Quote from: gwiz on 02/25/2017 02:59 PMWhat's poor about resolving cars from space?The Cartosat is supposed to have 25cm resolution
What's poor about resolving cars from space?
While the 101 foreign satellites that flew on the PSLV C37 on February 15 and ISRO’s own 714 kg Cartosat-2 mapping satellite have stabilised and reported back to Earth stations with the first bits of data, two experimental Indian nano satellites – INS-1A and INS-1B weighing 8.4 kg and 9.7 kg – are yet to achieve stability to begin operations.
While ISRO has put out the first set of images taken by the Cartosat 2 series satellite, there has been no information about INS-1 A and INS 1-B since their launch even as data from some sites monitoring the satellites have indicated that the two have not stabilised despite over 10 days in space.“Attempts are being made to stabilise the experimental nano satellites that were launched. The efforts are still on,’’ ISRO director for publicity D P Karnik said.The two nano satellites are being monitored by the ISRO Telemetry, Tracking and Command Network (ISTRAC) in Bengaluru. The experimental nano satellites are carrying instruments from ISRO’s Space Application Centre and the Laboratory for Electro Optic Systems. The data gathered will be used for internal purposes.“The nano satellites are an experimental class of satellites introduced by ISRO because there are many requests to use them for data collection for academic institutions. The universities do not have the knowledge to build satellites and tend to take a long time to build them. We want them to focus on the instruments since we can provide the nano satellite bus,’’ an ISRO official said. The ISRO official said ISTRAC was still in touch with the two small satellites launched 10 days ago.
ISRO’s top brass explained how they did it. K. Sivan, Director, Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, said, “Even to separate one satellite from the vehicle is complex, to put 104 satellites into orbit was not an easy job.” All the 104 satellites had to be put into orbit in just 600-odd seconds before the vehicle reached the South Pole, Sivan said. After India’s Cartosat-2 series satellite and INS-1A and INS-1B were put into orbit one after another, the remaining 101 were shot into orbit in “sets” or in pairs separated at a 180 degree angle, he said.
The first pair of nanosatellites separated at 18 minutes and 32.80 seconds and the last pair was put into orbit at 28 minutes and 42.80 seconds from lift-off. Thus, in a span of 10 minutes, all the 101 nanosatellites were fired from the vehicle’s fourth stage in a sequence, ensuring that they did not collide. At about 29 minutes into the mission came the announcement from the Mission Control Centre: “Separation of 104 satellites confirmed.”
The two nano satellites of ISRO that had caused problems since being launched on February 15 on a PSLV workhorse rocket have stabilised, the space agency informed on Wednesday.
“After initial hiccups, things have settled and the satellites are under our control,’’ the director of ISRO’s satellite centre, Mylaswamy Annadurai, said. “Unlike large satellites, where we are able to provide more control system like thrusters, in a nano satellite the control facility is limited as availability of power is limited. Nano satellites are an experimental programme in ISRO,’’ Annadurai said.
The nano satellites, weighing 8.4 kg and 9.7 kg, were reported to be displaying uneven parameters after launch. Sources in the space agency reported “some difficulties in signals’’ between the two satellites and ground stations. ISRO put out images taken from the Cartosat 2D satellite on its website a couple days after the launch but did not reveal the status of INS 1A and INS 1B.The nano satellites are carrying instruments from ISRO’s Space Application Centre and the Laboratory for Electro Optic Systems. Data gathered will be used by the two agencies. “The nano satellites are an experimental class of satellites introduced by ISRO because there are requests from academic institutions to use them for data collection. The universities do not have the knowledge to build satellites and tend to take a long time… We want them to focus on the instruments as we can provide the nano satellite bus,’’ an ISRO official said.
On the sad note:I stumbled upon this tweet, that was retweeted by Peter B. de Selding' The CubeSat's launched by PSLV C37 triggered more than 400 conjuncture alerts with COSMOS 1674.'
Quote from: Rik ISS-fan on 03/20/2017 08:39 PMOn the sad note:I stumbled upon this tweet, that was retweeted by Peter B. de Selding' The CubeSat's launched by PSLV C37 triggered more than 400 conjuncture alerts with COSMOS 1674.' What does this mean?