Project Mimosa

Launch and the first communication with the ground station
Introduction
Orbital elements
Orbital motion in pictures
Last photographs of Mimosa before the launch
Related links

Launch and the first communication with the ground station

The Rockot launcher took off successfully from the Russian cosmodrome Plesetsk at the planned time 14:15 UT on 30 June 2003, Mimosa was the first satellite to be separated from the third stage at 15:02 UT over the Southern Pacific. At 15:42 UT the first signal from Mimosa was received at the ground station in Panska Ves; the second signal followed the first one at 17:17 UT and each of them took about 15 minutes. It was confirmed that all active devices aboard the satellite are in the normal operational mode. During the next two morning passes at 4:55 UT and 6:28 UT, it was confirmed that the satellite received commands from the ground station and performed them. From our co-worker in Plesetsk we obtained the video recording of the launch (Mimosa-start.zip 9.4 MB).

Before the launch

The launch

Introduction

MIMOSA (MIcroMeasurements Of Satellite Accelerations) is a small Czech scientific satellite which has been developed for the Astronomical Institute of Czech Academy of Sciences by the Czech company Space Devices. On its board, there is a sensible accelerometer intended for measuring the nongravitational forces, which are caused by atmospheric drag, solar radiation and terrestrial infrared radiation. The satellite will be launched on 30 June 2003 at 16:15:12 CEST from the Russian cosmodrome Plesetsk to a low earth orbit reaching the height of 320 km at perigee and 820 km at apogee, inclined at 96.8° to the equator. The main goal of the mission is to study the atmospheric density in the height domain 200-700 km that affects low flying satellites, causing them to burn up as they finally reenter the atmosphere (e. g. Sputnik, Skylab, Mir). The satellite Mimosa will be controlled from the ground facility at Panska Ves, situated in the northern part of the Czech Republic.

Orbital elements

Here we list the planned Keplerian orbital elements of the Mimosa satellite at the moment of its separation from the final stage of the launcher, on 30 June 2003, 15:02 UT.

semi-major axis	6948.578 km
eccentricity	0.035999
inclination	96.801°
raan	187.32°
argument of perigee	228.853°
true anomaly	9.723°

modified Julian date	MJD 52820.626065
day of year	181.626065
orbital period	5764.4s = 96.073 min
orbital frequency	14.99 rev/day
perigee height	320.3 km
apogee height	820.6 km
velocity at perigee	7.851 km/s
velocity at apogee	7.306 km/s
longitude asc. node	60°
change in raan	0.88° / day = 360° / 411 days
change in arg. of perigee	-3.44 ° / day = - 360° / 105 days
long-term change in perigee height	7.4 sin(w) km

(Notation: raan ... right ascension of the ascending node, w ... argument of perigee.)

The SGP4 two-line elements, used in various satellite tracking programs (the satellite number is made-up): MIMOSA 1 09999U 3181.62606481 .00000000 00000-0 00000-0 0 16 2 09999 96.8000 187.3629 0380079 229.5867 8.2452 14.96416437 10

Orbital motion in pictures

Download the animated gif picture (2.9 MB) of the first day of Mimosa in the planned orbit, demonstrating the communication of the satellite with the ground station in Panska Ves. In the picture bellow, the sunlit parts of the trajectory are highlighted by yellow, the thick brown lines indicate that the satellite is at 0° elevation, the white ones the elevation of 10°.