Search Exo Cruiser

Nov 28, 2014

Count Down for Orion EFT-1 Starting

EFT-1 should launch about December 4th, 2014.

[The EFT-1 liftoff happened Dec. 5, 2014, 7:05 ET. There were three attempts to launch it Dec. 4th but unsuccessful, two first attempts were interrupted by winds and the last one by a train valve which did not work properly. Then the launch window closed and further attempts shifted to the next day.] 

Nov 25, 2014

MEOSAR Medium-altitude Earth Orbit Search and Rescue [Service]

The MEOSAR uses GNSS (Global Navigation Satellite System) satellites that are primarily used for positioning, navigation and timing. As a secondary mission, satellites in the USA GPS constellation, the European Galileo constellation and the Russian GLONASS constellation have Search and Rescue equipment on the satellites.

The current Low-altitude Earth Orbit Search and Rescue (LEOSAR) satellites are being replaced with a new Medium-altitude Earth Orbit Search and Rescue (MEOSAR) satellite system.

The MEOSAR system will detect beacons in almost real-time (i.e within 5 minutes). If the beacon is detected by three or more MEOSAR satellites, then the location of the beacon will be determined as well. When the full constellation of MEOSAR satellites is in operation, this will mean location will be determined within 10 minutes, 95 per cent of the time.

ACR personal locator with GPS
[GPS-based Distress radio beacons, registered:

The most modern 406 MHz beacons with GPS (US$ $300+ in 2010) track with a precision of 100 meters in the 70% of the world closest to the equator, and send a serial number so the responsible authority can look up phone numbers to notify the registrator (e.g. next-of-kin) in four minutes.

The GPS system permits stationary, wide-view geosynchronous communications satellites to enhance the doppler position received by low Earth orbit satellites. EPIRB beacons with built-in GPS are usually called GPIRBs, for GPS Position-Indicating Radio Beacon or Global Position-Indicating Radio Beacon.

However, rescue cannot begin until a doppler track is available. The COSPAS-SARSAT specifications say that a beacon location is not considered "resolved" unless at least two doppler tracks match or a doppler track confirms an encoded (GPS) track. One or more GPS tracks are not sufficient.]

The new MEOSAR satellites will be launched by the Russian Federation, the European Union and the USA. An operational constellation is expected to be in place by 2017.

The MEOSAR system consists of MEOSAR satellites that detect emergency distress beacons (EPIRBs, PLBs and ELTs). The satellite sends the beacon message back to earth where it is detected by a MEOLUT (MEOSAR Local User Terminal). With sufficient information, the MEOLUT will generate a location for the distress beacon. The beacon activation information is forwarded to a Mission Control Centre (MCC) and then to the relevant Rescue Coordination Centre (RCC) which responds to the beacon activation.

The three MEOSAR satellite constellations will use transparent repeater instruments to relay 406 MHz beacon signals, without on-board processing, data storage, or demodulation/remodulation. MEOSAR satellite providers will make their satellite downlinks available internationally for processing by MEOLUTs operated by MEOSAR ground segment participants.

MEOSAR search and rescue system components

How does MEOSAR work?

The above diagram shows the major components of the MEOSAR system:

1. A distress beacon is activated and sends a 406MHz message. The message includes the beacon id (also known as the Hex id or UIN). If the beacon has a GPS, the message will include the GPS location.

2. Any MEOSAR satellites that detect the distress beacon relay the message back to earth on 1544.1MHz. The relayed message is detected by a MEOLUT.

3. If a MEOLUT receives sufficient information (typically, relay from three or more MEOSAR satellites) a location for the beacon can be calculated. The MEOLUT sends all information available from the beacon (the beacon id, the GPS location if it exists and the MEOSAR location if it can be calculated) to its associated Mission Control Centre (MCC).

4. The MCC forwards beacon information to the relevant Rescue Coordination Centre (RCC). If the beacon was located in New Zealand, for example, the beacon information would be forwarded to the New Zealand RCC in Wellington. If the beacon as located in Australia, the information would be forwarded to RCC Australia in Canberra.

5. The RCC then coordinates the search and rescue associated with the beacon activation.




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Nov 23, 2014

Galileo Started Badly (August 22, 2014)

Europe's satellite navigation system Galileo's full operational capability (FOC) phase started badly (22.8.2014) due to a design error in the Russian launch vehicle Soyuz-STB Fregat-MT. This is the first partial failure since 2011 for the Soyuz vehicle and about 20 successful launches since the 2011 failure. The problem left the pair of satellites (FOC-1 and FOC-2) in the wrong orbit, with higher apogee, lower perigee and an incorrect inclination compared to the planned circular orbit (see below).

[News update Jan. 5, 2015: After some maneuvers the FOC-1 orbit could be fixed to some degree and the same recovery maneuvers are planned for the sixth satellite (FOC-2), taking it into the same orbital plane but on the opposite side of Earth. The decision whether to use the two satellites for Navigation and SAR purposes as part of the Galileo constellation will be taken by the European Commission based on the test results later.]

Galileo FOC-1 and FOC-2 orbit errors

“After launch, we quickly discovered that one of each satellite’s pair of solar wings had not deployed correctly,” says Liviu Stefanov, Spacecraft Operations Manager. “At the same time, difficulties in receiving radio signals – indicated by unusually low power and instability – alerted us to the fact that the orbits could be incorrect. Basically, the ground stations were pointing to where we expected the satellites to be, and they weren’t there, so we weren’t getting good signals.”

It took three days to release the trapped solar wing of the first satellite, and then two days later the second Galileo’s stuck array was also freed.

Galileo FOC Satellites

It was determined that the best course of action would be to dedicate most of the vehicle’s propellant to raising the perigee (lowest point) of the orbit from 13,713 to 17,339 Kilometers. Once in that orbit, the satellite would be out of the most intense areas of radiation. Although the two spacecraft will not reach  their nominal working orbit, “the new orbit will fly over the same location every 20 days,” said Daniel  Navarro-Reyes, ESA Galileo mission analyst. “The standard Galileo repeat pattern is every 10 days, so achieving this will synchronize the ground track with the rest of the Galileo satellites.”

Soyuz 2-1B, Galileo FOC-1 and 2 Launch, August 22, 2014

Galileo FM01 is a 733-kg (660 kg dry) navigation satellite, one of the first two Full Operational Capability (FOC) satellites. These satellites carry two rubidium and two hydrogen maser atomic clocks and broadcast on L-band. They also carry the MEOSAR search and rescue transponder payload. They are built by OHB (Bremen) with navigation payloads by SSTL (Guildford). The earlier IOV test satellites were partly owned by ESA, but the FOC satellites are owned by the European Union's GSA (Global Navigation Satellite Systems Agency).

The spacecraft were placed in a wrong orbit. As planned, the Fregat upper stage made its first burn to put both satellites into in elliptical transfer orbit and then made a second burn intended to circularize the orbit at 23,500 km, inclined at 55.0 degrees. Unfortunately, the orbit was 13,700 km x 25,900 km, inclined at 49.7 degres, more elliptical than planned and with the wrong orbital inclination.

Russian officials report that the failure of the Fregat stage was caused when a cryogenic helium line installed too close to a hydrazine propellant supply line caused the hydrazine to freeze. The root cause was a design error, not a quality control error.

On 22 August, at 12:27 GMT/14:27 CEST, a Soyuz rocket launched Europe’s fifth and six Galileo satellites from Europe's Spaceport in Kourou, French Guiana. Rewatch the moment of launch here.






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Nov 18, 2014

The Dornier Do. X

Dornier Do. X at the Bodensee (Lake Constance), at the left Dornier-Werke GmbH factory buildings at Altenrhein Switzerland near Austria-Germany-Switzerland border crossing