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[任务跟踪] ISRO“月船一号”跟踪贴:5月19日提升轨道至200km

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潜艇4809 发表于 2008-11-1 17:55 | 显示全部楼层 |阅读模式

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本帖最后由 jingyan66 于 2009-5-21 10:30 编辑

月船一号相关数据

轨道高度:100km±15km
轨道倾角:90±5度
轨道周期:117.6分

The fourth orbit raising manoeuvre of Chandrayaan-1 spacecraft was carried out today (October 29, 2008) morning at 07:38 am IST. During this manoeuvre, the spacecraft’s 440 Newton liquid engine was fired for about three minutes. With this, Chandrayaan-1 entered into a more elliptical orbit whose apogee (farthest point to Earth) lies at 267,000 km (two lakh sixty seven thousand km) while the perigee (nearest point to Earth) lies at 465 km. Thus, Chandrayaan-1 spacecraft’s present orbit extends more than half the way to moon. In this orbit, the spacecraft takes about six days to go round the Earth once.
The health of the spacecraft is being continuously monitored from the Spacecraft Control Centre at ISRO Telemetry, Tracking and Command Network (ISTRAC) in Bangalore with support from Indian Deep Space Network antennas at Byalalu. All systems onboard the spacecraft are performing normally. One more orbit raising manoeuvre is scheduled to send the spacecraft to the vicinity of the moon at a distance of about 384,000 km from the Earth.

                               
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中文大意如下:

       ISRO于2008年10月29日早上7点38分对月船一号探月卫星进行了第四次以提高轨道高度为目的的变轨机动,在这次变轨中,卫星上的440牛顿液体发动机开机近3分钟,使其椭圆轨道长轴更长,近地点高度465km,远地点高度267000km。其远地点高度己经超过了地月距离的一半。轨道周期变为了6天绕地球一周。
        卫星的健康状况一直受到ISRO的遥测控制。在班格洛尔的跟踪和指令网络受到了位于bayalalu的印度深空网络天线的支持。现在卫星运行正常,下一次变轨将把卫星送至月球附近384000km的轨道。
darklighter 发表于 2008-11-4 14:56 | 显示全部楼层
ISRO宣布(http://www.isro.org/pressrelease/Nov04_2008.htm),北京时间11月4日07:26,“月船一号”成功进行了第五次近地点变轨。440N发动机工作约2.5分钟,探测器进入地月转移轨道。“月船一号”各系统工作正常,预计11月8日进行月球轨道注入(月球捕获)。
11月8日月球捕获的时间在北京时间晚上(之前有报道是20:27,也可能有所变化),届时月球捕获的高度究竟是1000km还是500km是一个可以关注的问题。
这次变轨发动机工作时间比较长(与只提高远地点的理想情况相比),可能是为了修正前面的误差(误差最可能出现在近地点幅角方面,之前几次变轨后的远地点或周期并没有什么问题),也可能计划就是如此(当然这比较奇怪,但考虑到似乎是最近才把原定1000km的月球捕获高度改成了500km,也不是不可能)。
这次变轨比最理想情况多消耗的速度增量,可以粗略估计为30-40m/s,对后续飞行的影响很小。
jingyan66 发表于 2008-11-5 08:53 | 显示全部楼层

“月船-1”如何提升到更高的轨道上

<p><font class="storyhead" color="blue" size="4"><b>How Chandrayaan-1 is raised to higher orbits</b></font></p>
<p>&nbsp;</p>
<p><font color="blue">Thursday, Oct 30, 2008</font> </p>
<p>&nbsp;</p>
<p>Chandrayaan-1 could have been fired to reach the moon, which is about 3,84,000 km from earth, in one shot. But that was not done. Instead the spacecraft is being moved towards the moon in increasingly elliptical orbits with an apogee (farthest point from the earth) increasing many times more than the perigee.</p>
<p>&nbsp;</p>
<p>“We could have done it one shot, but there is a possibility of missing the moon,” said M. Annadurai, Project Director of Chandrayaan-1 to this Correspondent. “So we have adopted an incremental increase in the orbits’ perigee.” </p>
<p>&nbsp;</p>
<p>That probably explains why the Indian Space Research Organisation (ISRO) has decided to settle for five increasingly elliptical orbits before Chandrayaan-1 reaches the moon’s sphere of influence. Why is the firing always undertaken at the perigee position? </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Firing at perigee </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>“<strong><font color="#ff0000">To increase the apogee, we must fire at the perigee [position]. And firing should consume less energy. So the firing is done at the perigee</font></strong>,” Dr. Annadurai explained.</p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000">One more reason to fire at the perigee is to ensure that the spacecraft can be tracked by 3-4 ground stations</font></strong>. “The spacecraft is allowed to complete one or more orbits till such time 3-4 ground stations can track it. But we will fire it at the earliest opportunity,” he said. </p>
<p>&nbsp;</p>
<p>But not always can one assume that the firing will happen as planned. So any change in this will in turn affect the apsidal line (imaginary line that connects the apogee and perigee). This should be corrected and maintained if the rendezvous with the moon is to happen. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Increasing the apogee </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>And what ensures that the apogee increases many hundred kilometres after every firing while the perigee changes by only a few kilometres? “When the firing is done exactly at perigee, the velocity increases and the apogee keeps increasing. There will be no change in the perigee position,” he said. </p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000">But firing the spacecraft exactly at the perigee position is only theoretically possible. This results in a small change in the perigee altitude</font></strong>. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Duration of firing </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>“It is not an instant firing [at the perigee]. It takes a few hundred seconds to complete the firing,” he said. But great effort is however taken to centre the firing around the perigee position. </p>
<p>&nbsp;</p>
<p>For instance, the first firing to take Chandrayaan-1 from the initial orbit to the first orbit (with an apogee of 38,000 km) took about 1060 seconds to complete. The second firing to take the spacecraft to the nearly 75,000 km apogee took 920 seconds. And the third firing to raise it to about 1,65,000 km apogee took 560 seconds. </p>
<p>&nbsp;</p>
<p>The fourth firing to take Chandrayaan-1 to 2,67,000 km will take about 190 seconds and finally the last raise to 3,80,000 will take 150 seconds. </p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000" size="4">Though the original plan was to reach 2,00,000 km apogee in the third orbit, ISRO could only raise it to 1,65,000 km. So will that lead to any problems? “This can be made up for in the next firing,”</font></strong> Dr. Annadurai said. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Use of propellant </font></p>
<p>&nbsp;</p>
<p>Will the change in the orbit-transfer strategy from five-and-half days to nearly a fortnight lead to increased fuel consumption and hence reduced mission life? “<strong><font color="#ff0000">The amount of propellant required to fire the spacecraft to 4,00,000 km is less, whether it is done in one shot or in stages</font></strong>. And the propellant is used only for changing the orbits and not for orbiting around the earth,” he explained. </p>
<p>&nbsp;</p>
<p>Orbiting around the earth is mainly through the gravitational force of the earth. But the gravitational influence of sun and moon would still play a role, though minor. Since the spacecraft goes around only for a few days in each orbit, there will not be any change in the orbits and hence the need to use propellant to correct the orbits would not arise.</p>
<p>&nbsp;</p>
<p>But that will not be case when Chandrayaan-1 orbits the moon for two years. “There will be a need to correct the orbit once in two weeks to maintain a 100 km circular orbit,” said Dr. Annadurai. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Less energy required </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>While earth’s gravitational force will exist even when the spacecraft moves further and further away from the earth, the force will decrease with distance. “So firing it to the fourth and fifth orbit will require less energy,” said Dr. Annadurai. “Since some propellant is already used in the previous firings, the overall mass would come down. So the effort required to fire reduces.” </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Reverse firing</font></p>
<p><font class="subsectionhead" color="red" size="3">&nbsp;</font></p>
<p align="justify"></p>
<p>Five-and-half days after the fifth firing, Chandrayaan-1 will have its rendezvous with the moon. </p>
<p>&nbsp;</p>
<p>Chandrayaan-1 will get nearer to the moon on November 8 when it reaches the 3,81,000 km apogee. </p>
<p>Though the moon’s influence will be predominant, the velocity of Chandrayaan-1 has to be reduced to enable the moon to capture it. Else, it can fly past the moon. </p>
<p>&nbsp;</p>
<p>Once captured by the moon’s gravity, the velocity of the spacecraft has to be reduced to help it reach its final destination of 100 km circular orbit around the moon.</p>
<p>&nbsp;</p>
<p>This is achieved by reversing what was done to raise its orbits.</p>
<p>&nbsp;</p>
<p>“First, the firing is resorted at both perigee and apogee positions. And the firing takes place only after the orientation of the spacecraft is reversed — turned 180 degrees,” he said.</p>
<p>&nbsp;</p>
<p>While the momentum of the spacecraft allows it to move in the same direction, the reverse firing helps it to reduce the velocity. The reduction in velocity is again undertaken in an incremental manner to reach the predetermined 100 km circular orbit around the moon. </p>
冷眼 发表于 2008-11-5 08:55 | 显示全部楼层
<font face="Verdana">A3的轨道多变,很难琢磨.....</font>
jingyan66 发表于 2008-11-5 09:12 | 显示全部楼层
<div class="msgheader">QUOTE:</div><div class="msgborder"><b>以下是引用<i>jingyan66</i>在2008-11-5 8:53:02的发言:</b><br/>
<p><font class="storyhead" color="blue" size="4"><b>How Chandrayaan-1 is raised to higher orbits</b></font></p>
<p>&nbsp;</p>
<p><font color="blue">Thursday, Oct 30, 2008</font> </p>
<p>&nbsp;</p>
<p>Chandrayaan-1 could have been fired to reach the moon, which is about 3,84,000 km from earth, in one shot. But that was not done. Instead the spacecraft is being moved towards the moon in increasingly elliptical orbits with an apogee (farthest point from the earth) increasing many times more than the perigee.</p>
<p>&nbsp;</p>
<p>“We could have done it one shot, but there is a possibility of missing the moon,” said M. Annadurai, Project Director of Chandrayaan-1 to this Correspondent. “So we have adopted an incremental increase in the orbits’ perigee.” </p>
<p>&nbsp;</p>
<p>That probably explains why the Indian Space Research Organisation (ISRO) has decided to settle for five increasingly elliptical orbits before Chandrayaan-1 reaches the moon’s sphere of influence. Why is the firing always undertaken at the perigee position? </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Firing at perigee </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>“<strong><font color="#ff0000">To increase the apogee, we must fire at the perigee [position]. And firing should consume less energy. So the firing is done at the perigee</font></strong>,” Dr. Annadurai explained.</p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000">One more reason to fire at the perigee is to ensure that the spacecraft can be tracked by 3-4 ground stations</font></strong>. “The spacecraft is allowed to complete one or more orbits till such time 3-4 ground stations can track it. But we will fire it at the earliest opportunity,” he said. </p>
<p>&nbsp;</p>
<p>But not always can one assume that the firing will happen as planned. So any change in this will in turn affect the apsidal line (imaginary line that connects the apogee and perigee). This should be corrected and maintained if the rendezvous with the moon is to happen. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Increasing the apogee </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>And what ensures that the apogee increases many hundred kilometres after every firing while the perigee changes by only a few kilometres? “When the firing is done exactly at perigee, the velocity increases and the apogee keeps increasing. There will be no change in the perigee position,” he said. </p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000">But firing the spacecraft exactly at the perigee position is only theoretically possible. This results in a small change in the perigee altitude</font></strong>. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Duration of firing </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>“It is not an instant firing [at the perigee]. It takes a few hundred seconds to complete the firing,” he said. But great effort is however taken to centre the firing around the perigee position. </p>
<p>&nbsp;</p>
<p>For instance, the first firing to take Chandrayaan-1 from the initial orbit to the first orbit (with an apogee of 38,000 km) took about 1060 seconds to complete. The second firing to take the spacecraft to the nearly 75,000 km apogee took 920 seconds. And the third firing to raise it to about 1,65,000 km apogee took 560 seconds. </p>
<p>&nbsp;</p>
<p>The fourth firing to take Chandrayaan-1 to 2,67,000 km will take about 190 seconds and finally the last raise to 3,80,000 will take 150 seconds. </p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000" size="4">Though the original plan was to reach 2,00,000 km apogee in the third orbit, ISRO could only raise it to 1,65,000 km. So will that lead to any problems? “This can be made up for in the next firing,”</font></strong> Dr. Annadurai said. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Use of propellant </font></p>
<p>&nbsp;</p>
<p>Will the change in the orbit-transfer strategy from five-and-half days to nearly a fortnight lead to increased fuel consumption and hence reduced mission life? “<strong><font color="#ff0000">The amount of propellant required to fire the spacecraft to 4,00,000 km is less, whether it is done in one shot or in stages</font></strong>. And the propellant is used only for changing the orbits and not for orbiting around the earth,” he explained. </p>
<p>&nbsp;</p>
<p>Orbiting around the earth is mainly through the gravitational force of the earth. But the gravitational influence of sun and moon would still play a role, though minor. Since the spacecraft goes around only for a few days in each orbit, there will not be any change in the orbits and hence the need to use propellant to correct the orbits would not arise.</p>
<p>&nbsp;</p>
<p>But that will not be case when Chandrayaan-1 orbits the moon for two years. “There will be a need to correct the orbit once in two weeks to maintain a 100 km circular orbit,” said Dr. Annadurai. </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Less energy required </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>While earth’s gravitational force will exist even when the spacecraft moves further and further away from the earth, the force will decrease with distance. “So firing it to the fourth and fifth orbit will require less energy,” said Dr. Annadurai. “Since some propellant is already used in the previous firings, the overall mass would come down. So the effort required to fire reduces.” </p>
<p>&nbsp;</p>
<p><font class="subsectionhead" color="red" size="3">Reverse firing</font></p>
<p><font class="subsectionhead" color="red" size="3">&nbsp;</font></p>
<p align="justify"></p>
<p>Five-and-half days after the fifth firing, Chandrayaan-1 will have its rendezvous with the moon. </p>
<p>&nbsp;</p>
<p>Chandrayaan-1 will get nearer to the moon on November 8 when it reaches the 3,81,000 km apogee. </p>
<p>Though the moon’s influence will be predominant, the velocity of Chandrayaan-1 has to be reduced to enable the moon to capture it. Else, it can fly past the moon. </p>
<p>&nbsp;</p>
<p>Once captured by the moon’s gravity, the velocity of the spacecraft has to be reduced to help it reach its final destination of 100 km circular orbit around the moon.</p>
<p>&nbsp;</p>
<p>This is achieved by reversing what was done to raise its orbits.</p>
<p>&nbsp;</p>
<p>“First, the firing is resorted at both perigee and apogee positions. And the firing takes place only after the orientation of the spacecraft is reversed — turned 180 degrees,” he said.</p>
<p>&nbsp;</p>
<p>While the momentum of the spacecraft allows it to move in the same direction, the reverse firing helps it to reduce the velocity. The reduction in velocity is again undertaken in an incremental manner to reach the predetermined 100 km circular orbit around the moon. </p></div>
<p>&nbsp;</p>
<p>这篇报道解释了调轨时为何在近地点点火及几次调轨近地点高度出现误差的原因。</p>
<p>&nbsp;</p>
<p><strong><font color="#ff0000" size="4">Though the original plan was to reach 2,00,000 km apogee in the third orbit, ISRO could only raise it to 1,65,000 km. So will that lead to any problems? “This can be made up for in the next firing,”</font></strong> Dr. Annadurai said。“月船-1”项目负责人讲的这句话似乎又说明第3次调轨确实存在较大误差?</p>
jingyan66 发表于 2008-11-5 09:22 | 显示全部楼层

“月船-1”项目负责人的一篇访谈

&nbsp;
<p class="MsoNormal" style="TEXT-ALIGN: center" align="center"><b style="mso-bidi-font-weight: normal"><span style="FONT-SIZE: 14pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">‘</span></b><b style="mso-bidi-font-weight: normal"><span lang="EN-US" style="FONT-SIZE: 14pt">Ready for missions to other planets’<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o:p></o:p></span></b></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Nov. 08-21, 2008<span style="mso-spacerun: yes">&nbsp;&nbsp; </span>T.S. SUBRAMANIAN <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Interview with M. Annadurai, project director, Chandrayaan-1 .<span style="mso-spacerun: yes">&nbsp; </span><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">M. Annadurai: “Our main objective was to provide a systematic chemical and mineral mapping of the entire moon.” <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New="New"  Roman'; mso-hansi-font-family: 'Times New="New"  Roman'">“</span><span lang="EN-US">WITH Chandrayaan-1 realised and launched, we are technically ready to take up a truly interplanetary mission,” says M. Annadurai, project director, Chandrayaan-1.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Speaking to Frontline on October 24 in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-comffice:smarttags" /><st1:City w:st="on"><st1:place w:st="on">Bangalore</st1:place></st1:City>, he explained, among other things, the logic behind the mission, laying stress on locating water and helium-3 on the moon. Annadurai, 50, has a B.E. (Electronics) degree from the Government College of Technology, <st1:City w:st="on">Coimbatore</st1:City>, and a postgraduate degree (M.E.) in the same discipline from the PSG College of Technology, <st1:City w:st="on"><st1:place w:st="on">Coimbatore</st1:place></st1:City>. He took over as the project director of Chandrayaan-1 in 2004. He was mission director for all Indian National Satellite (INSAT) projects from 1996. Excerpts from the interview:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong>What are the reasons that dictated the choice of 11 scientific instruments on board Chandrayaan-1? <o:p></o:p></strong></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Our main objective was to provide a systematic chemical and mineral mapping of the entire moon. Over and above that, we are to look for resources on the moon. We made our instruments basically covering these objectives. <strong><font color="#ff0000">The instruments we selected from abroad will technically overlap the returns from our instruments so that we can compare the results.</font></strong> That is why we have payloads for the optical region, near infrared region, low energy X-ray, high energy X-ray and even radio regimes. <strong><font color="#ff0000">We received 26 proposals from abroad. We also looked at the real competence of each organisation in terms of the instruments they projected and their ability to match our schedule</font></strong>. On these merits, we selected two instruments from the <st1:country-region w:st="on">U.S.</st1:country-region> and four from Europe [including one from <st1:country-region w:st="on"><st1:place w:st="on">Bulgaria</st1:place></st1:country-region>].<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong>Why is there so much of stress on confirming the presence of water-ice on the moon? <o:p></o:p></strong></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">In case we have to start a human civilisation beyond the earth, water is the minimum requirement. The second [objective] is the possibility of exploiting some of the resources available in lunar soil. In that category come uranium, thorium and helium-3.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Former President A.P.J. Abdul Kalam has spoken about the possibility of harvesting helium-3 in lunar soil and bringing it to earth. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Soil samples brought from the moon do indicate an abundance of helium-3. This happened in the 1980s. Basically, the laboratory models of helium-3-based reactors also started around that time. Putting these two together, they again started going to the moon in the early 1990s. If you look at it logically, in another 15 to 20 years if this resource is available and if it … [the fusion reactor] comes through, space technology can play a major role in bringing this resource from our nearest planet. Towards that, we have to build technologies in parallel and Chandrayaan-1 is the first step in that direction.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">We will go closer to the moon, then land on the moon and enable technologies to move around the moon and logically extend these technologies to bring samples to the earth. If everything happens by the time the reactors are ready, we will be at a point where we can, together, provide an energy solution for the future. This is the thinking now. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong>What were the facilities that you established at ISRO Satellite Centre, <st1:City w:st="on"><st1:place w:st="on">Bangalore</st1:place></st1:City>, for testing Chandrayaan-1? <o:p></o:p></strong></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">We basically made use of most of the facilities that were already in existence. We augmented some of them and some we made new.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong>What did you augment and what did you make new? <o:p></o:p></strong></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Byalalu [with its 32-metre and 18-metre antennas] is a full-fledged new facility. The Indian Space Science Data Centre is also totally new. It will serve not only Chandrayaan-1 but future missions.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">We augmented the clean room (at ISRO Satellite Centre where Chandrayaan-1 was built). We made the systems to provide the ultra-clean environment needed for Chandrayaan-1. This is the first time we have made science instruments that need an ultra-clean environment and have to be maintained without contamination for months.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong><font color="#ff0000">Integration of the instruments went on for nearly a year and a half</font></strong>. We made special instruments/arrangements in the clean room so that the instruments were maintained in a very clean set-up. These called for instruments to be purged with nitrogen. Our engineers made these instruments and the set-up.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">However, we had to ensure that the environment was conducive to engineers and scientists working there because nitrogen could harm them. So we had to monitor and control the environment during the entire period of one year and a half in the clean room. This called for a new set of monitoring and control instrumentation in the clean room where Chandrayaan-1 was kept most of the time. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Then there is the thermo-vacuum chamber. The earlier spacecraft had to work in an earth environment whereas this spacecraft has to work in the lunar environment. Even while retaining the existing chamber, we had to make special instrumentation so that Chandrayaan-1 is tested in the simulated lunar environment. So our engineers, in an ingenious way, simulated the thermo-vacuum environment.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">We simultaneously made new calibration facilities for some of the new scientific instruments we built ourselves and for those our collaborators brought.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Although Chandrayaan-1 is not treated as an interplanetary mission, we have used this opportunity – because it is travelling 3.84 lakh kilometres away from the earth – to include some of the technologies and ground instrumentation required for interplanetary missions. So Chandrayaan-1 is like an interplanetary mission as far as to and fro communication is concerned. This means, with Chandrayaan-1 realised and launched, we are ready technically to take up a truly interplanetary mission. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong>Did you face any difficulties in integrating the payloads from abroad into the spacecraft bus? What is the reason for the delay in launching the spacecraft when you had announced that it would go up on April 9, 2008? <o:p></o:p></strong></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">No [there were no difficulties]. <strong><font color="#ff0000">If you look at the delay, there were two reasons. As and when the instruments came, we integrated them. When I said it would go up in April, I had announced it long ago…, I purposely announced a schedule that was one year ahead of the realisable schedule.<o:p></o:p></font></strong></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><strong><font color="#ff0000">Our project report talks about a five-year schedule. The budget was cleared in September 2003 and the project was really formed in April 2004 and will complete five years only in April 2009. I launched the spacecraft in October 2008, which is four years and a half from April 2004. So, first of all, it is not a delay</font></strong>.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Secondly, why did I go from April to October 2008 – a delay of six months? As I pointed out earlier, my schedule was ambitious. We thought if the instruments kept coming in, we would be ready as per the schedule. When we add an instrument, it slightly disturbs the previous instrument already integrated [into the bus]. This is a risk. But we have to ensure that all the instruments work in tandem. You cannot correct the instrument that has already arrived. You have to correct the interface only. You have to arrange your house to accommodate a guest. You cannot ask the guest to change himself to suit your house. We have to make sure that things suit our guests.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">It was not one or two instruments but 11. Matching each other’s needs takes its own time. Accommodating 11 instruments is not easy…. Ours is a reasonable schedule because this is the first time we are making such instruments and this is a full-fledged mission. The spacecraft has to match not only our instruments but the newly set-up Deep Space Network. Whatever interaction takes place, it has to take place in the spacecraft also. It has to go in tandem.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">You have to look at the PSLV’s [Polar Satellite Launch Vehicle] constraint also. I cannot say that I want the rocket to lift 1,500 kg or 1,700 kg. That limit also has to be kept in mind. If you look at these constraints, we have done a reasonably good job. I don’t think we are delayed.</span></p>
jingyan66 发表于 2008-11-5 09:27 | 显示全部楼层
从上面这篇报道看ISRO在为“月船-1”选择有效载荷时,确实采取了相当开放的态度。不过,把这些万国牌的载荷整合到一起也花了不少功夫。另外,说到项目延迟问题时,有些狡辩的意味[em97]
jingyan66 发表于 2008-11-5 09:34 | 显示全部楼层

仍是那篇访谈,讲到了“月船-1”奔月调轨方案几经变更的过程

<p><font class="storyhead" color="blue" size="4"><b>Orbital challenges </b></font></p>
<p>&nbsp;</p>
<p>SENDING a spacecraft on a lunar mission involves navigating it, controlling it and communicating with it as it travels deep into space towards the moon. The moon’s gravity model is not uniformly spread as is that of the earth and is far more complex. Precise orbit-manoeuvring capabilities should be engineered into Chandrayaan-1 to prevent it from falling. That is why the Indian Space Research Organisation’s (ISRO) top brass was circumspect on October 22 when the PSLV-C11 put Chandrayaan-1 into its initial orbit with an apogee of 22,866 kilometres and a perigee of 256 km. “This is only the first step. We have a long way to go in time and space before we reach the moon,” they cautiously told reporters.</p>
<p>There are two or three ways of reaching the moon. The Russians and the Americans have used the tested approach of sending the spacecraft into a low-parking earth orbit and then boosting it to the lunar orbit.</p>
<p>&nbsp;</p>
<p>ISRO has repeatedly changed its plans for the manoeuvres to send Chandrayaan-1 to its final orbit of 100 km × 100 km above the moon. The initial plan was to put Chandrayaan-1 in a transfer orbit with an apogee of 36,000 km and a perigee of 285 km. Then commands to the propulsion system of the spacecraft were to send it into an extended transfer orbit. Subsequent manoeuvres were to send the spacecraft around the moon and then its orbit was to be reduced in stages until the spacecraft was finally put into a 100-km lunar orbit. In this plan, Chandrayaan-1 would have reached the moon in five and a half days. </p>
<p>&nbsp;</p>
<p>However, this plan was given up and a new plan was drawn up to put Chandrayaan-1into an initial earth orbit of 22,866 km × 256 km, raise it to a geostationary orbit of 37,000 km × 300 km, and again raise it to 73,000 km × 300 km. Following this, Chandrayaan-1 was to be propelled beyond the moon with an apogee of 3,87,000 km, brought back to circle the earth and then taken back to the moon, where its velocity was to be reduced to insert it into its lunar orbit and finally slot it into a 100-km lunar orbit. One of these manoeuvres, of propelling Chandrayaan-1 to the moon, bringing it back to the earth and manoeuvring it again to the moon, would have taken 11 days. That is why the ISRO top brass said on October 22 that Chandrayaan-1 would ultimately be placed into the lunar orbit at an altitude of 100 km on November 15, that is, three weeks from October 22.</p>
<p>&nbsp;</p>
<p></p>
<p><font class="subsectionhead" color="red" size="3">Change in strategy </font></p>
<p><font color="#ff0000" size="3"></font>&nbsp;</p>
<p align="justify"></p>
<p>ISRO gave up this strategy, too, and as on October 30, Chandrayaan-1’s orbit had been raised four times. First, it was raised on October 23 from its initial orbit of 22,866 km × 256 km to 37,000 km × 305 km, in which it took 11 hours to go round the earth once. Then, on October 25, its orbit was raised again to 74,715 km × 336 km, in which it took about 25 hours to go round the earth once. </p>
<p>&nbsp;</p>
<p>In the third orbit-raising manoeuvre on October 26, the spacecraft went deep into space and reached almost half the distance to the moon, with an apogee of 1,64,600 km and a perigee of 348 km. In this orbit, it took 73 hours to go round the earth once. </p>
<p>&nbsp;</p>
<p>In the fourth manoeuvre on October 29, commands were radioed to fire its engine and take the spacecraft to a highly elliptical orbit with the farthest distance of 2,67,000 km (two-thirds of the distance to the moon) and the nearest distance of 465 km. In this orbit, the spacecraft would take six days to go round the earth once.</p>
<p>&nbsp;</p>
<p>The fifth manoeuvre to raise the orbit was scheduled for November 4, to take it to a distance of 3,84,000 km. It will partially circle the moon and then go into a highly elliptical orbit around it. </p>
<p>&nbsp;</p>
<p>On November 8, after Chandrayaan-1 reaches the vicinity of the moon, its velocity will be reduced by rotating it in the opposite direction. The velocity is reduced so that the moon’s gravity captures the spacecraft and puts it into a lunar orbit. This has to be done with precision, in stages. Otherwise, the spacecraft will fly past the moon. </p>
<p>&nbsp;</p>
<p>If things go as planned, on November 15 the spacecraft will be slotted into the final orbit at an altitude of 100 km above the moon. </p>
<p>&nbsp;</p>
<p><i>T.S. Subramanian</i></p>
heito 发表于 2008-11-4 18:48 | 显示全部楼层
印度“月船1号”进入月球引力区  
2008年11月04日 18:45:08  来源:新华网
        新华网新德里11月4日电(记者周珺)印度空间研究组织4日说,印度首颗绕月探测器“月船1号”当天已顺利脱离地球引力进入月球引力区。
        印度空间研究组织探月项目主管萨蒂什对媒体说,印度当地时间4日凌晨5时许,“月船1号”上携带的液体远地点发动机启动约两分半钟后,该探测器成功变轨,并最终飞抵距月球表面1000公里的“捕捉轨道”,该轨道距离地球约38万公里。在这一轨道上,“月船1号”将对地球和月球进行拍摄。到目前为止,该探测器的运行一切正常。此后,“月船1号”会再次提速向月球靠近,按计划于印度当地时间8日进入距月球表面100公里的绕月轨道并稳定飞行。
       “月船1号”上载有11台来自印度和欧美国家的科研探测仪器,将在2年的绕月飞行期间对月球表面进行矿物及地形勘测。
       “月船1号”于10月22日由一枚极地卫星运载火箭发射升空。该探测器在进入绕月飞行轨道后一周将释放一颗撞击探测器撞击月球表面,为未来的月球车登月提供研究数据。

liudao 发表于 2008-11-4 18:51 | 显示全部楼层
11月4日央视消息,确定捕捉轨道为500公里.
jingyan66 发表于 2008-11-4 18:55 | 显示全部楼层
看到这个帖子就伤心,在XH上我可是跟踪了一年的,20多页的回复啊。一切都要重新开始了
liudao 发表于 2008-11-4 19:00 | 显示全部楼层
<div class="msgheader">QUOTE:</div><div class="msgborder"><b>以下是引用<i>jingyan66</i>在2008-11-4 18:55:58的发言:</b><br/>看到这个帖子就伤心,在XH上我可是跟踪了一年的,20多页的回复啊。一切都要重新开始了<img title="dvubb" alt="图片点击可在新窗口打开查看" src="http://www.9ifly.cn/chat/images/emot/em66.gif" align="middle" border="0"/> </div>
<p>虚幻真是老羊头不想玩了?如果属实,那这个人太次了,居然一声招呼都不打,什么人啊,还管理员!</p>
jingyan66 发表于 2008-11-5 08:40 | 显示全部楼层

11月15日,“月船-1”到达100km的月球工作轨道

11月15日,“月船-1”到达100km的月球工作轨道
Chandrayaan leaves earth’s gravity

Wednesday, Nov 05, 2008

CHENNAI: Chandrayaan-1 on Tuesday became the first Indian-built spacecraft to leave the earth’s gravity and head towards the moon.

It accomplished this significant milestone in its journey when it entered the lunar transfer orbit with an apogee of 3,80,000 km after its on-board engine fired for two and a half minutes from 4.56 a.m. The spacecraft will cross the 3,80,000 km-mark, that is reach the vicinity of the moon, on November 8. The moon is 3,84,000 km from the earth. Chandrayaan-1 is India’s dedicated science mission to study it in detail.

M. Annadurai, Project Director, Chandrayaan-1, said: “The spacecraft is in lunar transfer orbit. Everything is normal. We will do the lunar insertion manoeuvre of the spacecraft on November 8. We are working for the spacecraft to reach its final lunar orbit on November 15.”

On the mission, Mr. Annadurai said, “everything is proceeding as per plan. We will continue to monitor and track the spacecraft.”

En route to the moon, Chandrayaan-1 will take pictures of the lunar surface with the help of its scientific instrument called the Terrain Mapping Camera (TMC). The Indian Space Research Organisation (ISRO) has already switched on the TMC, which has beamed down pictures of the earth.

Commands for the crucial manoeuvre of putting Chandrayaan-1 in the lunar transfer orbit were radioed from the Spacecraft Control Centre, the nerve-centre of the operations now, located at the ISRO Telemetry, Tracking and Command Network (ISTRAC), Bangalore. ISTRAC can control the two massive bowl-shaped antennas, with diameters of 32 metres and 18 metres, at Byalalu village, 40 km away. These antennas keep a tab on Chandrayaan-1’s journey to the moon.

S.K. Shivakumar, ISTRAC Director, said: “Chandrayaan-1 is on the way to the moon now. Its apogee will be 3,80,000 km. It is the first Indian-built spacecraft to leave the earth’s gravity. It has enough escape-velocity to leave the earth’s gravity.”

When the spacecraft approaches the moon on November 8, the Spacecraft Control Centre will beam commands for inserting Chandrayaan-1 into the lunar orbit and it will be attracted by the moon’s gravity. On November 15, it will be lowered into its final orbit when it will start circling the moon over its poles at an altitude of 100 km. The spacecraft was in good shape, Mr. Shivakumar said. The 32-metre and 18-metre antennas were “very much tracking” it.
 楼主| 潜艇4809 发表于 2008-11-8 12:43 | 显示全部楼层
<p align="center"><img src="http://www.isro.org/Chandrayaan/images/mission2.jpg"/></p>
<p align="center">&nbsp;</p>
<p align="center">月船一号探月轨道图<br/><br/><img src="http://www.isro.org/Chandrayaan/images/radiation_big.jpg"/><br/><br/>印度ISRO发布的月球辐射环境图</p>
<p align="center">&nbsp;</p>
<p align="left"><strong><font size="4">月船一号上的有效载荷及用途</font></strong></p>
<p align="center">&nbsp;</p>
<p align="left"><font face="Verdana">Search for water-ice&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp; MiniSAR, HEX, SARA&nbsp; <br/>Chemical Mapping&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; C1XS, HEX&nbsp; <br/>Mineralogical Mapping&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;HySI, SIR-2, M3&nbsp; <br/>Topography Mapping&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; LLRI,TMC&nbsp; <br/>Radiation Environment&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;RADOM, HEX, C1XS&nbsp; <br/>Magnetic Field Mapping&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; SARA&nbsp; <br/>Volatile Transport&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;HEX&nbsp; <br/>Lunar Atmospheric constituent&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; MIP <br/><br/></p>
<p align="center"><img src="http://www.isro.org/Chandrayaan/images/map.JPG"/></font></p>
[此贴子已经被作者于2008-11-8 13:06:13编辑过]
aaok 发表于 2008-11-8 00:10 | 显示全部楼层
<font face="Verdana">&nbsp;有暗夜兄在,这样的贴我是不敢发了。</font>
aaok 发表于 2008-11-8 02:51 | 显示全部楼层
印度空间研究组织官员萨蒂什说,当天早晨5时左右,“月船一号”上携带的液体远地点发动机点火约150秒后,“月船一号”获得变轨动力,顺利进入距离地球38.4万公里、距离月球表面1000公里的轨道。 <br/>5号以后就再无新的消息,没有消息其实也是消息。它透露出二个消息。 <br/>1月船1号没有失踪,还在天上。尽管有可能已经飞向太阳或将要撞击月球,但它确实还在太空飞。 <br/>2月船1号没有按预定轨道进行绕月飞行,如果已经成功进行绕月飞行,印度人还不吹破牛皮呀。所以以上二点就是最新的有关印度探月卫星的消息。 <br/>
[此贴子已经被站长于2008-11-8 16:57:29编辑过]
aaok 发表于 2008-11-8 02:52 | 显示全部楼层
印度空间研究组织官员萨蒂什说,当天早晨5时左右,“月船一号”上携带的液体远地点发动机点火约150秒后,“月船一号”获得变轨动力,顺利进入距离地球38.4万公里、距离月球表面1000公里的轨道。 <br/>5号以后就再无新的消息,没有消息其实也是消息。它透露出二个消息。 <br/>1月船1号没有失踪,还在天上。尽管有可能已经飞向太阳或将要撞击月球,但它确实还在太空飞。 <br/>2月船1号没有按预定轨道进行绕月飞行,如果已经成功进行绕月飞行,印度人还不吹破牛皮呀。所以以上二点就是最新的有关印度探月卫星的消息。 <br/>
[此贴子已经被站长于2008-11-8 16:56:45编辑过]
wljs123 发表于 2008-11-8 09:54 | 显示全部楼层
阿三的有新消息吗?
暗夜流星 发表于 2008-11-8 11:17 | 显示全部楼层
<p>我只是说这个帖子重复了,没有别的意思,可以在原来的那个帖子里面讨论Chandrayaan-1的消息,乱开贴的毛病不好。</p>
<p>怀疑轨道的尽管怀疑,哈哈。</p>
diyue 发表于 2008-11-7 17:15 | 显示全部楼层

A3的月船看来是到不了月球了

A3月船的轨道偏差太大,累计偏差的时间有1天多,就算轨道够得上月球,时间也错过了,月球一天可是要走8万多公里的,怎么赶也赶不上。
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