Moon mission will have to be launched, latest by July 20, and not later, if the mission has to run successfully without risks of compromise or even failure
Lunar transfer trajectory (LTT) (the movement of the spacecraft from the Earth’s orbit towards the Moon’s orbit) has to be completed on August 1, which is referred to as T+17, or 17 days after the initially calculated launch at 2.51 am on July 15.
The scientist said delaying the launch beyond July 20 will mean making a rendezvous with the Moon at a different time and location, which could delay the lander’s separation, besides requiring more fuel. This, in turn, could reduce the life of the orbiter
He said longer lunar orbital insertion or delays would also prevent the lander from separating. He explained that delays in orbit could affect the orbiter’s pyro-circuit, whose objective is to generate energy to light up the lander’s thrusters to separate from the orbiter and begin its descent towards the lunar surface
He emphasised the need to launch not later than July 20, or wait and launch the mission in the next launch period
“Now we have to seal and insulate the joint from the cold or shift it away. The second option is tough if we were to work on the engine without dismantling the rocket. Now efforts are on to plug the leak without moving the rocket from the launchpad, so we can launch it sometime early next week,” said a source.
A senior scientist said the Chandrayaan-2 setback has presented some learnings for the indigenous cryogenic engine
CE-20, which was developed after studying Russian cryogenic engines used rigid joint. Isro adopted the rigid joint concept in several places. The rigid joints have lesser chances of leak, but if there is one, they have to be discarded and made again. ISRO doesn't have the luxury to discard and use another engine in short notice.
The Chandrayaan-2 experience may force Isro to make some changes in the cryogenic stage. We may not entirely drop rigid joints, but now we may think of having some add-ons like an ‘S’ loop or a ‘U’ loop that can help deal with such anomalies. This latest setback has been an unexpected learning curve
Chandrayaan-2 launch, which was called off due to a technical snag on July 15, 2019, is now rescheduled at 2:43 pm IST on Monday, July 22, 2019.
InForceO 181019Z JUL 19HYDROPAC 2326/19(63).BAY OF BENGAL.DNC 03.1. HAZARDOUS OPERATIONS, ROCKET LAUNCHING220830Z TO 221000Z JUL:A. AREA WITHIN TEN MILES OF 13-43.2N 080-13.8E.B. AREA BOUND BY12-30N 082-40E, 13-15N 082-50E,12-45N 084-10E, 12-00N 084-00E.C. AREA BOUND BY11-35N 085-00E, 12-25N 085-10E,11-45N 087-15E, 10-55N 087-05E.D. AREA BOUND BY08-10N 094-20E, 09-00N 094-40E,08-25N 096-15E, 07-35N 095-55E.2. CANCEL THIS MSG 221100Z JUL 19.//GENERAL.//
A1582/19 - GSLV- MKIII- M1 CHANDRAYAAN-2 ROCKET LAUNCH FM SHAR RANGE, SHRIHARIKOTA WILL TAKE PLACE AS PER FLW DETAILS. THE LAUNCH WILL BE ON ANY ONE OF THE DAY DRG THIS PERIOD.ACTUAL DATE OF LAUNCH WILL BE INTIMATED 24 HR IN ADVANCE THROUGH A SEPARATE NOTAM. LAUNCH PAD COORDINATES : 134312.00N 0801348.00E NO FLT IS PERMITTED OVER THE DNG ZONES DANGER ZONE -1: IS A CIRCLE OF 10 NAUTICAL MILES AROUND THE LAUNCH PAD. DANGER ZONE -2: I. 1230N 08240E II. 1315N 08250E III.1245N 08410E IV. 1200N 08400E DANGER ZONE -3 I. 1135N 08500E II. 1225N 08510E III.1145N 08715E IV. 1055N 08705E DANGER ZONE 4 I. 0810N 09420E II. 0900N 09440E III.0825N 09615E IV. 0735N 09555E END PART 1 OF 3. BTN 0830-1000 ON 22-31 JUL, 22 JUL 08:30 2019 UNTIL 31 JUL 10:00 2019. CREATED: 18 JUL 11:10 2019
The problem was resolved without changing any component - just "tightening it worked".
QuoteThe problem was resolved without changing any component - just "tightening it worked".
BENGALURU: Notwithstanding the last-minute scrubbing of Chandrayaan-2 launch on July 15, Isro may still be able to soft-land Vikram (lander) on the same day as it had initially planned —September 6-7. “There may be a slight change in strategy, but it won’t affect the actual day of landing,” a senior scientist associated with the mission told TOI on Thursday.
The agency will be able to achieve the landing on September 6-7 as its initial plan included a “buffer” time around Moon for two reasons: First, to give itself a second chance in case of hiccups that pushed the launch from July 15.
“Now, nothing in the initial approach is changing. We’ll still take 22 days to insert Chandrayaan-2 into the lunar orbit because we need 17 days around Earth for five orbit raising manoeuvres, and then five days for the lunarcraft to travel close to Moon,” a senior scientist explained. Also, the number of days Vikram needs to go around Moon in a 30kmX100km orbit before initiating deboosting procedures for landing will also be the same as planned initially—four days. The only thing that will change is the number of days the spacecraft goes around Moon before lander separation. According to initial plans, the spacecraft was to go around in a 100kmX100km orbit for 28 days before separation, and now it will go around for 21 days.
“Technically, the separation could have happened even after just one day of lunar insertion. The reason the orbiter had 28 days as per the first plan was because the July 15 window meant we reached there much earlier than the most suited day for landing (September 6-7), which gives us 14 full days (1 lunar day) on Moon,” the scientist explained.
“Now, we will reach Moon about seven days later than the initial plan, but still in 22 days from launch. And yet, we have enough time left for landing on the same date,” the scientist added. So, the total number of days of the mission will be reduced from 54 days to 47 days.
A shorter launch window on July 22—Isro chairman K Sivan had on June 12 said that all days of July after the 15th will only have one minute—another senior scientist said, won’t be a “problem”. “You don’t need to worry about the length of the launch window. Look at the last 20 missions and you’ll know that we’ve launched on the dot. So the length of the window shouldn’t be a concern even now,” a scientist said.
Comparison of previous and current flight plan.
UH25 (fuel) filling of liquid core stage (L110) of #GSLVMkIII-M1 commenced. #Chandrayaan2 #ISROStay tuned for more updates....
#Chandrayaan2 #ISROUH25 (fuel) filling of liquid core stage (L110) of #GSLVMkIII-M1 completedUpdates to continue...
Filling of N204 for the liquid core stage (L110) of #GSLVMkIII-M1 commenced#Chandrayaan2 #ISRO Updates will continue.....
https://twitter.com/isro/status/1153128666907332609
Does NASA's Deep Space Network participate in this mission in a supporting role?I know they participate in JAXA Hayabusa2 mission even though JAXA has deep space stations. The DSN also supports ESA even though it also has deep space stations. Have never seen info one way or the other for Indian missions.Thanks