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NASA’s Space Probe ‘Dawn’ To Return Due To Lack of Key Fuel

It has continued to gather high-resolution images, gamma ray and neutron spectra, infrared spectra and gravity data at Ceres.

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NASA, Hubble, Keplar, asteroids
Nasa's Opportunity rover might have 'died' on Mars. Flickr

After 11 years of gathering breathtaking imagery, and performing unprecedented feats of spacecraft engineering, Dawn — NASA’s space probe for the asteroid belt — is drawing to a close due to lack of a key fuel, the US space agency said.

Launched from Cape Canaveral Air Force Station in September 2007, Dawn was majorly tasked to study two of the three known protoplanets of the asteroid belt Vesta and Ceres, which when combined, make up 45 per cent of the mass of the main asteroid belt.

The spacecraft is likely to run out of a key fuel knwon as hydrazine — which keeps it oriented and in communication with Earth — between September and October.

When that happens, Dawn will lose its ability to communicate with Earth, but will remain in a silent orbit around Ceres for decades, NASA said in a statement late on Thursday.

“Not only did this spacecraft unlock scientific secrets at these two small but significant worlds, it was also the first spacecraft to visit and orbit bodies at two extraterrestrial destinations during its mission,” said Lori Glaze, acting director of the Planetary Science Division at Headquarters in Washington.

Dawn NASA. asteroid
Dawn will lose its ability to communicate with Earth, but will remain in a silent orbit around Ceres for decades. (IANS)

 

From 2011 to 2012, the spacecraft swept over Vesta, capturing images of craters, canyons and even mountains of this planet-like world.

Then in 2015, Dawn’s cameras spotted a cryovolcano and mysterious bright spots on Ceres, which scientists later found might be salt deposits produced by the exposure of briny liquid from Ceres’ interior.

“Dawn has shown us alien worlds that, for two centuries, were just pinpoints of light amidst the stars. And it has produced these richly detailed, intimate portraits and revealed exotic, mysterious landscapes unlike anything we’ve ever seen,” said Marc Rayman, Dawn’s mission director and chief engineer at NASA’s Jet Propulsion Laboratory, in California.

It has continued to gather high-resolution images, gamma ray and neutron spectra, infrared spectra and gravity data at Ceres.

Dawn NASA. asteroid
This colorful composite image from NASA’s Dawn mission shows the flow of material inside and outside a crater called Aelia on the giant asteroid Vesta. Flickr

 

Nearly once a day, Dawn will swoop over Ceres about 22 miles (35 kilometers) from its surface — only about three times the altitude of a passenger jet — gathering valuable data until it expends the last of the hydrazine that feeds thrusters controlling its orientation.

Also Read: NASA Rocket Launch Tests Supersonic Parachute for Mars Rover Landings

Engineers have designed Dawn’s final orbit, around Ceres, which has no atmosphere, to ensure it will not crash for at least 20 years — and likely decades longer, NASA said.

According to Rayman, Dawn’s is “an inert, celestial monument to human creativity and ingenuity.”(IANS)

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Human Sperm Retains Viability in Outer Space Conditions: Researchers

The study was presented at an annual meeting of European Society of Human Reproduction and Embryology in Vienna, Austria

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Each sperm has 37.5MB of DNA information in it.
Each sperm has 37.5MB of DNA information in it.

Researchers have found that human sperm retains its complete viability within the different gravitational conditions found in outer space.

The results could be a huge boost to zillionaires like Amazon founder Jeff Bezos who see the “colonisation” of space as an answer to the Earth’s ever threatened resources.

“If the number of space missions increases in the coming years, and are of longer duration, it is important to study the effects of long-term human exposure to space in order to face them,” said Montserrat Boada from Dexeus Women’s Health in Barcelona, whose group worked with microgravity engineers from the Polytechnic University of Barcelona.

“It’s not unreasonable to start thinking about the possibility of reproduction beyond the Earth,” Boada said.

The study was performed using a small aerobatic training aircraft (CAP10), which can provide short-duration hypogravity exposure.

The plane executed a series of 20 parabolic manoeuvres, providing eight seconds of microgravity for each parabola.

Overall, 10 sperm samples obtained from 10 healthy donors were analysed after exposure to the different microgravities found in space and ground gravity.

To overcome regulatory constraints and increase donor numbers, sperm banks in the UK and Australia began to market the act of donating sperm as a confirmation of masculinity. Pixabay

The sperm analysis comprised a full range of measurements currently performed for fertility testing — concentration, motility, vitality, morphology and DNA fragmentation — and results found no difference whatsoever in any of the parameters between the microgravity space samples and the control group samples from Earth.

Indeed, there was 100 per cent concordance in DNA fragmentation rate and vitality, and 90 per cent concordance in sperm concentration and motility, said Boada.

These minor differences, she added, “were more probably related to heterogeneity of the sperm sample than to the effect of exposure to different gravity conditions”.

Boada described this as a preliminary study and her group will now move on to validate the results and then to larger sperm samples, longer periods of microgravity and even fresh sperm.

Also Read: Xiaomi Confirms First Smartphones Under its New CC Series

One reason for using frozen sperm in this study was the known effect of radiation on fresh sperm, Boada noted.

“Radiation impairs the quality and viability of human sperm, and these effects are expected to be greater on fresh sperm than on frozen samples,” she said.

The study was presented at an annual meeting of European Society of Human Reproduction and Embryology in Vienna, Austria. (IANS)