The Orion capsule, the Space Shuttle replacement. The Orion capsule, the USA’s next generation of manned vehicles after the Space Shuttle, was lofted into orbit yesterday for its first brief test flight.
Clearly, when you look at the vehicle, it closely resembles the manned capsule of the Apollo era and this ‘next generation’ seems at first thought to be a retrograde step. However, Orion is about twice the size of the Apollo capsule and can accommodate 4 astronauts in reasonable comfort. Another advantage is of course that its design integrates the latest technology into the system. But its main benefit is safety – a lesson learned from the shuttle era. In the 30 years of Shuttle operation the US human spaceflight programme achieved a great many spectacular successes, but it also saw some tragic lows with loss of 2 crews in 1986 and 2003. The issue was the Shuttle’s complexity – although this allowed great flexibility in mission capability, it also made the vehicle dangerous. This was primarily because it had no genuine escape system for the crew.
Taking onboard these issues, the system designers of Orion have gone for relative simplicity in order to improve crew safety. The final launch vehicle for the Orion spacecraft – which is yet to be developed – will have a simple multi-stage configuration with an escape tower system to drag the manned capsule clear in the event of a catastrophic launch failure. Also the heat shield configuration of Orion is simpler than Shuttle, and protected from debris impact risk on launch, so reducing risk on re-entry into the atmosphere. So the philosophy is to launch people on a ‘simple’ and very reliable expendable launch vehicle, and launch the required hardware for the particular mission separately on a relatively less-reliable heavy lift launcher – the two component parts coming together and docking in orbit afterwards.
Coming back to yesterday’s test, the Orion vehicle was launched at 12.05 UT atop a (stand in) Delta 4 heavy lift expendable launch vehicle (see video).
Clearly, when you look at the vehicle, it closely resembles the manned capsule of the Apollo era and this ‘next generation’ seems at first thought to be a retrograde step. However, Orion is about twice the size of the Apollo capsule and can accommodate 4 astronauts in reasonable comfort. Another advantage is of course that its design integrates the latest technology into the system. But its main benefit is safety – a lesson learned from the shuttle era. In the 30 years of Shuttle operation the US human spaceflight programme achieved a great many spectacular successes, but it also saw some tragic lows with loss of 2 crews in 1986 and 2003. The issue was the Shuttle’s complexity – although this allowed great flexibility in mission capability, it also made the vehicle dangerous. This was primarily because it had no genuine escape system for the crew.
Taking onboard these issues, the system designers of Orion have gone for relative simplicity in order to improve crew safety. The final launch vehicle for the Orion spacecraft – which is yet to be developed – will have a simple multi-stage configuration with an escape tower system to drag the manned capsule clear in the event of a catastrophic launch failure. Also the heat shield configuration of Orion is simpler than Shuttle, and protected from debris impact risk on launch, so reducing risk on re-entry into the atmosphere. So the philosophy is to launch people on a ‘simple’ and very reliable expendable launch vehicle, and launch the required hardware for the particular mission separately on a relatively less-reliable heavy lift launcher – the two component parts coming together and docking in orbit afterwards.
Coming back to yesterday’s test, the Orion vehicle was launched at 12.05 UT atop a (stand in) Delta 4 heavy lift expendable launch vehicle (see video).
The system then executed 2 orbits of the Earth prior to a re-entry and splashdown at 16.30 UT. The second orbit was elliptical with a high point of 5,800 km to increase the re-entry speed to around 30,ooo km per hour – the resulting 2,000 degrees Celsius providing a rigorous test of Orion’s thermal protection system. The principal objectives of yesterday’s events were to test the capsule’s heatshield and parachute systems, both of which performed successfully. A NASA summary of the Orion system in general, and yesterday’s test in particular is given in the second video.
Although yesterday’s test was encouraging – the US human spaceflight programme is up and running – nevertheless there is long way to go. The Orion system comprises two main components – the capsule which was tested yesterday and a service module which is yet to be built. The service module (again similar to its Apollo predecessor) is the necessary system required to provide essentially life support and propulsion for the Orion capsule. The European Space Agency (ESA) and Airbus recently signed a contract with NASA to build a service module based on ESA’s Automated Transfer Vehicle (ATV), and this is scheduled to be ready for an unmanned test flight in 2017/18. You may recall an earlier blog post about this (24 September 2014) ‘Chance encounter with a rocket man’ when I ‘bumped into’ a NASA engineer on a walking holiday in West Wales who was working on adapting the Space Shuttle orbital manoeuvring system engine for use on ESA's ATV?
The Orion capsule/service module configuration. And then of course there is the requirement to develop a man-rated launcher for the Orion capsule/service module system. This is currently in the hands of US private industry, and a first unmanned test flight of this element is pencilled in for 2017/18. The first crewed launch of the whole system is not expected until around 2021, so don’t hold your breath! Given that the last flight of Shuttle was 2011, that’s a hiatus of 10 years in the US human spaceflight programme which is disappointing, in my opinion. The pace of events seems to be very slow, and with the vagaries of funding for such projects with changing political administrations in Washington DC, it does make you wonder whether the US will ever acquire sufficient momentum to take the next major steps in solar system exploration. I say this not as a critic of the US space effort, but as a supporter who wishes they’d just get on with it!
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