NASA at 50

Minnesota public radio is one of the many media currently celebrating this year’s fiftieth anniversary of NASA with a program yesterday on its history. The BBC also collected a series of videos of many of the space agency’s memorable moments, while Wired had an article about NASA’s half century of “towering achievements”. Kansas City Infozine interviewed several NASA veterans to talk about its accomplishments. The first of several 50th anniversary moments was last month with the signing of the act that brought NASA into existence.

The birth of NASA was the necessity of catching up with the Russians. On 4 October 1957, the Soviet news agency Tass announced to the world that the USSR had successfully placed Elementary Satellite 1 into an elliptical orbit about 900km above Earth. Elementary Satellite 1 became better known by its diminutive "Sputnik". It circled the globe every hour and a half and flew over America seven times a day, in almost taunting fashion. At the height of the Cold War, the Soviet Union had taken a giant technological leap ahead of the US.

When the general American public read about Sputnik, there was much predictable shock and surprise. The Space Age had begun, and it had nothing to do with American might. Many others felt that the oceans could no longer protect the mainland and the Russians had intercontinental warhead capability. The Eisenhower administration rushed to reassure the American people, but also offered their congratulations to Moscow for its achievement. US scientists were simply excited knowing that Sputnik was just the incentive needed to get their satellite program up and running.

Public opinion was now massive in favour of the creation of an aggressive exploration of space. And so, on 29 July 1958 US President Dwight Eisenhower signed the National Aeronautics and Space Act. The act would lead to the birth of National Aeronautics and Space Administration (NASA) on 1 October that year. The act provided for “research into problems of flight within and outside the earth's atmosphere, and for other purposes.” It declared that activities in space should be devoted to peaceful purposes for the benefit of all mankind and would require “adequate provision”. The act’s eight objectives were to expand knowledge of space, improve the quality of space vehicles, develop space travel for humans, establish long-range scientific studies, preserve the US role as leader in space, using military discoveries for civilian purposes, co-operation with other nations, and effective utilisation of US scientific and engineering know-how.

Since 1915, the field of aeronautic research had been the province of the National Advisory Commission for Aeronautics (NACA). NASA absorbed the NACA and kept the “Aeronautics” in its name. It also took NACA’s 8,000 employees, its $100 million annual budget, its three major research laboratories (Langley and Ames aeronautical laboratories and Lewis Flight Propulsion Laboratory) as well as two smaller test facilities.

The new organisation launched into space exploration programs with Project Mercury. With a well-honed media instinct, NASA decided from the outset its space program would need to be manned in order to keep the public onside. In 1961, Mercury began to pay dividends. In May, Alan Shepard became the first American in space, with a 15-minute suborbital mission. Eight months later, John Glenn became the first true US astronaut when he orbited the Earth. Project Mercury’s six flights achieved the goal of putting piloted spacecraft into Earth orbit and retrieving the astronauts safely.

Project Gemini built on the carefully-planned success of Mercury. Gemini had two-person missions, re-entry rockets within the capsule and the ability to alter its orbit. But on 25 May 1961, President Kennedy raised the stakes again with his “special message to the Congress on urgent national needs”. Given just a month after Yuri Gagarin became the first man in space, This famous speech called for America to take “longer strides” and take a leading role in space achievement. He committed the US to landing a man safely on the moon by the end of the 1960s and ten billion dollars to fund it.

Kennedy's speech was pure gold to NASA. His estimate as to the cost of the Apollo program was grossly inadequate and it had ballooned out to $25.4 billion by the time it ended. The program overcame the setback of the fire to the Apollo 1 capsule on the ground that killed three astronauts. For all future missions, most flammable items were replaced with self-extinguishing materials, pure oxygen was replaced by a nitrogen-oxygen mixture at launch and the hatch was redesigned to open outward and to be removed quickly.

NASA’s crowning moment came when Neil Armstrong carried out Kennedy’s goal, on time (though over budget) on 20 July 1969. The 17th mission brought an end to the Apollo program in 1972 and NASA looked to new challenges. In 1975, they docked in space with a Russia Soyuz craft in the world’s first international manned space flight. When US astronaut Thomas Stafford shook hands with Soviet Cosmonaut Alexei Leonov in the docking ring of joined Apollo and Soyuz spacecraft, it was an act that seemed to mark the end of the Space Race.

In the eighties, NASA returned to human spaceflight with the Space Shuttle program. The first flight of STS-1 (named “Columbia”) in 1981 demonstrated that it could take off vertically and glide to an unpowered airplane-like landing. But the 1986 Challenger disaster on take-off and the 2003 Columbia disaster on landing, seriously damaged NASA’s credibility and made it look for less awe-inspiring challenges. President Bush’s subsequent 25 year plan to return to the Moon and land on Mars has not met with the same enthusiasm as Kennedy’s earlier call.

But there have been many other successes in NASA’s unmanned program. The Hubble Space Telescope has greatly advanced cosmology and returned thousands of astonishing images after its mirror was fixed in 1993. NASA's scientific probes have explored the Moon and all the planets of the solar system except Pluto. Voyager 1 is now the further man-made object in space and is now in the heliosheath on the edge of interstellar space some 16 billion kms away from its home planet. And a new expanded space race is at hand with Japan, China and the EU joining the traditional players. American scientists now say they need the support of private enterprise to succeed in space. But despite concerns about its middle-aged spread, it is hard to imagine the future colonisation of space without some role for NASA.

Dark matters: life, the universe and everything

On Wednesday NASA launched a rocket carrying its new $690 million long distance telescope it hopes will provide answers to some of the universe’s enduring mysteries. The Delta II rocket blasted off from Kennedy Space Center carrying aboard the Gamma Ray Large Area Space (GLAST) telescope. After a 75 minute flight, GLAST was deployed into a low Earth orbit and NASA expect it to transmit its first data in three weeks time. “After a 60-day checkout and initial calibration period, we'll begin science operations," said Steve Ritz, project scientist at Goddard Space Flight Center in Washington DC. "Glast soon will be telling scientists about many new objects to study, and this information will be available on the internet for the world to see."

GLAST is designed to study high energy sources of radiation in the universe. The project is a five to ten year operation designed to detect high energy gamma ray bursts, pinpoint their origin and shed light on the black holes where they mostly seem to reside. According to NASA, the new telescope will give astronomers a superior tool to “study how black holes, notorious for pulling matter in, can accelerate jets of gas outward at fantastic speeds.” The idea is to use a form of light invisible to the human eye to study and trace the origins of one of the most powerful forms of energy known - gamma ray bursts.

Gamma rays are energy-laden electromagnetic radiation produced by sub-atomic particles. They sit at the lowest end of the electromagnetic spectrum beyond ultraviolet and x-rays with a tiny wavelength of 0.00001 millimetres (ten to the power of minus five). They are found in the hottest areas of the universe and are produced by dramatic events such as supernova explosions, destruction of atoms, and the decay of radioactive material in space. A gamma ray burst release can travel across vast distances of the universe, and are absorbed by the Earth's atmosphere. Gamma ray bursts are spectacular events and can release more energy in ten seconds than the Sun will emit in its entire ten billion year life.

Scientists are particularly interested in gamma ray bursts because they throw light on some of the earliest events in the universe. They are so bright they can be detected as far back as the earliest five percent of the universe’s life time – over 13 billion years ago. One of the aims of GLAST is to investigate the link between gamma rays and dark matter. They hope to confirm that gamma ray bursts from the centre of our galaxy will reveal the presence of dark matter. Although known to science since 1933, dark matter remains one of science’s more hypothetical concepts. Yet it is believed to account for the majority of the mass of the observable universe.

The discovery of dark matter was made by Swiss astrophysicist Fritz Zwicky who worked at the California Institute of Technology in the 1930s. Zwicky was aware of Edwin Hubble’s discovery that the universe was expanding. But he was also aware that galaxies tend to cluster in complicated local movements. He measured the red shift from individual galaxies to see what was holding them together. What he found astonished him: a cluster of galaxies can remain bound together for billions of years, but only if it contains enough material to trap the individual members. But when Zwicky calculated the combined gravity of the known components – stars, gas and dust – it was nowhere near sufficient to form the cluster.

Zwicky concluded there must be an extra contribution to the gravitational pull. This unknown force outweighed the visible stuff hundreds of times over. He called this material “dark matter”. While Zwicky’s findings were initially ignored, a gradual weight of evidence emerged to show, as scientist Paul Davies says, “the luminous parts of galaxies represent just the tip of the iceberg, and that most of the matter in the universe is in fact dark”.

It is dark matter that keeps the galaxy in the familiar disk shape and it is dark matter that ensures the Sun stays firm on its 250 million year circuit of the Galaxy. Without it, the Milky Way would unravel like an exploding flywheel. Ever keen to find human significance in the universe, Scientists have come up with bizarre anthropomorphic names to describe the types of dark matter they think might be out there. There are two broad categories: MACHOs and WIMPs. MACHOs are “Massive Compact Halo Objects”. These are concentrations of mass residing in the galactic halo. They include dwarf stars and giant planets as well as smaller objects such as asteroids and comets. These objects are too dim to show up in telescopes but still exist in abundance. Yet MACHOs probably count for only a small percentage of dark matter. The rest are likely to be WIMPs.

WIMPs are Weakly Interactive Massive Particles. They are not so much dark as invisible, mostly passing through ordinary matter without betraying their existence. Because dark matter is concentrated at the centre of galaxies, scientists envisage a thick invisible soup of WIMPs through which stars swim as they perform their loop across the Milky Way. As WIMPs are weakly interacting, they only very rarely hit an ordinary atom; and as they are massive particles, possibly as heavy as a uranium atom they could account for the remaining dark matter in the galaxy.

Most importantly, dark matter played an essential role in shaping the universe. The smoothness of the early life of the universe was removed as regions over-dense in dark matter drew on surrounding material to amplify their denseness. Normal matter alone would have been too feeble to create galaxies, stars and planets and dark matter was needed to assist the clumping process. Peter Michelson, a Stanford astrophysicist and a lead investigator on the GLAST project, describes dark matter as “"mysterious, unseen substance that gravitationally holds the universe together”. He hopes the glimpses of gamma ray bursts will provide clues as to how dark matter formed the universe. "When you look at the night sky with your eyes, it is fairly quiescent and peaceful," Michelson said. "The gamma ray sky is not. It's a very different view of the universe. We're seeing exotic things like black holes and neutron stars and coalescing binary systems at the end of their life when they collapse into a black hole and there's an explosion."