Space Exploration Stack Exchange is a question and answer site for spacecraft operators, scientists, engineers, and enthusiasts. It only takes a minute to sign up.
Sign up to join this community
In the history of space launches, which week has had the most space launches? It would be also nice to know the second and third place. I think its also interesting to ask about most busy month and day too but I am not sure if I should ask two separate questions or maybe should just rewrite the title question.
Related questions:
The below data is based on the JSR Launch Vehicle Database, 2017 Dec 28 Edition. Specifically, it's based on a SQL schema I built from the JSR data. The data is trivial to install on an Oracle or Postgres database. And there are CSV files, so it should be relatively easy to load the data into other tools.
Once you have the data loaded into a database, it's easy to crank out these kind of numbers. But the interpretation is tricky. First, as Andrew mentioned in his answer, how exactly do you define a "day" or a "week"? Also, what exactly is a "space launch"? JSR has 10 launch categories and it's not always clear which ones you want to choose. (JSR has the categories orbital, military missile, test rocket, atmospheric rocket, suborbital rocket other than missile, deep space, high altitude sounding rocket, reentry test, launch from world other than Earth, and suborbital spaceplane with human crew. The names in my data set are slightly different for some of them because I guessed before all the codes were clarified in 2019.)
35 days had three launches:
LAUNCH_DAY LAUNCH_COUNT
---------- ------------
1962-04-26 3
1963-11-27 3
1967-02-08 3
1968-03-05 3
1969-10-24 3
1970-04-08 3
1970-12-12 3
1971-09-28 3
1972-06-30 3
1974-05-15 3
1975-02-06 3
1975-09-09 3
1976-07-08 3
1977-08-24 3
1977-10-28 3
1978-01-10 3
1983-05-26 3
1984-11-14 3
1985-08-08 3
1985-10-03 3
1987-09-16 3
1988-03-11 3
1989-02-10 3
1989-02-14 3
1990-02-28 3
1990-08-28 3
1993-03-25 3
1993-06-25 3
1994-11-29 3
1995-03-22 3
1996-04-24 3
2005-12-21 3
2010-06-15 3
2012-05-17 3
2017-06-23 3
Query:
select to_char(trunc(launch_date), 'YYYY-MM-DD') launch_day, count(*) launch_count
from launch
where launch_status = 'success'
and launch_category in ('deep space', 'orbital')
group by trunc(launch_date)
order by launch_count desc, launch_day;
Based on the ISO week, 1985-10-21 to 1985-10-27 was the busiest with 7 launches:
LAUNCH_DATE FLIGHT_ID2
----------- ----------
1985-10-22 07:00:00 Kosmos-1697
1985-10-22 20:24:07 Kosmos-1698
1985-10-23 00:42:07 Molniya-1
1985-10-25 15:45:00 Kosmos-1700
1985-10-21 05:04:00 FSW
1985-10-25 14:40:00 Kosmos-1699
1985-10-24 02:30:00 Meteor-3
Many weeks had 6 launches:
1962-04-23 1962-04-29
1968-04-15 1968-04-21
1968-08-05 1968-08-11
1970-04-06 1970-04-12
1971-04-19 1971-04-25
1971-11-29 1971-12-05
1971-12-13 1971-12-19
1973-10-29 1973-11-04
1977-09-19 1977-09-25
1978-06-26 1978-07-02
1979-06-04 1979-06-10
1981-05-18 1981-05-24
1981-08-03 1981-08-09
1983-06-27 1983-07-03
1984-06-25 1984-07-01
1987-12-21 1987-12-27
1988-09-05 1988-09-11
1993-06-21 1993-06-27
1994-08-22 1994-08-28
1994-10-31 1994-11-06
2015-03-23 2015-03-29
Query:
select
to_char(trunc(launch_date, 'iw'), 'YYYY-MM-DD') week_start,
to_char(trunc(launch_date, 'iw')+6, 'YYYY-MM-DD') week_end,
count(*) over (partition by trunc(launch_date, 'iw')) launches_per_week,
to_char(launch_date, 'YYYY-MM-DD HH24:MI:SS') launch_date,
flight_id2
from launch
where launch_status = 'success'
and launch_category in ('deep space', 'orbital')
order by launches_per_week desc, week_start;
THE_MONTH LAUNCH_COUNT
--------- ------------
1971-12 17
1983-04 17
1984-06 17
1975-09 16
1976-07 16
1977-09 16
1982-06 16
1984-08 16
1985-10 16
1965-12 15
...
Query:
select to_char(launch_date, 'YYYY-MM') the_month, count(*) launch_count
from launch
where launch_status = 'success'
and launch_category in ('deep space', 'orbital')
group by to_char(launch_date, 'YYYY-MM')
order by launch_count desc, the_month;
THE_YEAR LAUNCH_COUNT
-------- ------------
1984 128
1983 127
1976 126
1975 125
1967 124
1977 123
1978 123
1981 123
1968 121
1985 120
...
Query:
select to_char(launch_date, 'YYYY') the_year, count(*) launch_count
from launch
where launch_status = 'success'
and launch_category in ('deep space', 'orbital')
group by to_char(launch_date, 'YYYY')
order by launch_count desc, the_year;
I've done a very quick and dirty guess by pulling out all the dates of "things that look like orbital launches" from the JSR dataset, and looking for clusters of dates. I have omitted launch failures and suborbital launches, and converted everything into calendar days. It also omits everything before 1963 (which are recorded differently) but I think we can reasonably assume the record was not set that early. All dates are using UTC.
It suggests the seven day period with the most launches was March 2015, with a total of eight launches - two launches on 25 March, one on 26, two on 27, one on 28, one on 30, and one on 31. (Details)
There were periods with 7 launches in 7 days in October 1967, December 1970, December 1971, December 1975, December 1977, February 1979, September 1985, October 1985, March 1988, and August 1994.
Busiest day - there seem to be a few dozen days (defined as single days in UTC) with three launches each, but none with four. So a bit of a wash there. There is, however, one 24-hour period with four launches - two late on 5 September 1989, and two early on 6 September (details).
Busiest month - by calendar month, there seem to be five tying for 17 launches (December 1971, July 1967, June 1982, April 1983, June 1984). Within a 31-day period, the record is 20, covering 29 November 1971 to 21 December 1971 (plus a bonus three launch failures, so came close to being 23 - details)
This was a fun data-analysis exercise!
