RISAT-1 Launch

TV Coverage
Live Coverage of the Launch of the Radar Imaging Satellite (RISAT-1)
Image Credit: NDTV

The launch time is 0017 UTC, or 5:17 PM Phoenix time, Wednesday.

The on board computer has taken over the countdown.

T-minus 10 minutes.

Successful Launch.

Second stage has begun its burn.

All systems are nominal.

Third stage has ignited around 5 minutes into the flight.

At 9 minutes into the flight, the fourth stage has ignited.

18 minutes into the flight, separation of the satellite has been completed.

Congratulations to India.

TV Coverage
Live Coverage: T-Minus 5 Minutes
Image Credit: NDTV

TV Coverage
Ignition
Image Credit: Doordarshan News

TV Coverage
Live Coverage: Ascent
Image Credit: Doordarshan News

TV Coverage
4th Stage Burn
Image Credit: Doordarshan News

India to Launch Radar Imaging Satellite (RISAT-1)

RISAT-1
Indian Space Research Organization (ISRO) Prepares the Radar Imaging Satellite (RISAT-1)
Image Credit: ISRO

India is preparing to launch their Radar Imaging Satellite (RISAT-1) on Thursday at 5:45 AM local time (2345 UTC and 4:45 PM Phoenix time Wednesday).

RISAT-1 is the heaviest remote sensing spacecraft that ISRO has ever built, weighing almost 1,900 kilograms. RISAT-1 will employ synthetic aperture radar (SAR) in its research.

The spacecraft is headed for a polar orbit, 536 kilometers above the surface of the Earth.

ED: New launch time is 0017 UTC, or 5:17 PM Phoenix time, Wednesday.

Earth from the International Space Station

Video courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center
Compiled by Michael Clark @ EpicFutureSpace
Videographer for NSS Phoenix

Fobos-Grunt Re-enters Earth’s Atmosphere

The Russian Fobos-Grunt spacecraft, launched aboard a two-stage Zenit-2 rocket on 9 November 2011 from the Baikonur Cosmodrome in Kazakhstan, was planned to travel to the Martian moon Phobos, gather samples, and return to Earth. Instead, the rocket motor failed to ignite, and the probe was stranded in orbit.

The Russian Defense Ministry reported that the spacecraft re-entered over the southern Pacific ocean around 10:45 AM Phoenix time on Sunday, 15 January (1745 UTC). The site was 775 miles west of Wellington Island off the coast of Southern Chile. There have been no reports of sightings.

More Planets than Stars – But Axial Tilt is the Key to Life

Planets
There is an average of more than one planet per star in the Milky Way
Image Credit: NASA / ESA / ESO

With the forthcoming publication in the journal Nature on 12 January, it is estimated that there are more than 100 billion planets in our Milky Way galaxy. That means more than one planet per star, and results show that there are more rocky small Earth-like planets than giant Jupiter-size gas planets.

Most recent discoveries have come from the Kepler Observatory using transit observations. Some of the earliest confirmation of gas giants came from radial velocity Doppler observations.

The conclusions in the Nature article are based on micro-lensing studies.

Recent results from the Kepler Observatory have shown the existence of three small, rocky planets around the star KOI-961, a red dwarf. These three planets, named KOI-961.01, KOI-961.02 and KOI-961.03, are 0.78, 0.73 and 0.57 times the radius of Earth. The smallest is about the size of Mars (see below). Follow-up observations were made by the Palomar Observatory, near San Diego, and the Keck Observatory atop Mauna Kea in Hawaii.

KOI-961
Relative size of the three rocky planets around KOI-961
Image Credit: NASA / JPL-Caltech

Since it is now clear that rocky planets exist around millions, if not billions, of stars, the question arises as to whether there is life on them, and whether it may resemble life on Earth.

Whether a planet exists in the “Goldilocks” region around a star depends on many factors. Three factors include the type of star, how far away from the star the planet resides and the atmospheric pressure of the planet. A red dwarf, such as Gliese 581, means the planet has to be closer than the Earth to our Sun. A white hot star means the planet has to be farther away. And if the atmosphere is low, like Mars, or to high, like Venus, liquid water is not likely.

A fourth factor is axial tilt. If a planet has no axial tilt (the spin axis is perpendicular to the plane of its orbit around the star) then the polar regions freeze and the equatorial regions bake. There is little exchange between these regions due to atmospheric circulation. Axial tilt, such as the Earth has, allows distribution of heat between the equator and the poles.

Even if a planet has axial tilt, a recent study shows that interaction at a close distance (within the “Goldilocks” region) with red dwarf will eliminate axial tilt in less than 100 million years. Bacteria on Earth required 1,000 million years to evolve. Theoretically, a planet with no axial tilt could possess bands between the equator and the poles where liquid water would exist. But, it is quite possible the atmosphere would collapse, with gases being driven off into space at the very hot equator, and freezing solid on the ground at the poles. Such a possibility faces the planets around KOI 961.

Systems with stars like our Sun present better possibilities. The “Goldilocks” conditions exist much farther out, and axial tilt is eliminated much more slowly, as our Earth is witness. Systems such as Kepler-22b are good candidates.

The conclusion drawn from these studies is that systems similar to our Solar System present the best opportunities for life.

Hayabusa – Dust From Itokawa – III

The issue of the journal Science from 26 August 2011 vol 333 pp 1113-1131 has six articles on the Hayabusa sample return mission from the asteroid Itokawa. The first article is discussed here, the second here, and this is the third:

Neutron Activation Analysis of a Particle from Asteroid Itokawa

A single grain from the Hayabusa mission has been analyzed by instrumental neutron activation analysis (INAA). The grain was mainly olivine, with minor amounts of plagioclase, troilite and metal.

This grain was one of the largest returned by the Hayabusa mission. The scanning electron microprobe (SEM) results show this to be a large crystal of olivine. Small pieces of silicate were attached to the surface. Radioactive analysis indicates that the grain is relatively homogeneous.

Comparison of the INAA analysis of this grain from Itokawa with from an LL6 chondrite (St Severin) and an L6 chondrite (Modoc) indicated an elemental abundance discrepancy.

Iron (Fe) and Scandium (Sc) abundance can be determined reliably, and the ratio is determined by the differentiation of iron into the core of a body during its formation. In particular, the Fe/Sc ratios from the Earth, Moon, Mars and 4Vesta are lower than those of chondrites. The ratios from Itokawa are higher than those from terrestrial olivine, and are thus from an extraterrestrial origin. This increases confidence that Hayabusa did return samples from Itokawa.

Nickel (Ni) and Cobalt (Co) typically diffuse into a metal phase. The ratio of Ni/Co in bulk chondrites plot along a line with carbonaceous chondrites. Samples from the Earth’s crust are relatively depleted in Nickel compared to Cobalt, and thus are distinguished from the grain returned from Itokawa.

In addition, Iridium (Ir) abundances were estimated, and the result indicates that the sample must have condensed from a fractionated nebula gas where refractory siderophiles such as Iridium had already condensed and been removed.

Hayabusa – Dust From Itokawa – II

The issue of the journal Science from 26 August 2011 vol 333 pp 1113-1131 has six articles on the Hayabusa sample return mission from the asteroid Itokawa. The first article is discussed here, and this is the second:

Oxygen Isotopic Compositions of Asteroidal Materials Returned from Itokawa

The first article in this series established that the major mineral assemblages of the asteroid Itokawa are olivine, pyroxene, plagioclase, iron sulfide and iron-nickel metal.

Minerals within bodies of the Solar System have unique oxygen isotope ratios, thought to be determined by gas-dust chemistry and accretion physics. However, the Earth and the Moon are the only bodies for which isotope ratios are known.

Twenty-eight (28) of the sample grains returned by Hayabusa were analyzed for oxygen isotope abundances. The ratios were compared to the ordinary chondrite meteorite Ensisheim (an LL-6 chondrite) and Earth minerals, and the uncertainty in measurements were calibrated against standard mean ocean water (SMOW) from Earth. The results show that the grains returned by Hayabusa are not of terrestrial origin. One of the Earth minerals was a fosterite crystal from San Carlos, Arizona.

Chondrites are classed as H, L or LL, and the samples from Itokawa are clearly L or LL and not H. The variation in ratios between samples indicates the degree of equilibration due to metamorphic heating. These data indicate that the samples from Itokawa experienced temperatures between 600 C and 720 C, which is lower than LL6 chondrites and higher than LL4 chondrites.

These results are consistent with those from those reported in the first paper and provide unequivocal evidence that ordinary chondrites come from S-Type asteroids.