File swan_sheet1.txt -- Last modified Fri Aug 25 10:36:39 1995

                   COMMISSIONING PHASE BLOCK SHEET

1. INSTRUMENT AND BLOCK NUMBER: SWAN, Block 1

2. BLOCK IDENTIFICATION: SWAN Early Switch-on

3. PURPOSE: Prepare for geocorona and moon observations

4. SUB-BLOCKS: (see Note 1)
   NR.   IDENTIFICATION
   1.1   Initial Switch-on
   1.2   Launch Lock Actuation and Mechanism Head Orientation
   1.3   Deep Sky Observation and High Voltage Adjustment
   1.4   Hydrogen Cell Verificaton

5. SUB-BLOCKS TABLE: (see Note 2)
   NR. - DURATION - PREVIOUS - COMMANDING - TELEMETRY - POINTING
   1.1    00:03       N/A        PRO           M         None
   1.2    00:25       Nom.      NRT-d          M         Nom.
   1.3    02:00       Nom.      NRT-d          M     	 Nom.
   1.4    00:20     X 1.3 Nom.  NRT-d          M         Nom.


6. SCHEDULING REQUIREMENTS: (see Note 3)
   Sub-block 1.1 preferably on day 3, latest on day 5.
   Sub-block 1.2-1.4 preferably on day 4, latest on day 5.
   Sub-block 1.1 one day (>18 hours) before 1.2 to monitor HK

7. SPECIAL REQUIREMENTS: (see Note 4)
   Requires coordination with FOT; science obs. low priority 
   in early orbit.
   Sub-block 1.2 and subsequent only if no thruster activation 
   planned for next two days, and if sensor unit temperatures above
   -10 C (to be checked in orbit).

8. SUCCESS CRITERIA AND/OR EXPECTED OUTPUT:
   SWAN on, HK normal, meaningful scientific data collected

9. RELEVANT PROCEDURES:
   n_ts_nm_sw_on

10. CROSS-REFERENCE TO TEST SHEETS: (list identifiers for test sheets)
    SWAN 1 (SU1 Launch Lock Activation for +Z face)
    SWAN 2 (SU2 Launch Lock Activation for -Z face)

11. RELEVANT SECTION OF TIMELINE (backpage)

Structure of this memo:
Block number: purpose
a. Preferred time as day & hour:minute from launch
b. Earliest time
c. Latest time
d. Estimated duration without contingency in hours:minutes
e. Where can it be broken into parts
f. Relevant procedures to be run by FOT
g. Prerequisites
h. Importance as scale 1 (highest) to 3 (lowest)

General: The order of the first 3 blocks is fixed
	Wherever possible additional NRT telecommands are mentioned,
	usually 1 or 2 OBDH block commands for on-line adjustments are planned

Block 1.1: Initial switch-on
a. 3 & 00:00
b. 3 & 00:00
c. 4 & 00:00
d. 00:03
e. not at all
f. n_ts_nm_sw_on
g. SOHO is in transfer phase, no thruster activations planned for next 2 days
h. 1

Block 1.2: Launch Lock Actuation and Mechanism Head Orientation
a. 4 & 00:00
b. 4 & 00:00
c. 5 & 00:00
d. 00:25
e. between SU+Z and SU-Z lock actuation and before head orientation

f. Critical OBDH-block-commands to be sent by FOT:
	NBLLOCKN,1;    for SU+Z 
	in case of problems: NRT session with special IWS procedure,
		sending OBDH-block command NBLLOCKR,1 automatically in
		20 sec time difference 12 times
   Command to be sent by FOT:
	NBLLOCKN,2;    for SU-Z 
	in case of problems: NRT session with special IWS procedure,
		(command NBLLOCKR,2)

g. Block 1.1 was successful, no thruster activations planned for next 2 days,
	at least 2 hours of RT-contact available,
	sensor unit temperatures are above 0 deg
h. 1

Block 1.3: Deep Sky Observation and High Voltage Adjustment
a. 4 & 02:25
b. 4 & 02:25
c. 5 & 12:00
d. 02:00
e. after 10 minutes any time
f. NRT-commanding only, about 15 OBDH block TCs with about 10 words each
g. Block 1.2 was successful, no thruster activation planned for 2 hours,
	at least 2 hour RT-contact available
h. 1

Block 1.4: Hydrogen Cell verification
a. 4 & 04:25
b. 4 & 03:25
c. 5 & 12:00
d. 00:20
e. After about 10 min. between SU+Z and SU-Z verification
f. NRT-commanding only,  2 OBDH block TCs with about 10 words each
g. Block 1.2 was successful, no thruster activation planned for 1 hour,
	at least 30 min RT-contact available
h. 1