Astro Watch

Roscosmos Suspends Dnepr Carrier Rocket Project Posted: 03 Feb 2015 04:41 AM PST The launches of Russian-Ukrainian conversion-based Dnepr carrier rockers within the Cosmotras international program have been suspended, Russia’s Federal Space Agency (Roscosmos) said on Monday. "Now the project for the launch of Dnepr carrier rockets has been suspended. The prospects of this program will be determined later," Roscosmos said. Сosmotras declined to comment on the statement.  Previous reports said two launches of Dnepr carrier rockets were planned for 2015. The previous launch of a Dnepr rocket took place in November 2014. A carrier rocket launched under the Dnepr program in June last year put a record 34 satellites into orbit for customers from 17 countries.  Dnepr is a three-stage liquid propellant rocket. Its first and second stages are standard stages of the inter-continental ballistic rocket RS-20 (SS-18 Satan). The Cosmotras company is responsible for converting the RS-20B rockets originally developed in Dnipropetrovsk, Ukraine, into the Dnepr space rocket.  It is launched either from the Baikonur space site in Kazakhstan or from the Yasny space facility in the Orenburg region in the south Urals. Credit: TASS

R.I.P. Venus Express: Remembering Eight Years on the Brink of Hell Posted: 02 Feb 2015 03:19 PM PST It was a hell of a ride to our hellish sister planet. Eight long years of studying Venus is way more than ESA scientists were expected from its mission. Venus Express spacecraft that launched on Nov. 9, 2005 and entered the orbit of its target planet on Apr. 11, 2006, was originally planned to last for 500 days. The mission was successfully extended three times and ended in slow death while entering Venusian hostile atmosphere this January. “Venus Express fulfilled its original overall goals, gathered most expected data, and in fact could accomplish its objectives beyond what was originally thought by exceeding its nominal mission several times,” Patrick Martin, ESA Venus Express mission manager told astrowatch.net. “It did much more than what it was planned for thanks to both a very robust spacecraft and very professional operations teams.” Welcome to hell Venus, one of the solar system's most inhospitable planets is a hellish place of high temperatures and crushing air pressure. The planet’s surface temperature of over 450°C, hot enough to melt lead and atmospheric pressure 92 times greater than Earth's, caused that earlier probes have lasted little more than two hours. But even though the conditions on the surface of Venus are extremely inhospitable today, it may once had a lot of water in the atmosphere, which is now mostly gone, and possibly even oceans of water like Earth’s. “Venus evolution towards a kind of inferno for life is still not fully understood. How a planet so similar to the Earth in many areas, with relatively similar distance to the sun has become such an inhospitable planet?” said Håkan Svedhem, ESA Venus Express project scientist. “This is the kind of science that Venus Express has been doing and we have been happy to have learned about our neighbor planet and uncovered some of its mysteries.” “This mission was a challenge for the main teams involved: the scientific, the planning and the operations teams, especially in what concerns the thermal constraints often brought close to its limits putting a continuous pressure over the teams and the spacecraft,” Svedhem added. Eight years of science Since its arrival at Venus in 2006, Venus Express had been on an elliptical 24‑hour orbit, traveling 66,000 km above the south pole at its furthest point and to within 200 km over the north pole on its closest approach, conducting a detailed study of the planet and its atmosphere. “For over 8 years in Venus orbit, Venus Express carried out a detailed study of the planet and its atmosphere with a very comprehensive set of instruments. The spacecraft and payload provided major results on the atmosphere and ionosphere, with also important conclusions about its surface,” Martin said. “It found the planet may still be geologically active, with lava flows likely created no more than 2.5 million years ago and possibly even younger. Amounts of hydrogen and deuterium in the atmosphere suggested that Venus once had a lot of water in its atmosphere.” Martin revealed that the most surprising discovery for him is the “super-rotating” atmosphere of Venus: “Other findings indicated that the planet continues to lose parts of its upper atmosphere to space, and that the ‘super-rotating’ atmosphere has seen wind speeds increasing from 300 km/h to 400 km/h over the last six Earth years.” Immediately after arriving at Venus in 2006, the spacecraft recorded a significant increase in the average density of sulphur dioxide in the upper atmosphere, followed by a sharp decrease. One possibility is that the dramatic swing in atmospheric composition was caused by buoyant plumes of volcanic gases released by a large eruption and floating upward. This is one of the major discoveries made by Venus Express. “This long mission around Venus has permitted not only a unique invaluable collection of scientific data but also long-term statistics about the planet's behavior and evolution,” Svedhem said. A cherry on the cake After eight years in orbit and with propellant for its propulsion system running low, Venus Express was tasked in mid-2014 with a daring aerobraking campaign, during which it dipped progressively lower into the atmosphere on its closest approaches to the planet. “This mission was essentially run flawlessly throughout its lifetime, and the only thing serious that happened to it was the lack of propellant to complete the raising of the orbit in November 2014, which led to the end of mission operations,” Martin said. “With just a little more fuel, the mission could obviously have gone further in 2015, but having been able to perform the aerobraking last Summer was really the ‘cherry on the cake’ for this mission.” Svedhem admits that at a certain point and after doing some aerodrag experiments, the mission team was confronted with the possibility to do aerobraking operations to lower the orbit apocenter and thus reduce the effect of the sun which required frequent, highly consuming propellant maneuvers. It was finally decided to leave it as an experiment towards the end of the mission since the spacecraft was not fully designed to withstand the high temperatures caused by the friction with the atmosphere. “The opportunity came finally in 2014 when the propellant estimation was predicting the end of its life. The aerobraking experiment provided not only a unique opportunity to explore the unknown atmosphere and altitude around 130 km but a European premiere to do aerobraking at a planet different from Earth,” Svedhem said. Venus Express aerobraking operations were successfully executed from June 18 to July 11, 2014. After some internal discussions, the mission team and the ESA management had to make the choice between leaving the spacecraft go into the atmosphere or make a last maneuver attempt to raise the percenter with the propellant left and get a final bonus of science towards the end of 2014. The spacecraft ran out of propellant and went to safe mode on Nov. 27. From that moment, it managed to get enough energy from the Sun to show that it was alive by sending a signal that has been detected by ESA and NASA ground stations. The last signal was detected on 18 January 2015. “We believe that the spacecraft is just about to enter into the atmosphere like a hero, holding its last breath down through its final atmosphere crossing,” Svedhem remarked. Venus in the spotlight The analysis of the data collected will continue being subject of study for the scientific community and will remain a reference for planetary science for many years to come. ESA scientists underline that Venus Express has not only been a successful scientific mission but has permitted the operations teams to develop innovative processes looking at the future. “As an example it is worth mentioning the full operations automation for the last two years of the mission, the provision of almost real time web data analysis tools for anomaly investigation or its efficient planning concepts being partially re-used for the Rosetta mission,” Svedhem said. There may most likely be Venus-related mission proposals for the ESA's M4 selection this year, which is the next medium-size mission to be selected. “However, there is no guarantee that Venus will get the winning ticket!” Martin said.

Iran Launches Fajr Satellite into Orbit Posted: 02 Feb 2015 01:28 PM PST The Fajr (Dawn) satellite, completely built by Iranian scientists, was launched Monday - on the second day of the national ceremonies marking the 36th anniversary of the victory of the Islamic Revolution in Iran (1979). Iranian Defense Minister Brigadier General Hossein Dehqan felicitated the Iranian government and nation on the successful launch and orbiting of the satellite, but did not provide any further details. The fully home-grown satellite which has been built by experts at the defense ministry's Aerospace Industries Organization proves the Islamic Republic of Iran's high capabilities to launch satellites into orbit, General Dehqan said. "It is also another indicator of the country's flourishing scientific growth in the state-of-the-art technologies," he added. The Iranian satellite was sent into the orbit - at the altitude of 450km - on the back of the home-made Safir-e Fajr launcher. The satellite made its first contact with its ground stations hours after it was put into the orbit, director of space projects at Iran Electronics Industries company, Mehdi Sarvi, told IRNA. “We should wait for Fajr satellite to complete its next missions,” he added. Iranian President Hassan Rouhani congratulated the nation the successful launch of Fajr satellite and said the Iranian scientists have entered a new phase in space sciences. “Thank God, today Fajr National Satellite was launched into space by domestic launcher named Safir-e-Fajr,” he said. Iranian Vice-President for Science and Technology Sorena Sattari announced on Sunday the country's plans to orbit a new home-made satellite. "We will launch a satellite this week," Sattari said in Tehran without revealing any further detail or the exact launch date. Safir-e Fajr rocket on the launch pad. Credit: iribnews.ir In October, Deputy Head of Iran Space Agency (ISA) Hamid Fazeli announced that Tehran was preparing to orbit three new home-made satellites, called Zafar (Triumph), Tolou (Sunrise) and Pars, from more powerful launchers and on the back of bigger carriers in the near future. "Launching the under-construction satellites, including Sharifsat and Nahid, are also among the short-term plans of the ISA," he added. Also, Iranian Vice-President for Executive Affairs Mohammad Shariatmadari told reporters in the same month that Iran hoped that its Sharifsat satellite would be sent into orbit this year. Fazeli had announced in May that Iran planned to launch three home-made monitoring satellites into orbit in the next Iranian calendar year (March 2015-March 2016). "Zafar, Tolou and AUT Sat will be sent into space onboard the Simorq satellite carrier," he said. Fazeli noted that the satellites would transmit images of the Earth's surface to ground stations. Zafar will be sent into a geostationary orbit, which is a circular orbit around 36,000 kilometers (22,320 miles) above the Earth's equator. The satellite will reportedly have a lifespan of one year and six months, and will capture images and transmit them to stations on earth. Tolou satellite will also carry out remote sensing and topography missions, and will travel in an orbit of 500 kilometers above from the Earth’s equator. Credit: farsnews.com, presstv.ir