India will try to track the faint UHF signals of EDM during landing.

[calapine]

On phone

GMRT India tracked signal to close to surface, then gone...

As tracking from earth was always experimental it's unsure what this means.

We need to wait for Mars Express to realign for a earth transmission. Another hour or so.



Fuuuuuuck. Please work!

[calapine]

[calapine]

[calapine]

That's from the TGO, confirming that it performed the MOI (Mars Orbit Insertion) successful.

Without being mean to Schiaperelli, TGO is the main part, losing it would be worse.


Regarding Schiaperelli, Mars Express received the carrier signal, but the information was not enough confirm the health of the lander.

TGO will transmit detailed telemetry later. We have to wait for another 1:30 hours.

Edit: I will also try being less excited.

[calapine]

 

[calapine]

Last info is that the contact was lost several hundred meters above ground, during the powered descent phase, after thrust r activation but before touchdown.

Edit 20:18 CEST: So what we have is that Mars Express detected twice a change in the EDL carrier signal Doppler shift. This shows the breaking action of first the parachutes and later the thruster. Than before scheduled touchdown...Loss of Signal.

Waiting for pass of NASA's MRO. If that data isn't conclusive than later at the night TGO will come into sight, it has the actual telemetry data.

Edit 20:30 CEST: Mission director: 1) TGO is successful in orbit and working 2) EDM signal was received for the majority of the time, but was lost before supposed touchdown. More info tomorrow morning.

[Merusk]

Well let's hope it's not another metric to imperial error.  This is the second ESA probe lost to Mars isn't it?

[Chimpy]

Headlines this morning say the parachute jettisoned too early.

[Khaldun]

Yeah, seems like it.

In other news, Juno went into safe mode for reasons that are not yet understood. It has come back and seems fine, but there are still a lot of worries about what happened, apparently.

[lamaros]

Yeah, seems like it.

In other news, Juno went into safe mode for reasons that are not yet understood. It has come back and seems fine, but there are still a lot of worries about what happened, apparently.

We found the alien observation post, so they had to quickly hack in and pretend it saw nothing.

[calapine]

Headlines this morning say the parachute jettisoned too early.

The (public) knowledge as of now is:

- Areobreaking and most of the parachute phase were nominal.
- 15 seconds before end of the parachute phase it was jettesioned prematurtly.
- After this the thrusters fired for only 3-4 seconds
- Another 19 seconds of telemetry were received, this was probably the free-fall until ground.

[calapine]

Well let's hope it's not another metric to imperial error.  This is the second ESA probe lost to Mars isn't it?

To know my knowledge Beagle 2 wasn't an ESA but a British UKSA mission, but technicalities asides, yes there was a prior attempt.

Technicalities not aside, the landing actually worked, the problem occurred when one of the solar panels didn't unfold, blocking the main antenna.

Beagle 2 had quite extreme constrains in time, volume, mass (74 kg for the entire lander) and monetary budget (it cost £66 million, the budget was half that).

Which lead to a very lean project and lots of innovations, but also some forced shortcuts: Drop testing was completely dropped (hehe) due to time constraints, lack of spare parts hampered shock and acceptence testing, not enough staff, etc..

Another area savings had to be made was live telemetry, which wasn't possible. When Beagle 2 didn't respond after landing it's fate was unknown for years until it was discovered by MRO.

The experience from this contributed to ESA's conservative - which now turns out be out prudent not conservative - approach of sending a landing demonstrator before the actual rover.

Another lesson learned is the telemetry: TGO received about 600 MiB from EDM which are now being analysed.


Some Beagle images:

[calapine]

1) It currently looks like the fault lay with the Onboard Computer who commanded early released of parachute and premature retro-thruster shutdown.

Current analysis shows the altimeter provided correct data.


2) NASA's Mars Reconnaissance Orbiter found Schiaparelli:



The dark spot is the impact crater, the bright spot below is the 12-m parachute.

[calapine]

A nice comparison of Schiaperlli's and Opportunity's landing sites. They are "on the same map" so to speak. The green circle is EDM's landing elipse, the margin of error area where it could have landed. It sits pretty much right in the middle, showing that targeting was good.

Yellow is the path Opportunity has taken since it's landing in 2003. Astounding how "slow" these rovers are actually are.

[calapine]

Looks like the we are zeroing in on the cause. Preliminary info is that radar altimeter software timed out, making the general navigation software believe it was already on the ground, leading to shut-off of the retro thrusters.

Software really is more failure prone than hardware nowadays in space.

Also without being a programmer this looks like sloppy or non existing fault-handling to me... Maybe a resident expert can elaborate?

[01101010]

More than half the time I read this thread and almost none of it makes sense. I just like to look at the pretty pictures, kinda like this one:

[Morat20]

I keep wondering why the explosion tends to arc out in a confined plane ahead of the spherical explosion.

I suspect there's a reason besides "It looks cool".

[HaemishM]

I'm gonna go ahead and blame gravity.

[calapine]

No idea either. And doublly weird because I specifically remember reading that "flat explosions in space" (see: Alien Nostromo explosion or Star Wars II) are a movie convention and not realistic.

Obviously nature missed that memo. I'll investigate and report back.

[01101010]

Well it is only an interpretation. But, if you have 2 dots that suddenly collide, I'd think the major activity would be with both expanding out from there leaving the plane at the point of contact untouched for a moment. Then magic happens.

[MahrinSkel]

Stars are oblate spheroids distorted around their rotational axis, usually quite significantly. When they collapse, there is going to be more mass outside of the collapse zone around the equator than anywhere else. That is the matter that will form the resulting nebula.

--Dave

[ajax34i]

I keep wondering why the explosion tends to arc out in a confined plane ahead of the spherical explosion.

I suspect there's a reason besides "It looks cool".

Not sure why the confined plane, but supernovas aren't spherical / symmetrical explosions. 

[Bunk]

So those of you that know better than me - is this entire thread dead now after last night?

[01101010]

So those of you that know better than me - is this entire thread dead now after last night?

Got a bad feeling that a lot of threads will die after last night. But I doubt it since most space stuff that gets in the news comes out of private companies.

[calapine]

So those of you that know better than me - is this entire thread dead now after last night?

Thinking Trump is a wildcard in that area too. Until 3 weeks ago the Trump campaign didn't have a space policy. They then hired fmr. Congressman Robert Walker as advisor with the task to draft one.

Some probably safe bets:

• SLS will go on as it's the child of Congress/Senate and exists despite Obama's effort to kill it.
• The same for Commercial Cargo/ Commercial Crew to the International Space Station. To one part these are year long contracts that are already locked in (and it's not as if there is an alternative.)
  They will also allow Trump to claim MAGA: Late 2018 / 2019 will be the first time American astronauts fly again in an American (=Boeing and SpaceX) capsules.
• The civil earth observation programme and anything Earth Science (clime change...ewww) related will get cut. These are unpopular with Republicans anyway and Trump campaign already mentioned they want to focus away from that.

I am curious what happens to the Orion capsule service module^[1]. There is NASA-ESA agreement that says that ESA  - as way to pay it's ISS share - will develop and build the first SM and then hand NASA the blueprints so they can make the next ones on their own. Behind the scenes however there are negations that ESA could supply the following SMs as well. No idea how a Trump administration () will affect this.

[1]Contains the engines, propellant, oxygen, water, solar cells and so on. Attached below the Crew Module.

[HaemishM]

I expect there will be a long list of climate scientists at NASA looking for new jobs on January 21, 2017.

[Goumindong]

I keep wondering why the explosion tends to arc out in a confined plane ahead of the spherical explosion.

I suspect there's a reason besides "It looks cool".

Because the star is spinning around an axis and so isn't actually a sphere. Rather; large spinning objects in space are oblate spheroids(minus tidal forces, wind forces, and roughness from structural rigidity)

When they collapse, the poles collapse first*. They're the areas with the highest relative gravity. They're simultaneously closer to the center of mass and they are subject to less centrifugal forces. So when the entire thing collapses it is essentially turning into a disk which then explodes like a disk... because it is one.

This is the same type of phenomena (the spin) that produce various directional radiation beams, produces em fields and so on and so forth. Its also possible that those forces created by the object spinning have a similar effect on the explosion. I want to say that objects spin because collisions are unlikely to be head on, and the spin is a natural result of the sum of the forces. And of course spins can only really have one axis and so that will generate an equilibrium spin depending on the input of the initial mass velocities.

Small objects and objects without spin would explode in a perfect sphere where they to explode.

*Not a physicist; but this is what should happen as far as i can tell.

Fake edit: late but posting it anyway because ftge

[Khaldun]

Re: this thread and the current situation, recall also that Gingrich is a big space nut and has often advocated a major role for government in it; plus Trump has at least some ties to the Y Combinator/Elon Musk pro-space world through Thiel. So it might be one of those areas where his admin does some surprising stuff that's good-surprising or at least better than the usual Republican no-money-for-science thing.