Tag: spaceflight

The discovery of volcanoes on Io

12:39 pm

discovery image

On March 8, 1979, as Voyager 1 was speeding away from Jupiter after its historic flyby of the gas giant three days earlier, it looked back at the planet and took some navigational images. Linda Morabito, one of the engineers in charge of using these navigational images to make sure the spacecraft was on its planned course, took one look at the image on the right, an overexposed image of the moon Io, and decided that it had captured something very unusual. On the limb of the moon was this strange shape that at first glance looked like another moon partly hidden behind Io. She and her fellow engineers immediately realized that this was not possible, and that the object was probably a plume coming up from the surface of Io. To their glee, they had taken the first image of an eruption of active volcano on another world!

Today, on the astro-ph preprint website, Morabito has published a minute-by-minute account of that discovery. It makes for fascinating reading, partly because the discovery was so exciting and unique, partly because it illustrated starkly the human nature of science research, and partly because of the amazing circumstances of that discovery. Only one week before, scientists has predicted active volcanism on Io in a paper published in the journal Science. To quote her abstract:
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Sierra Nevada is moving its mini-shuttle, Dream Chaser, into its own facility.

8:43 am

Sierra Nevada is moving its mini-shuttle, Dream Chaser, into its own facility.

This article isn’t really as positive as I’d like. For one, they haven’t even signed the lease for the building. Instead, it appears that the company is using this announcement, and the subsequent media coverage, to pressure the local city council to provide them subsidies. For another, the article mentions that drop tests of Dream Chaser will occur next spring, a significant delay from previous announcements. Both points make things appear far more tenuous than they should be.

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For the second time, a Progress freighter has launched and, after only four orbits, docked with ISS.

9:09 am

For the second time, a Progress freighter has launched and, after only four orbits, docked with ISS.

This was the fourth Progress launched this year, the second to follow an abbreviated four-orbit rendezvous with the space station. Russian flight controllers normally implement two-day rendezvous profiles, but they are perfecting procedures for single-day flights for possible use with manned Soyuz missions to shorten the time crews are forced to spend in the cramped ferry craft.

The Russians have used the leisurely two-day rendezvous path now for almost a half century. So, why are they suddenly trying to shorten the travel time to ISS to six hours? Though there are many good engineering reasons, I also suspect it is because they are now feeling the pressure of competition. The shorter travel time probably lowers their costs at mission control. It also makes using the Soyuz for manned flights more appealing. Dragon for example is presently using the two-day rendezvous path. And Dragon will soon become a direct competitor to Soyuz, when it begins flying humans in the next three to five years.

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The first results from Curiosity’s soil samples have come back.

1:38 pm

The first results from Curiosity’s soil samples have come back.

“Much of Mars is covered with dust, and we had an incomplete understanding of its mineralogy,” said David Bish, CheMin co-investigator with Indiana University in Bloomington. “We now know it is mineralogically similar to basaltic material, with significant amounts of feldspar, pyroxene and olivine, which was not unexpected. Roughly half the soil is non-crystalline material, such as volcanic glass or products from weathering of the glass. ”

Bish said, “So far, the materials Curiosity has analyzed are consistent with our initial ideas of the deposits in Gale Crater recording a transition through time from a wet to dry environment. The ancient rocks, such as the conglomerates, suggest flowing water, while the minerals in the younger soil are consistent with limited interaction with water.” [emphasis mine]

These results suggest that there has been very little water on the Martian surface for a very long time. They do not, however, mean that there is no water there now.

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It appears that NASA is at the moment unconcerned should the investigation into the Falcon 9 engine failure on October 7 cause a delay in the next Dragon supply mission to ISS.

9:06 am

It appears that NASA is at the moment unconcerned should the investigation into the Falcon 9 engine failure on October 7 cause a delay in the next Dragon supply mission to ISS.

The supply cache delivered to the station in early to mid-2011 by the now-retired space shuttle placed the six-person orbiting science lab on a firm footing well into 2013, according to Mike Suffredini, NASA’s space station program manager. “The launch date itself, in January, is not really critical to the program from a supply standpoint,” Suffredini told an Oct. 26 news briefing. “So we have some flexibility.”

In the short run a delay here would not be critical. A long delay, which is unlikely, would however not be good for operations on the station, and illustrates why it is very important to get the Orbital Sciences’ Cygnus cargo capsule up an running as soon as possible.

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A spacewalk November 1 will attempt to find and repair a coolant leak that could force a power reduction at the station.

5:34 pm

Construction workers in space: A spacewalk November 1 will attempt to find and repair a coolant leak that could force a power reduction at the station.

A slight 1.5-pound-per-year leak in the channel 2B cooling system has been present since 2007 and during a shuttle visit last year, two spacewalking astronauts added eight pounds of ammonia to the reservoir to boost it back up to a full 55 pounds. The plan at that time was to top off the system every four years or so to “feed the leak,” replacing the lost ammonia as required.

But over the past few months, engineers saw the leak rate suddenly quadruple, either because something changed at the original leak site or, more likely, because another leak developed somewhere else in the system.

Whether the leakage was caused by space debris or a component failure of some sort is not yet known. But the result is: If the leak continues at its current rate, the coolant will drop below a 40-pound safety limit and the system will shut down by the end of the year or shortly thereafter, taking power channel 2B down with it. While the space station can operate without the full complement of power channels, the loss of channel 2B would force flight controllers to power down equipment, eliminating redundancy and reducing the amount of research the crews could carry out.

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On Wednesday Richard Branson told an audience of students in Poland that the first paid tourist flight of SpaceShipTwo is at least 12 to 18 months away.

6:30 pm

On Wednesday Richard Branson told an audience of students in Poland that the first paid tourist flight of SpaceShipTwo is at least 12 to 18 months away.

That seems about right. This gives them about a year of powered flight tests, all manned but with no paying customers, in order to make sure the system is save for customers.

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