Like every other machine, satellites do not last forever. Whether their job is to observe weather, measure greenhouse gases in the atmosphere, or point away from Earth to study the stars, eventually all satellites grow old, wear out, and die, just like old washing machines and vacuum cleaners.
So what happens when a trusty satellite’s time has come? These days there are two choices, depending on how high the satellite is. For the closer satellites, engineers will use its last bit of fuel to slow it down. That way, it will fall out of orbit and burn up in the atmosphere.
The second choice is to send the satellite even farther away from Earth. It can take a lot of fuel for a satellite to slow down enough to fall back into the atmosphere. That is especially true if a satellite is in a very high orbit. For many of these high satellites, it takes less fuel to blast it farther into space than to send it back to Earth.
Burning metal and “spacecraft cemeteries”
Getting rid of the smaller satellites in low orbits is simple. The heat from the friction of the air burns up the satellite as it falls toward Earth at thousands of miles per hour. Ta-da! No more satellite.
What about bigger things like space stations and larger spacecraft in low orbit? These objects might not entirely burn up before reaching the ground. There is a solution—spacecraft operators can plan for the final destination of their old satellites to make sure that any debris falls into a remote area. This place even has a nickname—the Spacecraft Cemetery! It’s in the Pacific Ocean and is pretty much the farthest place from any human civilization you can find.
What about those higher satellites we blast farther away? Those we send into a “graveyard orbit.” This is an orbit almost 200 miles farther away from Earth than the farthest active satellites. And it’s a whopping 22,400 miles above Earth!
So is that the end of it for these far-away satellites? As far as you and I are concerned it is! However, some of these satellites will remain in orbit for a very, very long time. Perhaps someday in the future, humans may need to send “space garbage trucks” to clean these up. But for now, at least, they will be out of the way.
ISRO’s new communication satellite
- Launched on: June 29 at 2.45 a.m. [IST]
- Mass: 3,477 kg
- Life: 15 years
- Cost: ₹ 1,013 crore, including launch fee
- Launch vehicle: European booster Ariane-5 ECA / VA238
GSAT-17, the country’s newly launched communication satellite, will soon join the fleet of 17 working Indian communication satellites in space and augment their overall capacity to some extent. The 3,477-kg spacecraft was released into a temporary orbit in space as planned at 2.45 a.m. [a.m.] IST on Thursday about 39 minutes after launch from the European spaceport of Kourou in French Guiana. It was dusk at the South American near-equatorial spaceport.
(Image Source: The Hindu (www.thehindu.com)
GSAT-17 was sent up as the second passenger on the European booster, Ariane-5 ECA VA-238, according to ISRO and the European launch company Arianespace. GSAT-17, built mainly for broadcasting, telecommunication and VSAT services, carries over 40 transponders. It also has the equipment to aid Meteorology forecasts and search and rescue operations across the sub-continent.
“GSAT-17 is designed to provide continuity of services of operational satellites in C, extended C and S bands,” ISRO said. The satellite was released into what is called a temporary `geosynchronous transfer orbit’ or GTO, where it started orbiting distant 249 km at the near end to Earth and 35,920 km at the farthest point. Its operations were immediately taken over by the spacecraft command team at the ISRO Master Control Facility in Hassan.
“Preliminary health checks of the satellite revealed its normal functioning. In the coming days, orbit raising manoeuvres will be performed to place GSAT-17 in the geostationary orbit (36,000 km above the equator) by using the satellite’s propulsion system in steps,” ISRO said.
It normally takes around two weeks to reach and settle in its planned slot over India at 93.5° East longitude. Meanwhile, its various functional appendages such as antennas and solar arrays are deployed. The spacecraft was approved in May 2015 with an outlay of ₹1,013 crore, including its launch fee and insurance. Its co-passenger was the 5,700-kg Hellas Sat 3-Inmarsat S EAN shared by two satellite operators.
ISRO Chairman A.S. Kiran Kumar has earlier said they need double the number of communication spacecraft to support various users across the country. ISRO does not yet have a launcher that can lift payloads above 2,000 kg. As such it must hire foreign launch vehicles — mostly of Arianespace — to put its heavier communication spacecraft in orbit. Only this month, it tested its first GSLV-Mark III vehicle which can do this job for it.
“Today, GSAT-17 became India’s third communication satellite to successfully reach orbit in the past two months,” said an official release. It launched GSAT-19 on the new MkIII on June 5 and the 2,230-kg GSAT-9 or the South Asia Satellite on May 5, both from Sriharikota.
Designed and assembled at the ISRO Satellite Centre in Bengaluru, GSAT-17 has been at the Kourou space port since May 15, undergoing pre-launch checks and tests. Project Director Prakash Rao and a rotating team of over 20 ISRO engineers were attending to it during the period, said an ISRO official.
GSAT-17’s co-passenger has two operators. Hellas Sat 3 provides direct to home television and telecom services across Europe, West Asia and South Africa. Global satellite operator Inmarsat will provide in-flight Internet facilities for European airlines, as signified in the satellite’s tag EAN or European Aviation Network.
Computation of solar energy potential is essential to select the locations for solar photovoltaic (PV) thermal power plants. The use of remote sensing observations from geostationary satellite sensors is ideal to capture space-time variability of surface insolation. An android App for the computation of solar energy potential has been developed by Space Applications Centre (SAC), ISRO, Ahmedabad at the behest of Ministry of New and Renewable Energy, Govt. of India. It is a very useful tool for installation of PV solar panels for tapping solar energy.
The App provides monthly/yearly solar potential (in kWh/m2) and minimum/maximum temperature at any location. It also displays the location on the satellite image and provides azimuth/elevation angles as well as day length over different time periods in a year.
Following are the major features of the App:
- The App provides solar energy potential (in kWh/m2) at any given location.
- The required location can be keyed in or can be obtained through GPS.
- It gives monthly and yearly solar potential processed using Indian Geostationary Satellite data (Kalpana-1, INSAT-3D, and INSAT-3DR). It also offers monthly minimum and maximum temperature to calculate realistic solar potential.
- The location is displayed on the image with satellite data in the background.
- It also provides azimuth and elevation angles, and day length over different time periods in a year.
- Obstruction of sunlight due to terrain is also calculated using Digital Elevation Model (DEM).
- It also suggests optimum tilt angle for solar PV installation.
- This App needs an internet connection to calculate the results.
- The complete report can be saved as a PDF file.
The App can be downloaded from “New and Renewable Energy” section at vedas.sac.gov.in
The Survey of India (SOI) has launched new web portal called Nakshe to make open series maps available to Indians for free.
Organization : Survey of India (SOI)
Founder: East India Company
The portal was launched by Union Minister for Science & Technology and Earth Sciences, Harsh Vardhan on the occasion of 250th anniversary of SOI.
Features of Nakshe Portal
It will offer a free download of 3,000 Topographic maps or Open Series Maps (OSM) in a pdf format on 1:50,000 scale through Aaadhar enabled user authentication process. The maps are meant for development activities in the country and can be also used to plan scientific expeditions, research, and planning development projects. Topographic maps or OSM comprise natural and man-made geographical features including terrain or topography.
Note: Foundation for the scientific survey and mapping of the country was laid with The Great Trigonometric Survey (GTS) in the 19th century on 10th April 1802, by noted surveyors Col. Lambton and Sir George Everest. Interestingly, Everest has been named after former Surveyor General of India Col Sir George Everest. The measurement of the world’s highest peak has been made by the SoI.
NASA has released its 2017-2018 software catalog, which offers an extensive portfolio of software products for a wide variety of technical applications, all free of charge to the public, without any royalty or copyright fees.
Available in both hard copy and online, this third edition of the publication has contributions from all the agency’s centers on data processing/storage, business systems, operations, propulsion, and aeronautics. It includes many of the tools NASA uses to explore space and broaden our understanding of the universe. A number of software packages are being presented for release for the first time. Each catalog entry is accompanied with a plain language description of what it does.
“The software catalog is our way of supporting the innovation economy by granting access to tools used by today’s top aerospace professionals to entrepreneurs, small businesses, academia, and industry,” said Steve Jurczyk, associate administrator for NASA’s Space Technology Mission Directorate (STMD) in Washington. “Access to these software codes has the potential to generate tangible benefits that create American jobs, earn revenue and save lives.”
NASA published the first edition of its software catalog in April 2014, becoming the first comprehensive listing of publicly available software to be compiled by a federal government agency — the largest creator of custom code. Since then, NASA has shared thousands of its software programs with students, industry, individuals and other government agencies.
“Software has been a critical component of each of NASA’s mission successes and scientific discoveries. In fact, more than 30 percent of all reported NASA innovations are software,” said Dan Lockney, NASA’s Technology Transfer program executive. “We’re pleased to transfer these tools to other sectors and excited at the prospect of seeing them implemented in new and creative ways.” (The new NASA Software Catalog includes the code LEWICE, developed to help study the effects of ice on an aircraft in flight and to help create ice detection systems. Credits: NASA)
Some of the software available include codes for more advanced drones, and quieter aircraft. While access restrictions apply to some codes, NASA has automated and updated its software release process over the last two years to ensure that it is as quick, easy and straightforward as possible.
The software catalog is a product of NASA’s Technology Transfer program, managed for the agency by STMD. The program ensures technologies developed for missions in exploration and discovery are broadly available to the public, maximizing the benefit to the nation.