By Nick Heath, August 7, 2014
Flock-1
Ever dreamed of putting a spacecraft into orbit? The $500m price tag of building and launching a satellite is enough to bring most such fantasies back down to earth.
Undeterred, budget spacefarers have found a way to send a craft into space. The answer is to make things very, very small.
CubeSats are tiny satellites – the smallest measuring just 10×10×10cm (1U) and with a typical weight of three pounds. That diminutive size is designed to keep launch costs to a minimum, about $100,000 in one recent case.
The affordability of launching CubeSats, relative to commercial and military satellites that can be as big as a small bus, opens the door to space research for a wider range of people.
Since the form factor was devised by US universities in the late 1990s, dozens of CubeSats have been carried into orbit to research everything from the effect of low gravity on plant cell biology to new ways of spotting dangerous space debris.
NASA runs a programme to put CubeSats into orbit, providing opportunities for small satellite payloads to be carried on upcoming rocket launches.To date, NASA has selected 114 CubeSats from 29 states and this week began accepting bids for a new round of CubeSats to be carried on upcoming rocket launches.
Here is some of the fascinating research that these tiny spacecraft are making possible.
The Flock-1 fleet of 28 nano-satellites is the largest collection of earth-imaging satellites ever launched.
The Dove sats will collect imagery of the changing planet to aid humanitarian and environmental efforts. Potential applications include monitoring deforestation and the polar ice caps, as well as gathering data to help with disaster relief and to improve agriculture yields in developing nations.
Each 3U sat is designed to take pictures of the earth's surface at a resolution of between three and five metres.
The satellites were transported to the International Space Station (ISS) by the Cygnus CRS-1 logistics spacecraft in January this year.
Here are the first pair of satellites – made by San Francisco-based Planet Labs – being launched from the ISS.
SporeSat
SporeSat is an autonomous, free-flying spacecraft that is observing how plant cell biology alters in the low gravity of earth's orbit.
On-board experiments will investigate the effect of gravity on the reproductive spores of the fern, Ceratopteris richardii. Some plants, including C. richardii, use gravity to determine direction and to guide their roots down into the earth. Three lab-on-a-chip devices will compare the fern's behaviour in the low gravity of earth's orbit with that of ferns subject to higher gravitational forces, as a result of being spun.
Launched in April this year, the 3U spacecraft was designed through a partnership between NASA’s Ames Research Center and the Department of Agricultural and Biological Engineering at Purdue University.
PhoneSat
There may be a smartphone app to cover most eventualities, but controlling a satellite probably isn't one of them.
However NASA has been helping phones boldy go where no consumer tech has gone before with the its PhoneSat missions.
The first PhoneSat tested whether a then-$300 HTC Nexus One smartphone running the Android OS could control the flight avionics on a 1U CubeSat.
The PhoneSat missions are a bid to understand whether it would be possible to knock several zeros off the price of space-faring computers by replacing today's custom-built devices with the likes of smartphones, as well as increasing processing power by as much as a factor of 100.
Of particular interest was whether off-the-shelf computing hardware that hadn't been hardened could function in the extreme temperatures and high radiation of space. The first PhoneSat missions showed the phones operated for about one week in orbit.
The latest PhoneSat mission to blast off was 2.4, which used a Nexus S handset and had a two-way radio communications capability, along with reaction wheels to provide attitude control. It was placed in a higher orbit than previous PhoneSats when it launched in November last year.
Intelligent Payload Experiment
NASA launched the Intelligent Payload Experiment, or IPEX, to test technologies capable of driving an autonomous satellite.
The technologies piloted by IPEX would allow the planned HypsIRI satellite to determine more of its own actions without human input.
HypsIRI is planned to scan the surface of the earth for unusual events, such as a forest fire or volcanic eruption, and then alter its priorities and tasks in response to these events.
HypsIRI would also be able to be controlled more simply, with human operators able to specify swaths of ground that are of interest and let the satellite determine how best to survey these areas.
The 1U CubeSat was developed by Cal Poly San Luis Obispo and NASA and launched late last year.
The NEE-01 and 02
These space sentries are designed to help spot near-earth objects and to catalogue the space junk that litters orbit.
The high-definition, 720p camera on board the NEE-01 also allows it to spot small asteroids that are normally difficult to detect but have enough mass to pose a threat to populated areas.
NEE-02 is an upgrade over NEE-01, with high-speed digital transmission and a higher resolution video camera.
The craft were launched over the past two years by the Ecuadorian Civilian Space Agency.
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