The first steps of Space Exploration were taken by the launch of Sputnik 1 by the Soviet Union (USSR) in 1957. This launch initiated the popular “Space Race” between US and USSR. Unbelievably, Space launches and missions back then were not in favour of Science, but for a political and militaristic advantage in the Cold War. The launch of Sputnik 1 was followed by a series of successful missions and achievements by the Soviets; first man in space, first spacewalk, first probe to the Moon and many other firsts. US afraid of falling behind, scrambled to launch their first manned Mercury mission in 1961. Alan Shepard, spent 15 minutes in Space and was welcomed back a hero as the first American in Space. Soon after Shepard’s historic flight, President John F. Kennedy gave his famous “We choose to go to the Moon” speech. The rest, as they say, is history. US landed the first Men, Neil Armstrong and Edwin ‘Buzz’ Aldrin, on the Moon on July 21st 1969. This landing was followed by 5 more landings. The success of the Apollo program and the dissolution of the USSR made US the clear victor of the Space Race. After the Space Race, US began working on the Voyager Program, which would focus on exploration of the Outer Planets.
The Voyager Program consisted of the launch of two probes; Voyager 1 and Voyager 2. The Voyager Probes used the rare alignment of the Outer Planets which allowed them to perform a series of gravity assists, to get to the Outer Planets, which was faster and cost effective.
Voyager 1 was set to investigate Saturn’s Moon, Titan. Titan was a peculiar satellite, as it had a dense atmosphere, the only Moon in the Solar System to have one. Voyager 1 would perform a fly-by of Titan and use Titan’s gravity to slingshot it further into the Deep Space of the Solar System. This slingshot would take it out of the plane of the Solar System and thus will not be able to explore Uranus and Neptune. Voyager 1 will reach the Oort cloud in about 300 years and take about 30,000 years to pass through it. Although Voyager 1 was launched later than Voyager 2, it is now the farthest manmade object till date.
Each Voyager Probe has a Golden Record attached to it. The Golden Record is a message to whosoever may find the probe. It was compiled by Carl Sagan and other scientists. The record contains sounds and images selected to portray the diversity of life and culture on Earth. The Record also is inscribed with the basic Science and Mathematics the ETs can use to find us. The Golden Record is like a bottle with a letter, thrown off into the cosmic ocean.
Voyager 2 was set on a series of gravity assists to Jupiter and Saturn, followed closely by Voyager 1. At Saturn, their paths split and Voyager 2 went further to Uranus and Neptune. Voyager 2 was launched on August 20th 1977 whereas Voyager 1 was launched later on September 5th 1977. If undisturbed for 296,000 years, Voyager 2 should pass by the star Sirius at a distance of 4.3 light years. Voyager 2 is expected to keep transmitting weak radio messaged until at least 2025.
On February 14th 1990, at Carl Sagan’s request, the cameras on board Voyager 1 were directed to face the Earth to take a family portrait of the Solar System. The image captured was dubbed “The Pale Blue Dot”.
So, what does the future of space exploration hold for us? Well, it depends on what kind of Space Exploration, we aim for. Projects and missions dedicated for Space Exploration can be either manned or unmanned.
But these are all relatively explored regions of our vast universe. We have but just explored the shores of The Cosmic Ocean. The next step is to wade into the Ocean…
Probes have always been faster and cost effective. Having a low mass and payload, they don’t require a lot of resources. And probes can manage to stand the test of time in Space. So far, we have sent probes to explore the celestial bodies of our Solar System. It is time we aim for the Stars.
The nearest star to Planet Earth is Proxima Centauri, which is 4.2 light year away from us i.e 40.11 trillion kilometres away. If we send a probe there now, we probably won’t be alive to get a signal from the probe once it reaches there. The major problem with interstellar travel is the huge distances between stars. This wouldn’t be a problem if we could just go into warp speed and reach there in seconds, like in Star Trek and other Sci-Fi works. This technology is not available to us … yet
One idea put forward by Stephen Hawking, has to do with a release of a swarm of probes the size of postage stamps into Outer Space. These ‘nanocrafts’ will be propelled by a Lazer Ground System on Earth, hitting against the craft’s Solar Sail, which will accelerate the ship to approximately 20% the speed of light. At this speed, the crafts will reach Proxima Centauri and even maybe the Alpha Centauri Star System in about 20 years.
Manned Missions are highly expensive and require large amounts of resource in the form of supplies. And the most important factor of Manned Exploration Missions is Time. Man, has too insignificant and puny of a lifespan to explore the Universe. Only feasible explorations that can be done in the future are manned missions to Mars and maybe even Mercury.
All around the world several research projects are being carried out in Space Propulsion to help us achieve higher speeds. One such engine is the Ion Propulsion Engine. These engines shoot out ions at high exhaust velocities, which produce a tiny acceleration. This acceleration can help the ship reach significant speeds in a few weeks.
Are we ready to embark on an interstellar journey? Only time will tell…
Siddharth Menon, Mechanical Engineering