Two robotic probes were speeding towards the Moon at 8,000mph last night on a mission that will help to earmark future human camp sites, as hearings got under way in Washington that could shake up Nasa’s plans for returning Man to the lunar surface.

The launches of the Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS) from Florida represent what Nasa calls its “first step in a lasting return to the Moon”, nearly 40 years after Neil Armstrong became the first human to set foot there.

The twin voyage, which comes with a $580 million (£350 million) price tag, will produce the most precise and comprehensive measurements of the Moon’s topography yet made, with LRO mapping the surface over several years from an altitude of 31 miles.

The life of LCROSS will be somewhat shorter. On October 9 it will separate from its Centaur rocket casing, which will then hurtle the final 54,000 miles into the Moon, hitting it at 6,000mph and kicking up an estimated 350 tons of material. LCROSS will begin its own kamikaze descent four minutes later, flying through the debris plume and beaming back readings of its content — searching for the presence of ice or water vapour, hydrocarbons and hydrated materials — before it, too, crashes.

“LCROSS has been the little mission that could,” said Doug Cooke, the associate administrator for Nasa’s Exploration Systems Mission Directorate. “We stand poised for an amazing mission and possible answers to some intriguing questions about the Moon.”

The vision is for a manned base on the Moon by 2024, where astronauts could one day grow their own food, scout for new sources of mineral energy, plant the early foundations for a new civilisation and act as a staging post for onward missions to Mars by 2037. Finding a water source to support them will be the key.

Exactly how and whether Nasa proceeds with the plans is now uncertain, as an independent panel set up on the orders of President Obama began hearings on Thursday into whether the space agency has got its blueprints right.

Controversy and concern remain over the potential cost of its human exploration programme, the vehicles that it intends to use after it retires the shuttle fleet late next year, safety issues — and whether there is even any point in striking out for the Moon.

Few expect Nasa’s vision for Moon and Mars — laid down on the instructions of President Bush — to be scrapped.

The new head of Nasa, Major Charles Bolden, is known to have presented a robust defence of human exploration to the President during a face-to-face meeting held before his appointment last month, and a manned lunar base is considered a crucial staging point for onward expeditions to Mars. In testimony before the review panel on Thursday, Nasa’s space shuttle programme manager, John Shannon, echoed what many Nasa-watchers have long said: that the money simply is not there to realise the dream.

Congressional proposals show Nasa’s spending being frozen between 2011 and 2014, denying the billions of dollars of money the space agency had hoped for, while Congress has lopped 17 per cent off proposed Constellation budgets — for manned flights.

“The Constellation programme has put forward a viable architecture, but . . . it has not been funded to the level that we would need to see it through,” warned Mr Shannon, adding: “The congressional budget numbers that have been provided to Nasa basically took away the lunar programme.”

Wary of competition from Russia, China and Japan, which have all declared an interest in getting to the Moon themselves, America’s space plans are more likely to be shaken up than scrapped. The committee will publish its findings in August.

Mission goals

July 1969: Neil Armstrong takes first human steps on the Moon

September 2010: Final space shuttle mission when the Discovery makes farewell visit to International Space Station, ending 29 years of shuttle flights

2010-2015: Nasa has to rely on Russian spacecraft and possibly private carriers to transport crew and equipment to ISS

March 2015: First manned launch of Orion and Constellation’s first mission to ISS

2024: Completion of first permanent Moon base allowing astronauts to acclimatise to long-duration missions and prepare for multi-year journeys to Mars

2037: Target date for first astronauts to land on Mars Sources: Nasa/Presidential Vision for Space Exploration

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