Glenn
Schneider
Steward Observatory
University of Arizona
For background information on this unique opportunity: CLICK HERE
Eclipse Intercept Initiation - Second Contact Run@ 11:26:00 UT
One hundred seconds before second contact, at 11:26:00 U.T (gold circle), the Concord will complete a heading alignment change to a new heading of 112 degrees. This will alter its flight vector from its outbound course from Tenerife to prepare for second contact. Once on this heading the Concorde will fly through the second contact intercept (a distance of 61.6km in 100 seconds, see next panel) to the point of centerline run insertion at 11:30:50 UT (see third panel). A second heading change at that time (90 seconds after second contact to 66.6 degrees) will put the concord on the 1h05m long centerline run. The 4m50s second contact run should allow ample time to acquire the sun in photographic instruments before second contact. Remaining on this heading for an additional 190s (116.1 km) will allow observation and recording of post-second contact phenomena (edge prominences, chromospheric arc, etc.) before the required heading alignment change. |
ECLIPSE INTERCEPT START @ 11:26:00 UT CENTERLINE INSERTION INTERCEPT: 11:30:50 UT CONSTANT GROUND SPEED: 2200 KM/HR CONSTANT ALTITUDE AMSL: 60,000 ft. AIRCRAFT HEADING: 112 Degrees RUN START: 11:26:00 U.T. AIRCRAFT LATITUDE: 13.8235S AIRCRAFT LONGITUDE: 9.4486W TIME TO MID-ECLIPSE: -2390 seconds DIST TO MID-ECLIPSE: -1460.6 km SHADOW LATITUDE: 14.9267S SHADOW LONGITUDE: 9.0833W SHADOW WIDTH: 183.7 km SOLAR ALTITUDE: 47.8 degrees SOLAR AZIMUTH: 25.0 degrees AIRCRAFT HEADING: 112.0 degrees HOR. LOS ANGLE +3.0 degrees |
Second Contact @ 11:27:40 UT
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SECOND CONTACT @ 11:27:40 UT CENTERLINE INSERTION INTERCEPT: 11:30:50 UT CONSTANT GROUND SPEED: 2200 KM/HR CONSTANT ALTITUDE AMSL: 60,000 ft. AIRCRAFT HEADING: 112 Degrees CONTACT II: 11:27:40 U.T. AIRCRAFT LATITUDE: 14.0264S AIRCRAFT LONGITUDE: 8.9242W TIME TO MID-ECLIPSE: -2290 seconds DIST TO MID-ECLIPSE: -1399.4 km SHADOW LATITUDE: 14.6683S SHADOW LONGITUDE: 8.5050W SHADOW WIDTH: 184.7 km SOLAR ALTITUDE: 48.4 degrees SOLAR AZIMUTH: 22.3 degrees AIRCRAFT HEADING: 112.0 degrees HOR. LOS ANGLE +0.3 degrees |
Centerline Run Insertion - Completion @ 11:30:50 UT
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INSERTION + 10 SECONDS
MID-ECLIPSE INTERCEPT: 12:05:50 U.T, CONSTANT GROUND SPEED: 2200 KM/HR CONSTANT ALTITUDE AMSL: 60,000 ft. CLINE INTERCEPT + 10s: 11:31:00 U.T. AIRCRAFT LATITUDE: 14.3923S AIRCRAFT LONGITUDE: 7.8734W TIME TO MID-ECLIPSE: -2090 seconds DIST TO MID-ECLIPSE: -1277.2 km SHADOW LATITUDE: 14.1817S SHADOW LONGITUDE: 7.3750W SHADOW WIDTH: 186.7 km SOLAR ALTITUDE: 49.6 degrees SOLAR AZIMUTH: 21.6 degrees AIRCRAFT HEADING: 66.6 degrees HOR. LOS ANGLE +45.0 degrees |
Centerline Run Simulation
Click on the links to the right to view annimated simulations of the centerline run from insertion at 11:30:50 UT to mid-eclipse intercept at 12:05:50 U.T, and from mid-eclipse intercept to break-off at 12:35:50 U.T. Here, mid-eclipse refers to the time at which the Concorde is centrally located in the umbra, this is not temporally summetric with the start and and off the centerline run. |
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Centerline Run Termination @ 12:35:50 UT & Third Contact @ 12:38:40 UT
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THIRD CONTACT @ 12:38:40 UT CENTERLINE BREAK-OFF : 12:35:50 UT CONSTANT GROUND SPEED: 2200 KM/HR CONSTANT ALTITUDE AMSL: 60,000 ft. NEW AIRCRAFT HEADING: 39 Degrees CONTACT III: 12:38:40 U.T. AIRCRAFT LATITUDE: 10.4792S AIRCRAFT LONGITUDE: 14.2415E TIME TO MID-ECLIPSE: +1970 seconds DIST TO MID-ECLIPSE: +1203.9 km SHADOW LATITUDE: 11.0350S SHADOW LONGITUDE: 13.7883E SHADOW WIDTH: 192.7 km SOLAR ALTITUDE: 48.8 degrees SOLAR AZIMUTH: 327.0 degrees AIRCRAFT HEADING: 57.0 degrees HOR. LOS ANGLE +0.0 degrees |
ALTERNATE SCENARIO - Long Duration CIII Diamond Ring
A variation on the above theme with a planned mid-eclipse intercept a few minutes earlier (toward the west) can give rise to a contact 3 diamond ring of exceptionally long duration. Indeed, the duration of the CIII diamond ring can be tailored as desired, but traded off against time fully within the umbra. In designing such a plan we are still constrained by a viewing angle not to exceed 45 degrees from horizontal, and no intrusion of Angolan airspace. No graphics have been generated for this yet, but one proposition for a 4 minute long diamond ring is explained here.
A) Intercept centerline at ~ 11:30:50 as before, BUT with the aircraft slightly further down track (NE) at Latitude = 14.3520S, Longitude = 7.7787W. This is for a mid-eclipse intercept at 12:01:30UT (i.e., 1840 seconds, and 1124.4km after insertion onto centerline).
B) For a short while, as the shadow is moving faster than the aircraft, the Concorde will move westward with respect to the moving center of the shadow, but remain fully emmersed, until the umbral velocity drops to 2200 km/hour.
C) Mid-eclipse occurs at 12:01:30 with the aircraft and center of figure of the moon's shadow co-located at Latitude = 11.2550S, Longitude = 2.0833E, with the LOS to the sun +7.3 degrees and an altitude of 55.2 degrees.
D) Following this the aircraft, still overtaking the umbra begins to approach the edge of the shadow.
E) At ~ 12:28:50 U.T. the concord should decelerate from 2200 km./hr to 2131 km/hr over 10 seconds to reach this reduced speed at 12:29:00 U.T.
F) At 12:29:00 U.T., the aircraft will be at Longitude
= 11.2987E, Latitude = 10.7717S (1650 seconds, and 1008.3 km, past mid-eclipse)
and will experience third
contact while co-moving at exactly the velocity of
the umbral shadow. At a heading of 93.6 degrees the diamond ring
will be "frozen" in the sky.
G) From this point the topocentric lunar velocity will increase to 2199.3 km/second over the next 4 minutes (at 12:33:00 UT). By slowly increasing the aircraft ground speed by 68 km/hour over this 4 minute period the diamond ring will continue to remain frozen in the sky.
F) We can then continue on track for another two minutes
until 12:35:00 UT before executing a heading alignment maneuver to return
to Tenerife. At that time we will still be comfortably clear of the
Angolan coast by ~ 150 km.