End of an era: Atlantis and her crew were welcomed back as heroes on Thursday after landing at Kennedy Space Center and bringing Nasa's shuttle programme to a close.
Atlantis touched down almost invisibly on Runway 15 at the Shuttle Landing Facility at 5:57 a.m. EDT and rolled to a stop moments later to conclude the history making 13 day flight to the International Space Station and back. During the STS-135 mission Atlantis orbited the Earth 200 times and journeyed 5,284,862 miles.
The all veteran crew of space flyers comprised of Shuttle Commander Chris Ferguson, Pilot Doug Hurley and Mission Specialists Sandra Magnus and Rex Walheim.The finality of it all was at once thoroughly unbelievable that the shuttles would never fly again but utterly definitive at ‘wheel stop’ that we had witnessed the end of a historic and magnificent Era in human spaceflight.
The asteroid Vesta, as photographed by the orbiting Dawn spacecraft on July 17. Nasa now aims to place astronauts on an asteroid within 15 years
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NASA’s Mission To Send Astronauts To Asteroid
- It will take a spacecraft six months to reach an asteroid
- Nasa yet to decide which space rock would be the best to visit
- Scientists believe civilisation on Earth may depend on mission's success
- Mission is a stepping stone to the dream of flying astronauts to Mars
- Jupiter and Mars probes to be launched in August and 2012 respectively
An asteroid is a giant space rock that orbits the sun, like Earth. And someday one might threaten the planet. Sending people to one won't be easy. You can't land on an asteroid because you'd bounce off - it has virtually no gravity. Astronauts couldn't even walk on it because they'd float away. Reaching it might require a Nasa spacecraft to harpoon it.
The National Aeronautics and Space Administration (NASA) has its next big mission that will mark our history. This is about sending astronauts to an asteroid in less than 15 years. Many scientists in NASA were excited to realize its next big mission. However, some NASA scientists oppose the plan, contending that it is better to go back to the Moon, instead.
The Mission To AsteroidLike the Earth, an asteroid is a gigantic space rock that revolves around the sun. An asteroid may be a threat to Earth for it may crash into the Earth’s path in the solar system. According to studies, it is not easy to send a mission to an asteroid. The asteroid has no gravity so anyone cannot land on its surface without bouncing off. Astronauts would float on it if they attempt to walk on its surface. Because of this, the NASA would require a spacecraft which will harpoon it.
NASA Thinks Of Spacecraft For Asteroid MissionThe National Aeronautics and Space Administration (NASA) is thinking of a suitable spacecraft that could land on an asteroid. NASA is currently viewing the possibility of jetpacks, bungees, nets, spiderwebs, and tethers that will let the astronauts float on the surface of the asteroid. This will be done by having the astronauts attached to mini-spaceships.
“Star Trek” Shuttlecraft For The Asteroid MissionThe National Aeronautics and Space Administration (NASA) has envisioned a “Star Trek” like shuttle with a deep sea explorer and a pincer-like arms. These features would probably get within the working distance of the asteroid. The shuttle should be wide enough inside to accommodate the astronauts who will live inside the shuttle for two weeks at most.
The Time Plan In Reaching The AsteroidAccording to current estimates, an asteroid is reached for a period of half a year. However, the propulsion system in traveling such a distance in deep space is not perfected yet. A huge spaceship will be sent to cater football-field-sized solar panels. This will protect the astronauts from dangerous solar and cosmic ray bursts during their travel.
Which Asteroid To Visit?Up to this time, the National Aeronautics and Space Administration (NASA) has not yet chosen which asteroid will be the target for its mission. But this will be realized by a Presidential Order, hopefully in year 2025. The NASA scientists were anticipating and at the same time excited for the big mission. Chief Architect Kent Joosten of the Human Exploration Team at Johnson Space Center declared that the mission is the big step out into the universe, which is away from the Earth’s gravity completely. Although it is a risky mission, NASA scientists said that this is the kind of mission that they should be doing. A kind of mission that engineers will focus their attention to.
Challenges Ahead for NASA and the Asteroid Mission
It would take half a year to reach an asteroid, based on current possible targets.
The deep space propulsion system to fly such a distance isn't perfected yet. Football field-sized solar panels would help, meaning the entire mothership complex would be fairly large.
It would have to protect the space travellers from killer solar and cosmic ray bursts. And, they would need a crew capsule, maybe two, for travelling between the asteroid complex and Earth. And all those parts - mini-spaceship, habitat/living area, crew capsule, solar arrays and propulsion system - would have to be linked together in the middle of space, assembled in a way like the International Space Station but on a smaller scale.
Beyond all those obstacles, Nasa doesn't even know which asteroid would be the best place to visit.
All this has to be ready to launch by 2025 by presidential order.Kent Joosten, chief architect of the human exploration team at Johnson Space Center, said: 'This is the big step This is out into the universe, away from Earth's gravity completely... This is really where you are doing the Star Trek kind of thing.'
It has the dreamers of Nasa both excited and anxious.
Bobby Braun, Nasa chief technology officer, said: 'This is a risky mission. It's a challenging mission. It's the kind of mission that engineers will eat up.'
This is a matter of sending 'humans farther than ever before', said Nasa Deputy Administrator Lori Garver.
It is all a stepping stone to the dream of flying astronauts to Mars in the mid-2030s.
'I think it is THE mission Nasa should embrace,' said University of Tennessee aerospace professor John Muratore. 'To be successful at this mission, you've got to embrace all of the technologies that you need for Mars.'
Critics, including former Apollo astronauts and flight directors, have blasted President Barack Obama for cancelling George W Bush's plan to return astronauts to the moon. They dismiss talk of asteroid visits.
But that's because Nasa has not done a good job of outlining the fascinating details and explaining why it is important, said astronomer and former astronaut John Grunsfeld.
'Nasa doesn't have a story right now,' said Mr Grunsfeld, deputy director at the Space Telescope Science Institute. 'Exploration is nothing if not the articulation of a great story.'
The story begins with why Nasa would want to go to an asteroid. The agency has sent small spacecraft off to study asteroids over the years and even landed on one in 2001. Just last week, a space probe began orbiting a huge asteroid called Vesta, which lies beyond Mars. Scientifically, an asteroid is a remnant from the birth of the solar system, offering clues about how our planetary system began.
Logistically, Nasa wants to go to Mars, but that is distant and more difficult. So the argument is that going to an asteroid is a better testing ground than returning to the moon.
The reason Nasa Administrator Charles Bolden and others give is that this mission could save civilisation. Every 100million years or so an asteroid six-miles wide - the type that killed off the dinosaurs - smacks Earth, said Nasa Near Earth Object program manager Donald Yeomans.
If Nasa can get astronauts to an asteroid, they can figure out a way of changing a potential killer's orbit. They'll experiment with the safe one they land on, Mr Braun said.Getting to an asteroid will be tough - huge powerful rockets are needed to launch spacecraft and parts out of Earth orbit.Nasa promises to announce its design idea for these rockets by the end of the summer and Congress has ordered that they be built by 2016.It will take two or three or maybe even more launches of these unnamed rockets to get all the needed parts into space.
The crew capsule is the farthest along - with $5billion already spent - because Nasa is using the Orion crew ship it was already designing for the now dead moon mission and repurposing it for deep space.
Once in space, the ship needs a propulsion system to get it to the asteroid. One way is to use traditional chemical propulsion, but that would require carrying lots of hard-to-store fuel and creation of a new storage system, Mr Joosten said.
Another way is to use ion propulsion, which is efficient and requires less fuel, but it is enormously slow to rev up and gain speed. It would also require an electrical ignition source, thus the giant solar power wings.
If Nasa goes to ion propulsion, the best bet would be to start the bulk of the ship on a trip to and around the moon without astronauts. That would take a while, but if no one is on it, it doesn't matter, Mr Joosten said.
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