This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.bbc.co.uk/news/science-environment-30333120

The article has changed 9 times. There is an RSS feed of changes available.

Version 3 Version 4
Orion 'Mars ship' launch postponed Orion 'Mars ship' launch postponed
(about 5 hours later)
The first test flight of the US space agency's Orion "Mars ship" has been postponed, amid technical issues. Thursday's first test flight of the US space agency's Orion "Mars ship" has been postponed because of weather and technical issues.
The capsule had been due to launch atop a Delta rocket on a short journey above the Earth to prove key technologies.The capsule had been due to launch atop a Delta rocket on a short journey above the Earth to prove key technologies.
Its maiden voyage was due to take place from Cape Canaveral in Florida between 12:05 GMT and 14:44 GMT. Its maiden voyage was to have taken place from Cape Canaveral in Florida between 12:05 GMT and 14:44 GMT.
But the countdown was interrupted by a boat getting too close, by gusty winds and by troublesome propellant valves. But the countdown was interrupted by gusty winds and by sluggish fuel valves.
Engineers will try again on Friday. Engineers will try again on Friday. The launch window will be exactly the same as on Thursday, with the aim as ever to try to get away right at the start of the window at 12:05 GMT (07:05 local Florida time).
"Despite the valiant attempts of the launch team and mission managers around the country, we basically ran out of time in trying to troubleshoot," said Nasa spokesman Mike Curie. "We'll go make sure we've got a happy rocket and as soon as we do that we're going to get back to the pad and send Orion off to a very, very successful test flight," said Dan Collins from the Delta's operating company, United Launch Alliance.
The conical vessel is reminiscent of the Apollo command ships that took men to the Moon in the 1960s and 1970s, but bigger and with cutting-edge systems. The conical capsule is reminiscent of the Apollo command ships that took men to the Moon in the 1960s and 1970s, but bigger and with cutting-edge systems.
For this demonstration mission, it is being flown without people aboard. For this demonstration mission, Orion is being flown without people aboard.
The first delay on Thursday was because of a boat straying into the launch vicinity. Unacceptably strong gusts of wind then forced a subsequent halt in the countdown. The first two delays on Thursday were weather-related (although a cargo ship travelling too close to the launch range was a concern for a while, also). Sensors detected unacceptably strong gusts of wind in the vicinity of the rocket and automatically stopped the countdown clock.
And finally, there were issues with valves not operating properly on the rocket's big boosters. A third stop on the clock was caused by sticky fill/drain valves on the rocket's big boosters. These had become excessively cold in the presence of the liquid hydrogen propellant.
Lockheed Martin, the company developing Orion and running this test flight for Nasa, has another three days to get the mission off the ground before negotiations must take place for an extension.Lockheed Martin, the company developing Orion and running this test flight for Nasa, has another three days to get the mission off the ground before negotiations must take place for an extension.
Other space missions have bookings on the launch complex and they would have to agree to step aside. Unfortunately, the weather looks to be deteriorating over the next 24 hours. Other space missions have bookings on the launch complex and they would have to agree to step back, potentially delaying their operations as well. Unfortunately, the weather in some respects looks to be less favourable for a Friday attempt.
If it deteriorates further, a decision could be made simply to jump to Saturday. This would save on supplies of liquid hydrogen, some of which is lost every time the rocket in tanked up, while also giving launch crews a bit of rest.
'Big thing''Big thing'
Orion is being developed alongside a powerful new rocket that will have its own debut in 2017 or 2018.Orion is being developed alongside a powerful new rocket that will have its own debut in 2017 or 2018.
Together, they will form the core capabilities needed to send humans beyond the International Space Station to destinations such as the Red Planet.Together, they will form the core capabilities needed to send humans beyond the International Space Station to destinations such as the Red Planet.
For the time being, the Delta IV-Heavy rocket - currently the beefiest launcher in the world - is being used as a stand-in.For the time being, the Delta IV-Heavy rocket - currently the beefiest launcher in the world - is being used as a stand-in.
If all goes well on Friday, the Delta will send Orion twice around the globe, throwing the ship up to an altitude of almost 6,000km (3,600 miles).If all goes well on Friday, the Delta will send Orion twice around the globe, throwing the ship up to an altitude of almost 6,000km (3,600 miles).
This will set up a fast fall back to Earth, with a re-entry speed into the atmosphere close to 30,000km/h (20,000mph) - near what would be expected of a capsule coming back from the Moon.This will set up a fast fall back to Earth, with a re-entry speed into the atmosphere close to 30,000km/h (20,000mph) - near what would be expected of a capsule coming back from the Moon.
It should give engineers the opportunity to check the performance of Orion's critical heat shield, which is likely to experience temperatures in excess of 2,000C (4,000F).It should give engineers the opportunity to check the performance of Orion's critical heat shield, which is likely to experience temperatures in excess of 2,000C (4,000F).
They will also watch how the parachutes deploy as they gently lower the capsule into Pacific waters off Mexico's Baja California Peninsula.They will also watch how the parachutes deploy as they gently lower the capsule into Pacific waters off Mexico's Baja California Peninsula.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmosJonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos