By Paul Rincon
Science reporter, BBC News, Glasgow
The craft would carry instruments that gathered data about the atmosphere
Virgin Galactic is to look at carrying scientific instruments on board one of its space tourism vehicles to gather data on climate change.
The company will join up with the US National Oceanic and Atmospheric Administration (Noaa) for the venture.
The first instrument would provide data on atmospheric composition - particularly greenhouse gases.
The company said 280 customers had now reserved seats for sub-orbital space flights aboard the vehicles.
Virgin, owned by Sir Richard Branson, aims to be the world's first "spaceline", taking passengers to a maximum altitude of 68 miles (110km) on its SpaceShipTwo manned vehicle.
The boundary of space is generally accepted to be about 62 miles (100km) above the surface of the Earth.
"To my mind there is no greater or more immediate challenge than that posed by climate change," said Sir Richard.
"It's therefore more than fitting that the very first science to be conducted on board our new vehicles may be specifically directed at increasing our understanding and knowledge of the atmosphere and from there, to better inform our decisions as to the most effective ways of dealing with climate change."
Pushing the limits
"Almost everything Noaa does at the moment is at 25,000ft (7,600m) maximum altitude. It's quite difficult to find research aircraft that do atmospheric testing above that," Will Whitehorn, president of Virgin Galactic, explained.
"One of the things that we as an airline operator know is that the tropopause is rising slightly. That has had quite an effect on aircraft flying in the upper atmosphere and the amount of turbulence they get.
"This is probably related to the mix of greenhouse gases and the levels they are rising to that's moving the tropopause up."
Mr Whitehorn was speaking to journalists here at the International Astronautical Congress (IAC) in Glasgow.
SpaceShipTwo will be carried to about 50,000ft (15,200m) by its carrier aircraft WhiteKnightTwo. The spaceship then ignites a rocket engine and completes the rest of the journey on its own power.
Passengers will be able to see the curvature of the Earth and get out of their seats during the ensuing period of weightlessness.
The vehicle changes its wing configuration during re-entry for improved aerodynamics.
Tickets will cost $200,000 (£100,000) and the company has already received $35m in deposits.
NOAA is interested in flying atmospheric monitoring instruments on WhiteKnightTwo, because the carrier vehicle will be in regular flight above 50,000ft for the next year-and-a-half during its test-flight period.
WhiteKnightTwo has come to the end of its ground testing. It will soon carry out runway tests and is expected to make its first test flight in the coming weeks.
The vehicle will be carrying three instruments. One is going to measure CO2 and methane in the atmosphere.
The second will take "flask samples", allowing it to test for a much wider range of gases. These samples will be offloaded from the aircraft and taken to Noaa's laboratories in Boulder, Colorado.
The third experiment will carry a tube sample, which empties of gases on the way up to high altitude and fills up on the way down.
Mr Whitehorn said that when SpaceShipTwo began flying, it could provide NOAA with regular sampling of gases through the outermost region of the atmosphere - known as the ionosphere - up to 110km above Earth.
This would be important for calibrating data from a major NASA satellite mission called the Orbiting Carbon Observatory (OCO), which is designed to measure atmospheric carbon. The OCO mission is due to launch next year.
The early part of the agreement between Virgin Galactic and Noaa is on a "no exchange of funds" basis, Mr Whitehorn said, because it was currently classified as an experimental programme.
SpaceShipTwo is currently 60% complete. The company plans to unveil the finished craft next summer.