ISRO successfully tests boot-strap mode start on CE20 cryogenic engine
Bengaluru (PTI): The ISRO on Wednesday announced that it has successfully demonstrated the boot-strap mode start test of the CE20 Cryogenic engine, which powers the upper stage of the Launch Vehicle Mark -3 (LVM3) rocket.
The test was conducted for 10 second under vacuum conditions at the High-Altitude Test (HAT) facility at ISRO Propulsion Complex, Mahendragiri on November 7, it said.
According to ISRO, the CE20 cryogenic engine is already qualified for operation at thrust levels between 19 and 22 tonnes with a single start in flight and is cleared for use in the Gaganyaan missions.
Under normal conditions, the engine ignition begins under tank head pressure, followed by a turbopump start up using a stored gas start-up system, the space agency said. For future missions, multiple in-flight restarts of the CE20 engine will be required for mission flexibility, towards multi-orbit missions.
With the current configuration, each restart requires an additional start-up gas bottle and associated systems, leading to a reduction in vehicle payload capability, it said. "Hence, achieving boot-strap mode start - where the engine builds up to steady operation without external start-up assistance - is essential."
During the test, a multi-element igniter was employed in both the thrust chamber and gas generator to facilitate boot-strap starting, the agency added.
"In this test, following the ignition of the thrust chamber, the gas generator was ignited under tank head conditions, and the turbopumps were started without the use of the start-up system. Subsequently, boot-strap mode build-up and steady-state operation of the engine were successfully demonstrated," it said.
"With this achievement, ISRO has successfully demonstrated boot-strap mode starting of a gas-generator cycle cryogenic engine without any auxiliary start-up system, perhaps for the first time in the world - a significant milestone towards enhancing the restart capability and mission flexibility of future LVM3 flights," it added.
Let the Truth be known. If you read VB and like VB, please be a VB Supporter and Help us deliver the Truth to one and all.
Pak, Afghan forces trade fire along Chaman border: Report
Islamabad (PTI): A heavy exchange of fire between Pakistani and Afghan forces was reported from the key Chaman border, according to a media report on Saturday.
Injuries were reported from the district hospital, but no fatalities occurred, the Dawn newspaper reported.
Officials from both sides accused each other of instigating the flare-up late on Friday night across the border in the Balochistan province.
While Pakistani officials said that Afghan forces had fired mortar shells on the Badani area, Afghan Taliban spokesperson Zabihullah Mujahid claimed it was Pakistan that launched an attack on Spin Boldak, alleging that their forces were responding.
Pakistan's official sources told Dawn that Pakistani forces retaliated against the Afghan aggression and returned fire.
There were also reports of fighting on the Chaman-Kandahar highway, but these could not be immediately verified.
A senior official in Quetta confirmed on condition of anonymity that the exchange of fire started around 10 pm and continued until late at night.
The medical superintendent of Chaman district hospital said that three injured, including a woman, were brought to the medical facility.
There was neither any official word from the Inter-Services Public Relations -- Pakistan Army's media wing -- nor from the Foreign Office.
The Chaman border crossing, also known as Friendship Gate, connects Balochistan province to Afghanistan’s Kandahar.
Relations between Pakistan and Afghanistan have deteriorated amidst regular allegations by Pakistan regarding the failure of the Afghan regime to deny safe havens to Tehreek-e-Taliban Pakistan terrorists.
The two countries had agreed on a ceasefire following tensions last month, but the Foreign Office said last month that technically there was no truce as it was contingent on the Afghan Taliban stopping terrorist attacks in Pakistan, which they had failed to do.
