Space News thread

[Latindancer]

Cassini probe set to begin ‘Grand Finale’ dive into Saturn’s atmosphere.

We’ve enjoyed the benefits of having NASA’s Cassini spacecraft in orbit of Saturn for years. It’s almost like it’s always been there, looking down on one of the most awe-inspiring sights in the solar system. It only seems like forever because Cassini has sent back so much amazing stuff. Cassini began its observation of Saturn in 2004, and now it’s time for the probe’s final act as it runs low on fuel. Later this month, the spacecraft will begin a downward spiral that eventually sends it into Saturn’s crushing atmosphere. It’ll see some amazing things on the way, though.

Cassini was launched in October of 1997, taking almost seven years to reach Saturn. It arrived carrying the Huygens lander, which was successfully deployed on the surface of Saturn’s moon Titan in 2005. It was the first, and as far only landing to take place in the outer solar system. After deploying Huygens, Cassini continued its orbital observation of Saturn and its moons, but it did so from a distance. NASA didn’t want to risk damage to the probe from Saturn’s icy ring material, but they’ll be much more daring in the coming months. This mission made a number of discoveries, including the presence of hydrocarbon lakes on Titan and the water plumes on Enceladus.

Mission managers at NASA’s Jet Propulsion Laboratory (JPL) call Cassini’s final maneuvers the “Grand Finale.” Beginning on April 22nd, Cassini will expend some of its dwindling fuel to execute a close flyby of Titan, which is pretty massive as far as moons go. Titan’s gravity will slingshot Cassini toward Saturn where it will (hopefully) pass between Saturn’s upper atmosphere and the innermost D-ring. That gap is just 1,200 miles (1,930 kilometers) wide, and it’s not completely empty. Cassini is expected to be pelted by small particles, which can pack a punch as the probe is rocketing past as more than 76,000 mph (122,000 kph). NASA will orient the probe to shield the antenna from direct impacts.

Cassini will be closer to Saturn than ever before during the Grand Finale, and NASA plans to use that opportunity to the fullest. The probe will use its mass spectrometer to analyze the gases in Saturn’s upper atmosphere, sending back the most detailed data ever on the composition of a gas giant.

This slingshot maneuver is not the end of the Grand Finale — Cassini is expected to complete 22 of these extremely close orbits before it’s finally pulled down into Saturn’s atmosphere. Cassini will hit Saturn’s atmosphere on September 15th, beginning its final 3-minute dive into oblivion. NASA plans to use the last of Cassini’s fuel to keep the antenna pointed toward Earth so it can transmit data for as long as possible.

https://www.extremetech.com/extreme/...rns-atmosphere

[BaitongBoy]

^ Some pretty wild stuff...

[Takeovers]

Like a hotdog advertising?

[David48atTD]

It's an interesting fusion between Plane and Space travel explaining why planes can't fly into space ... and then, despite it's slow beginning, expands into the various Engines currently and proposed for use.




Published on Jan 27, 2017
Why can’t we fly a plane in to space, what stops it from just flying higher and higher until we are in space?

Well, there a several issues but assuming we are in something like a normal jet airliner, then one of the main problems is the air, or lack of it as we get closer to space.
A plane flies because as it is propelled forward, the wings, which are shaped to make the air flow faster over the top of them than the bottom, generate lift. As the plane goes faster the wings creates more lift and when the lift is greater than the weight of the plane, it will climb up in to the air.

For our plane to continue to climb it needs more speed to increase the lift. If you throttle back on the speed a bit, the plane will settle in to level flight and if you decrease the speed the plane will start to fall as lift from the wings is not enough to overcome the weight of the plane.

As our plane climbs higher and higher in to the atmosphere, the air becomes less and less dense, so the plane has to fly faster to create more lift until eventually it reaches an altitude where the engines cease to function correctly because of the lack of oxygen or the air is too thin to create enough lift.

Now, This is a greatly simplified way of looking at this because as you approach the speed of sound or Mach 1, which also changes with altitude and if your plane has quite straight wings, the airflow over the wing can become unstable and it loses lift.
This unstable airflow can also shake the control surfaces, that’s the flaps on the wings that go up and down, so violently it could break them and you then lose control of the plane. That’s why supersonic or hypersonic planes have highly swept back and often delta shaped wings like Concorde and the space shuttle.


Just as we need air to breath, so the engines need oxygen to burn the fuel to create thrust to propel the plane forward.
Jet Engine however can work at higher altitudes than people. We humans have a limit of about 8000 meters or around 26,000 feet, above this is what climbers call the “death zone” where there is not oxygen for humans to survive for sustained periods.

The summit of Mount Everest is 29,000 feet high and the air density there is about 33% of that at sea level. This means that with each breath you take, you are getting only 33% of the oxygen. If you were to stay at this altitude without additional oxygen you would suffer a condition called “Hypoxia” where due to the lack of oxygen, the body to slowly shuts down and dies and is the cause of most the 200+ deaths that have occurred on Mount Everest.

At 12,000 meters or around 40,000 feet, which is the upper limit of most modern airliners, the air density is about 18% of that at sea level. If you were in a plane that had a rapid decompression at 40,000 feet, you would have about 5-10 seconds to get your emergency oxygen mask on before you became unconscious.
Concorde flew at 60,000 feet or 18,300 meters and where the air density is just 7% of that at sea level. To achieve this height, it had to travel at Mach 2, twice the speed of sound or 1350 mph.

The highest-flying jet plane in level flight was the Lockheed SR-71 Blackbird with a height of 85,069 or 25,929 meters and where the air density is just 2% of that at sea level. At that height, it’s travelling at around Mach 3.2, or 2190 mph.
The SR-71 pilots had to wear a full pressure suit with its own oxygen supply in case of a cockpit depressurization or emergency ejection. This put to the test, when in 1966 an SR-71 piloted by Bill Weaver disintegrated at Mach 3.1 at an altitude of 78,000 feet, as it was performing a test flight to optimise it’s performance.

At that altitude, your blood will boil in a similar way to when you open a bottle of fizzy drink as the nitrogen in your blood turns to gas in the low-pressure atmosphere. The pressure suit worked and Weaver survived the decent from 78,000 feet but tragically the navigator, Jim Zwayer, died of a broken neck as a result the breakup of the plane.

Now while you would think that the SR-71 is fast, to get in to space you need to reach what is known as “escape velocity”. This is where you are travelling faster than gravity is pulling you back to earth and that speed is 25,020 mph or 40,270 kmph and If that wasn’t a problem then there is also the recognised altitude of where space starts which is 328,000 feet or 100,000 meters, well over 3 times the highest flight of the SR-71.

Normal jet engines like those in the SR-71, have a maximum air speed limit of about Mach 3.5 or 2685mph. Beyond that the air pressure and temperature becomes too high for the compressors in the engine to work effectively.
For hypersonic speeds, experimental unmanned aircraft like the NASA X-43 use a SCRAMJET engine.

Title: TimeTrain
Author: P C III
Source: Pipe Choir - Home

[Luigi]

Wot's all this about then?


NASA to announce finding which will ‘inform the search for life beyond Earth’



NASA is to announce a new finding which the space agency says will ‘inform the broader search for life beyond Earth’.

The space agency will announce the new finding at 2pm on Thursday this week.

The finding comes from NASA’s Cassini spacecraft, which is in orbit around Saturn, and from the Hubble space telescope.

‘These new discoveries will help inform future ocean world exploration – including NASA’s upcoming Europa Clipper mission planned for launch in the 2020s – and the broader search for life beyond Earth,’ NASA said.

The event will be held at the James Webb Auditorium at NASA’s headquarters in Washington.

Speakers include several members of the team from the Cassini orbiter, fuelling speculation that the announcement could be about Enceladus, Saturn’s sixth-largest moon.

Others suspect that the announcement could relate to Jupiter’s moon Europa – target of NASA’s Clipper mission.

Europa is thought to have a liquid ocean beneath its surface, holding twice as much water as there is on Earth, according to NASA.

NASA aims to put a spacecraft in orbit around Europa in the 2020s.

https://www.yahoo.com/news/nasa-anno...085752657.html

[Luigi]

There are three likely places for life outside of Earth in our Solar System.

Some sort of blind, translucent life (mainly around the underwater vents in Europa and Enceladus.) and possibly a (completely alien to us) methane based lifeform on Titan.

They've found water vapor vents on both Europa and Enceladus, which means that lifeforms could be spat out in the water vapour and then then fall to the surface for us to study at a much latter time (when we have landers), so no idea what this is about.

Unless perhaps they've been able to detect the by products of life within those water vapour eruptions, but I think that would have been possible before, or Hubble and Cassini aren't equipped with those sorts of tools.

[Luigi]

A report from a former NASA employee suggests that the finding relates to hydrothermal vents in an icy ocean on Saturn’s moon Enceladus.

If true, it could be highly significant – as many scientists believe life on Earth began in similar warm vents on the ocean floor.

Keith Cowing, who writes for Astrobiology, says, ‘The process is indicative of possible habitable zones within the ocean of Enceladus.



https://www.yahoo.com/news/nasa-anno...084053844.html

[crackerjack101]

Thanks. Green owned.

[Luigi]

Scientists believe ice-encrusted Enceladus - with an ocean beneath its shell - could have a life-supporting energy source.

An environment that some scientists believe led to life on Earth has been found on Saturn's ocean-bearing moon Enceladus, NASA scientists have said.

A discovery of molecular hydrogen was made in October 2015 - but has only now come to light - when NASA's Cassini spacecraft took samples as it passed 30 miles (49 km) above the moon's southern pole.

Hydrogen molecules were detected in vapour plumes emerging from cracks in Enceladus' surface.

Such conditions occur when hot rocks meet ocean water, and may have led to the beginning of microbial life on Earth more than four billion years ago.



Previous discoveries include geysers which shoot hundreds of miles into space from Enceladus - some of the material falling back onto the surface as a coat of ice.



A vast ocean - believed to be the source of the geysers - is said to be buried between 19 and 25 miles (30-40 km) beneath Enceladus' icy shell.

http://news.sky.com/story/is-there-l...ladus-10836071

[BaitongBoy]

Amazing how they "know" this...What size is this moon, Enceladus, in comparison to Earth?...Maybe it was mentioned already...

In the future, this will be like taking a "tour" of Niagara Falls or heading to Yellowstone...

What a fantastical sight to see...Looks a little like the Northern Lights...

[Luigi]

Tiny.

About 500km in diameter.

The energy involved to push water through 30km of rock solid ice must be absolutely enormous.

Everywhere we see a habitat of hot rocks and water on Earth, there is life.

[Takeovers]

Amazing how they "know" this

NASA has the Cassini probe in orbit around Saturn.

https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens

Cassini arrived at Saturn in 2004 and is still active. It has done flybys of many moons and provided a huge amount of knowledge about the Saturn system.

As it is now reaching the end of its life they are presently doing a few things that were regarded too dangerous before, like flying through the rings to get close up photos. Actually through gaps in the rings.

With the last bit of available fuel Cassini will be dumped onto Saturn itself. Providing pictures until it is swallowed by Saturn.

https://www.theguardian.com/science/...reveal-cassini

Images from the Cassini spacecraft are most detailed ever taken, and include previously unseen features within the rings

[Luigi]

Unfortunately Cassini doesn't have the equipment to actually test for life. I'd guess that they didn't know they'd be flying through water vapour and could sample the water from an alien subsurface ocean when it was designed and launched.

[Takeovers]

Unfortunately Cassini doesn't have the equipment to actually test for life. I'd guess that they didn't know they'd be flying through water vapour and could sample the water from an alien subsurface ocean when it was designed and launched.

There should be more frequent flagship missions like this. Even at a price of ~$2billion a flagship mission they should be able to do one every 2 years at least. Instead they are mandated by Congress to build the SLS/Orion monstrosity and pour $3billion into a completely useless system.

NASA is doing a really outstanding job on those probes, unmatched by other space agencies. Though ESA did very well with the Rosetta comet mission. The orbiter was great, only the lander failed.

[Takeovers]

NASAs Mars plans

The OIG, the Office of the NASA Inspector General has released a report on cost estimates for planned NASA Mars missions.

https://arstechnica.com/science/2017...sticker-shock/

The Journey to Mars has a price tag, and it will give Congress sticker shock

An "austere" plan

The NASA planning calls for one Mars orbital mission in 2033 which would "land" on the Martian moon Phobos. Where landing is a great word. Phobos is very small. Too big to jump off but minimal thrust will get a space ship off it. No Mars landing.


A 1 month Mars surface mission in 2037.


Two one year surface missions in 2041 and 2046.



That plan would stretch out for 3 decades and would cost at least $5 billlion a year starting now. A total of $450 billion. That's NASAs vision of a minimalistic "austere" Mars plan. That's if they stick to their cost estimates, something that has never happened.


To be fair. If NASA shuts down the ISS they could in theory do this with a moderate increase of their manned spaceflight budget.

Edit: Oops. I got that wrong. It would be $15 billion a year, tripling the present manned spaceflight NASA budget.


In contrast Elon Musk with SpaceX estimates $10 billion for his plans to establish and expand a permanent base well before 2030. While he is known for always taking longer than he planned he usually comes in at or below cost.

Edit: Again to be fair it is a real possibility that this time Elon Musk has taken on a chunk too big to chew. Failing is a real possibility.

[DrB0b]

Any fellow Asgardians here?

[Takeovers]

For some context to my above post.

Congress via NASA presently pours about $3 billion into developing SLS and Orion. The rocket and spacecraft for the Mars mission.

To make SLS/Orion useful they would have to fund the Mars missions. But they won't increase the budget, they have made that clear on many occasions. Which means the billions presently spent are just wasted money without any real purpose. They could use SLS to go to the moon, to give it a purpose. But with the development speed of SLS they run a real risk that the Chinese will beat them to a moon landing. Which leaves NASA with the solace that they have done it in 1969.

[Luigi]

If you were in charge of Nasa Missions, what 3 missions would you focus on developing TO?

[Takeovers]

what 3 missions would you focus on developing

They are very good and very successful on interplanetary missions. They have orbiters around Jupiter and Saturn. Try to get orbiters around Uranus and Neptun, which is hard because of the distances. Orbiter around Pluto would be exciting but even harder.

As I am most interested in Mars, get communication infrastructure in Mars orbit. It is a crying shame there are orbiters which can do high resolution photography but do it very limited because there is not enough data transmission capability to send them back to earth. Ideally send one of the military spy satellites to Mars. They can do even much higher resolution imaging, good to make a complete high res map of Mars. Actually NASA has two of them in store, given to them by the Airforce because they no longer need them. A very easy mission would be to send probes to the martian moons Phobos and Deimos. For some inexplicable reason it has never been done.

The Russians tried it but their probe Phobos Grunt never left earth orbit. They blamed substandard imported western electronics and an american radar system, not their faulty upper stage.

Use the ISS to test new methods of keeping muscles and bones strong in microgravity. Do an experiment on mice in a centrifuge on the ISS to see if they can have healthy offspring in Mars and Moon gravity. These experiments are presently not done because they cause vibration that can damage other microgravity experiments. Just put those off for a year and do these human spaceflight related experiments.

And get NASA off human spaceflight beyond LEO and ISS. Their plans are hugely complex and overpriced, never going to happen even with huge amounts of money spent on them.

That's more than 3, but it is what I would do if I could.

Edit: Give 10% of the present human space flight budget, around $500 million to SpaceX for doing their Mars plans, but with no NASA oversight over the project. NASA oversight would explode the cost and the timeline. That would ensure success at less than 3% of what NASA is planning, on a much larger scale and much sooner. But this last one is pure phantasy, never going to happen.

[Luigi]

Interesting, cheers TO.


This is a good, short Nasa video explaining their findings and what they mean for the potential of life being up there.

[Maanaam]

May be of interest to some. Was reading this morning;
So it was Jupiter I've been seeing while sipping my morning coffee.

10 Best Nights to See Planets, Summer 2017 Edition

https://www.inverse.com/article/3020...planets-summer.

[Takeovers]

China is steadily advancing.

Their new space transporter Tianzhou 1 is getting ready to launch. It will supply the coming chinese space station. Tianhou is probably the most capable transporter. It has the most complete capability, like propellant transfer to the space station plus supplies to the station. It has the biggest payload capability of all planned and flying transporters, russian and US. The japanese transporter carries similar mass but does not transport propellant. Tianzhou can not bring cargo back to earth. That will be done with their new manned capsule.

[crackerjack101]

Brilliant stuff as always TO. Thank you.

[harrybarracuda]

If you were in charge of Nasa Missions, what 3 missions would you focus on developing TO?

The number one has surely got to be a self sustaining ark capable of housing a significant population in case the earth gets twatted by a giant asteroid.

Just sayin' like.

[Takeovers]

The number one has surely got to be a self sustaining ark capable of housing a significant population in case the earth gets twatted by a giant asteroid. Just sayin' like.

That's covered by my last point. Give SpaceX $500 million a year. That will buy development of the transport system for shifting a million people to Mars. Though once developed the actual shifting should be funded with at least the annual amount NASA is now scheduling to get 12 people to Mars which is $15 billion a year for 30 years.

NASA is just not structured to do such things.

Also I would like to point out that the asteroid hitting or a super volcano erupting or even a major nuclear war are not the threats that worry me. It is the real threat of shifting in society. Like the one that made Donald Trump as president possible. A large portion of people completely immune to science and facts and reason may become the norm undermining a technological society.

This is what Elon Musk refers to as the window that is now open and we don't know how long it will be open so the time to get moving is now. Society, science and technology advancing is not a given. It happens only when people keep pushing. Falling back is just as likely to happen. Pointing to the end of the Roman Empire followed by the dark ages. When we fall back now we may never achieve the same level of technology again.