Shenzhou Design Changes Reason For Launch Delay
Beijing - Mar 13, 2002
A senior Chinese space official revealed Monday that problems with internal systems of the Shenzhou-3 (SZ-3) spacecraft was the major cause for the lengthy delay in launching the third test flight of China's future manned spacecraft a Beijing newspaper reported.
In an interview with the newspaper Beijing Youth Daily Zhuang Fenggan, Chairman of Science and Technology Committee of China Aerospace Science and Technology Corporation (CASC) and a consultant on advanced technology at China Aerospace Science and Industry Corporation (CASIC), said that the original plan was to launch SZ-3 last year.
Mission designers had hoped to improve the interior installation of the spacecraft on this mission. But problems appeared after the changes were implemented. This forced the design team to revert back to the previous interior set-up and delayed the mission to this year. Zhuang, however, did not provide any details of the changes and the problems encountered.
The 77-year-old aerodynamics specialist said, "I personally believe that it is best not to change the spacecraft installation. Even the subsequent SZ-4 and SZ-5 spacecraft should not make changes.
"If every mission has some changes, conditions of the space vehicle of each launch are definitely not identical. If such changes are kept up, conditions [of the spacecraft] would be different by the time the manned mission is launched. We simply cannot guarantee the reliability of the conditions at that time."
Zhuang further explained that demand on the reliability of the manned spacecraft was very high and such a reliability would not come from calculations but from verification through full testings.
He added, "Speaking as a technician, when the launch will take place is not important. It is important to guarantee the safe launch and return of the yuhangyuans ("astronauts").
"After the successful flight of SZ-1, some people had said that the follow-up mission should be manned to ride on the momentum. We clearly cannot do that."
Zhuang confirmed that before the rollout of the Changzheng-2F (Long March-2F) launcher with Shenzhou-3 (Shenzhou means "Magic Vessel" or "Divine Vessel") on board, technicians had completed all ground tests, including electrical inspection and simulation work. The entire mission procedure had been determined and every effort had been made to ensure perfection in each mission segment.
On SZ-3 there will be a dummy yuhangyuan on board as part of the test on the complex and expensive life protection system. Other tests will include checking the safety of the reentry system as well as conducting experiments on board and sensing the space environment. Like the SZ-2 mission, after the Descent Module separates from the Orbital Module for reentry, the Orbital Module will continue operation in orbit for about half a year.
The other significant difference in this mission is a piggyback launch of a satellite. Zhuang disclosed that a satellite would catch a ride into space aboard the CZ-2F rocket. But he did not say anything about the nature of the satellite.
When asked why primates such as monkeys were not launched on these test flights as the former Soviet Union and the U.S. had done with their early test missions of the manned capsules, Zhuang replied that China's approach would be using dummies that are rigged up with sensors.
"Unlike decades ago when many technical difficulties existed, making a dummy is now simpler. We could, say, measure simulated blood pressure using a dummy on a mission. If a monkey is launched into space, unless it is tightly secured and made immobile, the monkey could touch anything on board and cause troubles.
"Speaking from another perspective, we want to guarantee the safety of the yuhangyuans much as with the animals. Otherwise animal protection groups would protest," said Zhuang.
The long delay of the SZ-3 mission has pushed the timeline of the first manned flight further back. A year ago the Japanese newspaper Yomiuri Shimbun quoted a senior Chinese space official as saying that China could launch the first manned mission late this year. Last week Hu Shixiang, Deputy Minister of the General Armament Department of the People's Liberation Army (PLA), admitted that the timeline became unrealistic.
But Hu said that depending on the outcome of additional unmanned test flights of Shenzhou, the first manned mission could take place as early as next year.
Zhuang agreed that the first manned mission would surely not occur this year. If testing progresses smoothly, there may be another unmanned test launch this year.
He emphasized, "Speaking as a matter of principle, we have mastered manned spaceflight technical issues. But a new car that just leaves the factory can suddenly break down on the road. If problems with the spacecraft are not resolved before it breaks down, they could turn into major issues."
Subscribe To SpaceDaily Express
Shenzhou-3 On The Pad Awaiting Launch
Beijing - Mar 12, 2002
Senior Chinese officials have confirmed that the Changzheng-2F (Long March-2F) launcher with the Shenzhou-3 (SZ-3, Shenzhou means "Magic Vessel" or "Divine Vessel") spacecraft on board is now standing at a Jiuquan Satellite Launch Centre (JSLC) launch pad.