Comet on 26 October 2015 (b) – NavCam

This single frame Rosetta navigation camera image of Comet 67P/Churyumov-Gerasimenko was taken on 26 October 2015 from a distance of 310.4 km from the comet centre. The image has a resolution of 26.5 m/pixel and measures 27.1 km across.

The original image and more information is available on the blog: CometWatch 26 October – 6 hours apart

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Proposed 50-54 MHz Agenda Item for WRC-19

Logo WRC RA 2015Details have been released by Ofcom of the UK positions for WRC-15 which takes place in Geneva, November 2-27, 2015.

Ofcom’s statement references the document containing the European Common Proposals for agenda items for the next conference, WRC-19. One proposal is EUR-A25-2 – Primary allocation of the band 50-54 MHz to the Amateur Service in Region 1. The inclusion of this proposal is very welcome since it would facilitate further worldwide harmonization.

Although the proposal only references the Amateur Service such an allocation would be of great benefit to the Amateur Satellite Service.

A 50 MHz Amateur Satellite allocation would offer:
• low Doppler shift
• good link budget requirements
• relieve pressure on the only existing VHF amateur satellite allocation on 145 MHz.

Doppler
A 50 MHz signal from a satellite in an 800 km orbit would have a Doppler shift of +/-1.1 kHz during a 15 minute pass compared with +/-3.27 kHz at 145 MHz greatly easing tuning requirements.

Link Budget
The free space path loss at 50 MHz would be 9.2 dB lower than on 145 MHz. A low path loss is particularly important for small satellites with a limited power budget such as CubeSats or PocketQubes. These satellites may be just 10x10x10 cm or smaller and the limited surface area restricts the amount of solar power than can be generated. Typical transmitter output powers range between 100 mW and 400 mW. This power might be shared by a beacon and up to 5 SSB stations in the transponder passband, giving maybe 50 mw per station. Because of their size these satellites have to use simple omni-directional antennas such as a dipole or monopole

Satellite antennas for this band will need to be kept to a manageable size, this will help drive experimentation and innovation in antenna design for these frequencies. Where the band is used as a satellite uplink there is no need to utilize a full size antenna.

The low path loss of this band could facilitate the development of compact rapid deployment satellite ground stations utilizing omni-directional antennas for emergency communication scenarios.

Relieve Congestion
The existing satellite segment at 145.8-146.0 MHz is already congested with satellite downlinks. Most frequencies are already in use by four or more satellites. An additional VHF allocation would relieve the pressure.

ITU Footnote 5.282
This footnote currently covers the Amateur Satellite Service UHF and Microwave allocations between 435 MHz and 6 GHz.
It would be desirable if the footnote could be expanded to include operation in 50-51 MHz.
http://life.itu.int/radioclub/rr/arsfoot.htm

Read the European Common Position on Agenda Item 10

Ofcom statement http://stakeholders.ofcom.org.uk/binaries/consultations/wrc15/statement/UK_Positions_for_WRC-15.pdf

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Alignment test on LISA Pathfinder

LISA Pathfinder is being prepared for launch in the payload integration building, at the Centre Spatial Guyanais in Kourou, French Guiaia. Engineers are setting up alignment equipment around the spacecraft. The low-gain antennas of the Telemetry, Tracking and Command test can be seen with their anechoic caps.

LISA Pathfinder will test the fundamental technologies and instrumentation needed for such an observatory, demonstrating them for the first time in space. LISA Pathfinder is currently scheduled for launch with Arianespace flight VV06 – the sixth launch of Europe's small Vega launcher – on 2 December at 04:15:00 UTC.

Follow the team's preparations for launch

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Manicouagan Crater, Canada

This false-colour image featuring the Manicouagan Crater was captured by the Sentinel-1A satellite on 21 March.

Carved out by an asteroid strike some 214 million years ago, this crater in Quebec, Canada is known to be one of the oldest and largest impact craters on the planet. Experts believe that glaciers have since played a large part in its erosion.

Its concentric structure results from the shock waves transmitted by the impact. These somewhat resemble the rings that form when a pebble is dropped into water. So big and distinct, the crater can easily be observed from space.

The multiple-ring structure is some 100 km across, with the 70 km-diameter inner ring its most prominent feature. The annular Manicouagan Reservoir lake stretches more than 550 km from the source of its longest headstream.

This image was taken by Sentinel-1A, illuminating the landscape with horizontal and vertical radar pulses, from which the artificial colour composite was generated.

Diverse colours highlight variations of land cover. The varying tones of the same colour represent a difference in the land’s condition. Hence, while the blue tones represent bodies of ice and some water, the yellow and orange tones denote ageing vegetation of different types, mixed with patches of snow and ice.

Sentinel-1A satellite has been in orbit since 3 April 2014. It is a polar-orbiting, all-weather, day-and-night radar imaging mission for land and ocean services.

This image is also featured on the Earth from Space video programme.

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GSAT-15 begins the payload integration process for Arianespace’s next Ariane 5 mission

Preparations for Arianespace's sixth heavy-lift mission of 2015 have advanced into the payload integration phase, with the Indian GSAT-15 satellite passenger making its first contact with launcher hardware.

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GSAT-15 begins the payload integration process for Arianespace’s next Ariane 5 mission

Preparations for Arianespace's sixth heavy-lift mission of 2015 have advanced into the payload integration phase, with the Indian GSAT-15 satellite passenger making its first contact with launcher hardware.

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GSAT-15 begins the payload integration process for Arianespace’s next Ariane 5 mission

Preparations for Arianespace's sixth heavy-lift mission of 2015 have advanced into the payload integration phase, with the Indian GSAT-15 satellite passenger making its first contact with launcher hardware.

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Detailed information on the hunt for XO53

SSETI Express LogoFollowing on from the brief notes provided earlier, AMSAT-UK now have been given exclusive access to the full SSETI Express Phase E 400-800 THz Downlink Report. This report provides a clear insight into the work carried out during their recent campaign and to methods and equipment used.

It is worthy of note that ten years ago there was only one radio amateur in the launch team and that, since then, four of the other five team members have now obtained their licences.

Read the EXPRESS_E_ESA_2015-10-27_-_400-800_THz_Downlink_Report

As the report states, further observations will be much appreciated!

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Air Force announces winners of the 2015 Design Awards

The Air Force has announced the winners of the 2015 Air Force Design Awards. Eight projects were recognized for achieving excellence in design.

"These awards recognize the outstanding teamwork required to produce quality Air Force facilities, and the winning projects epitomize the skill and professionalism of our design teams," said Maj. Gen. Timothy Green, Air Force director of civil engineers.

The U.S. Air Force Design Awards program, established in 1976 and managed by the Air Force Civil Engineer Center, recognizes and promotes design excellence across the Air Force.
more...

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