Mexico volcano ash disrupts US flights for second day

Frustrated passengers stood in long lines at Mexico City's airport as US airlines canceled flights for a second day after the Popocatepetl volcano spewed a new column of ash.

United Airlines, Delta Airlines, Alaska Airlines and AirTran voluntarily scrapped 15 flights Friday as a precaution, but the airport did not restrict travel as it did not consider the ash a risk, airport spokesman Jorge Andres Gomez told reporters.

On Thursday, six US airlines had canceled some 60 flights, stranding 600 passengers, with many of them still looking for a way out of the Mexican capital Friday afternoon.

"They can't even give us chairs," Mexican traveler Gabriela Garcia said as she stood in a long line at a Delta counter with some 200 other people. "Nobody knows anything, nobody says anything, we've been standing for six hours."

Another Mexican traveler, Eusebio Pacheco, said that he had also been waiting in line for six hours with his wife, hoping to finally take off to the Canadian province of Quebec.

"We don't know anything, they don't tell us anything, we're desperate," he said, adding that two flights were canceled. They hoped to fly out on Saturday.

A Slovenian couple who were heading to Paris with Delta said they were advised to book a hotel and return in two days, with the airline saying it wouldn't pay for food or lodging since it was a weather event.



The airport spokesman said operations were getting back to normal later in the day and that flights from Europe and other regions had been landing all day.

The National Disaster Prevention Center had reported early Friday the 5,452-meter (17,887-feet) high volcano had blown a 1.5 kilometer (one mile) high column of ash that was heading west-northwest and produced low-intensity tremors in the last 24 hours.

In an evening bulletin, the agency said the volcano had spewed more gas, steam and ash which had dispersed as it blew west.

Authorities flew over the crater and saw molten rocks that were blown one kilometer into the air before falling on the mountain's slopes, it added.

Volcanic activity at the snow-capped Popocatepetl, located 65 kilometers (40 miles) southeast of the capital, has intensified since May, prompting authorities to raise the alert level to "yellow phase 3" for 27 days, just short of evacuation orders.

The disaster prevention center advised people living around the volcano to wear long sleeves and use masks or cover their mouths and noses with a cloth.

The Moon: The Future for Circumlunar flights and landings

Circumlunar flight can be more than just a test run. It can also be scientifically useful. The crew of Apollo 13 still managed to take useful photography of the lunar surface as they flew past, despite their circumstances.

A circumlunar mission presents the opportunities for observing the Moon, the Earth, and exploring the properties of deep space itself.

Return to the Moon
Much attention has been focused on plans by various nations to return astronauts to the Moon. At the moment, it doesn't seem that anyone will be landing there for at least another decade. America is revising its original plans for the Orion program, which calls for a return to lunar orbital missions and landings.

Some alternatives would see astronauts orbiting the Moon without landing, and also visiting asteroids.

Circumlunar Missions

There's one mission plan that's been discussed a lot in the past, but doesn't seem too popular right now. Circumlunar missions are a way of moving quickly beyond Earth orbit and reaching a target in space, without as much of the complexity of a landing or even entering lunar orbit.

Put simply, a circumlunar mission would send a spacecraft flying to the Moon, where it would pass around the Moon's far side, using the Moon's gravity to slingshot it back to Earth. A mission like this takes roughly six days to accomplish.

The Zond Program
In the 1960s, the Soviet Union introduced the Zond program, which was the world's first attempt at a manned circumlunar mission. Zond was a modified version of the Soyuz spacecraft, used to launch cosmonauts to Earth orbit. It would be launched to the Moon atop a Proton rocket, more powerful than the booster normally used to launch Soyuz.

Zond test missions were flown to the Moon and back with animals on board, but the missions were not entirely successful. The program was cancelled as America's Apollo program gained ground by sending astronauts to orbit the Moon, without a single cosmonaut flying a mission.

In 1970, the first manned circumlunar mission was flown, although the crew originally had no plans to make such a trip! Apollo 13 was intended to make America's third manned lunar landing.

Halfway to the Moon, the spacecraft experienced an explosion that crippled the Service Module and placed the survival of the astronauts in jeopardy. The crew was rescued by flying a circumlunar trajectory that used the Moon's gravity to help them return to Earth.

Today, circumlunar missions with Soyuz spacecraft have been proposed by at least one space tourism group. It is unclear when, or if, they will fly.

Circumlunar missions could be too expensive and complex for space tourism at the moment. But this shouldn't stop government space programs and aerospace companies from drawing plans.

A circumlunar mission could be a partial step towards a lunar orbital mission or a flight into deeper space. As the rescue of Apollo 13 demonstrated, the mission architecture has advantages of safety that aren't found in lunar orbital missions. This could take some of the risks out of testing new hardware in deep space.

Circumlunar flight can be more than just a test run. It can also be scientifically useful. The crew of Apollo 13 still managed to take useful photography of the lunar surface as they flew past, despite their circumstances. A circumlunar mission presents the opportunities for observing the Moon, the Earth, and exploring the properties of deep space itself.

Re-usable Launch Vehicles: Promised but not Delivered

There is a large up-front investment needed to develop and test any new launch system and companies either cannot raise enough money or are unwilling to take the risks associated with investing the needed funds.

The market for a reusable system is still immature, i.e., demand for launch services is in the embryonic stages, even though we have been launching satellites for over 50 years

Launch vehicle prices are sky high and they have been for a long time. This has presented a very high hurdle to space access for many potential space applications. There are literally tens of thousands of university experiments awaiting flight opportunities, but the cost is too high for students and faculty.

Hundreds of private-sector entrepreneurs have waited years for a chance to try new ideas and applications. Even large, established companies would like to stretch product lines through space experimentation, but have been frustrated by the high cost of launching trial products.

The promise of reusable space launch systems is dramatically lower costs to orbit. An ideal, fully-reusable system would be highly reliable, readily available and could cut costs by a factor of 10 or more. The introduction of such a system would open space access to thousands of denied users. So, why don't we have one?

There are several reasons. Technologies for fully-reusable orbital launch systems still evade the many companies that have attempted to design and build them.

There is a large up-front investment needed to develop and test any new launch system and companies either cannot raise enough money or are unwilling to take the risks associated with investing the needed funds. The market for a reusable system is still immature, i.e., demand for launch services is in the embryonic stages, even though we have been launching satellites for over 50 years.

Elusive technologies include truly reusable cryogenic tanks, low-maintenance thermal shielding, ultra-lightweight structures and advanced avionics. Financing such projects has been problematic, thanks to the many failures and overly-optimistic cost and revenue projections.

However, these hurdles will be overcome as the market matures. The one missing ingredient that would truly make reusable vehicles come to life is a "killer application" that would create a strong market demand for low-Earth-orbit flights.

There seem to be two possible business activities that might generate the needed market demand. One is the eventual human-tourism market that is just getting started with sub-orbital flights.

The other is the creation of a large, distributed space infrastructure of low-orbiting satellites that must be maintained over a long period of time. There is little doubt that the day will come when reusable systems are indeed a reality. The only question is: How soon?

If you want to know more about the design and technologies of launch vehicles register for a special session of the internationally popular course: Launch Vehicle Systems Design and Engineering, to be presented in Cocoa Beach on December 14-16, 2009.

UK RAF: Surplus Aircraft to be Leased out for Private Holiday Flights

The aircraft will be hired by commercial airlines and the RAF Roundel quickly painted over and replaced by commercial flagship colours for civilian use.

If the RAF need them back during a time of crisis they will be painted back again.

It is the first time that aircraft not needed by the military will be leased out to commercial airlines.

The idea is part of new measures to save the Ministry of Defence money.

Fourteen Airbus A330s are being bought by the company AirTanker and these will be leased by the Ministry of Defence.

The deal will cost the taxpayer an estimated £13bn over almost 30 years and is the world's biggest defence Private Finance Initiative.