CONDOLENCES were genuine, if a little abrupt under the circumstances. When the Planetary Society, the world’s largest space lobby group, released its response to Nasa’s pleas for more cash on Friday, the devastating explosion of the shuttle Columbia and the death of its crew of seven were dealt with briefly in the first paragraph.
Then it was on to talk of missions to Mars, Jupiter, Neptune and Pluto and the means of propulsion by which humans could eventually reach further into the solar system.
Members of the 100,000-strong society, founded by distinguished space scienti
st Carl Sagan, were urged to support a petition calling on Nasa not to be deflected from its mission of planetary exploration by the loss of the Columbia last weekend.
"Our human and robotic explorers must continue the great adventure so boldly begun," the petition declares.
There is little doubt that, prior to last Saturday morning, the crew of the ill-fated Columbia and their now grief-stricken families would have wholeheartedly agreed. As it is, out of tragedy comes opportunity.
Initial reaction to the disintegration of the Columbia suggested it was a devastating blow to the future ambitions of both the manned and robotic space programmes planned not only by the US but by other nations across the world.
As investigators continue to comb three states for the elusive remains of the ill-fated craft this weekend and clues as to what brought it down, a different picture is emerging.
"I am absolutely certain that manned space flight will continue, as will much of the rest of the planetary exploration programme," said Roderick Galbraith, professor of aerospace engineering at the University of Glasgow.
"What a nation needs to go into space is the political will. The Chinese are about to go up there and the Russians are still there. Do you imagine that the United States of America will want to be left behind?
"The loss of the Columbia may well have the effect of loosening the purse strings."
Nasa has been subjected to a decade of dwindling financial reserves, reduced manpower and cost overshoots. Shuttle programme budgets have been repeatedly squeezed as a result.
The death of Columbia came as little surprise to most space scientists concerned about the incredible stresses that launch and re-entry were putting on the ageing four-strong shuttle fleet. Only last year, Richard Blomberg, forced to resign as the chair of Nasa’s own Aerospace Safety Advisory Panel after repeated clashes with budget managers, warned in his parting shot letter: "I have never been as concerned for space shuttle safety as I am right now. All of my instincts suggest the current approach is planting the seeds for future danger."
It was a concern shared by space engineers worldwide. "It was almost inevitable that another shuttle crash would happen," said Colin McInnes, one of Scotland’s leading aerospace scientists. "There had been cracks in the fuselage here, problems with fuel pipes there and other little things that suggest that at sometime, something serious is going to go wrong. An accident was due."
It arrived shortly before 2pm on Saturday when Columbia, on its 28th mission, re-entered the Earth’s atmosphere travelling at a speed of 16,700mph. The dramatic break-up of the shuttle over the skies of Texas, against a clear blue background, was relayed live on American breakfast television to horrified viewers. At 1.59pm, Nasa finally lost touch with the doomed crew as the wreckage cascaded over three states.
Initial suspicions focused on potential damage to the shuttle’s underside shield of 27,416 heat-resistant ceramic tiles which may have been damaged during take-off. The tiles, which can withstand temperatures up to 1,648°C, protect the spacecraft from burning up on re-entry but video cameras clearly showed the Columbia’s left wing had been struck by a small block of insulating foam falling from one of the rockets taking it into orbit.
Damaged or missing tiles would allow intense heat to melt the shuttle’s aluminium airframe, leading to a catastrophic break-up. But tile damage is far from unknown - the same chain of incidents occurred on the Columbia’s maiden voyage more than 20 years ago and has never caused major problems before. Columbia’s crew were aware of what happened and had dismissed it, as did their Nasa controllers.
The falling block could also have damaged a wing flap or vertical stabiliser, meaning the autopilot could not have kept the shuttle at the precise 38-degree angle necessary for the tiles, damaged or not, to do their job. Intense heat, as picked up by the left wing sensors, could once again have penetrated the defences.
But there are other ways in which Columbia could have been damaged. One theory gaining ground is that the shuttle collided with an object on its way back to base.
Nasa documents reveal that space shuttles have been returning to Earth with a larger-than-expected number of dents and nicked windshields from space junk. Columbia itself was in the thick of the action. After a particularly long mission in 1996, two windows had to be replaced after engineers found 51 pits in them. They contained meteoroids, paint chips, aluminium, stainless steel, silver, copper and plastic, probably from collisions with bits of rocket motors and old spacecraft.
The risk of collision has brought about significant changes in mission practice. Shuttles frequently fly upside down and backwards to reduce the chances of exposing vulnerable parts of the craft to debris. Nasa controllers liaise with Air Force Space Command to make sure they are aware of larger objects and shuttle flight paths are changed if necessary.
If collisions with man-made objects can be mitigated, freak elemental occurrences are harder to handle. Space controllers are aware of unusual atmospheric phenomena called sprites, a form of lightning that flashes into space above thunder clouds.
Pictures taken by an amateur astronomer seven minutes before Columbia imploded show a bright streak of orange light, tinged with purple, zapping the shuttle from behind.
Some scientists believe that if Columbia was hit by a sprite, heat-shield tiles could have been blasted off, exposing the vulnerable airframe.
Of course, given the ever-present dangers of space flight and an ageing shuttle fleet, supporters argue that the loss of two flights in 113 missions is not bad going. But there will be short-term problems from the grounding of Columbia’s companion aircraft - the Discovery, Atlantis and Endeavour.
Foremost is the International Space Station itself, from which Columbia was returning. Although there are three astronauts currently on board, they are not in any danger and can last, without relief, until June . If they have to return to Earth aboard a Russian spacecraft, a dent in US pride is the price that will have to be paid.
The biggest setback will come from ambitious plans to extend the ISS’s capabilities this year. Five shuttle flights, including one by Columbia, were planned to complete the space station core and help carry out the scientific work that justifies its existence. Big delays are now expected.
A project to replace the ageing shuttle fleet, expected to last to 2020, with a new "orbital space plane" may now also be given greater priority.
All eyes will be on how the US presidency reacts. George Bush has recently agreed to raise the shuttle’s budget by $770m, a quarter, but it may not be enough to assuage the critics. Although preoccupied by the war on terrorism right now, the president may well soon need a flag-waving venture that underlines US superiority at work for all mankind’s benefit.
"It may not be long before Bush uses space to balance the current perception of America as an imperialist world power," said McInnes.
He may do it by helping in the conquest of other worlds.
After a Saturn probe arriving next year, unmanned scientific missions to Mars include the fully-funded Mars Reconnaissance Orbiter in 2005, a Mars Scout mission in 2007 and the Mars Science Lander in 2009, which will have an advanced nuclear power source, enabling the spacecraft to operate on the surface for years instead of months.
How long it will take for humans to be walking there depends on Nasa’s development of a new generation of nuclear-powered rockets capable of travelling at 75,000mph. The new multi-billion-dollar engines use the heat created by the natural decay of plutonium -238 to generate electricity. At present, spacecraft use chemical engines which restrict them to 18,000mph.
Nasa has at its head a new gung-ho administrator, Sean O’Keefe, who believes current propulsion systems resemble "exploring the old West in covered wagons. We’ve been restricted to the same speed for 40 years. With the new technology, where we go next will be limited only by our imagination".
Mars is just the first step if the new nuclear-propulsion systems can be perfected. Nasa is also seeking a budget for a Jupiter Icy Moons Orbiter (JIMO) to successively orbit the planet’s three moons, over a ten-year period in the search for subsurface oceans.
O’Keefe also wants funding to go to Pluto, Neptune and the asteroid belts. But, according to Galbraith, it is the manned missions that will capture the public imagination and keep funds flowing into space research.
"It’s true that it is cheaper to send robot missions," he said. "And it doesn’t cost lives. But the cultural experience that we can all share is lacking. Men will go to Mars and perhaps even beyond. More may die. But Man’s great drive to explore and stretch beyond the boundaries of his horizon will always be there."
