Feeds

Mixed bag of motors lifts India's budget Mars shot

Solid rocket boosters and hypergolic cocktails

Choosing a cloud hosting partner with confidence

India's budget* Mars Orbiter Mission (MOM) last week thundered heavenwards from Sriharikota spaceport atop a Polar Satellite Launch Vehicle (PSLV), en route to a rendezvous with the Red Planet in September 2014.

PSLV-C25 blasts off. Pic: ISRO

PSLV-C25 blasts off. Pic: ISRO

Weighing in at 500kg, plus 850kg of fuel, the MOM spacecraft was well within the 1,800kg lifting capability of the PSLV-XL ("extended") variant tasked with getting it Marswards.

The PSLV is an interesting beast, boasting a mix of solid rocket and hypergolic engine tech.

PSLV-C25 on the launchpad. Pic: ISRO

PSLV-C25 on the launchpad. Pic: ISRO

Its principal first-stage thruster boasts a mighty 139 tonnes of hydroxyl-terminated polybutadiene (HTPB) bound propellant. Strapped around this core are six solid rocket boosters (SRBs), four of which fire at launch and two which fire around 30 seconds into the flight.

Such engines are a popular choice among the rocketry big-hitters. The European Space Agency's (ESA) Ariane 5 uses two SRBs to provide an extra kick up the backside. They burn ammonium perchlorate composite propellant (APCP) - aluminium powder and oxidising ammonium perchlorate held in HTPB.

The PSLV's second-stage booster is, by contrast, a locally built Vikas engine burning approximately 40 tonnes of unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (N2O4).

The Vikas Engine. Pic: MTAR Technologies

The Vikas Engine. Pic: MTAR Technologies

Many nations are now ditching hypergolic cocktail burners in favour of engines using less volatile fuels.** Russia's long-serving Proton, for example, uses no less than 10 N2O4/UDMH motors - six in the first stage, three in the second and one in the third.

However, its planned replacement, the Angara 5 rocket, will rely on a kerosene/LOX-powered "Universal Rocket Module" first stage.

Similarly, China is eyeing kerosene/LOX for future versions of its Long March, which currently rise heavenwards thanks to N2O4 and UDMH.

Back at the PSLV, meanwhile, once the Vikas has done its job, seven tonnes of solid propellant power the third stage. After that, it's back to a hypergolic blend for the fourth stage, as two engines slurping monomethylhydrazine (MMH) and nitrogen oxides finally send the payload on its way.

The PSLV's exotic rocket motor mix has propelled it close to the top of the reliability league table. To date, it has executed "24 continuously successful flights", a performance described by the Indian Space Research Organisation as "superb". ®

Bootnotes

*£45m ($74m) - small change in Mars mission terms.

**For more on rocket motor propellants, see "Rocket boffinry in pictures: Gulp the Devil's venom and light a match".

Choosing a cloud hosting partner with confidence

More from The Register

next story
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
The next big thing in medical science: POO TRANSPLANTS
Your brother's gonna die, kid, unless we can give him your, well ...
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
NASA launches new climate model at SC14
75 days of supercomputing later ...
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
Simon's says quantum computing will work
Boffins blast algorithm with half a dozen qubits
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
5 critical considerations for enterprise cloud backup
Key considerations when evaluating cloud backup solutions to ensure adequate protection security and availability of enterprise data.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Getting ahead of the compliance curve
Learn about new services that make it easy to discover and manage certificates across the enterprise and how to get ahead of the compliance curve.