火卫一计划

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火卫一计划 (Фобос, Fobos) 是一项苏联太空计划，该计划由两颗无人空间探测器组成，以探测火星及其的卫星(火卫一和火卫二)。火卫一1号和火卫一2号分别在1988年7月7日和1988年7月12日使用质子K型运载火箭发射。

火卫一1号在前往火星的途中失联。火卫一2号成功进入绕火轨道，但在着陆器着陆之前失去联系。两个探测器使用了全新的探测器设计，继承了1975 年至 1985 年期间金星计划使用的4MV型探测器，以及维加1号和维加2号哈雷彗星任务中使用的5VK型探测器。每个探测器的质量为2600公斤（安装入轨机动部件后质量为6220公斤，为2011年发射的福布斯-土壤之前的最重深空探测器）。

这次计划除了苏联之外，还与其他14个国家合作，其中包括瑞典、瑞士、奥地利、法国、西德和美国等国（美国贡献了其深空网络来追踪这对探测器）。

## 目的

The objectives of the Phobos missions were to:

- conduct studies of the interplanetary environment;
- perform observations of the Sun;
- characterize the plasma environment in the Martian vicinity;
- conduct surface and atmospheric studies of Mars; and,
- study the surface composition of the Martian satellite Phobos.

## 设计

The main section of the spacecraft consisted of a pressurized toroidal electronics section, surrounding a modular cylindrical experiment section. Below these were mounted four spherical tanks (the Fregat stage) containing hydrazine for attitude control and, after the main propulsion module was to be jettisoned, orbit adjustment. A total of 28 thrusters (twenty-four 50 N thrusters and four 10 N thrusters) were mounted on the spherical tanks, with additional thrusters mounted on the spacecraft body and solar panels. Attitude was maintained through the use of a three-axis control system, with pointing maintained with Sun and star sensors.

## 火卫一1号

火卫一1号一开始运作正常，但在前往火星几周后，原定于1988年9月2日的联系却失败。控制人员与探测器失联，事后被查明是因为在1988年8月29日或30日上传的软件发生故障，姿态推进器停止运作。导致太阳能板无法再对准太阳，从而耗尽了电池电量。

Software instructions to turn off the probe's attitude control, normally a fatal operation, were part of a routine used when testing the spacecraft on the ground. Normally this routine would be removed before launch. However, the software was coded in PROMs, and so removing the test code would have required removing and replacing the entire computer. Because of time pressure from the impending launch, engineers decided to leave the command sequence in, though it should never be used. However, a single-character error in constructing an upload sequence resulted in the command executing, with subsequent loss of the spacecraft.

## 火卫一2号

火卫一2号在1988年7月12日使用质子K型运载火箭发射，并于1989年1月29日进入火星轨道。1989年1月29日，火卫一2号巡航阶段和火星轨道插入阶段成功，并收集了有关太阳、行星际介质、火星和火卫一的数据。火卫一2号号探测了火星表面和大气层及传回了37张分辨率高达 40 米的火卫一图像，火卫一2号在准备着陆器着陆之前失去联系。

## 系统和科学仪器

Phobos probes carried several instruments: solar x-ray and ultraviolet telescopes, a neutron spectrometer and the Grunt radar experiment designed to study the surface relief of Phobos.

The lander had an x-ray/alpha spectrometer to provide information on the chemical element composition of the surface of Phobos, a seismometer to determine the internal structure of Phobos, and the "Razrez" penetrator with temperature sensors and an accelerometer for testing the physical and mechanical properties of the surface.

The Phobos 2 infrared spectrometer (ISM) obtained 45000 spectra in the near infrared (from 0.75 to 3.2 μm) in the equatorial areas of Mars, with a spatial resolution ranging from 7 to 25 km, and 400 spectra of Phobos at 700 m resolution. These observations made it possible to retrieve the first mineralogical maps of the planet and its satellite, and to study the atmosphere of Mars. ISM was developed at IAS and DESPA (Paris Observatory) with support from CNES.

List of instruments:

- "VSK" TV imaging system
- PROP-F "hopping" lander. Only carried by Phobos 2.
- ARS-FP automatic X-ray fluorescence spectrometer
- ferroprobe magnetometer
- Kappameter magnetic permeability / susceptibility sensor
- gravimeter
- temperature sensors
- BISIN conductometer / tiltmeter
- mechanical sensors (penetrometer, UIU accelerometer, sensors on hopping mechanism)
- "DAS" (long-lived autonomous station) lander
- TV camera
- ALPHA-X Alpha-Proton-X-Ray Spectrometer
- LIBRATION Sun sensor (also known as STENOPEE)
- Seismometer
- RAZREZ anchor penetrometer
- Celestial mechanics experiment
- "ISM" thermal infrared spectrometer/radiometer - 1–2 km resolution
- near-infrared imaging spectrometer
- thermal imaging camera; magnetometers
- gamma-ray spectrometers
- X-ray telescope
- radiation detectors
- radar and laser altimeters
- Lima-D laser experiment - designed to vaporise material from the Phobos surface for chemical analysis by a mass spectrometer
- Automatic Space Plasma Experiment with Rotating Analyzer (ASPERA), an electron spectrometer and ion mass analyser from the Swedish Institute of Space Physics.
- "Grunt" imaging radar - Only carried by Phobos 1

## 后续

本计划的设计方案后来再次被用于延期已久的火星96任务（探测目标改为火星），但该任务最终因运载火箭D2组级点火失败而告终。此外，同样旨在探测火卫一的福布斯-土壤任务也在2011年失败。迄今为止，还没有探测器能够完全成功地抵达火卫一。

## 参考资料

- Articles in Nature 341 (1989) pages 581 - 619
- Phobos Project Information (NASA NSSDC)
- Fobos 1F
- ISM - Phobos-2 archive
- The Airport Terminal - also known as Mariner 9 #4209-75

## 外部链接

- High quality processed images from the Phobos 2 mission
- Phobos mission images from the Space Research Institute (IKI)
- Raw image data from the Phobos 2 ISM infrared instrument
- What we are searching for on Phobos - an article on the Phobos program at the Web site of the Russian Space Agency
- Another site with processed images from the Soviet Phobos 2 mission