SALSA in numbers
How the telescopes are used. Every figure is a total for whole calendar months; no individual users are shown. Bookings and observations by system admins, commonly used for tests or maintenance, are not included in the figures below.
Since the start
SALSA has existed since the early 2000s. The numbers below reflect the use since the start of this new web-based control system, launched in May 2026.
228
Registered users
not counting guests
1,213
Hours booked
46.1 h per week on average
517
Guest sessions
39.7 h in total, via “Observe now”
5,544
Observations saved
by logged-in users
Applies to everything below. Whole calendar months only; the current month is added once it has ended.
Hours booked per month
Booked telescope time, all telescopes together.
Where users are
Country is looked up from the connection when a booking or guest session starts. The ten most common countries are listed; the rest are grouped as “Other”, which can be opened to see them all.
Users with bookings
Distinct users per country · 34 countries
SE
40
DE
11
IT
8
GB
7
BR
6
ES
6
FR
6
EC
4
HN
4
NL
4
Other (24)
32
US
4
HU
3
IN
3
CH
2
AT
1
BE
1
CA
1
CL
1
CO
1
CZ
1
EG
1
GR
1
ID
1
IE
1
JP
1
KR
1
MD
1
MX
1
NO
1
NP
1
PL
1
RO
1
SG
1
UZ
1
Guest sessions
Sessions per country · 49 countries
SE
188
US
53
IT
49
IN
26
HN
20
NL
20
BR
17
DE
17
ES
14
CH
10
Other (39)
103
GB
9
HU
7
CO
6
RS
6
EC
5
FI
4
FR
4
GR
4
KR
4
LT
4
NO
4
PL
4
CA
3
CL
3
AT
2
CN
2
IR
2
IS
2
KE
2
MX
2
PR
2
RO
2
RU
2
SG
2
UZ
2
AD
1
AX
1
BE
1
BG
1
BY
1
DK
1
GH
1
IE
1
JO
1
KG
1
KZ
1
MU
1
PT
1
SI
1
Month by month
| Month |
Observations |
Bookings |
Hours booked |
Hours / week |
Users with bookings |
Guest sessions |
Guest hours |
| May 2026 | 851 | 59 | 142 |
32.1 | 28 | 78 | 4.5 |
| June 2026 | 678 | 49 | 144 |
33.6 | 22 | 33 | 2.0 |
| July 2026 | 647 | 43 | 170 |
38.4 | 18 | 42 | 3.4 |
| August 2026 | 284 | 50 | 109 |
24.6 | 20 | 131 | 9.8 |
| September 2026 | 570 | 80 | 161 |
37.6 | 37 | 147 | 13.0 |
| October 2026 | 2,514 | 146 | 487 |
110.0 | 45 | 86 | 7.0 |
| Total | 5,544 | 427 | 1,213 |
46.1 | 127 | 517 | 39.7 |
- System admins: their bookings and observations, commonly used for tests or maintenance, are not included anywhere on this page.
- Bookings: a run of back-to-back slots booked by the same user on the same telescope counts as one booking.
- Users with bookings: each person is counted once per period, so the total is not the sum of the months.
- Observations: spectra saved by logged-in users. Guest sessions do not save observations, so they are not part of this count.
- Hours / week: booked hours divided by the number of weeks in the period, so short and long months compare fairly.
- Guest sessions: anonymous “Observe now” use, counted separately from bookings. Guest hours count finished sessions only, each at most 30 minutes long.
- Months follow UTC.