Some M-96 and MGS details

Agapov Vladimir (avm@kiam1.rssi.ru)
Thu, 31 Oct 1996 21:01:12 +0300

Hello, Seesaters!

I'm sorry!
I wrote in previous message wrong time of launch of Mars-96. It would be proper
times in case of launch from LC81L. Since launch will take place from
LC200L (46deg02'22" N, 63deg01'58" E) proper times are

2048:52.9 UT on Nov 16
2048:24.3 UT on Nov 17 (alternate opportunity).

Launch azimuth is 61deg19'40".

Here is some details of Mars-96 launch profile:

T0+583.422s   - separation of Block D-2/Mars-96 from the 3rd stage,
                51.49N, 89.03E, 144.7 km
T0+ 643.422s  - 1st burn of the launching provision system block
                (BOZ)

T0+ 942.422s  - 1st ignition of the Block D-2 main engine

T0+1046.721s  - end of the 1st Block D-2 main engine burn,
                45.08N, 132.60E, 159.88km

T0+4032 ... T0+6280 - Block D-2/Mars-96 in Earth's shadow

T0+3835.320   - 2nd burn of the BOZ engine

T0+4134.32    - 2nd ignition of the Block D-2 main engine,
                38.90 S, 46.49 W, 163.3 km

T0+4138.32    - separation of the BOZ block from the Block D-2

T0+4661.14    - end of the 2nd Block D-2 main engine burn

T0+4677.20    - separation of the spacecraft from the Block D-2,
                8.24 N, 4.07 W, 464.16 km

T0+4692.136   - ignition of the spacecraft's small thruster for
                providing of the main engine burn

T0+4747.136   - ignition of the spacecraft's main engine

T0+4916.953   - end of the main engine burn, 23.44 N, 8.24 E, 1174.09 km

I'll try to prepare files with nominal state vectors in J2000 and B1950 for
this launch profile (points with some step, for example 10 min)

-----------------------------------------------------------------------
Here is some information concerning of Mars Global Surveyor launch that
I've extracted from JPL documentation.

Mars Global Surveyor will be launched from LC17 at the USAF Eastern Space
and Missile Center at the Cape Canaveral Air Force Station in Florida.
Launch site location is 28.446462 N, 279.4347 E, 6373.346 km (radius).

The 21-day launch period begins on November 5, 1996 and extends through
November 25, 1996. The launch period is composed of 32 instantaneous
launch opportunities.
The daily launch windows are of an instantaneous duration. Instantaneous
is defined as +-1.0 second.
A Delta II 7925 AUV (it will be the fourth launch of this modification)
is planned only during the second daily launch opportunity, synonymous
with a short coast parking orbit or an ascending node injection.

Three launch azimuths will be utilized during the MGS launch period. These
launch azimuth will be selected according to the following launch strategy:

(1) From Nov 5 through Nov 15, 1996, the Delta Program will plan
to support two instantaneous daily launch windows. At the opening of the
launch period, the separation time between the two instantaneous daily
launch windows will be 64 minutes. This condition will be achieved by the
judicious selection of two discrete launch azimuths:
        1st launch azimuth - 93.00 deg
        2nd launch azimuth - 99.89 deg

(2) From Nov 16 through Nov 25, 1996, the Delta Program will plan to
support one instantaneous daily launch window. The launch azimuth will
be selected to be consistent with the required declination of the launch
asymptote (DLA) for the Nov 25th launch date.

        launch azimuth = 110.00 deg

(3) All launch azimuths will be selected on the basis of maximizing launch
vehicle perfomance and meeting range safety requirements.

Parking orbit (circular ~185km) inclinations:

Launch Azimuth, deg   Parking Orbit Inclination, deg
      93.00                    28.470
      99.89                    29.818
     110.00                    36.500


                             MGS Launch Events

For the first ten days in the launch period, there are two opportunities to
launch each day. Here are the launch-event times for the 1st. 6 launch
opportunities (Eastern Standard Time = UTC - 5h). An opportunity to launch
will exist 30 seconds prior to the nominal liftoff time and will only be
used in the event the Eastern Test Range (EST) issues a collision avoidance
(COLA) warning.
---------------------------------------------------------------------------
             6-Nov-96  6-Nov-96   7-Nov-96   7-Nov-96   8-Nov-96  8-Nov-96
   Event
 Lift-Off  12:11:16.7 13:15:44.3 12:00:49.9 13:05:56.4 11:48:11.112:54:09.2
 Mach 1    12:11:49.0 13:16:16.5 12:01:22.1 13:06:28.6 11:48:43.312:54:41.4
 Maximum
 Dynamic
 Pressure  12:12:06.1 13:16:33.7 12:01:39.3 13:06:45.8 11:49:00.512:54:58.6
 Solid
 Motor
 Burn-Out
 (Ground
 Lit)      12:12:19.8 13:16:47.4 12:01:53.0 13:06:59.5 11:49:14.212:55:12.3
 Solid
 Motor
 Ignition
 (Air Lit) 12:12:22.2 13:16:49.8 12:01:55.4 13:07:01.9 11:49:16.612:55:14.7
 Solid
 Motor
 Jettison
 (3 Ground
 Lit)      12:12:22.7 13:16:50.3 12:01:55.9 13:07:02.4 11:49:17.112:55:15.2
 Solid
 Motor
 Jettison
 (3 Ground
 Lit)      12:12:23.7 13:16:51.3 12:01:56.9 13:07:03.4 11:49:18.112:55:16.2
 Solid
 Motor
 Burn-Out
 (Air Lit) 12:13:25.5 13:17:53.1 12:02:58.7 13:08:05.2 11:50:19.912:56:18.0
 Solid
 Motor
 Jettison
 (Air Lit) 12:13:28.2 13:17:55.8 12:03:01.4 13:08:07.9 11:50:22.612:56:20.7
 Stage 1
 Main
 Engine
 Cut-Off
 (MECO)    12:15:37.3 13:20:04.9 12:05:10.5 13:10:17.0 11:52:31.712:58:29.8
 Stage 1
 Jettison  12:15:45.4 13:20:12.9 12:05:18.5 13:10:25.0 11:52:39.712:58:37.8
 Stage 2
 Ignition  12:15:50.9 13:20:18.4 12:05:24.0 13:10:30.5 11:52:45.212:58:43.3
 Payload
 Fairing
 Jettison  12:16:02.7 13:20:30.3 12:05:35.9 13:10:42.4 11:52:57.112:58:55.2
 Stage 2
 First
 Cut-Off
 (SECO-1)  12:20:53.3 13:25:21.6 12:10:26.5 13:15:33.7 11:57:47.713:03:46.5
 Stage 2
 Restart   12:51:37.0 13:52:37.4 12:41:31.1 13:43:08.4 12:29:18.613:31:44.7
 Stage 2
 Second
 Cut-Off
 (SECO-2)  12:53:44.5 13:54:44.8 12:43:37.5 13:45:14.7 12:31:23.913:33:50.0

Orbit after SECO-2 is ~173x ~4600 km. Post-SECO-2 timeline is the same for
all launch opportunities.

 Stage 2
 Jettison  12:54:37.513:55:37.9 12:44:30.6 13:46:07.8 12:32:17.013:34:43.0
 Stage 3
 Ignition  12:55:14.813:56:15.2 12:45:07.9 13:46:45.1 12:32:54.313:35:20.3
 Stage 3
 Burn-Out
 (TECO)    12:56:42.113:57:42.5 12:46:35.2 13:48:12.4 12:34:21.613:36:47.6
 Yo-yo
 Deploy
 and
 Despin    13:01:19.414:02:19.8 12:51:12.5 13:52:49.7 12:38:58.913:41:24.9
 Stage 3
 Jettison  13:01:24.414:02:24.7 12:51:17.5 13:52:54.7 12:39:03.913:41:29.9
(Times in HH:MM:SS.S format)

POST-SECO-2 Timeline:

T    - SECO-2
T+ 50 s - Stage 2/Stage 3 spin-up
T+ 53.1 s - stage 2 jettison
T+ 90.4 s - stage 3 ignition
T+177.7 s - TECO (burnout)
T+455 s   - despin
T+460 s   - stage 3/spacecraft separation
T+587.6 s - solar array deployment initialization
T+698 s   - targeting interface point (TIP)
T+887.6 s - solar array deployment complete
T+887.6 ... T+1750.9 - spacecraft Sun search
T+1750.9 s - spacecraft transmit

Timeline from lift-off to SECO-2 is variable:

T0    - lift-off
T0 + 576.6  - parcking orbit insertion (SECO-1) for az. =93.00 deg
     577.3    az. = 99.89 deg
     583.6    az. = 110.00 deg

Parking Orbit to Stage 2 Restart Burn Coast Time varies for each launch
opportunity from 24 to 37.5 min.
Stage 2 Restart Burn Duration and Attitude vary for each launch
opportunity from 120 to 129 s.

For Nov 06 launch opportunities stage 2 restart time is

T0+2420.3 s - stage 2 restart for az.=93.00 deg
   2213.1 s   az.=99.89 deg
   2027.1 s   az.=110.00 deg


Best regards,
   Vladimir Agapov.