Universe Today - Juno Will Get No Closer To Jupiter Due To Engine Troubles
Jupiter’s south pole. captured by the JunoCam on Feb. 2, 2017, from an altitude of about 62,800 miles (101,000 kilometers) above the cloud tops. Credits: NASA/JPL-Caltech/SwRI/MSSS/John Landino
On July 4th, 2016, the Juno mission established orbit around Jupiter, becoming the second spacecraft in history to do so (after the Galileo probe). Since then, the probe has been in a regular 53.4-day orbit (known as perijove), moving between the poles to avoid the worst of its radiation belts. Originally, Juno’s mission scientists had been hoping to reduce its orbit to a 14-day cycle so the probe could make more passes to gather more data.
To do this, Juno was scheduled for an engine burn on Oct. 19th, 2016, during its second perijovian maneuver. Unfortunately, a technical error prevented this from happening. Ever since, the mission team has been pouring over mission data to determine what went wrong and if they could conduct an engine burn at a later date. However, the mission team has now concluded that this won’t be possible.
The technical glitch which prevented the firing took place weeks before the engine burn was scheduled to take place, and was traced to two of the engines helium check valves.
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"Nextbigfuture - Reaction Engines is making hypersonic planes and spaceplanes. Their key technology is a precooler. Reaction Engines is looking for an engine partner now. They needed BAE at the time and now they are at the point where they need Rolls or someone else. They have some good contacts with Safran through Airbus Safran Launchers. A large amount of money is being made available by the US DoD for testing the precooler in a hypersonic wind tunnel.
Apparently sealing the helium loop is hard. They don't know whether to work with an industrial partner to make their seals lighter or an aerospace partner to make their seals better.
They have new management with people from Safran Leonardo Helicopters. New management is much more focused on stepping stones rather than hoping to somehow get 10 billion dollars to do single stage to orbit.
US Air Force research lab investigations examined the thermodynamic cycle of the SABRE concept and found no significant barrier to its theoretical viability provided the engine component and integration challenges are met.
In late 2015 / early 2016, BAE Systems invested £20.6 million in Reaction Engines to acquire 20 per cent of its share capital and also enter into a working partner relationship.
BAE Systems will collaborate to accelerate Reaction Engines’ development of SABRE – a new aerospace engine class that combines both jet and rocket technologies with the potential to revolutionize hypersonic flight and the economics of space access.
SABRE is an advanced combined cycle air-breathing rocket engine. This new class of aerospace engine is designed to enable aircraft to operate from standstill on the runway to speeds of over five times the speed of sound in the atmosphere. SABRE can then transition to a rocket mode of operation, allowing spaceflight at speeds up to orbital velocity, equivalent to twenty five times the speed of sound. "