This is cool.

http://abcnews.go.com/Technology/wireStory?id=1512594

http://news.bbc.co.uk/1/hi/sci/tech/4599634.stm

And yesterday I read where the ESA is researching Ion engines... really cool stuff...

http://www.physorg.com/news9786.html
The test model achieved voltage differences as high as 30kV and produced an ion exhaust plume that travelled at 210,000 m/s, over four times faster than state-of-the-art ion engine designs achieve. This makes it four times more fuel efficient, and also enables an engine design which is many times more compact than present thrusters, allowing the design to be scaled up in size to operate at high power and thrust. Due to the very high acceleration, the ion exhaust plume was very narrow, diverging by only 3 degrees, which is five times narrower than present systems. This reduces the fuel needed to correct the orientation of spacecraft from small uncertainties in the thrust direction.


That seems super fast to me.

Wonder at the high end G-suit requirements for this kinda ride. heh

Fandros

The amount of thrust generated by the ion drive is actually extremely small. Its main advantage is that it can maintain the thrust for many thousands of hours enabling it to achieve very high velocities.

This Pluto probe would need a bit of a G-suit though. Just doing a rough back-of-the-napkin calculation, if the rocket launching it thrusts for 7 minutes (totally pulled out of my ass), then it will require about 6-7G's of thrust to get it to the 25km/s the article states it will travel at.

Obviously, increase the thrust time and the G requirement is lower, and vice versa.

Would definately require some sort of G suit tho. The human body isn't built to withstand more than 1 g for extended periods.

Fandros

I think a normal shuttle launch exerts about 3 G's on the crew until the solid boosters run out. I forget how many minutes that takes, but I could see where an extended firing of this probe's rockets could lower the G's to an acceptable level for a passenger to survive. I doubt anyone could take several minutes of 7 G's without sustaining brain damage at the minimum.

Let's find Bin Laden, strap him into one with some monitoring equipment and find out!

I'm not certain it would require much of a G-suit at all, would it? The speed it's travelling is very impressive, but it's not like that speed is reached at launch time:

To achieve that, Nasa must launch the probe before 3 February, so that it can "slingshot" around Jupiter and use the planet's gravity to achieve speeds of about 25km/s (56,000mph).

Wouldn't it depend on how much time it spends in Jupiter's field of gravity, as well as what speed the craft would be travelling at before entering that field of gravity? Of course, I'll concede that's just my intuition. I'm going to guess that Jensae's grasp of physics is a lot stronger than mine. ;)

I am curious about the retro-fitting required on the nuts and bolts end, or if the current methods of spacecraft construction would accomodate the more powerful engines.

Read on project Ajax... Add this to and you're going to go just real fast.

http://www.aeronautics.ru/plasmamain.htm

To hell with propulsion, get warp drive.

Coolest patent ever.

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=6960975.WKU.&OS=PN/6960975&RS=PN/6960975

The spacetime curvature imbalance, the spacetime curvature being the same as gravity, provides for the space vehicle's propulsion. The space vehicle, surrounded by the spacetime anomaly, may move at a speed approaching the light-speed characteristic for the modified locale.

Did a paper on it once a few years back, it's possible theorectically anyways, that if you set the acceleration right to keep it to '1G' and by that keep a sort of artificial gravity and offset the effects of low gravity on the body. Manned missions to the edge of our solar system. Now that would be cool.

I'm not certain it would require much of a G-suit at all, would it? The speed it's travelling is very impressive, but it's not like that speed is reached at launch time
Meh, I misread the article. I thought it said that it would achieve 25km/s at launch, and use Jupiter to accelerate further.

After rereading the articles, I couldn't find anywhere that said what the pre-Jupiter velocity was, so I broke out the calculator again.

They did say it would pass the moon in 9 hours. The moon is about 400,000km away, so that translates to 12.3km/sec.

This is about half the velocity I calculated before, so hence half the acceleration I calculated would be needed (again assuming a 7 minute burn), which would give around 3-3.5G, which is definitely tolerable by humans.

Accelerating around Jupiter will be a much lower acceleration due to the fact that it will accelerate over 10's of thousands of miles, compared to the dozens of miles of the original rocket acceleration.

As far as the shuttle, it's a bit different than traditional rockets - its rocket boosters are throttle-able. Non-throttleability (made up word there :)) was actually an issue with the Apollo missions. Near the end of the first stage, a great deal of mass was gone (the fuel that was burned), but the same amount of thrust was being generated, hence a high acceleration. I cant remember the exact number, but it was a high amount of G's for a short time before the first stage booster cut out.

Warning, this is a bit long, I love the subject matter and have followed the space industry for many years now.

its rocket boosters are throttle-able


The shuttles three main engines are throttle-able, the strap on solid rocket boosters are not. Once you ignite the solids (the solids are actually ignited by a large flame thrower from inside the booster itself) there is no turning back, you are going to take off the launch pad either in one piece or a billion little pieces.

The three main engines on the shuttle have propellant feed to them from the huge external tank (painted orange). The main tank is actually two tanks within one large tank, one tank holds liquid oxygen and the other liquid hydrogen. High speed pumps (can't remember the rate of flow but it is staggering) feed the fuel into the bell shaped engines on the back of the shuttle.

The shuttle, about 90 seconds into its ascent, must be able to throttle down its main engines to minimize the effects of "Maximum Dynamic Pressure", the point in the atmosphere during liftoff where the most damage could occur to the shuttle due to atmospheric pressure created by its own speed. Once past this point in the ascent the engines are throttled to full. The solid rocket boosters fire at 100% during their entire burn period.

The solid rocket boosters burn out fairly early in the approx 10 minute ascent leaving the external tank and the shuttles engines to do the rest of the work to get to orbit. The shuttle achieves a speed of 25,000 km/hour over that approx 10 minutes of ascent into orbit.



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The Pluto probe will be one of the fastest probes in the solar system.

The Pluto probe will reach Jupiter in a staggering 9 months. The Cassini probe currently orbiting Saturn took 3 years to reach Jupiter.

Once at Jupiter the Pluto probe will basically fly partially into its gravity well to gain an increase of speed and also to acquire some angular momentum for the rest of its trip (8 years) out to Pluto. At no time will the Pluto probe orbit Jupiter, the probe will simply be moving too fast and will not get close enough for Jupiter to capture the probe into an orbit.


One thing a lot of reporters don't talk about is the fact that the Pluto probe is carrying degraded plutonium to help power the probe over its multi decade mission. The Cassini probe now orbiting Saturn as well as other probes in the past have been launched from the Cape with similar fuel payloads.


A space craft carrying such a toxic fuel has never blown up on take off in the past, but there is always a first time. Hopefully Cape Canaviral won't have one of these mishaps, although a glowy green beach might attract some strange tourists.



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As far as ion engines go the U.S. has already built, launched and flown an ion engine space craft:

http://nmp.jpl.nasa.gov/ds1/ (http://nmp.jpl.nasa.gov/ds1/)

Deep Space 1 was a test bed for many new space probe technologies, the ion engine being one of them.



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As an above link described, the U.K. have also launched its own ion engine capable space craft:

http://www.esa.int/SPECIALS/SMART-1/ (http://www.esa.int/SPECIALS/SMART-1/)

The Smart-1 probe has used its Ion Engine as well as a unique gravity assist pattern from earth to achieve a flight to the moon. It is now currently orbiting the moon and doing some good science.

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The propulsion breakthrough you linked:

http://www.physorg.com/news9786.html (http://www.physorg.com/news9786.html)

This new ion engine being developed in Australia will be much more efficient and much faster than Deep Space 1 and Smart-1.

Can you imagine strapping a cluster of ion engines onto the back of a space craft and zipping over to mars in a matter of a few months, compared to years if we used conventional rockets.

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Sorry, I could go on and on about this stuff.

Here are a couple of links if you wish to follow the launch of the Pluto probe tomorrow (we have had two SCRUBS in a row now ;( ) at approx 1:00 PM EST;

A live log on the launch from an onsite reporter:

http://www.spaceflightnow.com/atlas/av010/status.html (http://www.spaceflightnow.com/atlas/av010/status.html)

Live coverage from NASA:

http://www.nasa.gov/multimedia/nasatv/index.html

I find the launch log to be very useful as they go into more detail than the commentators on Nasa TV.

Anyway, sorry for blah blahing =)

Cheers,

Excellent post... thanks for the research!

If you want to experience the thrill of ascent check out some of the videos on this site:

http://www.eclipticenterprises.com/gallery_rocketcam.php

Rocket Cam has been used on launch vehicles now for 8 years or so. The camera's are integrated into the fuselage pointed down. On the multi stage launch veicles you will see a view from the second stage, in some cases you get to see the third stage camera or the payload camera as well.

The Delta IV Heavy launch is particually impressive. This bahemouth of a launch vechile is scheduled to come online for the heavy lifting capabilities that the U.S. military is looking for in a soonish time frame. I cannot do it justice, this vehicle is enormous. All stages of this vehcile, including its booster stages are liquid oxygen / hydrogen configurations. I think its payload capacity is 10 tonnes, that is A LOT of tang if you ask me ;).

The Delta IV Heavy in the video was the test flight of this vehicle. I remember watching this launch live via the web and was startled to see the amount of flames that eminated from the launch pad when it lifted off. There was so much flame in fact that two thirds of the paint on the outer skin of the vehicle was scorched.

It was later discovered that too much Hydrogen was saturated into the area around the vechile before launch, what you see in the video is the Hydrogen in essence esploding =). Hydrogen saturation is common just before a vehicle launch, it helps the engines to ignite easier, the last thing you want is a misfire when trying to launch these vehicles.

If you have ever watched a shuttle launch you will see what looks like big sparklers near the engine bells close to lift off. These "sparkalers" are not meant to ignite the engine, they are there to burn off excess Hydrogen, obviously these "sparklers" either failed for the Delta IV launch or there was just too much excess hydrogen saturated into the surrounding air.

Watch the latest shuttle launch as well. You go from the launch pad to orbit, you even get to see the foam fall off and narrowly missing the underbelly of the shuttle.

I like the Deleta II launches as well. The Delta II's have up to 9 small solid boosters that fall off the vehicle three at a time during ascent. Hope no one is on a small boat down there.

Cheers,

Lokase

Successful launch today.

The probe just seperated from the 3rd stage and has escaped the Earth's gravity well.

Safe journeys New Horizons. See you in 9 months when you fly by Jupiter and evetually in 9 years when you swing by Pluto on your way to the Kuiper Belt.

Cheers,

Lokase

here is the press release
http://pluto.jhuapl.edu/images/mainPage/NHLaunchPressKit1_06.pdf

Here is the very interesting section on how the probe will be powered:


New Horizons Nuclear Safety

The New Horizons spacecraft derives its electrical power from a radioisotope thermoelectric generator (RTG), a lightweight, compact spacecraft power system that is extraordinarily reliable. An RTG has no moving parts, and uses neither fission nor fusion processes to produce energy. Instead, it provides power through the natural radioactive decay of plutonium (mostly Pu-238, a non-weapons-grade isotope). The heat generated by this natural process is changed into electricity by a solid-state thermoelectric converter.

RTGs enable spacecraft to operate at significant distances from the Sun or in other areas where solar power systems would not be feasible. They remain unmatched for power output, reliability and durability by any other power source for missions to the outer solar system.

The United States has an outstanding record of safety in using RTGs on 24 missions over the past 40 years. While RTGs have never caused a spacecraft failure on any of these missions, three missions experienced malfunctions for other reasons. In all cases, the RTGs performed as they were designed to do.
More than 40 years have been invested in the engineering, analysis and testing of RTGs. As described below, safety features of an RTG include the use of a specific type of fuel material, a modular design, and the use of multiple physical barriers to prevent any leakage.

First, the plutonium dioxide fuel contained in an RTG is a specially formulated fire-resistant ceramic that is manufactured as pellets to reduce the possibility of fuel dispersion in a launch or reentry accident. This ceramic form resists dissolution in water and reacts little with other chemicals. If fractured, the ceramic tends to break into relatively large particles and chunks that pose fewer hazards than small, microscopic particles.

Second, the fuel in each RTG is divided among 18 small, independent modular units, each with its own heat shield and impact shell. This design reduces the chances of fuel release in an accident because all modules would not be equally impacted in an accident.

Multiple layers of protective materials, including iridium capsules and high-strength graphite blocks, protect and contain the fuel and reduce the chance of release of the plutonium dioxide. Iridium, a strong, ductile, corrosion-resistant metal with a very high melting temperature, encases each fuel pellet. Impact shells made of lightweight and highly heat-resistant graphite provide additional protection.

Risk Assessment and Launch Approval

Any mission that plans to use an RTG as a power source undergoes a safety analysis carried out by the Department of Energy (DOE). The safety analysis report provides a comprehensive assessment of the potential consequences of a broad range of possible launch accidents. In addition to the DOE review, an Interagency Nuclear Safety Review Panel (INSRP), which is supported by experts from government, industry and academia, is established as part of a Presidential nuclear safety launch approval process to evaluate the safety analysis report prepared by DOE. Based upon the INSRP evaluation and views from DOE and other Federal agencies, NASA may then submit a request for nuclear safety launch approval to the White House Office of Science and Technology Policy (OSTP). The OSTP Director (i.e., the President’s science adviser) may make the nuclear safety launch decision or refer the matter to the President. In either case, the launch cannot proceed until nuclear safety launch approval has been granted.

Alternatives

New Horizons’ journey is planned to take it more than 4 billion miles from Earth, where the Sun is just a bright star in the dark sky. Light from the Sun is more than 1,000 times fainter at Pluto and the Kuiper Belt than at Earth. At this distance, no feasible alternate energy source is capable of providing sufficient and reliable electrical power for the New Horizons mission.
Radiation Hazards of Plutonium-238

Plutonium-238 cannot be used to make a nuclear weapon. Weapons are constructed from other isotopes of plutonium. Plutonium-238 gives off short-range alpha particles, helium nuclei that usually travel no more than about three inches in air. While the fuel is contained within its iridium capsule, the alpha radiation does not present a hazard, and the external dose resulting from the low levels of gamma and neutron radiation associated with the plutonium dioxide RTG fuel generally do not represent a significant health hazard. This external alpha radiation can be stopped by clothing, an outer layer of unbroken skin, or even a sheet of paper. The point at which Pu-238 can become a health hazard is when it is deposited into the body in tiny particle form and becomes lodged there.

If an individual were to inhale plutonium dioxide particles of a sufficiently small size to be deposited and retained in proximity to lung tissue, the alpha radiation could lead to forms of cancer. However, the ceramic form of plutonium used in an RTG, is made to inhibit the fuel from shattering into fine particles that could be readily inhaled.

The ceramic form of plutonium dioxide fuel also has low solubility in water, so it has little potential to migrate in groundwater or be taken up by plants. Plutonium dioxide also is highly insoluble in the human digestive system.
The New Horizons mission risk analyses show that the probability of a launch area accident with a release of plutonium is about one in 350 launches. Even in the event of a plutonium release, the risk to the public and workers is low, because the most likely launch area accidents involve small releases of plutonium dioxide that lead to either no exposure or exposure to very low radiation doses to individuals (significantly less than the doses due to natural background radiation). No additional cancer fatalities in the launch area would be expected from doses at this level, even over a time span of 50 years.


Cheers,

Lokase