Universe Today

November 9, 2007December 26, 2015 by Fraser Cain

Rosetta Is Returning to Earth for Another Flyby

Mark your calendars for November 13th, 2007. That’s the day ESA’s Rosetta spacecraft will be making a close encounter with Earth on its way to Comet 67/P Churyumov-Gerasimenko. What’s going on? The comet’s out there guys, why is Rosetta back home? Well, it’s all about speed.

Launching spacecraft is an energy intensive business. You can only get a spacecraft going so fast when it launches directly from Earth. But using a technique called gravity assist, spacecraft can use the gravity of a planet – such as the Earth – to get a speed boost. Most of the robotic explorers do it.

In order for Rosetta to make its encounter with Comet 67/P Churyumov-Gerasimenko in 2014, it needs to be going much faster. It already got a gravity assist from Earth back in March 4, 2005, and another with Mars on February 25, 2007. Now its time for a third on November 13. We won’t be done with Rosetta yet, either. The spacecraft is due to make a 4th and final flyby on November 13, 2009.

Before it returns for the 4th flyby, Rosetta will swing out across the asteroid belt and observe asteroid Lutetia, testing out its scientific equipment.

Finally, in 2014, Rosetta will reach Comet 67/P Churyumov-Gerasimenko and begin some serious investigations; even landing a probe down on its surface.

Original Source: ESA News Release

November 9, 2007December 26, 2015 by Fraser Cain

Station Astronauts Wrap Up Leftover Tasks

Although Discovery returned safely to Earth, there were still a few unfinished tasks. The astronauts on board the International Space Station picked up the torch, and wrapped them up in a 6.5 hour spacewalk on Friday. This helps prepare the station for the upcoming launch of Atlantis, to deliver the European Columbus module.

Discovery landed on Friday at the Kennedy Space Center in Florida, completing 15 days in space. In addition to bringing and installing the new Harmony module, the astronauts redeployed a solar array to a new location. And that’s where the problems happened. While they were unfolding the array, a guide wire was caught, and tore open a fold between solar panels.

The astronauts were were able to build “cufflinks” that reconnected the panels, but this additional spacewalk meant that other tasks couldn’t be performed.

The goal of Friday’s spacewalk was to wrap them up. Commander Peggy Whitson and cosmonaut Yuri Malenchenko went outside the station today to disconnect various electrical cables and stowing them away. Some route power to visiting shuttles the others connect the shuttle’s docking port to the Destiny laboratory.

On Monday, flight engineer Dan Tani will use the station’s robotic arm to move the shuttle’s docking port from its current location on Destiny over to the newly attached Harmony module.

And then on Wednesday, another spacewalk will move the Harmony node to its permanent location on the Destiny module.

Two additional spacewalks are planned to hook up power, cooling and data connections to the Harmony module.

This crew is going to be busy.

Original Source: NASA Station News

November 7, 2007December 26, 2015 by Fraser Cain

“Student Questions” for Astronomy Cast

If you’re a student or teacher, and you’re working through astronomy right now, we’d like to help you out. Pamela and I will be running a special edition of Astronomy Cast for high school students.
We’ll help you gather up all the astronomy questions from your class, and then we’ll do a special episode just for you, answering everything.

If you’re interested in participating, check out Pamela’s blog, where she explains things in more detail.

We’ll be announcing this in the podcast as well, but I just wanted to let you know here. A big thanks to NASAâ€™s Gamma-ray Large Area Space Telescope Education and Public Outreach program for sponsoring this.

November 7, 2007December 26, 2015 by Fraser Cain

Is China Building a Space Station?

There are mixed reports coming out of China on their plans to loft a space station by 2020. A Chinese aerospace engineer, Long Lehao, mentioned to journalists that the China National Space Administration was planning to build a “small-scale 20 tonne space workshop”. But then space officials at the agency denied the report. So what’s going on?

The Chinese official new agency Xinhua reported that Li Guoping, a spokesman for the agency said, “China at present has not decided on developing a space station.” That sounds like the possibility is still open, in my opinion.

China has mentioned in the past that they’d like to launch a space station of their own, some time in the next 10 to 15 years. But they never pinned down a specific date, like the 2020 goal announced by Long Lehao. If the agency does have a firm date, Lehao would know. He’s a leading designer for the Long March 3A, the rocket that carried China’s Chang’e-1 lunar satellite into space.

And speaking of Chang’e-1, this contradicting news arrives just as the spacecraft has entered lunar orbit. After a two-week journey to the Moon, the spacecraft performed an orbiting maneuver so perfectly that the agency thinks they’ve saved a bunch of fuel. This fuel should allow the spacecraft to orbit the Moon for longer, delaying the inevitable date when it crashes down.

The first photos from Chang’e-1 should arrive later this month. And by early next year, the probe will have measured the entire surface of the Moon at least once.

And just in case you’re hoping the spacecraft will be able to image the Apollo astronaut footprints, sorry, it doesn’t have the resolution. But I’ll bet it’ll be able to see the landers.

Original Source: Xinhua Article

November 7, 2007December 26, 2015 by Fraser Cain

Discovery Lands Safely in Florida

NASA’s space shuttle Discovery touched down in Florida today, landing at Kennedy Space Center, and wrapping up a successful assembly mission to the International Space Station. The shuttle’s wheels touched pavement at 1:01 p.m. EST, with Commander Pam Melroy and Pilot George Zamka at the controls.

During their 15 days in space, the crew of STS-120 covered more than 10 million km (6.2 million miles). They attached the newly delivered Harmony Node 2 module, and relocated P6 truss. During the construction, one of the station’s solar arrays was torn, and so the astronauts completed an extra spacewalk to repair the damage.

In addition to the crew members who flew to the station, Discovery was carrying a special guest back to Earth: astronaut Clay Anderson. He spent the last 5 months living and working on board the station, and required a special reclining chair during re-entry to get used to the strength of Earth’s gravity after so much time being weightless.

Despite the resourceful repairs to the station’s power generating solar array, NASA managers are concerned that construction on the station may lag. The problems during Discovery’s mission has delayed other work on the station, and now construction is nearly a work behind schedule. The other shuttle missions are crammed together so tightly that there’s hardly any slack time. An upcoming mission to launch the European Columbus module may be in jeopardy.

Another problem is the metal fragments discovered in a wheel that rotates the station’s solar arrays. Without them rotating to always face the Sun, the station won’t be able to generate enough power to accommodate a Japanese laboratory due to arrive in April, 2008.

The next mission – STS-122 – will bring the space shuttle Atlantis back to the International Space Station. It’ll be carrying the European Columbus laboratory. It’s scheduled to launch on December 6th, but could get pushed back.

Original Source: NASA’s Shuttle Blog

November 6, 2007December 26, 2015 by Fraser Cain

First Look at the Orion Crew Module

I know it seems like we’ve had the space shuttle forever, and will have it forever, but the program will actually be shut down in just a few short years. What comes next? The Constellation program will continue the US human spaceflight efforts, eventually bringing people back to the Moon. As part of the program, workers at NASA unveiled a mockup of the Orion crew module.

The lifesize Orion crew module was build by engineers at NASA’s Dryden Flight Research Center’s Fabrication Branch. No, this aluminum mockup won’t actually be flying. It won’t even be used for aerodynamic testing. It’s just going to help engineers figure out how to cram everything in.

As the engineers are developing the various avionics systems, instrumentation, wire harness routing, etc, they’ll want a life-size mockup of the module to test how things fit together. Eventually, you can imagine future astronauts crawling inside, and giving engineers their feedback on the placement of the instrumentation, the feel of the controls, and cushiness of the seats.

This mockup will help engineers until the first abort flight test vehicle, called “Boilerplate 1” arrives for testing. This next testing vehicle is a flying simulator that will mimic the flight characteristics of the actual vehicle. Boilerplate 1 will have the same mass, dimensions, and aerodynamic properties of the Orion capsule, so it can be tested in wind tunnels and atop rockets.

NASA is planning two pad abort, and four ascent tests of the launch abort system as early as 2008, and continuing on through 2011.

So, don’t worry, the age of the space shuttle is almost over, and the age of the Constellation program is almost here. Look out Moon, here we come.

Original Source: NASA Dryden News Release

November 6, 2007December 26, 2015 by Fraser Cain

Fifth Planet Found Orbiting 55 Cancri

Our Solar System has 8 planets, but another, 55 Cancri, is catching up fast. Astronomers today announced the discovery of a 5th planet in the system, located 41 light-years away. This newly discovered planet weighs in with 45 times the mass of the Earth, and might look similar to Saturn in composition and appearance. But the news gets better, it’s in the star’s habitable zone, and could have water-covered moons.

The discovery of a 5th planet around 55 Cancri was made by astronomers from UC Berkeley, and several other collaborating universities, with funding from NASA and the National Science Foundation. Their research will appear in an upcoming issue of the Astrophysical Journal.

Astronomers used the radial velocity technique to find the planets. This is where the velocity of the star is carefully measured. Periodic changes in this velocity mean that a large planet’s gravity is yanking the star back and forth. In this case, the discovery was even more difficult, because there were already known planets in the system, polluting the data.

“It is amazing to see our ability to detect extrasolar planets growing,” said Alan Stern, associate administrator for the Science Mission Directorate at NASA Headquarters, Washington. “We are finding solar systems with a richness of planets and a variety of planetary types comparable to our own.”

Perhaps the coolest part of this whole discovery: the planet orbits its parent star once every 260 days. This places it within its star’s habitability zone, where liquid water can be present. It’s a little closer than our Earth is to the Sun, but its star is also a little fainter, so it all evens out.

Obviously, this rules out the planet itself, but it could have a collection of moons, just like Saturn. Instead of Saturn’s icy moons, this 5th planet of 55 Cancri could have ocean moons.

Finding this planet was an enormous challenge. The discoverers have been making observations of 55 Cancri for 18 years, before the first extra solar planets were ever found. They had to make more than 320 velocity measurements to disentangle the 5 planets from the data.

Original Source: NASA/JPL News Release

November 6, 2007December 26, 2015 by Fraser Cain

Astrosphere for November 6th, 2007

For the photo… it’s Comet Holmes! I know, a big surprise, but I’m going to keep on hitting you with cool Holmes pics until it starts to fade. This one comes from tegwilym on the forum.

ESA has an interesting article about the different ways they peer at stars through planetary atmospheres.

astropixie Amanda Bauer took these amazing photos from the summit of Hawaii’s Mauna Kea, and talks about her experience viewing for Comet Holmes.

Alan Boyle explains why it’s hard to know when a volcano is going to explode.

Astronomy.com’s blog reviews Brave New Words, the Oxford Dictionary of Science Fiction.

A little bit of good news to an otherwise depressing view of global warming. Heat-trapping cirrus clouds may be disappearing as temperatures rise.

In case you missed it, the DARPA Urban Challenge was won by Carnegie Mellon University’s SUV, “Boss”. I want my robot car!

November 6, 2007December 26, 2015 by Fraser Cain

Podcast: Saturn’s Moons

We know that delaying this show one more week would be too dangerous, so here you go: Saturn’s moons. These are some of the most interesting objects in the Solar System, from the spongy Hyperion, to the geysers on Enceladus, to the rainy, misty, oceany Titan. They’ve kept Cassini busy for years, and scientists will likely be pondering them for decades.
Click here to download the episode

Saturn’s Moons – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

November 5, 2007December 26, 2015 by Fraser Cain

Chang’e-1 Enters Lunar Orbit

Chinese space officials announced that their Chang’e-1 spacecraft entered lunar orbit on Monday, completing a new milestone in the country’s goals of space exploration. The spacecraft is scheduled to begin scanning the lunar surface on Wednesday, but first, it has to complete two additional braking maneuvers.

Mission controllers gave the command at 11:15 local time from the Beijing Aerospace Control Center (BACC) for Chang’e-1 to make its braking maneuver – when it was 300 km from the Moon. It completed the maneuver 22 minutes later, entering a true circumlunar orbit.

This braking maneuver was critical. If it braked too early, the probe wouldn’t have been captured by the Moon’s gravity, and it would have drifted off into space. If it braked too late, it would have just crashed onto the lunar surface.

The spacecraft’s speed was slowed from 2.3 km/second to 1.9 km/second. It’s now traveling in a 12-hour elliptical orbit around the Moon, getting as close as 200 km above the surface, and then swinging out to 8,600 km.

Two more braking maneuvers are planned to lower its orbit; one on November 6th, and another on the 7th. When it’s all said and done, Chang’e-1 will be going a mere 1.59 km/second, in a 127-minute orbit. It will then begin its science operations.

If all goes well, Chang’e-1 will provide detailed images and data on the lunar surface. China has announced their plans to send a robotic lander to the Moon by 2012 years, and humans within 15 years.

It should remain in lunar orbit for about a year.

Original Source: Xinhua News Release