In today's edition:
- Minerals on Mars Point to More Recent Presence of Water
- Mission to Mars: Key health hurdle can be overcome, say scientists
- Could a hot air balloon help map Saturn moon?
- Space tourism flies into a legal black hole
Minerals on Mars Point to More Recent Presence of Water
Global mineralogical signs suggest that Mars was at least occasionally wet for the first two billion years of its existence.
In an article in the November issue of the journal Geology, scientists working with data from NASA’s Mars Reconnaissance Orbiter report that they have spotted widespread deposits of opals and related minerals on the surface of Mars.
Opals belong to a class of minerals known as hydrated silicas, with water molecules wedged into silicon-based minerals like quartz. The formation of hydrated silicas requires liquid water.
Most interesting is that the opal deposits lie in areas that appear to have formed only about two billion years ago. Previously, spacecraft have detected other water-bearing minerals like clays in regions that date back more than 3.5 billion years. Mars, like the other planets in the solar system, is about 4.5 billion years old.
In July, Dr. Murchie and other scientists reported that the orbiter had detected vast deposits of the claylike minerals on the older terrains. Images also showed ancient lakebeds with accumulations of the minerals, indicating standing water persisted for thousands of years.
The presence of water on Mars has been known for many years; its ice caps, easily visible from space, are largely made of frozen water. The unanswered question is how often the ice has melted.
The most intriguing possibility is that Mars, when it was less than a billion years old, was warm enough for lakes and oceans of liquid water — and with that, the possibility of life. The planet’s landforms offer compelling evidence for flowing water: immense canyons and channels, dried-up river deltas.
Planetary scientists are still trying to explain the transition of Mars from lots of water to today’s cold and dry climate.
James F. Kasting, a professor of geosciences at Penn State, believes he may have figured out how to warm up Mars. Greenhouse gas like CO2 isn't enought to keep Mars warm since it give -40F at most. Nitrogen dioxide however gives temperature up to 100F degrees.He said he still needed to demonstrate that the nitrogen dioxide would mix throughout the atmosphere rather than remain in pockets around the volcanoes. source
Mission to Mars: Key health hurdle can be overcome, say scientists
(AFP) – Scientists believe they have found a way of protecting astronauts from a dangerous source of space radiation, thus lifting a major doubt clouding the dream to send humans to Mars.
million miles) and more than 400 million kms (250 million miles) -- would take at least 18 months.is one of the greatest challenges facing Mission Red Planet sketched by the United States and Europe for some three decades from now. Even the shortest round trip -- distance between Earth and Mars varies between 55 million (34
During this time, the crew would be exposed to sub-atomic particles that can slice DNA on two and thus damage the tissue.
British and Portuguese scientists have taken a fresh look on the idea of Earth similar magnetic field around the the ship and say that the magnetic field does not, in fact, have to be huge -- just a "bubble" a few hundred metres (yards) across would suffice.
Their study, published on Tuesday in a specialist journal by Britain's Institute of Physics, draws on numerical simulation that is also used by experts in nuclear fusion, in which a hot plasma is kept in place by a powerful magnetic field.
Using a plasma lab at the Superior Technical Institute in Lisbon, the team tested a scaled down version of the device -- its full details are secret, as patents are being sought -- in a simulation of a of atomic particles.
Scaled up for a trip to Mars, the device would weigh around "several hundred kilos" (500-700 pounds) and use only about a kilowatt of energy, or around one half to one third of the typical power consumption of today's communications satellites, said Bingham.
The force of the magnetic field would replicate that of Earth's but, to minimise any risk to crew close to its source, could be carried in unmanned spacecraft flying either side of the crewship.
Bingham said the "mini magnetosphere" was being pitched both to the European Space Agency (ESA) and .
The field would scatter almost all particles dispatched in "cosmic rays. The ship however could be protected from it by a material, like a kevlar bulletproof waistcoat, against that threat." -- protons belched out by the Sun, , but it would not work against high-energy
In 2001, a NASA study found that at least 39 former astronauts suffered cataracts after flying in space, 36 of whom had taken part in missions beyond Earth's orbit.
Separately, the agency has tentatively estimated that a trip to Mars and back would give a 40-year-old non-smoking man a 40 percent risk of developing fatal cancer after he returned to Earth, or twice the terrestrial risk. source
My comment: Another cool thing. I like most the fact that it's Star Trek design! So, it could be done after all. And in the end, it's pretty logical, it just needed some decent simulations.
Could a hot air balloon help map Saturn moon?
Athena Coustenis, an astrophysicist and planetologist with the Paris Observatory, is helping draft a plan to send a hot air balloon to Titan, as well as an orbiting spacecraft and a surface probe. Called TSSM — the Titan and Saturn System Mission — this three-tiered approach to exploration could shed more light on the still-mysterious moon.
Although the atmosphere of Titan is filled with a smoggy orange hydrocarbon haze, it is primarily composed of nitrogen — just like Earth's. In fact, astrobiologists think Titan's atmosphere may be quite similar to how the Earth's was billions of years ago, before life on our planet generated oxygen.
Photos of Titan from Huygens probe from 2005 show a mountain of ice with river channels carving their way down to a lake of liquid methane shoreline. The Huygens probe eventually landed in a sandy river bed dotted with pebbles. This soft terrain would prove hazardous for a wheeled rover.
TSSM probe could be outfitted with a helicopter rotor to move around, floaters to prevent it from sinking if it landed on one of Titan's hydrocarbon lakes and a scoop to help it analyze the surface soil or liquid.
Huygens unexpectedly did gain some data of the surface upon landing. The probe heated the cold surface and caused some of it to evaporate, and an instrument designed to read the chemistry of the atmosphere caught a whiff of methane gas.
Our knowledge of Titan's geography has improved thanks to Huygens and Cassini. The Huygens probe proved the theory of a global ocean of hydrocarbon was incorrect, and from what the Cassini spacecraft has seen so far, the lakes of liquid hydrocarbon on Titan are mostly confined to the moon's north polar region.
The orbiter also could be used to study Enceledus, a tiny moon that previously had not garnered much attention. Cassini discovered that Enceladus has geysers of liquid water at its south pole, and this spray generates one of the rings around Saturn. Scientists are puzzled how this icy snowball could generate enough heat to keep water liquid.
Some may think the TSSM is too risky a mission, since hot air balloons and probes that float on liquid have never before been sent to alien worlds. But Coustenis says our exploration efforts beyond Earth always need to be on the cutting edge.
NASA and ESA are working in cooperation to develop an outer planets mission, and they are expected to choose between TSSM and a mission to Jupiter and its moon Europa in early 2009. Whichever mission they choose, the projected launch date is around 2020, with an arrival around 2030 © 2007 Space.com. source
Space tourism flies into a legal black hole
- 03 November 2008 by Paul Marks.
FOR the fledgling space tourism industry Falcon 1's successful launch on 28 September was hugely significant. When the rocket, built by SpaceX in Hawthorne, California, reached orbit 500 kilometres above the Earth it was the first privately developed rocket to do so.
Then two days later Virgin Galactic struck a deal with the US National Oceanic and Atmospheric Administration that will allow US scientists to monitor climate change using its spacecraft.
Last month, there was a the International Astronautical Congress in Glasgow, UK on the civilian space flight industry.
Yet despite growing confidence the question of safety stays. At the moment there are no global, legally enforceable standards that guarantee the safety of civilian spacecraft, says Gérardine Goh, a lawyer at DLR, the German Aerospace Centre in Bonn and an adviser to Germany's delegation to the UN's Office of Outer Space Affairs. "Ships have to be seaworthy, aircraft have to be airworthy. But there is no legislation as yet that will ensure a spacecraft is spaceworthy," she told IAC conference delegates.
So along with like-minded engineers, lawyers and policy makers at the International Association for the Advancement of Space Safety, a Netherlands-based not-for-profit group, Goh is advocating the development of minimum safety standards for civilian spacecraft.
They hope their ideas will one day feed into rules adopted by a future global regulator, possibly a UN-backed one. This might ensure safety in space in a way similar to how the UN's International Civil Aviation Organisation currently regulates safety in aircraft. "There is currently no international minimum safety standard for mass commercial space flight," Goh says. "We need a basic UN treaty that gives us that."
For example, one way companies are planning to get tourists into space is with an aircraft "mother ship" that carries a rocket to an altitude of around 16 kilometres before launching it, says Goh. "But with an aircraft launch, the ICAO air safety standards only apply to the mother ship and to the rocket capsule until it has separated. After that, we have no agreed safety standards for the capsule itself. That's a big problem."
So from 16 kilometres to the Kármán line, the point 100 kilometres up where space is deemed to start, the rocket will be travelling in a legal vacuum, where lawyers cannot agree whether it is a plane or a rocket. Some say only air law applies at or below 100 kilometres. Others, like Goh, argue that if you are in a fully functioning rocket, some agreed minimum safety measures should apply to the spaceship's design. Such confusion could expose fledgling space firms to a debilitating blizzard of writs in the event of an accident.
Other aspects of the UN's 1967 treaty on the exploration and use of outer space may also need revisiting if civilian space flight proves successful. For instance, countries are obliged to rescue and repatriate astronauts who crash or land in their territory. Governments might decide that the costs of rescuing space tourists should be met by the space flight operators.
Civilian space flight companies hardly need a reminder of the risks they are working with, as the field has already experienced its first major tragedy - on the ground. In 2007, three engineers were killed and three others badly injured when nitrous oxide rocket fuel exploded for reasons that remain unclear during fuel flow tests at a Scaled Composites facility in Mojave, California. The firm is building WhiteKnightTwo, a carrier aircraft, and SpaceShipTwo, a six-seater rocket, for Virgin Galactic. Scaled was fined by California's health and safety regulator and is modifying its technology to reduce risks.
Civilian space companies tend to believe that safety is already built into their designs. For example, the VSH will have an ejector seat for every tourist and crew member - allowing them to bail out of a crippled craft at around 40,000 feet (12 kilometres).
The notion of applying minimum regulations is fiercely resisted in the US, where the Federal Aviation Administration's Office of Commercial Space Transportation (AST) has no plans to regulate civilian space flight safety until 2012. The Commercial Space Launch Amendments Act of 2004 states that civilian space flight regulation must not "stifle" the developing technologies with onerous rules, says AST chief George Nield. sourceMy comment: I think that such regulation is definitely needed. More and more rich people want to let's say visit space. Rich people don't like to die and if this happen /even with all the safety they probably require / they will want to be able to sue someone and those regulations will provide precisely this. Nothing more than legal responsibility in space. I have already written on the issue- I think people should start extending the laws to outer space-sooner or later, we'll get commercial space flights, it's best to be ready for that moment, than to wait accidents to happen, people to get discouraged and then to encourage them.