By Alok Jha

GUARDIAN NEWS SERVICE: Lack of funds forces closure of brainstorming institute that dreamed up space elevator and crops on Mars

In almost 20 years of research, it has been the home of some of the most daring ideas to aid exploration: space elevators, crops that could grow on Mars and a shield to protect our planet from global warming. But now Nasa's Institute of Advance Concepts (Niac) has fallen victim to a very down-to-earth problem - a lack of money.

The US space agency is set to close its futuristic ideas factory as part of a cost-cutting exercise which it hopes will help pay for ambitious plans to explore the moon and Mars. Bobby Mitchell, who works at Niac's headquarters in Atlanta, said: "From what I understand, Nasa are out of money. We haven't got an official notice yet but we have heard from Nasa that they are going to discontinue funding."

Former Nasa scientist Keith Cowing said the decision to close Niac was "just plain stupid". Writing on his Nasa Watch website, he directed comments to Nasa's administrator, Mike Griffin: "Advanced spacesuits ... will open the surface of the moon - and then Mars - to meaningful and productive human exploration. Where are you going to get all of the things you need to put on those Ares rockets so as to allow their crews to carry out their missions, Mike? Or do you 'just need a good map'? Explorers without the right tools die - or turn around - and head back home. Wrong answer, Mike."

Niac was set up in 1988 as a way to brainstorm revolutionary ideas that go beyond anything Nasa does today. It draws $4m (GBP2.04m) every year from the agency's $16bn budget and funds about a dozen projects every year for long-term ideas, things that could come to fruition within 10 to 40 years.

The institute is most interested in grand visions and big ideas thatmight inspire new technologies - and scientists have traditionally beentold they should not feel encumbered by what is possible today. Ideas where the technology to make something work has not yet been developed or the science is not entirely understood are welcomed.

Despite this wide remit, Niac has kickstarted several ideas that havesubsequently been picked up for further development by Nasa. Most recently, Nasa got interested in a Niac project called the New Worlds Imager, a space probe designed to take pictures of planets outside our solar system.

Taking such pictures is difficult because light coming from the planetsis obscured by stars. To get around this, Webster Cash, of the University of Colorado at Boulder, planned a pair of spacecraft - a starshade (the astronomical equivalent of sunglasses) and a collector - that works as a giant pinhole camera. The starshade would be 0.8km in diameter with a 10-metre hole at its centre and would sit more than 200,000km from the collector, blocking the stars' dazzling light.

Wendy Boss and Amy Grunden, microbiologists at North Carolina StateUniversity, worked on Niac-funded projects that looked at ways of growing food on other planets. Taking her inspiration from organisms that live in the most extreme environments on Earth, Prof Grunden genetically modified plants such as rye. In theory, astronauts on long missions could take the GM seeds with them, saving on the cost of taking food supplies into space.

Many of Niac's projects fall into the realm of science fiction. Theinstitute is famously home to the space elevator, an idea first proposed by Arthur C Clarke in his 1978 novel Fountains of Paradise, to transport people and equipment cheaply into space.

In the Niac proposal, a cable would be attached from the ground to asatellite in geostationary orbit around the Earth. Vehicles could thenclimb the tether and escape gravity without the need for rockets. But no one has yet designed materials that would be strong enough for the elevator to work.

Robert Angel of the University of Arizona was recently funded to lookinto creating a 1,988km-wide shield to protect the Earth from the sun'srays and counteract global warming. "Such a space-based solution mightbecome an urgent priority, worth trillions of dollars if abrupt climatefailures appear otherwise inevitable," he wrote in the outline for thisproject. "We propose to identify near-term research and space missionsneeded to understand whether a shield could be completed within a fewdecades at an affordable cost."

Martin Barstow, head of physics and astronomy at Leicester University in Britain, said it was important to have a mechanism for scientists to think about radical ideas. "It's important that people have the freedom to be able to do this [but] I don't think you need a separate entity. You just need the mental framework, the capacity for people to have time made available." Nasa has been reorganising its activities since 2004, to pay for the technology it needs to meet its goal of getting humans back to the moon and then on to Mars.

The plans include developing the new Orion exploration vehicle, shapedlike the Apollo space capsules last used in 1972 but three times bigger, to replace the space shuttle, and two new Ares I rockets that will blast the astronauts and equipment separately into space. Nasa has slashed more than $300m from the International Space Station's science budget and many robotic exploration missions have been either cancelled or put on indefinite hold.