37
/ ' " ' J X I I • I ,. ·; - ) r / ,, I GSFG CONTROL l: C-ENTER I ( I N' OVEMBER ' 30, 1'969 I .... ---:--:----'---,-------'- GODDARD . SPACE FliGHT CENTIR GREENBELT, MD. / / Rob Mercer
/
' " ' J
X I
I • I
,. ·;
- )
r / ,,
I
GSFG OP~RATIONS, CONTROL l:C-ENTER
I ( I ~
N'OVEMBER ' 30, 1'969 I
....
---:--:----'---,-------'- GODDARD. SPACE FliGHT CENTIR GREENBELT, MD.
/
/
Rob Mer
cer
,;.
.. , ·:
1
{.
Re l ease l'Jo. 17 J une 4, 1 9GS
HOUSTO!'l, TEXAS -- Analysis by Norad Spadat computational
faciliti e s 1·evcals the follo-.ving earth sate llites we r e within
1000 km (about 600 miles ) of GT-4 Spacecraft at the time Ao tronaut
J ames l>lcDivitt :reported the eatollita a ighting:
Object I dentification
*Fragment
*Tank
*Fragment
Omicron 'l'ransit 411.
Omicx·on Tranoit 4l'•
*Fragment
Spadats Numb er
975
9 32
514
646
477
726
~Fragment 874
Omicron Transit 411. 124
10x20 Foot Debr in of Pegasu3 -- Shroud (A or B) not a \"'ork-ing part of Satellite 1305
Yo-Yo Dc-S~;>in
Weight- 2' to 3' 167
Di s tan ce Time {csrt fr om GT-4
2156 439
3 101 740
3:04 1';27
3 :06 905
3:07 979
3:09 62:)
3: 13 905
3:13 72~
3: 16 757
3 : 18 6 84
in Kilometers
Pegasus B at 3a06 (CST) was about 2000 k m i n t he pro~r direction t o
bo observed by tho aatronauts.
0 4 ' t o 6 ' i n l cn0tn duNn to 15~ in l ength , 2' to 6~ i n width, 15
I -
t
t
I I
I I
I
I
I I
Rob Mer
cer
·-·
-~--·-----.~...--.-.
. •' ·.~.
' .
-.. ---~--~---rr .......
... .
' ...
. !! II :I I
; l:'
I fl
.. ---.
-·-------------
uu M~©~~~ -t~GT~~~u
On J{mc 3, 1965, GT-4 Pilot Major James McDivitt and U.S. Major Space walker Edward While were launched into orbit from Cape Kennedy.
Edward White in the opening orbits got out of the GT-4 and wa~ed Uu·ough space for 20 minutes, twice
' as long as .i\lexei Lconov did for the USSR.
In a letter from Major McDivitt to Hayden .Hewes, dated .i\pril 22, 1965, Major l\fcDivilt relates that he has seen a great number of peculiar lights and objects in the skies at night and even· in the day. However, in almost every instance he was able to identify these objects. As for sighting an object ·that he {or certain identify the shape and size of and not be able to explain, "I'm afraid I just haven't seen this sort of thing," But he added "Ilowever, I know that there have been many reports of UFO's, and I just cannot speak for the other people."
Major .McDivitt sighted three objects while in space during the four day space flight.
McDivitt said the fi rst object was a cylindrical object sighted . over Hawaii. He look five frames oJ movie film of it, but officials said all it shows is a unidentifiable white dot with a tail of light and a fanlike glow. ·(cover photo)
The GT -4 went iJJto its 21st orbit at 6:55 p.m.
MsDivitt spotted the second object during the 20th orbit, as the Spaceship \V'l~ \Vh idinn <;l.f\~n.c-c fh~ J Tniinrl ~t.-,t.or
Gemini control asked McDivitt: "You still looking at that tlting up there?"
McDivitt replied: "I've lost it. It had big arms sticking out of it, it looked like." · He said he had only seen it for about a minute, and had taken pictures wilh a movie camera although the position of the sun prevented any recognizable photographs.
There was some speculation it was the Pegasus 2 meteoroid detection satellite launched lllay 25. 1965.
Space agency officials ordered ·an immediate <:heck by space tracking agencies to sec what the objects were.-
The Air Force tracking center at Colorado Springs, Colo., which keeps. track of man-made ob]ects in space is currently following 1,391 objects. Object No. 1,390 is GT-4 and object No_ 1,391 is its burned ·out second stage rocket booster.
The Pegasus 2 was about 1,200 miles from the GT-4. Dr. Dwayne Catterson, flight medical expert, said he did not know if an object within 1,200 miles could be identified by the human eye. "But certainly if the contrast was great enough between sunlight bn -the object and background he could see an object there and he might well see reflection giving shape from the arm."
The third sighting came on the 38 orbit, officiali! said McDivitt described the object which was siglitcd over
. China as looking like "a bright star moving fast." He did not attempt to make pictures of if. The spacb flight . took them G2 Urnes around tl!e globe, ~ *'"'*"' 1 ,.,~ ., t'f'lf) C'O .t ... .. a .... _
Rob Mer
cer
-
Public Affairs Office George C. Marshall Space F light Center National Aeronautics and Space Administration Marshall Space Flight Center, A labama
Phone: 453-0034, 453 - 0035 (Curtis Hunt - residence - 8 52 - 1763)
August 4 , 1969
IMMEDIATE RELEASE
R elease N o. 69 - 170
MARSHALL SPACE FLIGHT CENTER , Ala. --Pegasus C, the third
meteoroid technology satellite launched by a Saturn I rocket, has r eente red
the earth's atmosphere to end four years in orbit.
The North American A ir Defense Command (NORAD) reported tha t the
satellite r eentered at 2:04a.m . CDT over the Indian Ocean at 3. 4 degrees
nor th and 56.7 degrees east.
P egasus A and Pega s u s B a r e sti ll in earth orbit. T o free the radio
frequencies, all three had been " turned off" last yea r after serving their
purposes for more than double the de s ign lifetime.
The three satellites , mounted on the forward end of S-IV stages , were
launched b y the ·last three Saturn I rockets. They sent data back to earth
on meteoroids striking the detecto r panels of the 96 -foo t 11wings. 11
Pegasus C was still operable at the time of reentry. A command was
sent to the satellite a few hours before reentry which cau sed the beacon to
begin operating . At that time the batteries were still working. The beacon
was switched from batt eries to solar power and allowed t o oper ate until the
v ehicle was destroyed by reentry heat.
T he Pegasus s a tellites were developed under direction of the NASA-
Mar shall Spa ce Flight Center, the orga nization responsible also fo r
develo pment of the Saturn family of heavy launch v ehicles.
###
Rob Mer
cer
INTERNATIONAL
ASSOCIATION OJ" GEODESY
CENTRAL BUREAU FOR SATELLITE GEODESY
SMITHSONIAN ASTROPHYSICAL OBSERVATORY 60 GARDEN STREET
CAMBRIDGE, MASS. 02 138 U.S.A.
Major Hector Quintanilla, Jr. Wright-Patterson Air Force Base Project Blue Book FTD, TDEW/UFO Dayton, Ohio
Dear Major Quintanilla:
14 January 1966
In response to a request from Dr. J.Allen Hynek, of Dearborn Observatory, I am sending you a list of satellites (artificial) of visual magnitude 1.0 or brighter; the magnitudes are visual estimates by Moonwatch observers.
International Name designation
60 Iota l Echo l
64 04 A Echo 2
65 09 A Pegasus A 65 39 A Pegasus B 65 60 A Pegasus C 65 87 A Proton II
* = few observations
KLH/bhs cc:Mr.Martin
Mr.Hirst Mr.Rolff Dr.Hynek
SBADATS no. Maximum mv reported
49 +l
740 +0
1085 +1 1381 +1 1467 -1 1701 +1*
Rob Mer
cer
i
Star Ca talog 60 Garden Street Cambridge Massachusetts 02138
Dr.J.Allen Hynek Dearborn Observatory Evanston, Illinois
Dear Dr. Hynek:
-·
May 22, 1965
The information which you requested regarding sat.ellites with visual magnitudes of 3.0 or brighte r is given below. All are orbiting as of this date . Many of the s ate llites launched in 1965, however, have magnitudes estimated from only a few observat i ons, and thus for those objects, the magnitudes are to be considered less reliable.
International designation
'60 Epsilon 3 60 Zeta 1 60 Iota 1 60 Nu 2
61 Alpha l
62 Omicron 1 62 Beta -Alpha 62 Beta-Kappa 62 Beta-Tau 6
. 63003A 63027A 63030A 63042B 63047A 63049A
64004A 64004B 64005A 64030A
64050B 64053A 64074A 64076A 64080B 64084A
65004A 65006B 65009A 65009B · 65011D 65014A 65016C 65027A 65027C
Name
Fragment Sputnik 4 Midas 2 Echo 1 Rocket Courier lB
Sames 2
Ariel 2 Rocket Alouette
none Debris Injun 3
None None Dual Tetrahedron None Centaur 2 Rocket of an unnamed
Echo 2 Debris of Echo 2 Saturn 5 Star flash
Rocket Cosmos 42 Cosmos 44 S55C AD-1B Rocke t Cosmos 51 San Marco
Tires 9 Rocket Cosmos 53 Pegasus A Command Mod. Debris Cosmos 56 Cosmos 58 Grav .Grad .3 Snapshot Fragment EGRS 4
Spadata No.
36 43 49 59
70
285 426 444 520
527 613 622 682 694 703
Maximum magnitude reported
+3 +3 +0 +3
+3
+2 +3 +1 +3
+2 +2 +3 +3 +0 +3
-2 +0 -1
740 741 744 811 - - - ----·---··- +2 \--· 866 876 924 931 948 957 •
978 984 1085 1088 1092 1097 1292 1314 1316
+1 +1 +2 +3 +2 +2
-1.5 +2 +0 +1 +3 +2 +3 +3 +3
Rob Mer
cer
I 7 l I ""=' f '
OR 1317-~
Rob Mer
cer
...
DAYTON DAILY NB.,'S 24 Oct 66
Mysterious Balli ~space Junk'
By JACK JOXES, Daily 1'\Pws StaH W1·itcr
A mysterious hat·rl, metal sphere, found in a \Visconsin woods b.v a forest ran.u;er Oct. 13 has ber.n
· identif ied as space debris which re-enlerecl th e earth's atmosphere, Wright-Patterson Air Force base officials announced today.
Base officials woulc\ not hilmmer (ailerl to clrnt it and elaborate on the identity o( the object except to say that · a detailed analysis i~ now under way to determine its metallic composition.
THEY declined lo answcl' whether it was of Ru~sian or American origin.
The charred spherical object. slightly over one fool in diameter and weighing 29 pounds. was found by Wisconsin Slate Fot·est Ranger James A. Pietila in a woorted area near Tomahawk, Wis.
He gave the objeet to the Artigo Air Force ·station a t
· Antigo, Wis ., whic h shipped it to WPAFB.
Ul'\LESS designed to do so, ll is unusual for pieces of sr>ace boosters or their pay]o<~rls to r e-enter the earth's a tmosphl'rc withou t hurning up. lhc Air 1-'orce sai rl .
1\ ~r>okc~man <~l the Tomahawk r>ol ice station said the day aftet· the discovery that the object " s howed the effects of intense hea l , as though i t h ad come back through the earth's atmosphe.re."
He said hitting it with a
scrilping it with a file failed to scratch il.
' '11' WAS \ ·cry hnrrl ," he said, "it had lo come through the air."
Maj. P. G. Seoll of Anlio:o
AFS was unable lei identify the object.
He estimated the sphere harl been in the woods about I\\'O
weeks. He sairt it had printed numerals on the out.s.ide and was of a non-magnetic metal.
.1' I
Rob Mer
cer
VOLUNTEER FLIGHT OFFICER NETWORK SATELLITE RE-ENTRY Nffi.J"SLETTER December 8, 1969
Smithsonian Astrophys i cal Observatory 60 Garden Str eet, Cambridge, Ma. 0214f•
The information contained in this newsletter is printed primarily for the Flight Operations Department and Flight Personnel of VFON member airlines. This newsletter is also sent to research agencies making beneficial use of its contents. Pleas e advise this office of any needed fur ther distribution of this newsletter to other agencies that might likewise find the information useful.
CATALOG NUMBER 4129 1551 4060 3924 1376 1092 4059 4128 4099 3153 4219 4087 3868 3297 4253 4000 4136 2519 4108 3913 3404 3774 3846 3915 4198 0004 1965 2397 3114 3782
SATELLITE 1969-88B 1965-20CX 1969-64H 1969-21U 1965-21E 1965-llD 1969-64G 1969-88A 1969-64R 1968-20B 1969-96A 1969- 641 l969-29T 1968-52B 1969-102B 1969-56A 1969-90A 1966-97B 1969-64U 1969-29AE 1965-82NE 1969-20B 1969-31A 1969-41B 1969-82BM 1958-Alpha 1 1965-82HA 1966-74B 1968-0SB 1969-21E
SOURCE USSR USSR us
USSR us
USSR us
USSR us us
USSR us
USSR us
USSR us
USSR us us
USSR us
USSR USSR us us us us us us
USSR
NAME Intercosmos 1 Rocket Body Cosmos 61/62/63 Debris Inte1sat III F-S Debris Cosmos 269 Debris OPS lf7353 Debris Cosmos 54/55/56 Rocket Body Intelsat III F-5 Debris Intercosmos 1 Payload Intelsat III F-5 Debris OPS #7076 Payload Cosmos 308 Payload Intelsat III F-5 Debris "Meteor" Debris OPS #5259 Payload Cosmos 311 Rocket Body Biosat-D Payload Cosmos 303 Payload OV3-2 Rocket Body Intelsat III F-5 Debris ''Meteor" Debris Titan 3C-4 Debris Cosmos 268 Rocket Body Cosmos 275 Payload OPS #1721 Payload OPS /17613 Debris Explorer 1 Payload Titan 3C-4 Debris OPS #6810 Payload OPS #6236 Payload Cosmos 269 Debris
As of this date, the box scores in s pace are as follows:
Total objects now in space: 1836
Earth orbiting payloads Earth orbiting debris Space prob es Space debris
us 291
1072 18 27
1408
USSR 74
295 14
5 388
UK
3 0 0 Q 3
CANADA 3 0 0 Q 3
ESTIMATED DECAYED DATES Dec. 16, 1969 Dec. 19, 1969 Dec. 19, 1969 Dec. 23, 1969 Dec. 27, 1969 Dec. 28, 1969 Dec. 31, 1969 Dec. 31, 1969 Jan. 01, 1970 Jan. 03, 1970 Jan. 04, 1970 Jan. 10, 1970 Jan. 11, 1970 Jan. 12, 1970 Jan. 16, 1970 Jan . 18, 1970 Jan . 22, 1970 Jan. 23, 1970 Jan. 29, 1970 Jan. 30, 1970 Feb. 02, 1970 Feb. 03, 1970 Feb. 07, 1970 Feb. 10, 1970 Feb. 14, 1970 Feb. 18, 1970 Feb. 20, 1970 Feb. 21, 1970 Feb. 22, 1970 Feb. 23, 1970
FRANCE ESRO FED REP GERMANY 5 3 1
22 0 3 0 0 0
_Q 0 Q 27 3 4
Possible satellite re-entry or bright fireball sightings are immediately sent to the Smithsonian Astrophysical Observatory for processing. These repor t s are considered helpful toward improving our knowledge of the middle and l ower atmospheres, as well as other aspects of today's space development.
Steps should be taken to advise and assure all flight crew members that unidentified sightings, regardless of nature, the pilot reporting them, and the airline involved are all considered to be o! the utmost confidence. They are also considered to be of extreme importance to scientists associated with this project.
Rob Mer
cer
Fol101ving are satellites that have re-entered the earth's atmosphere, a continuation from the last list you r eceived .
CATALOG DATE LOCATION BALLISTIC NUMBER SATELLITE SOURCE NAME DECAYED TIME {GMT} RE-ENTRY {DEGREES} CO-EFFICIENT 3254 1963- 14BU us FTV Debris 11/02/69 4117 1969-83B us ESRO 1-B Rocket Body 11/03/69 0714 ±08min 02?6S 121~8W .03025 0922 1964-72A us OPS #3062 Payload 11/05/69 1452 !()9 min 54?2N 112:7W .01976 4182 1969-93A USSR Cosmos 306 Payload 11/05/69 4121 1969-25G us OUI - 18 Debris 11/06/69 4091 1969-64Q us Intelsat III F-5 Debris 11/08/69 4186 1969-95A us OPS #8455 Payload 11/08/69 3725 1969- 82RG us Titan 3C-4 Debris 11/11/69 1344 1965-20P USSR Cosmos 61 Debris 11/14/69 1659 1965-82W us Titan 3C-4 Debris 11/20/69 4223 1969-98A USSR Cosmos 309 Payload 11/20/69 4088 1969-64M us Intelsat III F-5 Debris 11/21/69 4224 1969-988 USSR Cosmos 309 Rocket Body 11/22/69 1855 i-23 min 38~1S 159:2E .006315 4114 1969-83A ESRO ESRO 1-B Payload 11/23/69 0952 ±Q3min 30~0N 342?0E . 01851 4232 1969-lOOA USSR Cosmos 310 Payload 11/23/69 4233 1969-100B USSR Cosmos 310 Rocket Body 11/23/69 0633 t()6min 11:3N 24?5E .01696 422 5 1969- 99A us Apollo 12 Payload 11/24/69 2058 4235 1969-98D USSR Cosmos 309 Debris 11/25/69 3799 1969-21G USSR Cosmos 269 Debris 11/26/69 4234 l969 -98C USSR Cosmos 309 Debris 11/26/69 4089 1969-64N us Intelsat III F-5 Debris 11/27/69 4236 1969-98E USSR Cosmos 309 Debris 11/30/69 1337 !()3min 43~6S 69:8E .010524 4001 1969-56B us Biosat-D Rocket Body 12/01/69 2303 t35aia 9:2N 72:3& .014o52 4076 1969-73A USSR Cosmos 295 Payload 12/01/69 1759 i12min 2?8N 107?5E .01226
Following are statistics compiled from the "Volunteer Flight Offi cer Network" proj ec t as of this da te:
Airlines participating Countries cooperating Total Flight crew members involved Total unduplicated air route miles Total reports ieceived
117 54
45,961 2,809,046
2,035
Broken down as Follows : 1,597 Bright fireball sightings
103 Reports of 41 different satellite re- entries 54 I nfrasonic sightings 46 Reports of cataloged and uncataloged debris
re-entries 69 Unidentified sightings 32 Reports now being processed 40 Reports that were sent in .as unknown and have
s ince been identified as : bright naked eye visible satellites; weather ballons; satellite launches; ballistic missiles in flight; and upper atmosphere rockets probes (cloud type) Ro
b Mer
cer
SMITHSONIAN ASTROPHYSICAL OBSERVATORY, CAMBRIDGE, MASSACHUSETTS 02138 EPHEMERIS VI
SHELLI TE 6605601 1966 56 A SOC NO, 2253 PAGEOS
S· N EO . CROSS ING T !ME UT LONG , W
0 35,9 3 35.8 6 35 . 8 9 35.7
12 35 . 7 15 35,b 18 35 . 5 21 35 , S
341.32 26.45 71 . S8
ll 6o 72 161 . 85 206 , 98 2S2.11 297 , 24
SHADOW ENTRY 351 SHADOW EX IT 57
0 35,4t 3 35,4 6 35.3 9 35 , 3
12 35.3 15 35.2 18 35o2 21 35o1
342.38 27.51 72,64 ·
117.78 162.91 208 . 05 253 . 18 298 . 32
SHADOW ENTRY 351 SHADOW EXIT 59
0 35. 1 3 35,0 6 35,0 9 35,0
12 34 , 9 1 5 34,9 1 8 34 ,8 21 34 , 8
343,45 28.58 73 ,72
118,86 163.99 209,13 254 , 26 299,40
SHADOW ENTRY 349 SHA DOW EXIT 59
0 34,8 3 3 4. 7 6 34,7 9 34.7
12 34,6 15 34,6 18 34,6 2 1 34,5
344,54 29 . 67 74 , 81
119 . 95 165 , 08 210 , 22 255,36 300 . 50
SHADOW ENTRY 349 SHADOW EXIT 59
ORBIT ANGLE
LATI · CORRECTION TO HTolN TUDE TIME LONG,w MILES
1970 JANUARY 10
0 SN 15 5N 30 SN 45 SN 60 SN 75 SN 90
105 NS 120 NS 135 NS 150 NS 165 NS 180 NS 195 NS 210 NS 225 NS 240 NS 255 NS 27 0 285 SN 300 SN 315 SN 330 SN 345 SN
o. oo 15.00 29.97 44, 88 59,67 7 4, 13 8 4, 57 74 , 13 59 ,66 44, 86 2'1.95 14.99 -, 00
- 14 , 98 -29 ,94 -44, 84 -59,64 -74, 12 - 84.57 -74.12 - 59.65 · 44,86 - 29.95 -14,99
1970 JANUARY 11
0 SN 15 SN 30 SN 45 SN 60 SN 75 SN 90
105 NS 120 NS 135 NS 150 NS 165 NS 180 NS 195 NS 210 NS 225 NS 240 NS 255 NS 270 285 SN 300 SN 315 SN 330 SN 345 SN
o. oo 15.00 29,97 44.88 59,67 74.13 84.57 74, 13 59 . 66 44, 86 Z9e95 14,99 - . oo
-14 .98 -29 . 94 -44, 84 -59 , 64 - 74.12 - 84 , 57 -74 ,1 2 - 59 .65 -44 . 86 -29 . 96 - 14,99
1970 JANUARY 12
0 SN 15 SN 30 SN 45 SN 60 SN 75 SN 90
105 NS 120 NS 135 NS 150 NS 165 NS 180 NS 195 NS 210 NS 225 NS 240 NS 255 NS 270 285 SN 300 SN 315 SN 330 SN 345 SN
o. oo IS . OO 29, 97 44,88 5 9 , 67 7 4,1 3 84 , 57 74.13 59 . 66 44.86 29,95 14.<;19 -.oo
- 14.98 - 29.94 - 44.84 -59.64 -74.1 2 -84 .57 - 74 .1 2 -59,65 -44.86 - 29.96 - l4.QQ
1970 J ANUARY 13
0 SN 15 SN 30 SN 45 SN 60 SN 75 SN 90
105 NS 120 NS 135 NS 150 NS 165 NS 180 NS 19S NS 2 10 NS 22S NS 240 NS 255 NS 270 285 SN 300 SN 315 SN 330 SN 345 SN
o. oo 15. 00 29. 97 44. 88 59. 67 74.13 84 . 57 74 . 13 59.66 44. 86 29. 95 14. 99 -. oo
-14. 98 - 29 . 94 -44. 84 -59 , 64 - 74 , 12 - 84 . 57 -74.1 2 -59 . 65 -44,86 - 29.96 -14.99
. o 6,0
u.a 17,4 23,0 28 . 6 34.3 40 , 3 46 , 7 53,4 60.7 68.5 76 , 9 8S . 9 95,4
IOS . 2 115 . 0 124.8 134 , 3 143.2 151 .7 159 .S 166 . 8 173 . 6
.o 6 . 0
11 .8 17,4 23.0 28 . 6 34.4 40 , 4-46.8 S3.6 60,9 68,8 77 .2 86.2 95.7
105.S 115. 3 125.1 134,5 143. 4 15 1.8 159 . 6 166 . 8 173.6
. o 6 . 0
1lo 7 17,4 23. 0 28 , 6 34,4 40.S 46,9 53 . 7 61 , 1 69,0 77,5 86 , 6 96 , 0
105 . 8 115.7 125 .4 134 . 7 143 . 6 152,0 159 ,7 166.9 173.6
.o 6 . 0
11.7 17.4 23,0 28,6 34 . 5 40, 6 47 . 0 S3 . 9 61 . 3 69 . 3 77.8 86 . 9 96 . 4
106.1 116, 0 12S .6 135. 0 1 43 . 8 152. 1 159.8 167 , 0 173 , 6
. oo , 05
359.81 358,93 356.41 347,64 2 78.6 1 209 , 6 4 201 , 05 198,83 198,36 198,65 199.30 200,09 200,78 200,94 199,50 191,77 123 . 6 7 55.46 47,39 45,44 44-.97 44, 99
.oo
. 04 359,81 358,93 356.41 347,64 278.62 209 .66 201.08 198.87 198,41 198.71 199.37 200.17 200.8 7 201.03 199,58 19 1.84 123.73
55 . 50 47.42 45.46 4-4-.99 4-4.99
. oo
. 04 359,80 358,93 356.41 347,65 278 , 63 209 , 68 201.11 198.9 1 198 ,46 198 . 77 199 ,44 200 , 25 200 ,95 201 .11 199 . 66 191 . 9 1 123.79 5S.S5 47, 4 6 45,48 45 ,00 45.00
.oo ,04
359,80 358,92 356.41 347,65 278.64 209,70 201.14 198 . 9S 198. 51 198,83 199,51 zoo, 33 201,03 201.19 199 . 74 191 , 98 1 23 ,85
5 5 . 60 47,49 45.51 45 . 0 1 4S,Ol
1949 1811 1718 1673 1676• 1726• 1821 • 1960• 2 138 • 2349• 2585• 2832 3071 3282 3440 3S27 3530• 3450• 329 6 • 3086* 2843• 2591 • 2H8• 2131•
1941 1807 1718 1677 1683• 1737• 1835• 1977• 2157• 2369• 2605• 2850 3087 3292 3 444 3524 352 1• 3436• 3278• 3066• 2824• 2573• 2333• 2119•
1934 1804 1719 1681 1691• 1748• 1850• 1993• 2175• 2389• 2625• 2868 3101 3302 3448 3521 3512 3421 • 3260• 3047• 280S• 2556• 2319• 2108•
1927 1801 1720 1686 1700• 1760• 1864• 2011 • 2194• 2409• 26440 2886 3115 3311 3451 3Sl8 3503 3407• 3242• 3028• 2786• 2539• 2305• 20970
ABs, MAG, 0 EPOCH 40566 o000000 MJD
S·N EO.CROSSING TIME UT LONG,W
0 H . S 3 34,5 6 31t , lt 9 34 ,4
12 34,4 15 34,4 18 34 .3 21 34,3
345,64 3 0 .77 75 , 91
12 1 . 05 166,19 2 11 , 33 2S6 ,47 30 1.61
SHADOW ENTRY 347 SHADOW EX IT 59
0 34,3 3 34.3 6 34.3 9 34 .2
12 34,2 15 34 . 2 18 34 , 2 21 34 ,2
346 . 75 3 1 .89 77 , 03
122.17 167.3 1 212.45 257.59 302.73
SHAOOW ENTRY 34 7 SHADOW EX l T 59
0 34. 2 3 34 . 1 6 34.1 9 34.1
12 34 . 1 15 34,1 18 34.1 21 34 .I
347 . 88 33 . 02 78 . 16
123 . 30 168e44 213 . 59 258 . 73 303.87
SHADOW ENTRY 346 SHADOW EXIT 59
0 34 ,1 3 34 .1 6 34 , 0 9 34,0
12 34,0 15 34 , 0 18 34.0 21 34 , 0
349, 02 3 4 . 16 79, 30
124, 45 169,59 214,74 259.88 305 , 03
SHADOW ENTRY 344 SHADOW EXIT 61
ORBIT ANGLE
LAT! · CORRECTI ON TO HT , lN TUDE TIME LONG , W MILES
1970 JANUARY 14
0 SN 15 SN 30 SN 45 SN 60 SN 75 SN 90
lOS NS 120 NS 135 NS 150 NS 16 5 NS 180 NS 195 NS 2 10 NS 22 5 NS 240 NS 255 NS 270 285 SN 300 SN 315 SN 330 SN 345 SN
o. oo 15.00 29o97 44, 88 59.67 74, 13 84,57 74.13 59 .66 44,86 29.95 14.99 -.oo
• 14.98 - 29 . 94 · 44.84 - 59.64 - 74 . 12 - 8 4 .57 - 7 4 . 12 - 59 . 65 - 44 , 86 • 29 . 96 - 14,99
1970 JANUARY 15
0 SN 15 SN 30 SN 45 SN 60 SN 75 SN 90
105 NS 120 NS 135 NS 150 NS 165 NS 180 NS 19 5 NS 210 NS 225 NS 240 NS 255 NS 270 285 SN 300 SN 3 15 SN 330 SN 345 SN
o.oo 15.00 29.97 44.88 S9.67 74.13 84.S7 74.13 59.66 44.86 2 9 o95 l 4o99 - .oo
-1 4,98 - 29.94 -44.84 - 59 . 64 - 74 ,1 2 - 84 . 57 - 7 4. 12 - 59 ,65 - 44 , 86 - 29 . 96 - 14.99
1970 JANUARY 16
0 SN IS SN 30 SN 4S SN 60 SN 75 SN 90
105 NS 120 NS 135 NS 150 NS 165 NS 180 NS 195 NS 210 NS 225 NS 240 NS 255 NS 270 285 SN 300 SN 31S SN 330 SN 34 5 SN
o. oo I S.OO 29 , 97 ~~. 88 59,67 74 , 13 84,57 74.13 S9o66 44 , 86 29 . 95 14.99 - .oo
- 14 .98 - 29 . 94 - 4Lt,84 - 59 .64 - 74,12 - 84.57 - 74. 12 - S9 . 65 - 44,86 - 29,96 - 14 . 99
1970 JANUARY 17
0 SN 15 SN 30 SN 45 SN 60 SN 75 SN 90
105 NS 120 NS 135 NS ISO NS 165 NS 180 NS 195 NS 2 10 NS 225 NS 240 NS 2S5 NS 270 285 SN 300 SN 315 SN 330 SN 345 SN
0 , 00 15. 00 29,97 44 , 88 59, 67 7 4,1 3 84.57 74 . 13 59 . 66 44,86 29 . 95 14 , 99 -.oo
-1 4 , 98 - 29 . 9 4 - 44 , 84 - 59 . 64 - 74 .1 2 - 84 e57 -7lt, 12 - 59 . 65 - 44,86 -29.96 - 14 . 99
. o 6 , 0
11.7 17. 3 23 , 0 28.7 34, 5 40 , 6 47,1 54,1 61 . 5 6 9, 5 78 . 1 87.2 96,7
106,5 116.3 125,9 135 . 2 144.0 152 . 2 IS9,9 167 , 0 173 o7
,o S .9
11.7 17.3 23 , 0 28,7 34 . 6 40.7 47.3 54 .2 6l o7 69,8 76.4 87 , 5 97 . 0
106 , 8 116 , 6 126.2 135 . 4 144, 2 152 . 3 160 , 0 167.1 173.7
o. o S , 9
ll . 7 17.3 23 . 0 28 . 7 34,6 40 , 8 4 7 , 4 54,4 61,9 70.0 78,7 87,8 97 . 3
107 , 1 116,9 126 ,4 135 . 6 144 . 3 152 , 5 160 , 1 167 . 1 173 . 7
. o 5 . 9
11 , 7 17, 3 23. 0 28.7 34 . 7 40 , 9 47. 5 54. 6 62. 1 70 , 3 79, 0 88.1 97 . 7
107, 4 11 7 . 2 126 . 7 135 . 8 144 . 5 152 , 6 160 .1 167 . z 173 . 7
. oo , 04
359 , 80 358 . 92 356 . 41 347 . 66 278 , 66 209, 72 201.17 198,99 198.56 198 . 89 199.58 200,41 201.11 201,27 199.81 192,05 123 . 91
55.64 47.53 45,53 45,03 45 , 01
.oo
. 03 359 , 79 358 , 92 3S6,41 347 , 67 278 , 67 209,74 201.20 199 . 03 196 , 62 198,9 5 !99,66 200 ,49 201.19 201.3S 199.89 192.12 123 , 96
55 . 68 47 .56 45 . 55 45.04 45 . 02
360,00 , 03
359.79 358 , 92 356,42 347,67 278 , 69 209.77 201.23 199,07 198 , 67 199 , 02 199.7 3 200.56 201 . 28 201,43 19 9,96 192 . 18 124, 02
55 . 73 47 . 59 45 . 57 45 , 05 45 . 03
. oo , 03
359. 79 358.92 356, 42 347 . 68 278 . 70 209 , 79 20 1.26 199 .11 198.73 199 , 08 199 , 8 0 200 ,64 20 1.36 201.5 1 200 . 04 192 . 2S 12 4 , 07 55 . 77 47 . 62 45.59 45 , 07 45 , 03
1921 1798 1721 1691 1708• 177 1• 1879• 202~·
22 13 • 242 8• 2663* 2903 3 12 9 3320 3453 3514 3493 3392• 3224* 3009• 2768• 2522• 2291 • 2087*
1914 1796 1722 169 6 17170 1783• 189 4• 2045• 2232• 2448* 2682* 2920 3142 3328 3455 3509 3482 3377* 3206• 2989• 2749* 2506* 2277• 2077•
1909 1794 1724 1702 1726• 17960 1909• 20620 2251• 2467it 2701 • 2937 3155 3335 3457 3504 3471 3361• 3188 * 2970* 2731• 2490• 2264* 2067*
1903 1792 1726 1707 l73S 1808• 1924• 2079• 2270• 2487• 2720• 2953 3 168 3343 345A 3499 3460 33460 3 170• 295 1• 27 13• 2 474• 2251 * 2058
Rob Mer
cer
SATELLITE ooosoo l 1966 56 A SOC NO, 2253 PAGEOS 1 ABS,MAG, 0 EPOCH 40588,000000 MJ D
5 - N EOoCR055 l llG OR~IT LATI• CORRECTION TO HT .IN S-N EO.CROSSING ORBIT LATJ - COR~ECT I ON TO HT, IN TI ME UT LONuoW AN GLE TUDE TIME LONG.W MILES TIME UT LONG ,W ANGLE TUDE TIME LONG ,W MI LES
1970 JANUARY 18 1970 JANUARY 22
0 )4 , 0 350 . 17 0 SN o . oo . o .oo 1898 0 34.4 354,93 0 SN o,oo o .o 360.00 1881 3 34,0 35.32 15 SN 15.00 5.9 ,03 1191 3 34.5 40,08 15 SN 15.00 5,9 .oz 1789 0 34 , 0 80 .46 30 SN 29,97 11.7 359.19 1729 6 34.5 85.24 30 SN 29,97 11.7 359,78 1741 q 34,0 l 25oo I 45 SN 44,88 11,3 358.92 1113 9 34,5 1 30,39 45 SN 44,88 17,4 358,92 1140
12 34,0 170.75 60 SN 59,67 n.o 356.42 1145 12 34.5 175,54 60 SN 59.67 23 . 1 356. 45 1785 15 34,0 215.90 75 SN 74,13 28,8 347.69 182 10 15 34,& 220,70 75 SN 74,13 29.0 347 ,74 1873• 18 34,0 Zo1o05 90 84 , 57 34.8 278,72 1939• 18 34,6 265,85 90 84,57 35,0 278,79 2002• 21 34.0 306.19 10 5 NS 74.13 41,0 209.82 20970 21 34.6 311,00 105 NS 74,13 41,4 209.92 2lb7*
120 N5 59.66 47.7 201,30 2288* 120 NS 59.66 48 ,2 201.44 23b3 • 135 NS 41ft , 8b Sit, 7 199.16 2506* 135 NS 44.86 55.5 199.35 2581• 150 NS 29.95 62,4 198.78 27380 150 NS 29,95 63.3 199.01 28080 165 NS 14,99 70.5 199,15 2969 165 NS 14,98 71,6 199,42 3028 180 NS -.oo 79.2 199.88 3180 180 NS -. oo 80,4 200.17 3222 195 NS -14 .98 88.4 200.72 3349 195 NS -14 .98 89.7 20 1 .04 3370 210 NS -29 .94 96.0 201,44 3458 210 NS -29.94 99.3 201,76 3455 225 NS - 44.84 107.7 201,59 3493 225 NS - 44.84 109 .0 201.90 3465 240 N~ - 59 .64 117.5 200,11 3449 240 NS - 59.64 118.6 200.39 HOO 255 NS - 74.12 126.,9 192 , 31 3330• 255 NS •Ho12 127,9 192,56 3266• 270 -84.57 136.1 124.12 3152• 270 ·84.57 136,9 124.32 30790 285 SN -74.12 144.,7 55.81 29330 285 SN - 74.,12 145.3 55.96 2859• 300 ~N - 59.65 152.7 47.65 2695• 300 SN -59.66 153 .2 47.76 2626• 315 SN -44 .86 160.2 45.61 Z458tt 315 SN -44.86 lo0.5 45.69 23990
SHADOW ENTRY 344 330 SN - 29.96 167.2 45.08 2239• 5HAOOW ENTRY 342 330 SN -29.96 167.4 45.12 2 1920 SHADOW EXIT 61 345 SN -14 .99 173.8 45.04 2049 ~HAOOW EXIT 61 345 SN -14 .99 173 .8 45 ,06 2017
1970 JANUARY 19 1970 JANUARY 23
0 34.0 351.34 0 ~N o.oo- .o . oo 1893 0 34.7 356.16 0 SN o.oo . o .oo 1877 3 34.0 36.49 15 SN 15.00 5.9 .03 1790 3 34.7 41.31 15 SN 15.00 5.9 ,02 1789 6 34.1 81 . 64 3 0 SN 29.97 11.7 359.79 1731 0 34.7 86.46 30 SN 29.97 11. 7 359,78 1745 9 34.1 126.78 45 SN 44.88 17.3 358.92 1120 9 34.8 131.62 45 SN 44.88 17.4 358 , 93 1748
12 34. 1 171.93 60 SN 59.67 23.0 356.43 1754 12 34.8 176.77 60 ~N 59.67 21.1 356,45 1795 15 34o1 2 17 .08 75 SN 74.13 28.8 347.70 18330 15 34.8 221.93 75 SN 74.13 29.0 347.75 1886• 18 34.1 262.23 90 84.57 34.8 278.73 1955• 18 34.9 267.08 90 84.57 35.1 278.81 20 17• 21 34.1 307.38 105 NS 74.1~ 41.1 209.84 21140 21 34.9 312.24 105 NS 74.13 41 .6 209.95 2185•
120 NS 59.66 47.8 201.33 2307• 120 NS 59.66 48.4 201.48 2382• 135 NS 44. 86 54.9 199.20 25250 135 NS 44. 86 55.7 199.40 25990 150 NS 29.95 62 . 6 198.84 27560 150 NS 29.95 63.5 199.07 2825• 165 NS lt.. .99 70.8 109 .. 21 2994 145 NS 14.98 71.9 199.48 30'o2 180 NS -.oo 79. 5 199,95 3191 180 NS - .oo 80.7 200.25 3232 195 NS -14.98 88.8 200.80 3355 195 NS •14.98 90.0 201.12 3374 210 NS - 29.94 98.3 201.52 3458 210 NS -29.94 99.6 201,84 3453 225 NS -44.84 108. 0 201.67 3487 225 NS -44. 84 109.3 201.98 3457 240 NS -59.64 117.7 200.18 3437 240 NS -59.64 118.9 200.46 3387 255 NS -74.12 127.2 192.37 3314• 255 NS -74.12 128.2 192.62 3249* 270 -84.57 136. 3 124,11 3133• 270 •84.57 137.0 124.37 3061* 285 SN -74.12 144.8 55,85 29140 285 SN -74.12 145.4 56.00 284 1• 300 SN -59 . 6 5 152.8 47.68 2677flt 300 SN • 59.60 153.3 47.79 2610• 315 SN -44 .86 160.3 45.63 2443tt 315 SN -44.86 160. 6 45.70 2385•
SHADOW ENTRY 344 330 SN -29.96 167.2 45.09 2227• SHADOW ENTRY 340 330 SN - 29 .96 167,4 45 . 13 2181* SHADOW EX IT 61 345 ~N -14.99 173.8 45.04 2041 SHADOW EXIT 61 345 SN -14.99 173 . 9 45.06 2010
1970 JANlJARY 20 1970 JANUARY 24
0 34.1 352 . 52 0 SN o.oo o . o 360. 00 1889 0 35.0 351.40 0 SN o.oo . o .oo 1874 3 34.1 37.67 15 SN 15.00 5.9 . 02 1789 3 35.0 42.55 15 SN 15.00 5.9 ,02 1789 6 34.1 82,82 30 SN 29.97 11 . 7 359.78 1734 0 35.0 87,71 30 SN 29.97 11.7 359.78 1749 9 34.2 127 .91 45 ~N 44.88 17.3 358 , 92 1726 9 35.1 132 , 86 45 SN 44.88 17.4 358,93 1755
12 34.2 173.12 60 SN 59.67 23.0 356 , 43 1764 12 35 .1 178 o02 oo SN 59 , 67 23 . 2 356.46 1806 15 34,2 2 18.27 75 SN 74.13 28 . 9 347.71 1840* 15 35 ,2 223.18 75 ~N 74 . 13 29 . 1 347 .76 19000 18 34.2 263.42 90 84,57 34.9 278.75 1970• 18 35,2 208.33 90 84 . 57 35.2 278.83 2033• 21 34.2 308,57 105 NS 74.13 41.2 209 , 87 2132* 2 1 35 , 3 313 .49 105 NS 74 .1 3 41,7 209,98 2202•
120 N5 59.66 47. 9 201.37 2326* 120 NS 59.66 48.5 201 .5 2 2400• 135 NS 44.86 55,1 199,25 25440 1 35 NS 44,86 55,9 199,45 2618• 150 NS 29.95 62.8 198,89 27740 150 N5 29 . 95 63 . 7 199. 13 28420 165 NS 14. 99 71 .1 199.28 2999 165 NS 14.98 72 .1 199. 55 3056 180 NS -. oo 79.8 200,02 3202 180 NS -.oo 81 . 0 200. 32 3H1 195 NS -14. 98 89.1 200. 88 3361 195 NS -14.98 90. 3 201 . 20 3378 2 10 NS - 29.94 98.6 201.60 3458 210 NS - 29.94 99. 9 201 . 92 3450 - --- ~2.5 NS - ja.4. .. 84 108-.4 201.75 3480 225 NS -44.84 109 . 6 202 . 05 3449 2 40 NS -59 .64 118,0 200,25 3425 240 N5 -59.64 11 9 .1 200. 53 3373 255 NS -74.12 127.4 192 .44 3298• 255 NS -74.12 128o4 192.67 32330 270 -84.57 136.5 124.23 3115* 270 -84.'57 1 37 . 2 124 . 42 3043• 285 SN - 7 4 .12 145,0 55.89 2896• 285 SN · 74 . 12 145.6 56.04 2823• 300 SN ·59.65 152.9 47. 71 2660• 300 SN -59.66 153. 4 47 . 81 2593• 315 SN -44 .86 160.4 45,65 2428• 315 SN -44. 86 160,6 45.72 2371•
~HADOW ENTRY 342 330 SN -29.96 167.3 45.10 22150 SHADOW ENTRY 340 330 SN - 29.96 167. 5 45. 14 2171• SHADOW EXIT 61 345 SN -14.99 173 .8 45.05 2032 SHADOW EXIT 61 345 SN -14.99 173.9 45.07 2003
ELEMENTS OF 6605601 = TIME IN DAYS u.r. 1970 JANUARY 21
EPOCH = TO : 1970 JANUARY 2o000000 DT = T-TO DT2 or .or 0 34.2 353.72 0 SN o . oo .o . oo 1884 ARGUMENT OF PER I GEE CDEG . I = 62.3549 - 1.141 820T 3 3 4. 3 38.87 15 ~N 1'5. 00 5,9 . oz 1789 R. A, COATE) OF NODE CDEG.I = 138,2073 - o1 7880DT 6 34.3 84.02 30 SN 29.97 11 . 7 359. 78 1738 INCLINATION CD EG , ) = 84.5466 9 34,3 129.17 45 SN 44.88 17.3 358. 92 1733 ECCENTRIC lTY = .149975 -.0008660DT
12 34. 3 174.32 oo SN 59 .67 23.1 356.44 1174 SEMI-"'AJOR AXIS I ~EGAMETERS I = 10.553571 15 34.4 219.48 15 SN 74.13 28 . 9 34 7 . 72 1859• ME AN ANOMALY I REVS) = . 63597 • 8.oo7o3ZDT -.00015ooDT2 18 34.4 264 .63 90 84.57 35.0 278.77 1986• 21 34.4 309. 78 105 NS 74,13 41.3 209.89 2149 •
120 NS 59.66 48.1 201,41 2345• MODIFIED ORBITAL ELEMENTS 135 NS 44.86 55,3 199.30 2563• 150 NS 29 .95 63.0 198.95 2791• REFERENCE T1 ME 1970 JANUARY 10 OHOURS 56.30MINS . U.T. 165 NS 14.99 71.3 199,35 3014 INCLINAT I ON 84 .55 OEG . 180 NS - .oo 80,1 200 .1 0 3212 ASCENDING NODE I LONGol 346.44 DEG. WEST 195 NS - 14.98 89.4 200.96 3366 PR IME ~WEEP I NTERVAL ONE DAY -4.64 MIN. 210 NS - 29.94 99.0 2 0 1,68 34 56 ARGUMENT OF PERIGEE 53.18 DEG. 225 NS -44.84 108.7 201.83 3473 RATE OF CHANGE .... 14264 DEG. PER PERIOD 240 N5 -59.64 118 . 3 200.32 3412 ANOMALISTIC PERIOD 179.885 MIN . 255 NS - 74 .12 127.7 192.50 3282• RATE OF CHANGE . oooa8 MIN. PER PERIOD 270 - 8 4.57 136 , 7 1H.28 3097• ECCENTR I C 1 TY o143013 285 SN - 74.12 145 .1 55 . 93 2877• RAD I US OF PERIGEE 562 1.0 MILES 300 SN -59 . 66 153. 0 47.73 2643• RAD I US OF APOGEE 7497 .I MILES 315 SN -44.86 160 . 4 45 . 67 2413* RA TE OF CHANGE -5.4R MlLE5 PER DAY
SHADOW EN TRY 342 330 SN - 29,96 167 , 3 45,11 2203• ASCENDING NODE I R, A, OATEI 136. 77 DEG, SHADOW EXIT 61 345 SN -14.99 173 .8 45, 05 2024 RATE OF CHANGE -.1 7880 DEG . PER DAY
LATITUDE OF PERIGEE 52 . 83 DEG .
EXPECTED MAGNITUDE 2 TO 5
Rob Mer
cer
Star Catalog 60 Garden Street Cambridge Massachusetts 02138
International designation
60 00601 60 00901 60 01302
61 00101
62 04902
63 003A 63027A 63 030A 63 047A 63 049A
64 004A 64 005A 64 01lA 64 047A 64 053A 64 072A 64 074A
65 009A 65 011B 65 014A 65 039A 65 039B 65 052B 65 060A 65 060B 65 087A
Name
Midas 2 Echo l rocket, courier 1B
Samos 2
rocket, Alouette
none none Dual Tetrahedron centaur 2 rocket
Echo 2 Saturn 5 none Syncom C Cosmos 44 none Explorer 23
Pegasus A cosmos 55 cosmos 58 Pegasus B rocket rocket, Cosmos 70 Pegasus C debris, Pegasus c Proton 2
September 66
SPADATS no .
43 49 59
70
426
527 613 622 694 703
740 744 759 858 876 922 924
1085 1090 1097 1381 1385 1432 1467 l4bl:) 1701
+3 +0 +3
+3
+2
+2 +2 +3 +2 +3
- 1 -1 +2 +3 +3 +3 +2
+l +2 +2 +1 +2 +2 - l +2 +l Ro
b Mer
cer
SATELLITE PREDICTIONS BY THE USE OF EPHEMERIS VI
I ntroduction
In order to be able to observe a satellite, it must obviously be
above the observer ' s horizon; it must be in sunlight, i.e., not in the
earth ' s shadow; the time must be sufficiently long before sunrise and
a fter sunset for the sky to be dark; and the observer must know just
where in the sky to point his telescope at a given time in order to see
it.
Positions in the sky can be indicated in several different ways.
We shall do so by: (see Figure I)
Altitude, which is the angular elevation in degrees above the horizon, and
Azimuth, which is the "bear ing" measured clockwise from North. It is similar to t.he compass bearing except that it is measur ed in degrees instead of compass points. For instance:
Nor th- East Azimuth 45° West= Azimuth 270°,etc.
So much for the position of the satellite as seen by the observer.
Now consider how to define its position in space.
Imagine a line drawn from the satellite t o the center of the earth.
Where this line cuts the earth's surface is called the Sub-Satellite Point.
(As we shall make frequent. use of this term, we shall abbreviate it to "Sub
Point.")
I f we know the latitude and l ongitude of the Sub-Point and the height
of the satelli te above the surface of the earth, its position in space is
determined. This i nformation is obtainable from the Ephemeris and from it
we can determine its position in the sky as seen from a known observing
site.
We shall start by dealing with this problem and consider the question
of illumination later.
-1-
Rob Mer
cer
Section ( 4) - Illumination
To the right of 0olumns 7 and 11 there are asterisks on certain linea.
These mean that at theq,e latitudes (moving S-N when the asterisks follow col.
7 and N-S when they follow col. 11) the satellite is in sunlight and in a
suitable position for observation. Note that the satellite can be sunlit --but not in a suitable position for observation. If ,it is in a direct line
between the earth and the sun, it will only be _ illuminated on the side away
from the earth; moreover, there will be nowhere on earth in darkness from
which it can be seen.
Example 4
In the section of the ephemeris for May 15, the satellite is in
sunlight fram near latitude -40° S-N to latitude 0° N-S. But between
+20° S-N ani +40° N-S, it is directly between the earth and the sun.
Between -20° N-S and -45° S-N, it is in shadow.
How do we know it is in shadow here and not between +20° S-N and
+40° N-S'l
This information is given in the last line of the section, which
also gives the latitudes of shadow entry and exit with more exactness
than the asterisks.
Note: The figures given in the entry/exit line do not always agree
exactly with the asterisks which can only be trusted for a rough indication.
-9-
Rob Mer
cer
Section (5)- Selection of Equator Crossing
To select an equator crossing that will bring the Sub-Point near your
site, it is only necessary to apply the procedure of Example 3 in reverse.
Instead of applying a correction from column 5 or 9 to a selected S-N equator
crossing to get the longitude of the Sub-Point, at a given latitude, you apply
the correction for your latitude with reversed sign to your longitude to find
a suitable equator crossing.
As there are in general two longitude corrections for each latitude,
there will be two S-N equator crossings that will bring the Sub-Point near
your site.
Example 5
Suppose we require a crossing on May 15 to bring the Sub-Point
near a site in ;position: 0
Longitude: 87 Latitude :-30°
The longitude correction for -30° S-N is +28?51. Applying
this with reversed sign to your longitude gives, to the nearest
degree, 58°. Looking in col. 2, we see that the nearest S-N
equator crossing is 57~35 at llhl~ .
Similarly, using the correction for -30° N-S from col. 9, we
get about 311°. The nearest tabular figure to this is 302?44 at
3h38~4.
However, before deciding that an equator crossing will give a suitable
satellite pass for observation, you must first see that the satellite is
illuminated near one or both of the points at which it crosses your latitude.
In the above example, it would be in shadow at the N-S crossing of latitude
-30°, so the second equator crossing would be of no use.
It is also necessary to make sure that it will be dark enough when the
satellite reaches your latitude.
-10-
Rob Mer
cer
Exam;ple 6
Take the first equator crossing found in Ex:am;ple 5. Applying
the appropriate time correction, we find that it will be near the
site at:
llhl~ - 14m= 10h58m U.T.
to the nearest minute .
To correct U.T . to local time, we must subt·ract one hour for every
15° of west longitude, so the local time will be:
10h58m - 5h48m = 5hl 0m
It will certainly be dark enough at this time on May 15 in
latitude -30° .
-11-
Rob Mer
cer
• /~0
•• /IS'
No. 1 a...
Rob Mer
cer
Section (6) - C~lete Prediction
We shall start by giving an example of a prediction using only the
methods already described and then discuss the selection of the best point
for observation and how to find it. The example will be given without the
details of the calculation, merely referring for these to previous examples.
Example 7
Prediction required for May 29, 1965:
Site longitude : 114~0 0
Site latitude : +29.0
(i) Finding suitable equator crossing (see Example 5)
Refer to last section of ephemeris. Nearest tabular latitude to site : ~30° Only 1lluminated on S-N crossing. Now: 114° + 28° = 142° Nearest tabular 8-N equator crossing:
Time (U.T.) : llh53~ Longitude : 129~07
(ii) Check of l ocal time (see Example 6)
(iii)
Applying time correction from col. 4 and c9rrection for lon~itude of site, local time is: 11 h53m + 14m - 7h36ID = 4 Olm, at which time it will be dark.
(Note in passing that the next 8-N equator crossing at ~3h4~ would not do, as the local time then comes out to be 5h55m, well after sunrise.)
We shall make predictions for the site: +20°, +30° and +35° 8-N.
Position No. Latitude Lonaitude
l +20°(8-N) 1111?91
2 +30° (8-N) 100.65
3 +35°(8-N) 93·32
nearest the
.2
12 09.9
(iv) Azimuth , G.C .A. and heignt (see Examples 2 and 3)
Above positions are plotted on Chart No. la and measured. Heights are read from ephemeris.
-12-
Rob Mer
cer
(v)
Position No. Azimuth G.C.A. Heifiht l 167<?5 9~3 948 miles
2 80.5 11.9 873 miles
3 64.5 18 .6 832 miles
Altitude and summa;sy ~see Exa.m;ele _l}
Read from Chart No. 2. Position No . Time,U.T.) Azimuth Altitude Slant Ranse
1 12h02~4 167~5 48~0 1170 miles
2 12 07.2 80.5 37·5 1250 miles
3 12 09.9 64.5 21.0 1620 miles
Note: Azimuth and altitude are given to the nearest half degree. Greater accuracy is hardly possible by this simple method and is seldom necessary in any case.
If the satellite passes near your site at the right time and in sunlight,
the above method will nearly always find ~point in the orbit at which the . '
satellite can be observed, and many observers are content with this. It is,
however, not necessarily the best point.
As a general rule, to which there are exceptions, the best time to
observe ~he satellite is when it is nearest to you. If the height is chang
ing appre ciably, this point is not easy to find, but it is easy enough to
find where the ·Sub-Point is nearest, which is good enough.
Look at Chart No. la. The line through the three positions plotted in
Example 7 marks the path of the Sub-Point, moving in the direction of the
arrow . It is slightly 'curved, but unless unusual accuracy is required, a
straight line ruled between positions Nos. land 2 is good Fnough . The nearest
point to the site on this line is obviously the point A where the perpendicular
from the site meets the line.
-13-
Rob Mer
cer
The G.C.A. and azimuth of A are measured in the usual way. We get the
t ime and height by interpolating between the figur e s at positions Nos. 1 and
2 i n proportion to the distance of A along the l ine between these points .
The f oll owing example shows how it is done.
Example 8
Measuring along the line in the s ame way as when measuring for
G.C.A., we get:
Position No. 1 to A 5~5 Position No . 1 to No. 2 14~3 Ratio 0. 39
Time at A (U.T.) 12h0~4 + 0.39 ( 12h0~2 - 12h02~4) 12 04. 2
Height of A ~ 948 + 0.39 (873 948 0.39 X 75
We also find for the point A:
948) 919 miles
Azimuth : 130?0 ; G. C.A. 7<?8 Hence: Altitude: 53~0 ; Slant Range: 1090 miles
The complete prediction therefore is:
Time ( U. T. ) : Azimuth Altitude Slant Range :
12ho4r;t2 130?0
53?0 1090 miles
A word of warning should be given here. The above method assumes that
time and height change uniformly from position No . 1 to No . 2. This is always
nearly enough true as regards time but not always with t he height . The error
caused by ignoring this is seldom likely to cause troubl e , but there are a few
cases in which it can.
We shall conclude with an example of a prediction for the Southern Hemi
sphere t hat will also illustrate a point concerning shadow entry.
-14-
Rob Mer
cer
Rob Mer
cer
Example 9
Date prediction required: May 24, 1965
Site longitude: 186?0 Site latitude : -42~0
(i) Nearest tabular latitude in sunlight : -35° N-S 186° - 129° : 57°
Nearest tabular S-N equator crossing: TiJne (U.T.) : 8~st!l2 Longitude 62~88
( ii) Approximate local time: 8h5tfl - 4? - l2h24m = l9h4?' At this latitude in May, the site will be in darkness.
(iii)
(iv)
Position No. Latitude Lo!!ejitude Time ( U.T.~
1 -35° (N-S) 191~59 8hl3~6 2 -40° (N-S) 1e2.o3 8 16.8
See Chart No. lb. Note that for the Southern Hemisphere we use the chart inverted.
On plotting site and Sub-Point positions, we see that the perpendicular from the site meets the track at about latitude -39~3. But shadow entry is at -39?~so, as the satellite is moving southw:ard, it will be in shMow at - 39? 3· We must therefore choose a point north of shadow entry - and not too close, in case the ephemeris is slightly in error.
To simplify the calculation, we select the point halfway between position No. l and No. 2. This gives:
Height: 990 miles Time correction: 43~
We shall l eave the reader to complete the working. The final prediction is:
Time (U.T.): 8hl5~2 Azimuth 352~0 Altitude 68~5 Slant Range: 1050 miles
The above explanations and examples may appear rather long-winded. That
is because we have tried to explain just what we were doing and why at each
stage instead of laying down a series of arbitrary rules. In practice, a pre
diction is very easily made from Ephemeris VI and takes only a short time.
-15-
- -·-------~·- ·-- -~-------------·~- - · ... - . ·----~..._ __ -· - -· ~~.
Rob Mer
cer
•n.c.LU AlftCII'IIniCAL --· ~~ • .. , Iii
II&T U , IMS
IAftU.Ift 1- tara 1,~ 1
- pf'Mlctt--- • o ... lUI ol-0 .._.._.-.., 10, IMS bcllMtlo. • 47!1618 T, • lily 11.0, t-- to..,., IJ.T. lc-trletty • 0.0-S + I.M4 • 10-4 ( t•'l' ) .,.._ of ,.,q. • U- + ,~,.. (c-T,) a-t .... Jol' aala • 7 .771575 __.un • U8k oo- of -bla-• JM~757 • l:oWin cc-r,> --~,. ( .... ). 0.1.)1 + u .• ,.,.. (t-T.) + ~-"". 10-4 lt_·'l.)t
- fo.f:~u ultrmE{ou SUflliTE 6000901 1960 I OTA ''
L UUlliU -~00901 ---nllo\TUII I i fQUAl(R FO~ OTHE~ lATIJUOES $-11 -·-TH I -'N-SOIJTM ~ SOUTH-HOIUH HOUM-SOUJH
UIIE tmc. I UT. I ~~::. lll*. HT. I!M. Tl~ LOIIG4 "'· lEU. n• L-. lilT. TillE LOIIG. HT. IE All. .Jill£ LOK• "'· IEAJt. Ulll ••• ~ou. ~~~ lit-E 1 c;ou . COitlJ /1111 Itt- II I &Ill 1111 COllA. COlt~. IIIII 111-fl cou. COUJ IIIII llt-fl (I) {.a.) (J) (I,.) 51
flAY 1~. 1~l4- I (I') (<f) /0) (II) "" 19, 1965
I l{;t: g •••• no.oo ~'·' 26.6 -13.26 592 90.0 26.6 -83.30 t92 90.o '~ 1 .... 9 zn.n ~J.S _,,.,. 596 9o . o ~ 26.1 -U.4Z !196 90.0 2 1 •• 3 29141) 45.0 22.0 -61.05 611 72 . 3 n.2 -105.51 592 101. J I , ... ~ 102• ... ~s .o n.s -•tuT s•• n., I 10.1 -10S.6J 615 IOl.l
~ l.O UT·~' ~c .o 18.3 -~5. T~ 639 60.1 H. I -uo.o 605 119.) J 11.9 Jn.n j ~o.o 11.1 .... , . ., 609 60 . 7 H.• - uo.e MJ 119,) I
6
··~ . 3-,6•11 n.o 15.5 -)6106 661 54 . c n.s -110.51 62) 125.9
J ... ~ ······~ .... .,..n 6ll ~.1 l"·' -no.M
610 IU.O• 7 M.9 J4ol9 )0.0 13.1 -28.69 696 49.5 39.9 ·1H.I9 644 130. s 9 11.0 21•12 !C.O U.l •Zhll "' ~· .5 I )9.t -lU.tl ...
~::::' 9 ... ~ SJ.62 20.0 1.6 -·11.3- 756 4!.7• -~.] -149.27 692 . 1)6 .2• 11 u.s "'" 20.0 •• , -1H~ 695 43.1 ~-.1 -l,.t.u lSI 11 ..... 12.)<1 o. o. o . 186 19.9• 52.6 -l66.c.t 110 140.1• I! •• o u;oe I o • o. Ill ,, .•. S2. l -166.61 Ill 1~. 1· I! n.• 111. 06 -2c.o - 9.1 17.22 1018 41.6• -s2.2 1n.n ~· 136.4• I~ ,. .. l14oll - • -1.1 17•29 9U 4! •••
I !!:: ~~!:: lOll JJI.~ I u .11.9 U9• ll -Jo.o -14.2 28oH lOll 49.!• -47.2 1!6.05 1011 uo.J I 16 51.1 lU•M .-3o.o -u.e 21151 IOU ~ .. ,. 1071 u o . J 11 11•4 UI.IO -J5.0 -11.1 35.66 1105 53.9• -44.- 121.111 1054 126.1
11 ~-· 112.16 -!5.0 -1··· U•l9 1051 5).9• -'IU,9 Ul.91 HO~ ll6o1 I 19 11.9 lt7~U ""'0-0 -2o.s "'·19 ll30 60.6 -41.1 Ht • .Z. 1019 119.~ 1 ZO 48.1 200.19 -40.0 -19.9 ~!1H 1016 -~0.5 1l9.w 1121 119.~ 21
··~ zzs.tS -~s .o -25.0 6C.2l 1150 72.2 -)6.t 10~.14 1126 107.1 n n.7 2lto TZ 1-45.0 -24.4 60~43 1121 -!5.9 104.30 u.-r IOl.l , ll 1.9 u~.11 -~T.S -!0.1 I loll 1151 90.c -lC.I 12.21 1151 90.0 I_ _ _ -~LS. ::,10.2 _ U...J! u.u __u.CL, SHAOOII ENTRY LAT. -2t.3 Ell IT LAT. -32.~
SHADOW LAT. -•U.l
11n 16, 196S "n 20, 1965
c 51.4 2n.Jt u.s 26.7 -IJ•22 594 90.0 26.7 -U.M - 90.0 c 27.2 251.~5 41. s 26.2 ·13. 35 59) 90.0 26.2 -11.40 U3 90.0 z 4t.9 Jl2oll -s.o 22.1 -61.01 611 72.) Jl.) ·10,.~, ,.. 1GJ.7 z 2D.l ZIT• IT 45.0 21.6 -ua~ s .. 12.3 JO.I -lOS.~ 608 107.7 4 4J.4 340.1) u.o u .~ ·4So71 650 60.1 H.O -ue . .,. , .. 119.) 4 14.2 JU.IC ~o.o n.9 -H.n 6U 60 ·'
)-.5 -12C.91 61Z 119.1 • , •• 9 9.55 n.o 15.6 -)6.0- 6to 54.0 Jlo7 -no .... 61J us • • • l.l ,~-. ., )5.0 15.2 -]6.1- 635 ~.1 JT.z -uo.,. 651 126.0• I 30.4 ll oZ1 30.0 1!.2 -u.n 111 49.4 -0.1 -an ... ., 1!0.5 • I.! U.l6 )C.O lZ .I -21.16 657 49.5 39.7 -1)1.96 614 130 . 5• 10 Zt.t n.oc 2C.O 1.7 ·17.32 TT4 41.'7• 4~.- ·149.25 . .,. 136.2•
" 54.1 HoOI 20.0 1.4 -11•39 701 _, .7 44.1 -1~9.12 .,., 1)6.)• ll u.~ 95.12 c. o. c. 906 ,_,. s2.T -161 ... ?90 140.1• II 41.3 70oll c. o. o. 129 , .•. 52.~ -U16 ... ... 140.1• 14 10 .9 114•44 -2c.o -9 .1 11 • 20 1035 .. 1.6• -sz.1 14l.ZI •• 1:16.4• I I 41.9 t9o64 -zc.o -1 . 9 17.21 964 43.6• -s2.o 147 .)2 1002 1)6.4
16 ~-~ U3 o l6 -30.0 -1~.3 28.)8 1C92 49.Jo -41.) 116.0) 1001 IJO. 7 IS Jt.4 ua.u -Jc.o -1).9 21 . 49 1032 .. 9.3• -~6.9 1)6.0 1064 130.7 ll 57.9 111.11 -35 .o -11.2 Hob3 1117 51.9 -H.S lU.'PS 1011 1H.I 17 11.9 15f .. ,. -)5.0 -16 . 7 35.76 1065 53 ••• -44. 0 12 1.87 1094 126.1 19 51.~ 210. • o -4c.o -zo.e 45.16 lUI 60.6 -~t.z llt.ll ll'76 119.4 19 n.~ 18S.ll --.c.o -20.0 45~29 IC91
60 · '· -40.7 119.,.. 1120 119.4 2l " · 9 239.32 -45.0 -25.2 60.2~ liSJ 12.2 -16.7 104.11 1111 IOl.t
21 J6,C 2H.H -~5.0 ·24.6 60.39 IIJI 72.2 -16.1 104.26 1144 107 .1 23 31.4 2 61. 04 -47 .5 -30.9 8 2•" 1141 90.0 -Jl.O 82.19 1141 90.0 Zl 9.5 ZHoiT -47.5 ·30.~ IZ.ll 1151 to.c -30.1 82.35 I lSI 90.0 S~ACOW E~TAY LAT. -2'1.5 EXIl LAT. - 29.5
SHADOW E~TU LAT. -16.] EXll LAT . -19. T
"AY !1. 1•6! "AY 21. 1965
!.0. zn.n ~T.S 26.) -13.32 592 90.0 26.1 -ll.M 592 90.0 1 31.9 296.76 47.5 26.9 -e3.1l 5n 90.C Z6.9 -n.u "'' 90.0 . u.s ]00.62 45.0 21.7 -1>1.11 601 12 ,) )0."1 -105.57 601 107.7 3 Z5.~ ns. 41 45 .o 22.~ -60.91 t26 72.3 11.5 · ICS.U ,., IO'lo l "
4 50.0 329.15 ~c.o u.o -4S.IO 622 60.7 H.6 -120.1'1 6H 119.3 s 11.9 354.20 4C.O 11.6 -~5.61 661 60.7 n.1 -uo.n 592 119.3
6 H . S !51.07 JS,O 15.3 -n.ll f45 H.O 31.3 -130.!16 645 126.0 l u . ) l2o92 35.0 ts.l -n.oo '"" 54.0 !1.8 -uo.~ .. 4 llS.9 I n.t 26.10 30.0 11.9 -21 · T4 670 49 .s 39.1 - 137.9' 670 130.5• 9 5.1 51• 14 30.0 1).3 ·21.64 727 49.4 ~.z -lH.IJ 621 uo . s
10 30.1 ss.5z 20.0 ' ·' - 17.17 724 H.7 H.2 -149.30 lH 136. ,. 10 "·' 10.)5 2C . O 8 . 7 - IT ,JI 792 4].7• "·5 -l49.2l 661 l'J6.Z• ll ~~.1 ... 2, c. o. o • 141 39.9• 52.6 -166.69 ~8 140.1• 12 52.1 109.07 c. c. o. 926 ,. ... 52.7 -166.66 lJG 140. 1• 14 17 •• 112.91 -zc.c -1.9 IT. 25 913 4] .6• -s 2 .1 147.JO 914 t lMI.~ 14 46.) 137.H - zo .o -9 .2 n.u IC52 <\1.6• -sz. 1 14 7.26 911 l.M.4• 16 11.1 141. 7C ·- 10. 0 -14.0 21.46 1049 4'9 .l• -4l. C 136.10 1050 no. 1 16 :M.I 116.51 - 10.0 - 14.4 21 . 35 1105 49 .) - 47.4 U6.C:Z 912 1)().7•
u 4 •• 170. 42 -l~.c - 16.9 )5.72 ICIO 51 . 9• - •4-2 121.11 IOU 126.1 II 3J,1 tn.n -n.o -IT,] H.U 1121 S3.'l -"·' 121 . T4o ICIZ 1 126.1 19
"· 2 199.1~ --c.o - 20.2 45.26 . 1 110 60.6 -4"0-:1 rrt-;-)0 Ill t-19oo4 2 G-l6 · ·I -kU-+•! -40-.0 -z.o..:r ~..u_w.s b0.6 -~I.) 119.19 1062 119.4
21 Sl . T 211.17 -~s . o -24.7 60.J5 11J9 T2. 2 -36.3 IC4.21 IIJ9 107.8 22 zo.3 251•&7 -4~ .0 - 15.3 60.20 11~5 72.2 -36.1 1C4.01 1101 101.1 23 u.z Z56.6C -41.5 - !0 .5 12. 26 1152 90 . 0 - )0. 5 12.30 IISZ 90.0 -~1.5 -)1.1 82.12 1144 to.c -ll.l 12.16 1144 90.0
S .. JDOW ENUY LAT. -1C.O fliT LAT , -37.6 SHOt Oil ENTU LA J • -32 . 4 EXIT LAl. - 26.4
"" 22, 196~ MAY llo 1965
0 U.l 211." 47.5 21.0 - I 3.13 f01 9C .0 27ol -U.ll 601 9t.o lt. T 21s. n
_,_, z•.~ -11. 29 59 1 90.( 26.4 - n.n ,.1 90. 0 2 f.) 310.10 45.0 zz.~ -60 .9 3 t15 U.J n.• -loS.Jt ,.. lOl.J
u.z 31 ~.04 45.0 21-1 -61 . 01 60t 71.3 )!.( ·lOS. 54 "' 101.1 4 0.1 n1. 12 4C.O 18 .7 -4 s . 64 673 60. "1- u.J -uo. 11 Sll ll9.) ~~. 7 H2.n 40.0 u . 2 -4s . n 610 10.7 )4. 7 -uo.a 613 119.] ~ H,2 7.54 ~'. 0 "·' -H.91 lOI 5 4 .c w.o -uc.~ ,.1 us.9
7 tt.z 11.~. 15.0 U.4 -36.09 656 ~ -~ )7 . 4 -1~0.54 6)! 12h9 1 H.T 36.26 JC.O 13 . 4 - 21.62 742 49.~ 40.4 -IJT.?t 6ll ue.s t U .l 40.22 JC.O n.o -2f•T2 611 4t.S 39.1 - 131. 92 .,. uo.s• ' H.z 64.91 2C.O 1 .1 -17.29 110 41.1• 4~ • ., -14t.l9 .... IM.Z
II .. , 61•~ zc.o a.s -17 .36 HO 41.7 ~4.2 -149.29 707 136. 2• II 34.7 9).69 o. o. o. '1~5 ) .... sz •• -161 .... lS! t .. _o. 12 59.1 u ... c. c. o. 161 )9.9• 52.6 -161 ... 121 140.1• n z1.z IZZ.41 -zc.o - 9. 3 n.n IC67 41.~· -s2.1 1H.;M ., IJ6.3• 14 Sf ,] 126.)9 -2c.o -9.0 n.z, I COl 4).~- -52.2 HT.11 "' 136.~ U U.T 151 . 13 -1C,O -1~.5 zs.n 1116 ~· .l -~7.4 116.01 .. , UCI.h I I 46 . 6 15!.11 -1C.O -14.1 21•4) JC64 4t _, . -47 . 1 U6 . Cl ICIH 110.7 IT U-2 1 , •••• - JS.O ·17 .4 15.51 1115 5).9 -".6 ua.n loot tM.l II 40. l liJ.IJ -15.0 -17.0 ,,., lt~4 SJ,t• -~4.3 121.11 1061 ll6.1
" ••• 201.56 -•c.o -zo.e 45.10 IUO 60 •• -~1.4 llt.ll IOU 119.4 10 Jt.l 212.56 -4C.O -20.3 45 . 2l 1121 .0.6 -~t.C II 9.27 1100 119.4 21 !.I 2Jl.U -45 . 0 -25.4 60.18 IUS TZ.2 -16.'1 104.0. ,.,.. lOf.t u n.J 241.21 -4t.o - z-.t 60.31 IIH 12.2 -36. 4 I04.1T liS) 107.1 zz 51,6 266.0C -47.5 -H.z az.c9 1131 to.o -Jl. l u.u lUI 9o . o
""''·' -30 . T az.zz 1153 90.0 •JC.l 12.Z. liSl 90.0 $HI COli ENTRY lAH -J~.T £11 T LA f. -2J. z SHADOW Ell laY LAH -21. 1 fill lAI. -35.2
Rob Mer
cer
To Satellite
Figure 1.
Satellite
Horizon
Center of Earth
Figure 2.
-2-
Rob Mer
cer
I I
SIJEll Iff 6000901 1960 IOTA StTHliTE f>OC090 I 1960 IOTA ICIUATOI FOil Ollff:l LUI WOES fGUUOII fOR OTHER LAllntOU S-tl llllf
SDel..._TH IIOIIlW-101/TH s-• SINif-OIIlH _ .... .,., ..
~~- LAT. TIN: LOttS. ftl. SEolll. fiiiE uaJ "'· .... TillE. LOllS. lH. T IIOE LOlli,. HT. lfM • 'UIIf. lc..l "'· •••• IUO fill con. COIR. 11011 111-EI COlli. COIIII~ IIIII IN-ti I Uti IWI cou. CIHIR. ""' 111-fl CDitlt. tlllllll. IIIII llt-fl ... , 21. 1961
G ···1 294.11 n.s l7.2 ·83.09 "" lT. IMI ··'} 607 90.C Z,7.2 -43.U 107 90.0
l U.6 3U.H 4!.0 Z2.6 -60<89 645 72.l 11.1 -105.~ 517 101.1 I 16.1 H9•10 47.5 28 . c -8n89 641 ttt.o 4 .... 1 3!2<15 4C.O 11.8 -45.40 687 u.o -112 • ., .. , ... o 60.7 · H.5 · UlloM H4 119.3 1 9.6 )41.11 4~.0 2].) ·60.72 691 12.1 J:l,., -10I.U 61l lOloY . ""·' 20. It 15.0 16.0 -1,494 724 ~.c 38.2 - 130.35 5'91 US.9 5 ' .o 16.52 4C.O 19.4 -4!.45 HO ,0.7• •• 3 -120.411 '" li9.J 8 n.o \9.58 10.0 11 . 5 -za.59 760 4'9 .. •• 40.5 ·U.,. l5 602 uo.5 6 56.5 45.ll 15.0 10.5 -35.11 10 16.5 '" s..co 19.0 -uo.14 Ill U5.9 11.29 zo.o 8.9 ·17•21 819 43. 7• 44.8 •149.15 6)6 1 .... 2 I 49.9 1).94 3C.O IJ,9 -28.48 .,. .9.4• 41.3 -137.54 u 10.0 107.01 579 ue.s c. o. O• 96• 39 . 1• 52.9 -ue.u n• 140.0* IO .... 102 .... 20.0 9.2 ·17.20 909 H.e• 45.6 -1···· ,., ne.2 14 1.5 U5. 71 -2c.c · 9.3 11•15 1082 <\3.5• ·!2.2 l4T>.Z7 169 n •. ,. IZ J6.8 1!1.16 c. o. o. ICJ7 39.1• s:J.4 -1116 ... ... 141.0• 15 S..9 16~.~4 •Jc.o -14 .'b 2hl1 1126 .... , •47.4 136.01 9U 1!0. 7• 14 30.' 160.I!H ·20.0 -•.6 11.C9 1129 u.s 119 11 50.4 l'H.I~ -35.0 -17.5 Ho55 114) 53.9 -···· ua.;-rz ... 126.1•
-5l.9 147.3!1 116.3• 19 4!.9 211.11 •4C.O -20.9
16 n.8 118- 78 -1c.o -14.~ ze•n 1153 49.2 -4J.2 U6.11S .5 Ul.6• 45.07 l1 !4 60.6 -41.4 ll 'f.lll 1031 119.4 II 11 . 2 211.4'1 -)5.0 -11.9 15.41 nn 5J.r -···· Ill.~ ''" U6.1• 21 17.4 250.59 -45.0 -25.5 60.15 11 54 12.2 -37.0 104.04 10111 101.1 lC 10.7 Z46o2C -4C.O -21.] .... ,. 1153 60.6 -41.4 119.15 .,. 119. 40 23 1C.9 219. JO -47.5 -31.] 82.06 1130 90.C -31.) 82.111 IUO 90.0 22 4.1 Z74.9l -45.0 -H.9 6C.06 un 12.2 •Jl.1 104.00 10l0 an.e SHADOW E"TAY UT, -n.o EXIT liT. ·"·' Z3 57.6 ]0).62 -47.5 -31 .5 8Z.oo 1011 90.0 -)1.6 82.04 1017 90.0 S~ADOII EIIUT LIT. -<3.7 EUT L& r. -•.z
"" 24, 1965
"" 28, 1965 I H.l 308.02 47.5 ?7 •• -tr!.04 6H 90.0 27.~ -81.01 614 90.0 l 11.8 H6. 7J 45.0 . ll.8 -60.85 657 n.l n.o -105.29 518 107.7 . 1 H.O J3Z.H 47.5 28.2 ·82 .!4 t52 90.0 2.6. 2 -12 •• 652 '1),0 5 ll.1 5 •• s H.O l<l.O -45.56 702 60.7 15 .1 -120.61 582 119.] 3 44.5 1.04 45.0 23.5 -6(.67 112 12.] )2.9 -105.01 1111 107.7 7 4.8 34.16 ]5.0 H.! -JS.il Hi 54.C• 18 •• -uo.30 516 125.9 5 )7.9 29.75 4C.O 19.6 -45.41 766 60.7• 36.5 - ua.39 ,.. 119.] I 51.2 62.18 lC,O ll.6 -28 .s6 778 o\4.4• 40.7 -1]7.70 !95 130.5 1 31.4 51.46 35.0 16.6 -35.78 814 54 .0• )9.2 -1)0.01 571 125.9
10 61.7 91.59 2C.O 8.9 -11.25 849 43.7• 45.0 -149.10 624 1 .... 2 9 24.8 87.16 ) 0. 0 14.0 -28 • .-5 !54 49.4• H.6 -137.41 ,.,. ue.s ll 45.2 uo.u c. o. o. ~84 :J4;.f• 5].( -166.59 n6 140.0. ll 11.3 115.11 zc.o 9.2 -u.u 92<1 4'1..6• 45.1 -141.90 ,., Ull.l 14 11.7 1"9.02 -2o.o - q •• n .n 1095 41.5 -52.2 141.21 eu 136.)0 13 11.7 144.58 c. o . c. 1054 39.8• 53.6 -U6.U 65] ...... u Jl,l 17J,H -1C.O -1~ .7 2S.29 1135 49.3 -~1.~ ue.o1 925 no ... 15 5.2 lllo29 -2o.o -9.6 ll' .oa lUI 4] .5 ·!>1.1 147.). "'' .•. ). II H.6 106.45 -H.O · 17.6 )5.53 1149 53.9 -4~.6 128. n 967 126.1• 16 51.6 202.0C -]C.O -15.0 21.21 liST 49.2 -41.1 136.0., .. 4 ••••• 2C 19.1 2HoH -4(.0 ·21 .0 45 •04 1U6 60.6 -41.4 119.15 1013 119.4 u n .1 230,71 -35.0 -17.9 l5.~5 1157 51.8 -44.! 121.n -I ue.o. 22 12. s 263.1! -45. 0 ·25.6 60.12 1151 72.2 -31.0 to4.az 1061 10.,.8 lt ~5.5 259.41 -~c.o -21.] 44.96 1149 60.6 ·41.4 119.16 911 ll .....
-47.5 ·31.4 82.04 1121 90.C - 31.4 82.01 1121 90.0 22 )9.0 2Uol2 -45.0 -n .9 60.05 1124 72.2 -JJ.1 104.00 1002 107.6 SHICOW OUT liTo -!9.0 EXIT lAJ, -16.2 -47.5 -31.6 81.99 1CT2 90.(; -n.• u.ol 1072 90.0
SMIDCII ENlRV LAT. ·H.1 EXIT Ul. -2.1 MAV 25, 1965
•av 29, 1965 c t.c 292. 5~ ~7-5 21.6 - 82.H 621 9C .C 21.6 -u.c4 6Zl 90.0 1 59.5 321. )0 45.0 22.9 •60o81 t68 72.3 12.2 -105.24 5'fl 101.1 0 32.4 116.83 41.5 28 •• ·12.79 664 90.C ze.• -ll. ll 664 90.0
' 5J.O 350.02 4C. O 19 .I -45.!) 116 60.l 15.9 -120.56 511 119.2 2 25.9 345o54 45.0 23.6 -•4:.63 727 72.3 n.t -105.01 616 IOJ.l 5 44.4 u.B 35.0 16.2 -J5.18 151 S4.C• 38.5 -uo.zo 512 125.9 4 19. J '"'·24 4C.O 19.7 ·45.37 716 60.1• 36.8 -12o.u 590 Ut.] 1 39.9 H.44 lC.O 1). 7 -28~51 795 49.4• 40.9 -117.65 !89 ll0.5 6 !2.8 42.95 n.o 16.8 -15.75 832 54.0o 39.5 -no. az ,.,. ., .. 9 33.4 lfo.lt 2C.O 9.0 -17 >24 868 .,.,. 45 . 1 -149.06 614 ll6.2 • 6.2 Jl.6t 1C.O 14.1 -21.42 Ill 49.4• 41.8 ·ll7.42 ,.,, 110.5
11 26.8 104.11 c. o. o. 1001 )9.8• 53.1 -166.56 100 140.0• 9 59.6 100.3t 2C.O 9, 3 ·11.16 941 43.6• 46.C ·141.14 5111 136.2 n 20 .) 133.51 -2o.o -9.5 I J. 12 1107 4).5 -52.1 147.]0 829 136.3• 11 SJ. t 129.07 c. c. o. I C69 39.1• 51.1 ·166.31 640 140.0 15 13.8 162, lC - 1c.o ·14.7 28.21 11~2 49.2 -47.4 136.02 906 130.6• 13 46.5 151.18 ·2C.O -9.7 ll.07 1145 43.5 -51.6 HlAZ n1 IJ6.Jo 17 7.2 191.01 -'5.0 ·11.7 15>51 1153 53 .e -~4.6 128. n "9 126. 1• " 40.0 18<>.48 -JC.O -15.0 2e.2c 1158 49.2 ·47.C 136.10 IIZ5 130 ... 19 0.7 219.12 -4c.o ·21.1 45.02 1157 60.6 -41.5 119.14 996 119.4• 11 ]].4 215. 19 -)5.0 -n .o J5o44 • 1156 5J.a -44.4 Ul.ll •• 1;Ja.O• 2C 54.2 2U. 4! -45.0 ·25.7 60.10 1147 72.2 -11.1 104.01 1D'4 107.8 i9 26.9 24J,9C -•c.o -21.4 44.95 "" 60.e -41.3 ut.u ttt 119.)• 2l 47.6 217.15 -4l . s ·31.4 az.cz 1112 90.C -)1.5 12.06 1112 90.0 21 20.3 272.6C -45.0 -25.9 6C .c~ IllS 72.2 - 37.1 104.01 914 10l.Oo
SH.tDOW ENUT LAl. -•o.y · UIT L AT. -13. 0 23 U. 7 30& . Jl ·47.5 -31 . 6 81.99 1C51 90.C -n.• ez.oJ 10!11 te:.o S .. AOOW ENTRY LAT. ·45.6 EXIT LAl. c.~
"IV 26. 196!
c 41.1 105.16 47.5 n.e -82.94 no 9C.C 27.8 -82.99 630 90.0 t )4.6 n<r.n 45.0 · n . l - 60.76 682 12~J 3Z.4 -105.19 !96 101.1 P.ODiflfD CIB IUL flEOOTS FOR EARTH S.tTEll ITE 6COII90l • ze.o ).21 4C.O 19. , -45.49 IH 60 . 7 )6.1 -12 0 . 51 !82 119.2 6 21.5 31.99 15.0 16.4 -1s .es 175 54 .co "·' -110.20 519 125.9 REfUEIICf TillE 1965 y 5 ... 15 2 .. 8 . 12 " UY I 15.0 60.7C 30.0 o.a ·Z8.50 815 .. 9 .lt• 41.1 -1)1.6() 513 130.5 l HCliiiAT IC~ 47. 2e DEG.
IC ••• ... 42 2C.O 9. 1 - 11.22 888 4'J.l• 45.1 -149.01 604 136. 2 ISCENCll"' IICDE Ill!"'. I 279.15 DEG. WEST 12 1.9 lld. 1! c. o . c. IC 20 l9.f• 5]. 3 -166.52 6114 140.0• PII IIOE SIIEH IIIIEAV At. ONE DAY - 17. 35 •1M. I! ss.J 146.14 -2c.o ·9.5 1hl0 1119 4J.5 -52.0 147.32 809 116. 3• ARGU~fMl Cf PEAIGIE 82.19 DEG. IS .... 11 5.55 -3C.O - 14 .@ 21.25 1149 49.2 -41.3 136.01 886 130.6• •• T( Cf CI'ANCE 0.31295 CEG. PU PEA lOt 17 u., 204.2t -)5.0 - 17 .8 15.49 1156 H.l - 44.6 121.72 9Z9 1U.1• AIIC~.tliSTIC PEIO!Ct: 113.628 Milt . 19 n.T 232.97 ·4C.O -21.2 45.00 1156 60,6 -41.5 119 . 15 911 119 ... UTE Of CI<AhGE -0.00042 'IN. PER PEA lOt: u 19.2 zu . .e -4~.0 -25.8 f>CoCI 1141 12.2 -11.1 104.CO 10)8 101.1 ECCENf.ICITT C.C5 770 u u •• 290. )9 -47. 5 -)1.5 12.01 1100 9C.C -J1.5 12.05 1100 90.0 UOI ~S Of' PUIGU 4549.7 IOIUS
SHADOII EIHIY UY. -42.) EX IT LAT. -9.5 RAC IllS G APOGEE 51C7.0 llllfS AUf OF C".tii$E - 0. 30 "llES PU C.tl
ASCEhOIIIG HOOf ...... ! )44.84 HG. All( Cf Cl'iNH ·3 .40l10 OH. PEl O.tY
lAYJliiOf tf Pfii&EE 46.69 Oft;, ltUO Ill IIPftYfO UGIOIIUO~ IS •I
Rob Mer
cer
CHART FOR DETERMINfNG ~LEVATfON 8 SLANT ~ANGE: OF SAtELLITE I
,_.
AU. OIS'faNc!S ARE IN StATUtE t.IILES • !I STA'fUf! MILES EOUAl APP~ktMAtEt.Y 8 KILOMHE,.,.
to•
3~00
.....
~~ "' c~ 3000
~~ "' ;§ - ......
~~ ~::J ~ij 2~00 Cillo..:
:r~ ~ ~·
"' w~ w~ ~~ 2000
~~ C)
w s~ ~!!: 1- 1~00
~~ ~ ~ . ~--~ :J::;e \o2"{ ~~
' ....
1000
TO CENTER OF EARTH
TO CENTER OF EARTH
46
C ha.r t No. 2..
"" ~ ~ "
il:-zo• J...$;!
.::.."" (q
~ ~
,. i<.t .§
I..; .IDA""O ,_A CHAitr ~~ .::: G V£/S AND fl. ArlttNSOit. ~
OBSERVER'S HORIZON
Rob Mer
cer
Cha.rt No .3 'I
.. ~
~ i'-·- .. - -. - - - -........ _
1...-1.,.,. ... • .,..,. ,..,..,...... ------WI - t•• ~
I ... ......_.... - ... ... -... .. too ro· l,o' lo o'
Rob Mer
cer
- ---· - -- --- - - - - ----·----·- ---· -:
Section (l) - Altitude
See Figure 2. This is a cross section through the center of the
earth taken so as to include the satellite and the observing site.
The altitude is the angle between the tangent at the site, repre
senting the observer's horizon, and the l ine from the site to the satellite.
We can determine the magnitude of this angle if we know the height of
the satellite and the distance along the earth's surface from the site to
the Sub-Point. As this distance is measured on the spherical surface of the
* earth, it is, of course, an arc of a great circle . ' We shall refer to it as
the G.C.A. Note that it is measured, not in miles, but in degrees, just as
latitude and longitude are.
The re is a f or.mula for calculating altitude from height and G.C.A.
but it i s easier to read it from a chart such as Chart No. 2, which is nothing
more than an enlarged version of Figure 2, with the angles and distances marked
off, the latter in statute miles. In addition to the altitude, the chart
enables the distance from the observer to the satellite (the "Slant Range")
to be r ead off. It is useful to know this as a guide t o how bright the sat
elli te is likely to appear.
Example ( 1)
Take:
The chart shows:
Altitude= 45°;
G. C.A. Height
10° 910 miles
Slant Range = 1200 miles.
Chart No. 2 illustrated here is on too small a scale to g"ive very
accurate result s, particularly when the slant range is small, but larger
scale copies of the chart are available. For very cl ose satellites other
cha rts of a different type can be used.
* A "great circle" on the earth's surface is one that divides it into halves, such as the equator or a meridian. others, such as the parallels of latitude (except the equator) are called ."small circles ."
-3-
Rob Mer
cer
Section (2) - G.C.A. and Azimuth
So far, we have assumed that height and G.C.A. are known. Ae will
be seen shortly, the ephemeris gives the height and (among other things)
the lntitude and longitude of the Sub-Point. Using these and the-posi
tion of your site , the G.C.A. and also the .azimuth can be worked out from
n forrnulR but are more easily if less accurately obtained by direct measure
ment on a m11p .
A map to be used for this purpose should meet the following require
ments ns cl osely as possible1
(i) It should be at least 30° square with the position of tbe site near the middle .
(ii) The scale should be uniform; that is, distances on the map should be in the same proportion to distances on the ground in all parts of the map .
(iii) Directions from the site to other points should be the same as the corresponding directions on the ~~round.
The map we shall use (Chart No. l), while not of t,he best type for the
j ob, i s good enough for our purpose and has the advantage of being adaptable
to any site within a fairly wide range of latitude. It shows nothing but
lines of l atitude and longitude. Other details, such as coast lines, are not
r equi red and would merely complicate the map to no purpose.
Start by marking in the longitudes in steps of 5° on the heavy lines so
that your site is near the middle of the map. Mark the position of your site
and that of the Sub-Point and measure the distance between them. This is best
done with dividers, measuring against the vertical (latitude) scale of the map.
Since the scale of the map is not quite uniform, varying a little at different
latitudes, it is best to measure near the latitude of the site.
To obtain the azimuth of the Sub-Point (which~ is, of course, also that
of the satellite), simply draw a line due North from the site and another from
site to Sub-Point and measure the angle between them with a protractor. Take
care to measure clockwise from North.
-4-
Rob Mer
cer
N Chart No. 1
•.
Rob Mer
cer
Example {2)
Refer to Chart No. 1. We have taken the positions to be:
Latitude : Longitude:
We find: ~(Lc.A. Azimuth
~1 312:5
Sub-Point
+4oc 900
(The computed figures are : G.C.A. - e:2o; Azimuth 312~05·)
-5-
Rob Mer
cer
Section (3) - Latitude 1 Longitude and Time from Ephe~eri~ VI
Refer to the specimen copy of Ephemeris VI for E~ho r:
It will be seen to be divided into sections, one for each day, and
each section is divided into eleven columns which have been numbered for
reference. Each sheet of the ephemeris covers a period of 15 days.
In order to appreciate the meaning of the ephemeris more clearly, firct
look at Figures 3 and 4 which illustrate the relative motions of the satelliL~,
the orbit and the earth; and then at Chart No. 3 which shows the track of th0
Sub-Point for one particular revolution.
Orbit
Figure3.
~ion of Earth (A), Orbit (B), and Satellite (c)
-6-
Figure 4.
Relative motion of Orbit and Earth (A+B); and motion of Satellite (C)·
Rob Mer
cer
Let us start a t the point •1here the Sub-Point c rosses the equator from
South to North .
Since this particular satellite moves e astwa1u in it orbit faster than
the earth rotates eastward under i t (most of them do), the ub-Point crosses
each successive parallel of latitude at a point farther Eas than the last.
When it has reached a latitude roughl y equal to the angle inclinatton of tht: .,ij- !/•:
orbit plane to the equator, it turns. southward, crossing t~e equator again,
this time from North to South, on the opposite side of the t arth. 'I'he pat.h is
then traced out in reverse in the Southern Hemisphere tmd tlhe Sub-Po! nL f lnU ly
crosses the equator again from South to North. As the earth has been rotating
eastward under the orbit, it •rill do so at a longitude farther West thau i.hat
at which it started.
Observe that, except at the extreme North and South points, the Sub-Point
crosses each parallel of latitude twice.
Now return to the ephemeris.
Columns 1 and 2 give the t ime and the longitude at which the Sub-Point
c r osses the equator from South to North on each successive revolution. Times
are give n in hours, minutes and one decimal and longitudes in degrees ann two
decima: 3. Longitudes a r e measured West .
Column 3 gives a se r ies of selected latitudes to which the remaining
columns refer.
Columns 4, 5, 6 and 7 refe r to the latitude crossings at which the
Sub -Point is moving from South to North; and the remaining columns to t hose
at which it is movi ng from North to South.
Columns 4 and. 8 give the corrections to be a1JplJ.ed to the times .in
column l,and col umns 5 and 9 give the corresponding corrections to the
longitudes in column 2.
Columns 6 and 10 give the height of the satellite in miles. Ignore
columns 7 and 11. They give the direction of motion of the Sub-Polnt , blrt
we shall not use t h i s inf ormation.
-7-
Rob Mer
cer
The use of the ephemeris will be best explained by means of an example .
Example ( 3)
Look at the section headed May 15, 1965 . About halfway down
cols. land 2, we find a South to North equator crossing at:
Time (U.T .) 13h. 6~0 Lpngitude 86~08
0 Looking in col. 6 opposite latitude 0 , we find that the height
is 811 miles.
Now follow the satellite round, following the arrows (corresponding
to the line on Chart Nb . 3) .
At latitude +35° S-N, we have, using columns 4, 5 and 6;
Time ( u. T. ) l3h 6U:o + 1?.1 = l3h2l ~ Longitude 86?08 - 36?17 = 49~91 Height 627 miles
At latitude +35° N-8, now using columns 8, 9 and 10 :
Time ( U. T. ) 13h 6U:o + 3~2 13~ 3~3 Longitude 86~08 - 130?60 = -44~ 52 = 315?48 . Height 670 miles
Still following the arrows, we note that after passing latitude 0°
_North to South, the corrections change sign. This simply means that they
are now to be applied to the S-N equator crossing to~ard which the satellite
is moving, .not from which it is moving, as we have been doing so far .
Thus, if we want to follow the same revolution, we must now apply the
corrections to the crossing at:
Time (U.T.) Longitude
At latitude -30° 8-N
Time (U.T.) Longitude Height
l4h59~6 114~81
(col~. 4, 5 and 6) we hav
l4h59U:6 - 13U:S = l4h4~ 114~81 + 28~51 = 143?32
1016 mil s
The Sub-Point track on Chart No. 3 was drawn f r this revolutio~ and
we have indicated the three points worked out in the above Example.
-8-
Rob Mer
cer
NEWS RELEASE NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
WALLOPS STATION, WALLOPS ISLAND, VIRGINIA 23337
TELEPHONE: VALLEY 4-3411 • EXTS. 584 and 579
FOR RELEASE: Thursday, February 22, 1968
Release No. 68-3
WALLOPS LAUNCHES SIX
EXPERIMENTS OVERNIGHT
The National Aeronautics and Space Administration
conducted six chemical cloud experiments between sunset last
night and dawn today from its Wallops Island, Va., Station.
Liftoff times were 6:17p.m., 12:09 a. m., 1:30 a.m.,
3:00a.m., 4:30a.m. , and 6:02a.m. EST. There were seven
launches scheduled in this series. The second launch planned
for 10:30 p.m. was cancelled because of payload problems .
Thre e different chemicals--triethylborane (TEB), tri-
methylaluminum (TMA), and sodium--were used in this series,
t o continue the study of short term and seasonal variations
in wind structure in the upper atmosphere. Similar tests were
conducted at Wallops in January and July 1966, and August 1967.
The dawn firing was a sodium vapor experiment which
generated a reddish-orange cloud visible for hundreds of miles
-more-
Rob Mer
cer
-2--
along the East Coast. The other five payloads consisted of
TEB (first one) and TMA (the next four) vapor trails which
formed pale green and blue clouds, less visible than the
sodium.
The payloads were flown on Nike-Apache research rockets
and the vapor trails were ejected at ·altitude ranges of about
50 to 90 miles. Data on wind conditions were obtained by
photographing the motion of the trails from five camera sites
within a 100-mile radius of Wallops Island.
The first rocket was equipped with a photometer for
observing airglow in sunlight above the dark earth to get
a vertical profile (or chart) of atomic oxygen. The five
other payloads carried Langmuir probes for measuring e lectron
energy distribution.
The launchings were conducted in cooperation with the
GCA Corporation, Bedford, Mass., under contract to NASA's
Goddard Space Flight Center, Greenbelt, Md. William T. Burns
was the Wallops Station Project Engineer, responsible for
coordinating pre-launch, launch, and tracking operations.
if iNfo
Rob Mer
cer
