OrbitalHub

A successful ten-second test firing of the Aerojet AJ26 engine was conducted at NASA\’s Stennis Space Center. The Aerojet AJ26 liquid fuel engine will power the first stage of the Orbital Sciences Corporation\’s Taurus II launch vehicle.

Read more about Orbital Sciences Corporation\’s Taurus II launch vehicle…

Credits: NASA

The Iridium satellite constellation, owned and operated by Iridium Communications Inc., is used to provide voice and data coverage over Earth’s entire surface.

Sixty-six satellites orbiting the Earth in low Earth orbit at 781 km altitude and 86.4 degrees inclination allow for pole-to-pole communication.

The Iridium modems deliver truly global communication capabilities. The solutions that incorporate the Iridium technology range from maritime voice terminals to vehicle tracking solutions. Most recently, we have seen them embedded in maritime robots like the iRobot seagliders collecting data in the Gulf of Mexico after the DeepWater Horizon accident.

Even if the majority of the applications are surface-to-surface communication, there have been attempts made to use the Iridium network for high-altitude communication. As such, weather balloons and sounding rockets have used the network to download data back to Earth.

A novel communication method for CUBESAT payloads using the Iridium network is proposed by Henric Boiardt and Christian Rodriguez from Florida International University for the PicoPanther payload, one of the entries in the Florida University Satellite competition.

The main challenges to overcome in order to adapt the Iridium technology to microsatellite communication in low Earth orbit are the miniaturization and the Doppler effects.

The CUBESAT standard was developed by California Polytechnic State University and Stanford. The standard specifies that one unit structure is a 10cm x 10cm x 10cm cube. This is quite a restrictive size-factor constraint.

The Doppler effects have to be considered due to the velocities at which the satellites operate in low Earth orbit. To minimize these effects, the microsatellite using the Iridium network to communicate with the ground station must have an orbit similar to the communication satellites in the network, which is a polar orbit. For the same reasons, Iridium itself supports inter-satellite links only between satellites orbiting in the same direction. Otherwise, the frequency shift due to orbital relative velocities would make communication unreliable.

If the proposed method is proven feasible, the Iridium network would definitely bring near-continuous communication to microsatellite technology.

On November 5, 2010, the fourth satellite of the COSMO-SkyMed constellation was placed into Earth orbit by an ULA Delta-II launch vehicle. COSMO-SkyMed is a constellation of four satellites equipped with X-band SAR (Synthetic Aperture Radar) technology. The satellites are able to monitor the Earth day and night, in all weather conditions. They are designed for military, civil, and commercial use. COSMO-SkyMed is the first Earth observation system fully designed and built in Italy.

Read the press release of the Italian Space Agency…

On October 30, 2010, the Progress M-08M cargo spacecraft docked to the Pirs Module at the International Space Station. The docking procedure was performed manually by Alexander Kaleri.

Read more about the International Space Station…

Credits: Mark Dowman

Airships are making a big comeback now as the energy consumption for all modes of transportation is being re-analyzed. Missions with special requirements like surveillance and reconnaissance missions and transportation of heavy payloads to remote outposts are the main driver for the reinvention of the airship.

But Earth is not the only place where airships can be deployed. There are a number of destinations in the solar system that would make a perfect environment for deployment and operation of airships, like Mars, Venus, and Titan – Saturn’s largest moon.

The presence of an atmosphere makes possible the use of vehicles that can fly within atmosphere for planetary exploration. Also, planetary exploration with low-powered vehicles like airships really makes sense considering the fact that energy is always at a premium.

So far, the only extraterrestrial deployment of an airship was performed during the Vega mission to Venus, in 1984. Two balloons were released and they floated 54 km above the planet’s surface for nearly two days.

Lighter-Than-Air (LTA) AERial ROBOTS (AEROBOTS) would present some advantages over their Heavier-Than-Air (HTA) siblings and the traditional planetary scouts, the exploration rovers: they would have long-duration mission and long-distance capabilities, they would not have to deal with obstacle avoidance problems, and they have low-power consumption. However, the environment in which the airship will operate will impose some restrictions on the capabilities of the airship (consider things like atmospheric composition and density, temperature, and the amount of solar radiation available). More on the planetary environments in the solar system and airship evaluations for each one of them can be found here.

NASA has funded a number of projects for solar system exploration that make use of aerobots. The Jet Propulsion Laboratory’s Planetary Aerobot Program is developing balloons to support scientific payloads in the atmosphere of other planets in our solar system. You can find more details about JPL’s Planetary Aerobot Program here.

On October 27,2010, a Soyuz-U launch vehicle lifted off from Baikonur Cosmodrome with Progress M-08M. The Progress cargo spacecraft is scheduled to dock at the International Space Station on Saturday, October 30, 2010.

Read more about the International Space Station…