Latest on Chinese 'Long March 5' 25 tonne payload rocket

[gunsandrockets]

The latest on the Chinese CZ-5 modular launch vehicle puts it's date of introduction at 2011. It's supposed to have a maximum payload of 25 tonnes to LEO, and replace the earlier rockets for smaller payload jobs.<br /><br />Compared to the Proton, the 'Long March 5' has equal payload to LEO, but much better payload beyond LEO since it uses LOX/LH2 for the upper stages. China already has a 21 tonne mass LOX/LH2 upper stage in service (the CZ-3A-3), that combined with the existing Shenzou and the lift of this new booster opens up all kinds of interesting manned mission possibilities.<br /><br />http://www.sinodefence.com/space/launchvehicle/cz5.asp<br /><br />http://www.spacepolitics.com/archives/000903.html<br /><br />http://www.astronautix.com/stages/cz3a3.htm<br /><br /> <i>Title edited </i>

 

[gunsandrockets]

In 1968 Apollo 8 went into orbit around the moon, not free-return but honest-to-god orbit, thanks to the power of the Saturn V rocket and the powerful Apollo Service Module. Could China recreate a similar feat as early as 2012? Perhaps, and here is how...<br /><br />By 2012 China is supposed to have already accomplished certain spaceflight milestones: operation of the 21 tonne cryogenic CZ-3A-3 upper stage, operational status for the 25 tonne payload CZ-5 booster and Earth-Orbit-Rendevous/docking of the Shenzou manned spacecraft. These elements plus a 4-tonne storable-propellent-stage/docking-module (used for LOC and TEI) could be combined so as a manned Shenzou spacecraft could orbit the moon and return to Earth. This lunar mission would need two launches and use EOR.<br /><br />The first launch would be a CZ-5 rocket sending a payload of the 21 tonne CZ-3A-3 stage combined with the 4 tonne LOC/TEI stage into LEO. Then a manned Shenzou spacecraft could be launched into LEO using it's normal launch vehicle, the CZ-2F. (Since the CZ-2F uses storable propellants, launch timing for the Shenzou is easy. ) The Shenzou rendezvous in orbit and docks with the rocket stack awaiting it.<br /><br />The CZ-3A-3 stage then does the Trans-Lunar-Injection burn, placing the stack on course for the moon, then is discarded. The Shenzou service-module conducts the mid-course correction burn. As the stack approaches the moon the LOC/TEI stage burns about half it's propellent to brake the Shenzou into lunar orbit.<br /><br />After circling the moon for up to a week, the LOC/TEI stage burns the rest of it's propellent for Trans-Earth-Injection, sending the Shenzou back towards Earth. Final course corrections and maneuvering employ the Shenzou service module.

 

[henryhallam]

Interesting...<br />Like Apollo 8, such a mission would not have the "lifeboat" option of an LM. So everything had better work right first time!

 

[mattblack]

GO CHINA!! <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[themanwithoutapast]

If they would do a manned mission beyond LEO, the most likely thing to do is a lunar slingshot-flyby mission and not risk lunar orbit insertion.<br /><br />That said, given that Roskosmos would pull off a lunar flyby within 3 years, if someone comes up with the cash, a lunar flyby of a manned Shenzhou, say by 2015, is entirely possible. It would also make for great propaganda, therefore it is not entirely unlikely. It, however, all depends on all upcoming Shenzhou missions to be successful and the CZ-5 to go into service in 2011-2013 and fly successful as well.

 

[astrowikizhang]

"The first launch would be a CZ-5 rocket sending a payload of the 21 tonne CZ-3A-3 stage combined with the 4 tonne LOC/TEI stage into LEO."<br /><br />I think CZ-5 will have a new LOX/LH2 upper stage. The CZ-3A-3 stage has 3m diameter but CZ-5 will have a 5m core. And CZ-3A-3 stage seems too long to be stacked on top of the CZ-5.<br /><br />"The CZ-3A-3 stage then does the Trans-Lunar-Injection burn, placing the stack on course for the moon, then is discarded. "<br /><br />The CZ-3A-3 stage can only put 5,100 kg payload to Geosynchronous transfer trajectory (on CZ-3B), why do you think it will be able to send 4 ton storable-propellent-stage/docking-module plus 8 ton Shenzhou to TLI?

 

[astrowikizhang]

Current Chinese Lunar project (Chang'e) focuses on un-manned probs. Now they are working on a small prob that will round the moon. It will be launched on now-available rocket like CZ-3B. The second step is to land a robotic craft on moon. The third is to return lunar samples. Very unlikely they will carry out a manned flyby mission like Zond.

 

[astrowikizhang]

It is from China main stream media:<br /><br />China is planning a few unmanned moon-landing space flights. An unmanned flight near the moon will take place in 2007. China will realize the moon landing in 2012, and will take samples of the moon back to the earth in 2017.<br /><br />http://english.people.com.cn/200604/06/eng20060406_256486.html

 

[vt_hokie]

Do the Chinese still launch over populated areas, like they did when the Intelsat 708 launch killed all those people?

 

[astrowikizhang]

Intelsat 708 is launched from Xichang, where Chinese rocket launched commercial payload to GEO. The site was built in a valley miled from the LCC and populated area. <br /><br />The CZ-3B was not destroyed by the range safety control. It flew a long distance before hitting a small hill on the way heading to the LCC. The accident killed tens of people, including whose who working in the space center for this launch. Some of them were watching the liftoff. A man was blown from the roof by the shock wave.<br /><br />Shenzhou is launched from Jiuquan, where Chinese launched ICBM and payload to high inclination orbits. The site is in a desert.<br /><br />Another space center is in Taiyuan and launches to solar orbit. It is near the capital of the Shanxi province.<br /><br />Mao decided to move the military industry and bases deeply inside the territory during Cold War. His concern was to defend invasion from the super powers. The very same strategic protected the country from Japanese in the WWII. Security and environment issue was ignored. That is why those space centers are located in far center west China, and rockets inevitably fly over populated area in east China. But the jettison of the boosters and first stage is designed to avoid falling onto heavily populated big cities.<br /><br />It is said that CZ-5 will be launched from a new site to be built in Hainan island. It will be the first space center by the sea, and focused on commercial launchs. But due to the collapse of the international launch market and the uncertainty of the Chinese space station program, CZ-5 and the new launch site will need to get approved.

 

[gunsandrockets]

"Current Chinese Lunar project (Chang'e) focuses on un-manned probs... Very unlikely they will carry out a manned flyby mission like Zond."<br /><br />I never claimed that China had any plans for any manned lunar mission in the near furture. My point is, China's existing space plans create the capability of launching a lunar mission in the near future.

 

[gunsandrockets]

" ...a lunar flyby [by] a manned Shenzhou, say by 2015, is entirely possible."<br /><br />If a mere lunar flyby was all, China could almost do such a thing today, they wouldn't even need a new larger launch vehicle. The only thing missing is experience with Earth Orbit Rendezvous, experience China plans to gain by 2010.

 

[gunsandrockets]

"I think CZ-5 will have a new LOX/LH2 upper stage. The CZ-3A-3 stage has 3m diameter but CZ-5 will have a 5m core. And CZ-3A-3 stage seems too long to be stacked on top of the CZ-5."<br /><br />Well, my plan describes using the CZ-3A-3 as payload delivered to orbit, not as one of the CZ-5's stages.<br /><br />"The CZ-3A-3 stage can only put 5,100 kg payload to Geosynchronous transfer trajectory (on CZ-3B), why do you think it will be able to send 4 ton storable-propellent-stage/docking-module plus 8 ton Shenzhou to TLI? "<br /><br />Because my plan never employs the CZ-3B launch vehicle. The performance of the CZ-3A-3 stage, fully fuelled and parked in LEO, is not the same as a third stage of the CZ-3B launch vehicle.<br /><br />As the link I previously provided shows, the CZ-3A-3 stage is comparable to one of the larger versions of the Centaur upper stage. The CZ-3A-3 has a loaded mass of 21 tonnes, 18 tonnes of which is propellant, and has an ISP of 440 seconds. By my calculations the 33 tonne stack of the Shenzou + LOC/TEI stage + CZ-3A-3 stage would gain a velocity of 3.5 km/s at burnout of the CZ-3A-3, which is plenty of velocity for TLI. <br /><br />Your questions caused me to recalculate my assumptions which led to interesting results, one of which is the LOC/TEI stage is too light and another is the CZ-3A-3 stage isn't even neccessary. My original plan overlooked the whole performance of the new CZ-5 launch vehicle. If the CZ-5 performs as advertized, Shenzou EOR with an CZ-3A-3 TLI-stage isn't needed, as the CZ-5 by itself could send the Shenzou complete with a LOC/TEI stage towards the moon.<br /><br />The link for the CZ-5 claims it would have the capability of placing 25 tonnes into LEO or 14 tonnes into GEO. That is performance in scale with the Titan IV launch vehicle. That means the CZ-5 should be able to send about 14 tonnes towards the moon, since the delta V requirement for TLI are less than that for GEO.<br /><br />So my revised plan is even easier and

 

[astrowikizhang]

"The link for the CZ-5 claims it would have the capability of placing 25 tonnes into LEO or 14 tonnes into GEO. "<br /><br />That is the heavist configuration of CZ-5, http://www.astronautix.com/lvs/czn504ho.htm<br /><br />It will be as powerful as Delta IV Heavy is, sending payload of the size and weight that Space Shuttle can send to LEO. Such a launch vehicle should be able to support the moon-fly-by mission. <br /><br />"That means the CZ-5 should be able to send about 14 tonnes towards the moon, since the delta V requirement for TLI are less than that for GEO. "<br /><br />That is my question. Why do you think the upper stage can send the same mass to TLI as it does to GTO? TLI requires a higher Apogee that needs more thrust, more burning time and more propellant.<br /><br />"No multiple launches, no Earth Orbit Rendezvous, just a single CZ-5 with a payload of an 8 tonne Shenzou and a 6 tonne LOC/TEI stage. "<br /><br />Just like the Zond missions that Soviet attemped and failed in 1960s. http://www.astronautix.com/craft/soyz7kl1.htm

 

[mlorrey]

TLI takes marginally less dv than GSO. The dv difference between GTO and LLO is only 1400 m/s at most. GTO to GSO dv is 1500 m/s. So you should be able to get to LLO cheaper than GSO. Going into LLO, then getting out again on a direct approach to Earth would require 2100 m/s.<br /><br />So, you should be able to get 14 tonnes PLUS 100 m/s of dv propellant into LLO with the CZ-5. With 14 tonnes, you've got plenty of mass for a crew module and service module with enough dv for the return trip.<br /><br />The NASA CEV Block 2 (Lunar crew) is supposed to have 1724 m/s of dv, plus 50 m/s of dv in the RCS thrusters. So it has plenty of dv for the mission. <br /><br />Looking at Shenzou, its service module only has 380 m/s of dv. This is going to need to be significantly improved if Shenzou is going to be used for lunar missions. I suspect that some weights engineers are going to be needed to trim excess structural mass from the crew and orbital modules. Perhaps eliminate the OM entirely, or ejected in LLO for the return trip. This should significantly improve dv on the existing fuel supply.<br /><br />Shenzou is also only a bit over 7.8 tonnes, leaving plenty of mass for a lunar lander. I suspect that this is what they will attempt to do: Shenzou and a lander, launched from the CZ-5, with no Orbital Module and expanded fuel tanks on the SM. This will allow them to go for a lunar landing. If the CZ-5 becomes viable before 2010, I'll bet that they just go and do it, not give any indication to the outside world that they are going to do it, and kick NASA in the teeth.<br /><br />

 

[astrowikizhang]

"TLI takes marginally less dv than GSO. The dv difference between GTO and LLO is only 1400 m/s at most. GTO to GSO dv is 1500 m/s. So you should be able to get to LLO cheaper than GSO."<br /><br />I think the TLI burn will happen on LEO instead of GTO. The upper stage first burn for LEO insertion, then re-stared for TLI. Apollo missions start TLI on the orbiter of 180 km by 165 km. The TLI deltaV provided by S-IVB stage is about 3000-4000 m/s.<br /><br />CZ-5 can send 14 t to GTO, not GSO, so the payload still need the deltaV for GSO insertion, that is the 1500 m/s mentioned. Assuming the LEO-TLI deltaV is higher then LEO-GTO deltaV, the intact mass could be sent to lunar orbit will be much less than 14 t.

 

[mlorrey]

I wouldn't say "much less" than 14 t. After all, we've seen GSO satellites reach GSO after the GTO-GSO burn on their upper stage failed, and used merely their thrusters and a swing around the moon to reach GSO. As the current Shenzou has 1,000 kg of fuel presently, it stands to reason that about 3-4t should be sufficient to attain required dv.

 

[gunsandrockets]

"Such a launch vehicle [CZ-5] should be able to support the moon-fly-by mission. "<br /><br />More than just a fly-by, it should be able to support a lunar-orbital mission.<br /><br />"Why do you think the upper stage can send the same mass to TLI as it does to GTO?"<br /><br />I never said 'same mass to TLI as to GTO'. I compared the TLI payload to GEO payload, not to GTO payload. It takes more delta V to send the same payload to GEO than to TLI. The various sources on the CZ-5 are in conflict, some say 14 tonnes GTO and some say 14 tonnes GEO. But it really doesn't matter since the delta V difference between GTO and TLI is trivial, only 0.7 km/s...<br /><br />http://www.pma.caltech.edu/~chirata/deltav.html<br /><br />"[Shenzou lunar mission] Just like the Zond missions that Soviet attemped and failed in 1960s."<br /><br />First off not all Zond missions failed, Zond 7 was successful...<br /><br />http://www.astronautix.com/articles/sovpart1.htm<br /><br />"1969-08-08: Zond 7 - Soyuz 7K-L1 s/n 11L - Circumlunar flight; successfully recovered in USSR August 13, 1969. Only completely successful L1 flight that could have returned cosmonauts alive or uninjured to earth. Landed 50 km from aim point near Kustani in the USSR. "<br /><br />Secondly the Zond circumlunar missions were fly-by missions, not orbital missions...<br /><br />http://www.astronautix.com/details/zond6810.htm<br /><br />Third, the Zond missions used a risky atmospheric-skipping reentry technique. Fourth, the Proton launch vehicle used for the Zond missions had much less lunar mission payload than the CZ-5 is supposed to have. So Zond missions are not comparable to the Shenzou lunar mission I propose.<br /><br /><br /><br />

 

[gunsandrockets]

"Looking at Shenzou, its service module only has 380 m/s of dv. This is going to need to be significantly improved if Shenzou is going to be used for lunar missions."<br /><br />Which is why my Shenzou plan adds a 6 tonne LOC/TEI stage with 5.3 tonnes of hypergolic propellant to the Shenzou. The LOC/TEI stage performs braking into lunar orbit and later the Trans-Earth-Injection burn to leave lunar orbit. That leaves the Shenzou Service Module to perform all other maneuvers and as reserve.<br /><br />"Shenzou is also only a bit over 7.8 tonnes, leaving plenty of mass for a lunar lander. I suspect that this is what they will attempt to do: Shenzou and a lander, launched from the CZ-5, with no Orbital Module and expanded fuel tanks on the SM. This will allow them to go for a lunar landing."<br /><br />I don't think the CZ-5 has anywhere near the margin for a Saturn V style one-launch LOR lunar-landing mission. Even cutting down the Shenzou as you suggest won't make up the mass needed for even a minimal lander. But one CZ-5 should be able to comfortably send a two or three man Shenzou into lunar orbit.<br /><br />The Chinese already have plans for an unmanned lunar-sample-return mission, planned for 2017. The Soviet 1970 LSR mission was launched by the Proton, sending a 5 tonne lander to the moon. The Chinese CZ-5 should be able to send a much larger lander.<br /><br />Now look what is comparable in mass to the old Soviet lander,...<br /><br />http://www.astronautix.com/craft/lmllight.htm<br /><br />The Langley Light one-man open-cab lunar lander! If the Langley Light hypergolic-fueled lander was scaled up for two men it would mass about 8.5 tonnes. Do you see what I'm getting at? If the Chinese are clever, their unmanned lunar-sample-return spacecraft could also double as a basis for a Langley Light style open-cab manned lander.<br /><br />So with two launches of the CZ-5, China could send the lander in

 

[astrowikizhang]

"http://www.pma.caltech.edu/~chirata/deltav.html "<br /><br />Thanks for your link.<br /><br />"First off not all Zond missions failed, Zond 7 was successful... "<br /><br />I mean the Zond project failed to send Cosmonauts round the moon and back alive.<br /><br />"Fourth, the Proton launch vehicle used for the Zond missions had much less lunar mission payload than the CZ-5 is supposed to have."<br /><br />I think Proton has a lower capibility to send payload to GEO or lunar orbit partly (or largely) due to the higher latitude of Baikonur.<br /><br />"So Zond missions are not comparable to the Shenzou lunar mission I propose."<br /><br />If Chinese really want to send men around moon, very likely they would develop something resembles Zond, as Shenzhou likes Soyuz.

 

[gunsandrockets]

"I think Proton has a lower capibility to send payload to GEO or lunar orbit partly (or largely) due to the higher latitude of Baikonur."<br /><br />The Proton has a bigger problem than launch lattitude. The beyond LEO payload of the Proton is seriously compromised by the lack of a high ISP upper stage.

 

[no_way]

If ( when ? ) the chinese figure out the idea of dry launch, EOR architecture and work out the necessary docking and fuel transfer technologies, they can definitely put a man on the moon with exisitng launchers. I suspect they will push for fly-by as well ASAP just to claim that they are capable of sending humans further out to space than any other nation.

 

[mlorrey]

"If Chinese really want to send men around moon, very likely they would develop something resembles Zond, as Shenzhou likes Soyuz. "<br /><br />Actually, the Zond WAS, in fact, the Soyuz, with no Orbital Module. If, as I suggested, the Chinese launched a Shenzhou without its OM, they could replicate the Zond mission with the CZ-5 and existing delta-V budget. Without the OM, Shenzhou's mass would drop from 7,800 kg to 6,300 kg. <br /><br />6.3 tonnes with the fuel budget capable of sending of 15 tonnes to GTO means delta-v for a circumlunar mission, easily. It would also expand the dv of the Shenzhou due to the lower vehicle mass to about 500 m/s.<br /><br />Given the larger volume of the Shenzhou v the Soyuz capsules, they could easily send a 3 man crew on a six day mission around the moon.<br /><br />The Shenzhou OM isn't really used much for living space anyways, it appears they pack it full of electronics for their "science" missions (likely with a significant "earth observations" capacity).

 

[gunsandrockets]

"If, as I suggested, the Chinese launched a Shenzhou without its OM, they could replicate the Zond mission with the CZ-5 and existing delta-V budget. Without the OM, Shenzhou's mass would drop from 7,800 kg to 6,300 kg. 6.3 tonnes with the fuel budget capable of sending of 15 tonnes to GTO means delta-v for a circumlunar mission, easily."<br /><br />To restate the obvious, why cut down the Shenzou for a flyby mision when the proposed launch vehicle, the CZ-5, already has gobs of excess capacity to do the job? That doesn't make any sense.<br /><br />The only reason the Soviets cut down the Soyuz for the Zond lunar flybys is because the Proton rocket didn't have enough payload to send a complete Soyuz on the mission.<br /><br />

 

[krrr]

Let's just do the math correctly.<br /><br />The CZ-5 is supposed to deliver 14 tonnes to GTO. This is a delta-v of 2450 m/s from LEO.<br /><br />Delta-v for TLI, however, is 3150 m/s. This means that payload towards the Moon would be 11.5 tonnes at most.<br /><br />Together with a ~3.5 tonne LOI/TEI stage, a Shenzhou would still be able to enter lunar orbit, but only a higly elliptical one.