Vega 1
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (March 2011) |
Soviet Academy of Sciences | ||
COSPAR ID | ||
---|---|---|
SATCAT no. |
| |
Mission duration | Balloon: 2 days Orbiter: 2 years, 1 month and 15 days | |
Spacecraft properties | ||
Spacecraft | 5VK No. 901 | |
Spacecraft type | NPO Lavochkin | |
Launch mass | 4,840 kilograms (10,670 lb)[1] | |
Start of mission | ||
Launch date | December 15, 1984 Proton 8K82K | , 09:16:24 UTC|
Launch site | Baikonur 200/39 | |
End of mission | ||
Last contact | 30 January 1987[2] | |
Orbital parameters | ||
Reference system | Semi-major axis 6,558 kilometres (4,075 mi) | |
Eccentricity | 0.03080 | |
Perigee altitude | 159 kilometres (99 mi) | |
Apogee altitude | 202 kilometres (126 mi) | |
Inclination | 51.5° | |
Period | 88 minutes | |
Flyby of Venus | ||
Closest approach | 11 June 1985 | |
Distance | ~39,000 kilometres (24,000 mi) | |
Venus atmospheric probe | ||
Spacecraft component | Vega 1 Balloon | |
Atmospheric entry | 02:06:10, 11 June 1985 | |
Venus lander | ||
Spacecraft component | Vega 1 Descent Craft | |
Landing date | 03:02:54, 11 June 1985 | |
Landing site | 7°30′N 177°42′E / 7.5°N 177.7°E (north of Aphrodite Terra) | |
Flyby of 1P/Halley | ||
Closest approach | 6 March 1986 | |
Distance | ~10,000 km (6,200 mi) | |
Insignia of the mission |
Vega 1 (along with its twin
The craft was powered by twin large solar panels and instruments included an antenna dish, cameras,
Venus mission
The descent module arrived at Venus on 11 June 1985, two days after being released from the Vega 1 flyby probe. The module, a 1,500 kilograms (3,300 lb) sphere with a diameter of 240 centimetres (94 in), contained a surface lander and a balloon explorer. The flyby probe performed a gravitational assist maneuver using Venus, and continued its mission to intercept the comet.[4]
Descent craft
The surface lander was identical to that of Vega 2 as well as the previous six
The lander successfully touched down at 7°12′N 177°48′E / 7.2°N 177.8°E in the
Tools on the lander include:
- Thermometers
- Barometers
- UV absorption spectrometer—ISAV-S
- Optical aerosol analyzer, Nephelometer—ISAV-A
- Aerosol particle-size counter—LSA
- Aerosol mass spectrometer—MALAKHIT-M
- Aerosol gas chromatograph—SIGMA-3
- Aerosol X-ray fluorescence spectrometer—IFP
- Hygrometer—VM-4
- Soil X-ray fluorescence spectrometer—BDRP-AM25
- Gamma-rayspectrometer—GS-15STsV
- Penetrometer / Soil ohmmeter—Prop-V
- Stabilized oscillator / Doppler radio
Balloon
The Vega 1 Lander/Balloon capsule entered the Venus atmosphere (125 kilometres [78 mi] altitude) at 2:06:10 UT (Earth received time; Moscow time 5:06:10 a.m.) on 11 June 1985 at roughly 11 kilometres per second (6.8 mi/s). At approximately 2:06:25 UT the parachute attached to the landing craft cap opened at an altitude of 64 kilometres (40 mi). The cap and parachute were released 15 seconds later at 63 kilometres (39 mi) altitude. The balloon package was pulled out of its compartment by parachute 40 seconds later at 61 kilometres (38 mi) altitude, at 8.1 degrees N, 176.9 degrees east. A second parachute opened at an altitude of 55 kilometres (34 mi), 200 seconds after entry, extracting the furled balloon. The balloon was inflated 100 seconds later at 54 kilometres (34 mi) and the parachute and inflation system were jettisoned. The ballast was jettisoned when the balloon reached roughly 50 kilometres (31 mi) and the balloon floated back to a stable height between 53 and 54 kilometres (33 and 34 mi) some 15 to 25 minutes after entry.
The mean stable height was 53.6 kilometres (33.3 mi), with a pressure of 535 millibars (535 hPa) and a temperature of 300–310 K (27–37 °C; 80–98 °F) in the middle, most active layer of the Venus three-tiered cloud system. The balloon drifted westward in the zonal wind flow with an average speed of about 69 metres per second (230 ft/s) (248 kilometres per hour [154 mph]) at nearly constant latitude. The probe crossed the terminator from night to day at 12:20 UT on 12 June after traversing 8,500 kilometres (5,300 mi). The probe continued to operate in the daytime until the final transmission was received at 00:38 UT on 13 June from 8.1 N, 68.8 E after a total traverse distance of 11,600 kilometres (7,200 mi) or about 30% of the circumference of the planet. It is not known how much farther the balloon traveled after the final communication.[5]
Halley mission
After their encounters, the Vegas' motherships used the gravity of Venus, also known as a gravity assist, to intercept Halley's Comet.
Images started to be returned on 4 March 1986, and were used to help pinpoint
Vega 1 made its closest approach on 6 March at around 8,889 kilometres (5,523 mi) (at 07:20:06 UT) of the nucleus. It took more than 500 pictures via different filters as it flew through the gas cloud around the coma. Although the spacecraft was battered by dust, none of the instruments were disabled during the encounter.
The data intensive examination of the comet covered only the three hours around closest approach. They were intended to measure the physical parameters of the nucleus, such as dimensions, shape, temperature and surface properties, as well as to study the structure and dynamics of the
The Vega images showed the nucleus to be about 14 kilometres (8.7 mi) long with a rotation period of about 53 hours. The dust mass spectrometer detected material similar to the composition of
After subsequent imaging sessions on 7 and 8 March 1986, Vega 1 headed out to deep space. In total Vega 1 and Vega 2 returned about 1500 images of Comet Halley. Vega 1 ran out of attitude control propellant on 30 January 1987, and contact with Vega 2 continued until 24 March 1987.
Vega 1 is currently in
of 281 days.See also
References
- ^ a b "Vega 1" (PDF). NASA. Retrieved 2022-12-02.
- ^ NASA.gov
- ^ V. A. Agureikin, S. I. Anisimov, A. V. Bushman, G. I. Kanel', V. P. Karyagin, A. B. Konstantinov, B. P. Kryukov, V. F. Minin, S. V. Razorenov, R. Z. Sagdeev, S. G. Sugak, V. E. Fortov, (1984). "Thermo-physical and gas-dynamic studies of the meteorite shield for the Vega spacecraft". High Temperature 761-778 22(5). WoS:A1984ALC5000020 Scopus:2-s2.0-0021489019
- ^ a b NASA—NSSDC—Spacecraft—Details
- ^ a b "NASA Database—Solar System Exploration; Missions; By Target; Venus; Past; Vega 1". Archived from the original on 2013-06-15. Retrieved 2015-04-11.
External links
- Vega 1 Measuring Mission Profile by NASA's Solar System Exploration
- Vega mission images from the Space Research Institute (IKI)
- Raw data from Vega 1 and Vega 2 on board instruments
- Soviet Exploration of Venus
- Vega 1 Mission Comet Halley Data Archive at the NASA Planetary Data System, Small Bodies Node