Tag Archives: rendezvous

67P from less than 200 miles

67P on August 3

Today’s Rosetta image of Comet 67P, shown above, gives us a different angle of the comet. The spacecraft was only 186 miles (300 kilometers) away when it snapped the picture, and this side view emphasizes the nucleus’s jagged shape.

I am reminded of what happens to a block of ice when you spray warm water on it. It begins to melt away, but very randomly and unevenly, producing very weird shapes and the surface evaporates off. In the case of Comet 67P, the nucleus is a dirty ball of ice, and the Sun’s rays have been causing its surface to evaporate off every time it approaches the Sun. Thus, we get a very weird shape.

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

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.

Using video game software, Surrey Satellite has devised a way for nanosatellites to seek each other out and then dock to form a larger satellite.

The competition heats up: Using video game software, Surrey Satellite has devised a way for nanosatellites to seek each other out and then dock to form a larger satellite.

If the STRaND-2 satellites are able to dock with one another, it opens up a whole new world of space engineering. Instead of building one large spacecraft, as in conventional satellite manufacturing, or using microsatellites flying in formation as is being developed currently, dockable satellites would be modular “space building blocks” according to [Surrey]. Satellites could be made as plug-and-play components that could be sent up in segments using smaller, cheaper rockets or piggybacked with other payloads and then linked together. This would not only be a cost savings, but would allow for much greater design flexibility. It would also make it much easier to repair, maintain, refuel or upgrade satellites. Today, a satellite with a failing power system is an expensive write off. Tomorrow, it would simply a matter of sending up a new power module.

Even the fight against space junk would benefit, since a dockable micro-satellite with a booster pack could easily dock with a dead satellite and either return it to the Earth’s atmosphere or out to a space disposal area.

Dragon has been approved to approach within one mile of ISS tonight in its first rendezvous test.

Dragon has been approved to approach within 1.5 miles of ISS tonight in its first rendezvous test. More information here.

If this goes well tonight, Dragon will next attempt to approach the station close enough for its robot arm to grab it.

NASA has announced a February 7 launch date for SpaceX’s next test flight of Falcon 9 and Dragon

NASA has announced a February 7 launch date for SpaceX’s next test flight of Falcon 9 and Dragon to ISS.

They also have approved allowing Dragon to do a test berth with ISS on this flight, assuming the first test approach goes well.