Nuke the Nukes?

I hear complaints all the time that we should be using solar panels for power all over the solar system so that we can finally get rid of the nukes. The fact is, we use solar panels for electrical power everywhere we can! Solar panels in space – while not inexpensive – are a good choice when and where we can use them. They are within the budget of most national space agencies, they are relatively light weight and they can conform to just about any geometry. And these considerations do not mention the political issues involved.

So then why do space craft use nuclear power so much?

The answer is twofold: quantity of power and mass.

When NASA launches for the outer planets beyond the asteroid belt, they use nuclear power generators. Or when space agency needs a lot of power, like the upcoming Mars Science Laboratory, they will use a nuclear power system. The nuclear sources is a lot smaller, has much less mass and can provide much more power than solar cells in these missions. Further, without nuclear power, we simply could not explore the solar system beyond the asteroid belt – there is just not enough sunlight and the spacecraft and its mass would be overwhelmingly large!

Grand Adventure from 25 Miles Up

We’re back! Thanks to Ralph Buttigieg again for stepping in and covering the blog whilst we were away. It is an awesome thing just to get back and read Ralph’s great work!

Ralph did a remarkable job at uncovering the “near-space” region that is nearly totally ignored. And I am very pumped over the scheduled September jump from the edge of space by Frenchman Michel Fournier (photo shown).

Talk about amazing! Freefalling trough 99% of the atmosphere at supersonic velocities is just an astonishing feat. In my opinion – it is one of the most amazing feats of human exploration ever and an off-the-scale grand adventure! We think of this kind of thing as impossible - but here he is.

I try and imagine what it must be like to actually step out of a floating platform in near vacuum (on purpose) and then fall 25 miles straight down – some four times higher than a commercial jet! An amazing idea – and we pray sincerely for his safety! We promise to keep you in touch with this adventure as it unfolds.

Electric Dreams

The all electric Gavonator. Courtesy Jalopnik.com

Ralph Buttigieg

Sydney, NSW

Australia

While Dennis wants to unplug his home from the power grid I 'll like to plug my car into the grid. Petrol is about 1.35 $AU per liter here at the moment. Thats about $US 3.75 a gallon. According to news reports its expected to reach $1.50 per liter soon.

So I was interested to read that a Silicon Valley company Tesla Motors, has just released a hot little electric sport car. The roadster two seater can do 0-60 in four seconds, has top speed of 130MPH and is supposed to have a range of 250 miles. At $100,000 it's way out of my price range but I'm sure movie stars and dot.com millionaires will love it. Its powered by 6800 lithium ion batteries similar to the ones used in mobile phones. Despite the hype the batteries remain the big problem with electric cars. While the new batteries provide much better performance then the old heavy lead acid batteries they are still limited by cost and cycle life. After a few years those batteries are going to burn out and need to be replaced. Replacing 6800 batteries won't be cheap.

There has been much research in longer life batteries and companies like A123 Systems and Altairnano claim to have the technology. I'll believe it when I see it but some of the batteries have already began to appear in power tools.

Of course hybrid cars have been available for several years. They are a favorite with A-list actors, the socially aware elite, Green Party members and global warming believers which should make everyone else suspicious. Surely a car that has both electric and an internal combustion engines is going to be more unreliable. But its good for the environment right? Nope. researchers have looked at the total energy cost to manufacture and drive a hybrid and compared it to a large car like a Hummer. Surprise, surprise, the Hummer uses less energy. It might be a gas guzzler but its far easier to manufacture and will last a lot longer then a hybrid.

Oh well, looks like I won't be driving electric cars just yet. I'll just have to keep using Cityrail's electric trains.

The Exploration of Near Space

Captain Kittinger's big jump

Ralph Buttigieg

Sydney NSW

Australia

Next month Frenchman Michael Fournier will attempt a remarkable feat. From Canada he will ascend to an altitude of 40,000 meters in a giant helium balloon. Then he will step out from his small gondola and jump. If successful he will beat several longstanding records including highest sky dive, currently held by Captain Joseph Kittinger, (31.3 km 1960) and highest human flight, 34.668km set in April 5 1961 by Malcom D. Ross and Victor A. Prather. For a few minutes he will be in microgravity but atmospheric friction will soon begin to bite. Even so he will be falling at supersonic speeds for part of the dive. There's more to it then just breaking records too. There is some interesting technological developments such as his lightweight spacesuit. Also aeronauts and astronauts are going to need safe high altitude bail out procedures.

One of the advantages Near Space has over Outer Space is while mobility is a problem, access is relatively easy. A weather balloon will get a payload there. That flight can be tracked by radio and a parachute can return the payload to Earth. Amateurs, university groups etc. have been sending experiments up, in what are called nearcrafts , for years.

One group that has had a long history of Near Space exploration is JPAerospace. Their missions have flown payloads for schools, private individuals and others. Although a group of mostly volunteers the USAF took them seriously enough to provide a grant for the construction of a giant unmanned airship. It is hoped that the Ascender airship can reach an altitude of 100,000 feet (30km).

The Ascender airship. JPAerospace

Michael Fourneir is not the only explorer venturing into Near Space. Last November Indian Vijaypat Singhania claimed the hot air balloon record when he reached 21 km. Theres also competition from Britain. The QinetiQ 1 team of Andy Elson and Colin Prescot hope to reach 40km. Another team , which includes pilots Steve Fossett and Einar Enevoldson, hope to soar into Near Space on a sailplane.

Near Space is an ideal frontier for true explorers. Its challenging, interesting with important discoveries waiting to be made. Yet it's a frontier cheap enough to be explored without a government bureaucracy . The next few years should provide some interesting results.

The Shore of the Endless Sea

The view from Near Space. JPAEROSPACE.

Ralph Buttigieg

Sydney, NSW

Australia

On Quantumlimit.com we have discussed the unexplored frontiers of Outer Space, Oceans, the remote regions of Earth and the subterranean realm. But theres another unexplored region, one thats only 20 km away. The region known as Near Space.

Conventional aircraft can not go higher then about 20km. The air at higher altitudes is just too thin for engines to work. Spacecraft can not orbit lower then about 100km as atmospheric friction would bring the satellite down. The high areas in between remain out of reach for proper exploration.

Balloons can get there but they are unguided and can not reach the upper regions. Sounding rockets can go higher but their stay has to be brief. NASA had the solar-electric remotely operated aircraft Helios which reached a record breaking 29 523 meters, however it crashed near Hawaii in 2003.

Explorers (aeronauts?) in Near Space would require a space suit as the conditions are similar to Earth orbit. The sky would be black and they would be above 99% of Earth atmosphere. The temperature is below zero and ultraviolet radiation would be a danger. So little is know about the upper regions that some scientists have jokingly called the mesosphere the ignorsphere.

There is considerable interest in Near Space for possible applications. A near space platform would be an excellent observation post both for monitoring the surface and astronomy. Also high altitude platforms could be used as cheap communication “satellites”.

However exploration is what this blog is about and Near Space has several mysteries to be unraveled. Such as; just what are Noctilucent clouds? These clouds are seen at high latitudes in summer and are about 85 km up. They are composed of ice crystals but how can they form in such thin atmosphere? Also they were first recorded in 1885 so are they a new phenomenon or were they just not recorded earlier?

Another mystery; a few years ago British and Indian scientist sent up a balloon to 41 km and returned dust samples. Now this region was supposed to be sterile but the dust samples had bacteria and fungus. How did the bugs get there? The stratosphere is not supposed to mix with the lower troposphere. Do they occasionally mix due to some unknown process or what? Some scientists have taken the highly controversial position that the life actually comes from Space.

So whats up there? We will need to go and find out. I'll discuss some of the attempts to explore the frontier next time.

The Dangers of Artificial Gravity

Ralph Buttigieg

Sydney NSW

Australia

Rotating centrifuge from the movie Mission to Mars

Artificial gravity was discussed in depth here by Dennis. It can be achieved by spinning the spacecraft (centrifugal force) but , like a lot of things, the devil is in the details. I'll spare everybody the maths and instead refer you to a gravity calculator. Run a few numbers through. You will see the way to increase the gravity level is by increasing the radius of the spaceship or by increasing the spin rate. Now you don't want to make the craft too big so the RPM is important. Experiments were done years ago in a centrifuge to see what spin rate humans can handle. Its been generally agreed that just about everyone suffers no ill effects at 1-2 RPM and most people will adapt to 3 RPM. However even 3 RPM can take a while to adapt, a bit like sea sickness. After that the number of people who can acclimatised rapidly drop off. Hardly anyone can handle 6RPM + . The trouble is severe nausea and dizziness caused by the Coriolis effect. An explanation of the Coriolis Effect can be found here but is I understand it, the problem is that your head will be traveling faster then your feet and head movements will cause illness. This meant that the internal centrifuge on 2001 Space Odyssey's Discovery , Dennis's favorite fictional spaceship, couldn't be used as it rotated at 6 RPM.

Engineers have tried to get around this problem by designing large space habitats. The main advantage of the Stanford Torus habitat design of the 1970's was that the RPM could be kept down to one. Others had spaceships spinning from lengthy cables attached to a counterweight.

Well, recent studies indicate people are more adaptable then previously thought. Previous experiments have taken test subjects from zero to full rotation in one go. The new tests had the subjects taken up in steps and had them preform exercises at each stage. It now appears people can adapt to well over 6 RPM, perhaps over ten.

Theres experiments have produced some interesting results:

Other discoveries surprised the researchers, too. For example, after rotating for a while, people in their study no longer perceived the Coriolis effect. The veering pull on their arms and legs seemed to vanish. Their brains had compensated for it, so their minds no longer took notice of it.

Even stranger, when test-subjects first return to a non-rotating environment, they report feeling a Coriolis-pull in the opposite direction. It's just a trick of the mind, notes DiZio. After another 10 to 20 attempts at a goal-oriented motion, their brains readjust to the non-rotating world, and the phantom effect goes away.

DiZio and Lackner have found that people can adapt to rotational speeds as fast as a carnival-ride-like 25 rpm. That's about as fast as people turn their bodies during day-to-day life. For comparison, a spinning spaceship would likely rotate more slowly, perhaps 10 rpm, depending on the size and design of the craft.

It looks like Arthur C Clarke may have been right after all.

Genesis 1 launch successful

Ralph Buttigieg

Sydney, NSW

Australia

You may remember my post on Bigelow's Aerospace inflatable space station plans.

Well, I woke today and was delighted to read that the prototype, Genesis 1, was successfully launched:

An experimental inflatable spacecraft bankrolled by real estate magnate Robert Bigelow rocketed into orbit Wednesday to test technology that could be used to fulfill his dream of building a commercial space station.

The Genesis I satellite flew aboard a converted Cold War ballistic missile from Russia's southern Ural Mountains at 6:53 p.m. Moscow time. It was boosted about 320 miles above Earth minutes after launch, according to the Russian Strategic Missile Forces.

The launch was a first for the startup Bigelow Aerospace, founded by Bigelow, who owns the Budget Suites of America hotel chain. Bigelow is among several entrepreneurs attempting to break into the fledging manned commercial spaceflight business.

More on the project can be found here. Lets hope the inflation goes well.

Update: So far so good Here the latest from the Bigelow site:

Genesis I Mission Update

5:20 PST Bigelow Aerospace has received confirmation from the Genesis I spacecraft that it has successfully expanded.

We have also confirmed that all of the solar arrays have been deployed.

4:15 PST Bigelow Aerospace mission control has begun to acquire information from the Genesis I spacecraft. The ISC Kosmotras Dnepr rocket has flawlessly delivered the Genesis I into the target orbit of 550km altitude at 64 degrees inclination. The internal battery is reporting a full charge of 26 volts, which leads us to believe that the solar arrays have deployed.

The internal temperature of the spacecraft is reported to be 26 degrees Celsius and we have acquired the spacecraft's Global Positioning System (GPS) signal that will enable us to track the ship in flight.

We have initiated communication with the ship's onboard computers and expect to download more information over the next few hours.

- Robert T. Bigelow

Keep a watch on the Bigelow website for the latest.

Ralph

Jewel of Saturn

Shown here is a photo of Saturn’s titanic moon Titan set against Saturn’s rings. Here we can see the sun behind Titan and shining through its atmosphere. The astonishing thing about Titan’s atmosphere is its characteristics. It has an atmosphere 1.6 times as dense as earths. That’s about like being at a depth of 21 feet of sea water. Even though Titan is enormous as moons go – it is larger than the planet Mercury, its density is quite unlike Mercury or earth. It is mostly water ice, so its density is less and therefore its gravity is less. Add all that up and it means that Titan’s atmosphere is deep because its gravity cannot hold it in close as does the earth’s.

Therefore, in this photo one can see the thickness of the atmosphere as it reflects light though it like an enormous celestial jewel. The atmosphere around Titan is ten times as deep as earth’s atmosphere, rising some 500 miles into space!

WOW!

WOW! Discovery now paves the way to get back on some kind of regular schedule in space and finish the International Space Station.

It was a beautiful mid-afternoon launch from the vantage point of my front yard. There were only a few wispy, white clouds here and there, but nothing to obscure the brilliant white contrail lifting vertically in the sky toward space.

It was a beautiful launch on a gorgeous holiday. Godspeed discovery!